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About this booklet…

This is not a course book of cataract surgery.

Based upon the personal experience of the author, this

pocket book is designed to help the beginners to start

performing the basic maneuvers required by the cataract

surgery by phacoemulsification.

The booklet is organized in a nonconventional

manner, starting with Theoretical Glimpse, a short

chapter containing information about embryology,

anatomy, physio-pathology and clinics. I have chosen a few

theoretical data with direct implications in the clinics and

surgical procedures which, in my view, should be known by

any ophthalmologist that decided to start lens surgery.

The second chapter, Starting Cataract Surgery

by Phaco with the Main Steps during Wetlabs was

written as if I was talking to a beginner. I described the main

steps of cataract surgery by phaco for one technique that I

consider very simple and appropriate to start with. I believe

that any beginner in cataract surgery by phaco should

practice first on animal eyes, before starting his/her first

operation on human eyes. I imagined assisting a beginner to

perform the first steps during wetlabs and I wrote the

explanations.

The last chapter of the pocket book, One way to

start with…, represents the description of the main steps

of the technique that I prefer because I consider it the

easiest for operating cataract by phacoemulsification. This

chapter is demonstrated on a movie recorded during one of

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my surgeries. I considered this technique of operating

cataract a good, easy and safe variant that could be used by a

beginner who starts performing on the human eyes.

I believe that after several years of successful cataract

surgery by classic extracapsular technique, in which the

surgeon but also his/her patients are pleased with the final

postoperative results, the advancing of the surgeon to the

next level – cataract surgery by phacoemulsification, is a

decision that requires patience and calm in passing over

the “learning curve”. This passage comes always

together with intraoperative incidents, sometimes accidents,

with cases that do not evolve well because of the corneal

decompensation or other posterior or anterior segment

complications.

When the surgeon who has an experience in classic

technique, carefully establishes which cases can be operated

by him/her as a beginner in phaco technique and which one

should be avoided, when he/she is able to be calm in front of

different intraoperative complications in order to manage

them in the best possible way, when he/she is able to be

patient in treating and compensating the cases that have a

difficult postoperative evolution, when he/she has a good

collaboration with a vitreo-retinal surgeon who accepts to

operate the posterior segment complications, the passing

over the learning curve is easier.

Iasi, April 2010 The Author

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Content

1. Theoretical Glimpse ……………………………….. 4

2. Starting Cataract Surgery by Phaco with the

Main Steps at Wetlabs ………………………………….. 43

3. One way to start with… ………………….. 56

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1. Theoretical Glimpse

Embryology

Fig.1. Lens embryology.

Early in embryogenesis, in the 25th day of gestation,

the formation of the human crystalline lens starts with the

differentiation of the lens placode. By the invagination of

the lens placode from the 29th day, the lens embryology is

continuing with the development of the lens vesicle. During

a complex process of differentiation inside of the vesicle, the

lens cells become lens fibers and epithelial cells. By the

multiplication and growing up of the lens fibers, the

structure of the lens is outlined, resulting in the main layers:

lens capsule, lens cortex and centrally, lens nucleous.

As the lens fibers are isolated by the lens capsule, very early

during the embryologic life, before the development of the

immunologic system of the body, the lens proteins do not meet the

immunologic system and thus, they are not recognized by this one as

being physiologic. As a consequence of these phenomena, when the

lens components pass outside, through the lens capsule, they may

lead to inflammatory reactions having different degrees of severity

according to the quantity of the lens material coming in contact with

the immunologic system of the aqueous humour. This is the

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mechanism of different disorders diagnosed before cataract

surgery (phacoantigenic uveitis, phacolytic glaucoma) but also of

certain complications after cataract surgery (inflammatory

reactions determined by the lens remnants left after incomplete

cleaning of the capsular bag, or, increasing of the intraocular

pressure as a result of the inflammation).

During the embryologic life, the lens nutrition is

realized by tunica vasculosa lentis, a blood vessels system

that connects the lens capsule with the optic nerve head and

represents the origin of the vascular networks of the

anterior segment (iris and ciliary body), primary vitreous

and anterior part of the optic nerve. The tunica vasculosa

lentis disappears shortly before birth as a result of an

orderly process of programmed cell death, however a

physiologic adhesion between the lens capsule and the

hyaloid capsule – anterior vitreous complex still persists.

As there are physiologic connections between the lens capsule

and the anterior vitreous, the variation of the pressure in the

anterior chamber during cataract surgery by phacoemulsification

leads to movements of the whole vitreous body. These mechanisms

explain the posterior vitreous detachment frequently observed after

cataract surgery by phacoemulsification, as well as the onset of the

retinal detachment, especially in eyes with previous conditions

predisposing to this posterior segment pathology (e.g. peripheral

retinal holes, retinal degeneration in the peripheral retina, etc).

When the variation of the anterior chamber pressure is very

high because the aspiration – irrigation systems are not

appropriately adjusted or, because the surgeon maneuvers are not

very delicate, the risk of the retinal detachment increases even more. As there are connections between the posterior lens capsule

and anterior vitreous, any pars plana vitrectomy performed on

the phakic eyes leads to a trauma on the lens capsule when the

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surgeon is removing, as better as possible, the anterior vitreous, by

aspirating and cutting. The cataract surgery, in all its steps, is much

more difficult in vitrectomized eyes and probably should be avoided

by beginners in phacotechnique during their learning curve.

The posterior lens capsule trauma during pars plana

vitrectomy can be microscopic and minor. However, these

damages may influence the lens capsule “tonus” because they modify

the exchanges of water and electrolytes between the lens and its

aqueous environment. In this case, the capsulorrhexis can be much

more difficult because the lens capsule tension is sometimes lower.

Making deeper the anterior chamber by filling it with cohesive

viscoelastic solutions, the conditions for the capsulorrhexis can be

improved.

Sometimes, the pars plana vitrectomy may lead to breaks in

the posterior capsule. In these cases, the opacification of the lens

is usually observed in the first days after posterior segment surgery.

When the capsulorrhexis fails in such cases, I prefer to perform a

central hole in the anterior capsule with the vitrectomy cutter or a

small “can opener” hole. I usually work with a lower aspiration rate

and use the vitrectomy cutter, in order to avoid pushing some lens

remnants in the vitreous compartment through the posterior capsule

hole. In these cases, I prefer to implant in sulcus a multipiece

foldable intraocular lens with hard haptics. I also use the new

foldable monobloc intraocular lenses with 13 mm total diameter

designed by Medicontur company for implantation in sulcus.

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Anatomy

The eye inside of the orbit

The ocular globes are placed inside of the orbits, which are two bony cavities localized aside the nose root.

The anatomy of the orbit is very important for establishing

the positive and differential diagnosis in different ocular pathologies, but also for anterior and posterior segment surgeries requiring local periocular anesthesia.

Each orbit has pyramidal shape and presents 4 walls:

superior – adjacent to the frontal sinus and cranial fossa

internal (medial) – separating the orbit from the ethmoid and sphenoid sinuses

inferior – representing the roof of the maxillary sinus

external (lateral) – adjacent to the temporal fossa

The medial and inferior walls of the orbit are the thinnest ones, being frequently affected in the orbital trauma, associated or not with the herniation of the orbital structures into the neighbouring sinuses. The external orbital wall covers and protects only the posterior half of the ocular globe. That is why the anterior ocular half is very vulnerable and usually damaged in the lateral cranial trauma. Knowing these correlations is very important in establishing the complete diagnosis in complex situations after trauma, as well as in planning the anterior segment or combined surgery.

As in any surgery for traumatic cataract the surgeon can be confronted to many surprises, I consider that beginners in cataract surgery by phaco should judge carefully, before starting the operation, if the case could be managed by themselves during their learning curve or they should better refer the case to a much more experienced surgeon.

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Fig. 2. Topographic relationships of the eye in the orbit. 1 – eyelids, 2 – tarsus, 3 – frontal bone, 4 – maxillary bone, 5 – orbital fat, 6 – superior rectus muscle, 7 – inferior rectus muscle, 8 – superior oblique muscle, 9 – inferior oblique muscle, 10 – superior temporal vortex vein, 11 – inferior temporal vortex vein, 12 – optic nerve, 13 – annulus of Zinn, 14 – optic canal, 15 – lateral rectus muscle, 16 – cornea, 17 – sclera, 18 – maxillary sinus, 19 – upper lid retractor, 20 – conjunctiva.

The apex of the orbit presents the optic foramen

through which the optic nerve, the ophthalmic artery and sympathetic nerves are passing through (Fig. 2).

The content of the orbit is very complex, being

represented by numerous components (Fig. 2): - ocular globe, the most voluminous component of the

orbit, occupying about 1/5 from the orbital volume. The support and motility adnexes maintain the globe in its position.

- 7 extraocular muscles: 4 rectus muscles (that have their origin at the orbital apex, create a muscular cone

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around the ocular globe, and insert onto the ocular walls, in the anterior quadrant), 2 oblique muscles, the superior and inferior, the elevator of the upper lid (which have the origin at the orbital apex, the insertion on the superior tarsus margin, and realize the lifting the upper lid). There are also other muscles, less represented (Müller muscle and the lower lid retractors), that contribute to the general orbit architecture, as well as to the ocular and palpebral motility.

- blood vessels: arteries (with the origin in the ophthalmic artery) and veins (drainaging in the ophthalmic veins)

- capsulo-ligamentar apparatus represented by the extraocular muscles fasciae, ligaments, intermuscular septum, orbital septum and Tenon capsule, that maintain the ocular globe position inside of the orbit.

- cranial nerves: optic - II, oculomotor - III, trochlear - IV, branches from the trigemen – V, abducens VI, branches from facial –VII and ciliary ganglion

- lacrimal gland placed superior laterally in the orbit, within the orbital bone fossa

- orbital fat that is filling up the whole orbital space between all of these structures

The Tenon capsule is a membrane that covers the

ocular globe. It starts posteriorly to the globe, on the optic nerve sheath, and ends on the sclera, 3 mm posteriorly from the limbus, where it fuses with the conjunctiva.

The subtenonian space lies between the Tenon capsule and sclera and its topography must be known by the surgeons that perform a special kind of local anesthesia called subtenonian anesthesia.

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Fig. 3. Structure of the eye. 1 – cornea, 2 – sclera, 3 – iris, 4 – pupil, 5 – ciliary body, 6 – lens, 7 – zonula of Zinn, 8 – choroid, 9 – retina, 10 – optic nerve, 11 – lamina cribrosa, 12 – central retinal vessels.

The ocular globe is like a ball, having a content inside of a container – the ocular wall (Fig. 3). The ocular wall has 3 superposed coats:

external coat, the resistance one, represented in the posterior 5/6 by the white and opaque sclera, and anteriorly by the transparent cornea. The sclero-corneal limbus makes the junction between the two parts.

medial coat, the uvea, is the vascular layer of the eye. It is represented in the posterior segment by the choroid and in the middle part of the eye by the ciliary body. In the anterior segment, the uvea is reflected in the frontal plane, creating a diaphragm – the iris, with a central orifice – the pupil. The diameter of the pupil is variable in size by the action of the pupillary muscles, some of them dilating the pupil (mydriasis) while the others constricting it (miosis).

inner coat, the retina, covers the internal surface of the ocular wall, from the posterior towards the ciliary body.

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As the pupil acts like a diaphragm through which the light rays are passing on their way to the retina, the architecture of the pupil should be respected during the cataract surgery, so that, at the end of the surgical session, the pupil remains round, free of tractions and mobile.

Being placed in a frontal plane, behind the iris, the

transparent lens is anchored to the ocular wall at the ciliary body level, through a fibrils system – the zonula of Zinn (Fig.3).

The lens-zonula complex divides the ocular cavity in

(Fig.3): - posterior compartment – the vitreous cavity, containing

the vitreous gel - anterior compartment localized in front of the lens, filled

with aqueous humour – a liquid secreted by the ciliary body

The anterior compartment of the ocular globe is

divided by the iris in 2 chambers that communicate through the pupil (Fig.3):

anterior chamber - between the iris and the cornea

posterior chamber – between the iris and the lens The fluids filling the eye exert a pressure onto the

relatively inextensible ocular walls, the intraocular pressure IOP. In the non glaucomatous population, the normal IOP is between 10 – 21 mmHg.

The aqueous humour is secreted by the ciliary

processes of the ciliary body (Fig.3), enters through the pupil in the anterior chamber, wherefrom it is drained outside the eye, passing through the anterior chamber angle – the irido-corneal angle. The aqueous humour production

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and its intraocular dynamics are practically the main factors that influence the intraocular pressure.

The vitreous is a transparent gel, without any

vascularization or innervation. It occupies the 4/5 from the ocular volume, has a well determined and relatively constant volume, being covered by the transparent hyaloid.

As the vitreous has no blood vessels or innervation, the vitreous disorders never lead to “red eye” and do not hurt either.

In different proliferative retinal diseases, a fibrovascular network can develop in the vitreous gel, sometimes leading to vitreous hemorrhage.

The crystalline lens

The natural human lens is a transparent structure,

without any innervation or vascularization, resembling with

a biconvex lens, placed in a frontal plane, back to the iris, in

front of the retina.

As the lens is not vascularized, the lens pathology does not

include “red eye” signs and symptoms. The lack of the lens

innervations explains why the lens disorders do not hurt. However,

the complications determined by the lens pathology may be

accompanied by red eye, pain, high intraocular pressure, etc. When

these complications appear before cataract surgery, they should be

treated before opening the eye in order to have a successful

treatment and postoperative outcomes.

Together with the iris (Fig.3), the lens realizes the

delimitation between the posterior ocular compartment

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(containing the vitreous body) and the anterior one (filled

with aqueous humour).

The maintaining of the ocular architecture after cataract

surgery, as close as possible to the physiologic status, is very

important in order to decrease the risk of posterior segment

complications. That is why the implantation of the foldable

intraocular lens in the capsular bag represents the best variant in the

great majority of the cases. However, when this goal cannot be

reached out of different reasons related to the complexity of the eye

pathology or to the cataract surgery complications, the implantation

of any type of artificial lens is a better option than letting the eye

aphakic.

Fig. 4. The lens inside of the eye. 1 – cornea, 2 – sclera, 3 – iris, 4 – pupil, 5 – ciliary body, 6 – lens, 7 – zonula of Zinn, 8 – anterior lens capsule, 9 – equatorial zone, 10 – lens cortex, 11 – lens nucleous, 12 – posterior lens capsule, 13 – vitreous body.

The lens is anchored to the ocular walls, in the pars

plicata region of the ciliary body (Fig.4), by means of a

system of elastic fibrils – zonula of Zinn. The insertion of

these fibrils is localized in the equatorial region of the lens,

around the structure. This disposition of the zonula allows

the maintaining of the lens in its physiologic position by the

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centripetal forces that act in the frontal plane even when a

small part of these fibrils are destroyed.

In some cases in which the cataract is developed on subluxated

lenses or when the cataract surgery is complicated with ruptures of

the zonula fibrils, but the integrity of the zonula is maintained in

about 3/4 of the total circumference, the insertion of a tension ring

in the capsular bag followed by the implantation of a lens “in the

bag” could be a valid option.

As the circumference of the destroyed zonula cannot be exactly

appreciated during surgery, in cases with large zonula ruptures I

consider the safest option the anterior vitrectomy followed by the

implantation of a posterior chamber intraocular lens sutured to the

sclera or an iris-claw lens implanted back to the iris.

At birth, the human lens measures about 6.4 mm

equatorially and 3.5 mm anteroposteriorly, having an

weight of 90 mg. The lens continues to grow up throughout

the life, so that the adult lens measures about 9 mm at its

equator and 5 mm in the anteroposterior axis, while the

weight is approximately 255 mg.

The biconvex shape of the lens together with these

parameters can be very different in congenital abnormalities

(e.g. sferoidal lenses in Marfan syndrome, etc) and also can

vary according to the degree of hydratation of the lens (e.g.

intumescent cataract in different situations when the lens is

swollen, diabetic cataract, etc).

Together with the morphometric characteristics, also

the refractive power of the lens varies throughout the life.

The eye may become more hyperopic or myopic with age,

according to the variation and growth of different ocular

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structures and parameters – especially the cornea and the

ocular axial length.

The antero-posterior thickness of the IOL is smaller than that

of the natural lens, so that after cataract surgery, the anterior

chamber angle always enlarges. This evolution of the anterior

segment architecture can be a therapeutic solution in some eyes

with narrow angles and episodes of closed angle glaucoma.

As the dimensions, as well as the dioptric power of the lens,

are variable during childhood, the correction of the aphakia in

congenital cataract surgery is a subject of controversies. The

cataract surgery by phacoemulsification and the implantation of a

foldable IOL seems to be the most accepted option because it prevents

the amblyopia.

An anteroposterior horizontal plane passing through

the ocular optic axis shows the following layers in the lens

structure (Fig.4):

anterior lens capsule is an elastic, transparent

membrane, semipermeable for the water and

electrolytes from the aqueous humour, thus allowing

the nutrition of the lens. On its backside, the anterior

lens capsule is lined by the lens epithelium, a single

layer of cells extended towards the equator. The

peripheral equatorial epithelial cells are implicated in

the lens growing because they generate new lens fibers

that are continuously deposited over the preexisting

ones. The anterior lens capsule is thicker in its central

area around the optic axis (14 µm) than in the

peripheral region, nearby the equator (21 µm). The

equatorial lens capsule has a thickness of 17 µm

and has the zonula fibrils attached to its outside face.

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The elasticity of the lens capsule allows the manipulation of

the lens fragments inside of the capsular bag during cataract

surgery in the techniques that crack the nucleous.

Careful hydrodissection and hydrodelineation are very

important for a good cleaning of the lens cortex during cataract

surgery that decreases the incidence of the further opacification of

the posterior, but also the anterior lens capsule.

anterior cortex, containing lens fibers that are the

most deeply localized, the most differentiated and

older.

The degree of the anterior lens cortex opacification allows or

impedes the appreciation of the nucleous hardness that helps the

surgeon to plan the technique. Sometimes, a white liquefied anterior

cortex can be easily removed by irrigation-aspiration and then, a

small nucleous, even hard, can be aspirated after

phacoemulsification. In other cases, the removing of the liquefied

anterior cortex exposes a big hard nucleous that makes difficult the

phacotechnique. On the contrary, after the aspiration of the white

and opaque peripheral lens cortex, the discovered nucleous can be

found soft, being easily removed by using the phacoprobe.

lens nucleous, containing the oldest lens fibers and

having a higher density than the anterior and

posterior lens cortex because, throughout the life, no

cell is lost from the lens while the structure is growing

up continuously.

The color and transparence of the lens nucleous varies

throughout life because the old fibers are continuously pressed by the

newly formed ones and because with aging, the lens components

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vary. Sometimes, a nucleous that appears relatively transparent and

probably not very hard at the preoperative examination can be very

difficultly removed by phacoemulsification and inversely, a nucleous

that has been appreciated as hard, appears as soft in the tip of the

phacoprobe. The “elasticity” of the cataract surgeon in taking new

decisions during cataract surgery according to the present situation

contributes to successful surgical results.

The higher the age of the patient, the harder the lens nucleous

is. Under the age of 40 years, the density of the nucleous is not so

high, so that the nucleous can be easily removed, frequently only by

irrigation – aspiration.

A good hydrodelineation helps very much the surgeon to

remove the lens nucleous without further complications, no matter

which technique is used during phacoemulsification.

posterior cortex is practically, from the clinical

point of view, the lens remnants after the removal of

the anterior cortex and nucleous. It contains fibers

with different degrees of opacification, according to

the clinical type of cataract.

The posterior cortex fibers can be more or less attached to the

posterior capsule so that their removal by irrigation-aspiration has

different degrees of complexity. A good hydrodissection makes easier

the cleaning of the posterior capsule by the lens remnants.

posterior lens capsule continues the equatorial

lens capsule in the posterior part. It has no

epithelium, as compared to the anterior one, but is

also semipermeable to the nutrients coming from the

aqueous humour that fills up the space between the

lens and vitreous – hyaloid complex. The posterior

capsule is thinner in its center (4 µm) than the central

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part of the anterior capsule, but thicker in its

periphery (23 µm) as compared to the peripheral

anterior capsule.

In certain circumstances, the posterior lens capsule has a high

breaking risk during cataract surgery, requiring careful maneuvers

(e.g. pseudoexfoliation syndrome, myopic eyes, etc).

The posterior capsule can be opacified as a result of injuries,

or in different clinical types of cataract not related to trauma.

Sometimes an opacified posterior capsule is safer to be left opaque at

the end of cataract surgery in order to be cut postoperatively by YAG

laser procedures, than to be broken during an insistent cleaning

maneuver.

The posterior capsule is kept as a support for the further

implanted posterior chamber IOL. Sometimes, even in case of breaks

or ruptures of the posterior capsule, the anterior vitrectomy can

create conditions for a safe implantation in sulcus of the posterior

chamber IOL.

When the implantation of the posterior chamber IOL is

appreciated as not safe and stable, when the anterior vitrectomy

cannot be successfully performed, or when the beginner does not

have the experience to end the surgery, in my view, the best solution

is to cancel the implantation of an IOL and to refer the patient, in

time, to another surgeon that can manage the case in a better way.

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Physiology

The nutrition of the lens is realized completely from

the aqueous humour because the transparent lens has no

vascularization. The exchanges between the lens and its

environment filled with aqueous humour are:

active processes mediated by different enzymes of

the lens epithelium cells. These processes are specific

for the anterior capsule.

passive phenomena at the level of the entire lens

capsule, based on its semipermeability.

The combination of the two types of transport

mechanisms is described by the theory of the lens pump-

leak system.

The lens has 66% of water and 33% proteins, this

ration varying very little with aging. The lens cortex is more

hydrated than the nucleous. These biochemical aspects are

also the consequence of the pump-leak system of the lens.

The passive phenomena described for the lens at the level of its

capsule explain certain clinical types of cataract produced by

metabolic dysfunctions that influence the ionic imbalance in the

aqueous humour. The diabetic cataract is the classic example of

these pathologic mechanisms in which the increase of the sugars in

the aqueous humour is followed by an increased concentration of

these biochemical compounds inside of the lens. The higher

concentration of the lens sugars attracts the water inside of the lens,

leading to the lens swelling and finally to its opacification. The first

episodes of these processes are reversible (and the cataract called

reversible cataract), but the time passing, the repeating of these

disturbances produces permanent lens opacification and cataract,

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impeding the visual acuity. This type of cataract can be seen in

patients younger than 50, in which the soft lens content can be

usually removed very easy only by aspiration-irrigation. Similar

pathologic mechanisms leading to soft cataracts can be observed

in galactozemia.

Different drugs chronically administered can also determine

biochemical modifications in the lens, later leading to cataract. When

the lens is not so old so that the cataractogenic mechanisms to

include age changes as well, these drugs–induced cataracts are

usually soft.

The lens is placed on the optic axis, in front of the

retina and represents the most important filter in front of

the natural rays in the way to the “retinal screen”. The

natural lens absorbs the ultraviolet rays B (295 – 315 nm)

and A (315 – 400 nm), letting the visible (400 – 760 nm)

and infrared A (760 – 1400 nm) radiations pass towards the

retina.

As the absorption of the ultraviolet radiations leads to

reactions of photosensibilization inside of the lens, having as a result

the production of free radicals that destroy the cells, the exposure to

ultraviolet radiation leads to cataract. When these phenomena

are produced on a young lens, the cataract is soft, easily removed by

phacotechnique.

The new IOLs have the properties of the natural lens as a

barrier in front of the ultraviolet radiations on their way to the

retina. However, they cannot stop “blue radiations” that can stress

an old and already damaged retina (e.g. in age related macular

degeneration). The “yellow IOLs” have both the capacity to be a

filter for ultraviolet and blue radiations and could be preferred

especially in patients with macular pathology.

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The crystalline lens represents a part of the eye optic

system, being involved in the focalization of the light rays

onto the retina. The convergent power of the lens is variable,

between +20 D and +30D, from the total power of +60 D of

the ocular optic system.

The convergent power of the lens is modified by the

contraction of the ciliary muscles, acting by means of the

zonula fibrils, during the accommodation process. The

amplitude of accommodation represents the amount of

change in the refractive power of the lens as a result of the

accommodation process. The amplitude of accommodation

decreases with age, from +12 + 16 D in adolescents, to

+4+8D around the age of 40 years. After the age of 50, the

accommodation decreases to less than + 2 D, as a result of

the age changes produced in the ciliary muscles but also in

the lens, leading to the loss of its elasticity.

The multifocal IOLs placed in the posterior chamber, on the

natural lens place, mimic the accommodation process. When the

cataract surgery is accurately performed and the preoperative

calculation of the multifocal IOLs is correct, such multifocal

pseudophakic eyes should not require additional glasses. However,

these goals are difficult to be reached and that is why the

phacotechnique with the implantation of multifocal IOLs should be

probably avoided by beginners.

According to its position on the optic axis of the eye, the

dioptric power of the monofocal IOL implanted after cataract

surgery is variable for the emetropic postoperative status: around

+21 D for posterior chamber lenses, about + 20 D for posterior

chamber iris-claw lenses, about + 18 D for anterior chamber

lenses or about +19 D for anterior chamber iris-claw lenses.

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The calculation of the IOL power uses a few mathematic

formulas in which some ocular constants must be introduced:

dioptric power of the cornea (keratometry), ocular axial length

(biometry) and refractive constant of the planned artificial IOL.

When the surgery does not plan a multifocal IOL, the

calculation of the IOL power should be realized according to the

patient requirements, after a preoperative meticulous discussion. An

active patient would need an emetropic status after cataract surgery

for distance and would prefer glasses for near activities. A very old

patient or a patient with a locomotor handicap could prefer a myopic

status after cataract surgery that allows him/her to see at near and

to wear glasses for distance.

The power of the artificial IOL differs according to the patients

requirements, but also to the postoperative status of the eye. In

patients requiring combined anterior and posterior segment

surgery for cataract and retinal detachment, when I plan to

suture an encircling band, I usually take into account that the

placement of the external indentation induces a permanent

miopization of the eye with about – 2 D and I calculate the power of

the IOL by considering this variation. In eyes requiring posterior

segment surgery with internal tamponade with silicone oil for

different periods of time according to the severity of the posterior

segment disease, the postoperative refraction of the eye varies

toward the hyperopia with + 2,+3 D. I usually calculate the power of

the IOL so that the difference between the 2 eyes is not higher than

2D before, and also after the silicone oil removal.

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Pathology and Clinics

The information of this chapter are organized from the

cataract surgery point of view, containing aspects of

pathology and clinics in different types of cataracts that, in

my view, should be preoperatively judged according to the

general pathologic context of the eye.

The cataract surgery outcomes depend on the

preoperative plan established after a careful examination

and anamnesis of the patient, but they also depend on the

flexibility of the cataract surgeon to change the previously

established plan and to adapt it to different circumstances

which can appear during surgery.

Hard cataracts

The most common hard cataract is age related

cataract, especially in advanced stages. This is also one of

the most frequent clinical type of cataract and a very

common cause of visual impairment in old adults.

Due to the continuous formation of the new lens fibers

that are deposited on the nuclear older ones throughout life,

the lens nucleous is compressed, becoming harder and

harder. There are numerous biochemical modifications due

to aging, some of them not being completely understood

(cleavage of the lens proteins, formation of high-molecular-

weight protein aggregates, formation of water bubbles

around the lens proteins, increasing the lens pigmentation,

etc). The degree of the lens capsule degeneration varies

according to the cataract stage.

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As the lens structure modifications with aging are physiologic

and observed in all patients, with or without other ocular or general

diseases predisposing to cataract, in old patients, all cataractous

lenses will be characterized by different degrees of nucleous hardness

according to the age. That is why the planning of the cataract

surgery should take into account the condition that is suspected to be

the cause of the cataract, but also the patient age.

There are numerous clinical types of age related

cataract. Their careful preoperative examination helps the

surgeon to plan the best way for operation, according to the

condition of the lens capsule, opacification of the lens

content, zonula status, nucleous hardness and other

associated ocular pathologic conditions (glaucoma,

malformations of the anterior segment, previous operations,

etc).

Before planning the cataract operation, the surgeon

should analyze in which lens region the opacification is

more important:

- in the nucleous (nuclear cataract) – the nucleous has

different degrees of sclerosis and yellowing, its removal

being more or less difficult during the phacotechnique

By modifying the phacomachine parameters, by working with

patience, by using bimanual technique and protecting the cornea

with viscoelastic materials, the surgeon can also successfully manage

hard nucleous by phacotechnique and through small incisions.

However, such cases are not the best ones for a beginner in the

phacotechnique.

25

- in the cortex (cortical cataract) – frequently, the

nucleous is not very hard in such types of cataract and

the phacotechnique can be managed successfully.

According to the degree of the “pupillary red”, the

capsulorrhexis can be performed in normal conditions,

even when the lens content is white. In the latter

situation, a higher magnification of the image, the

following of the lens capsule foldings and the use of lens

capsule dye can be useful.

As the tension of the lens capsule allows a good manipulation

while performing the capsulorrhexis, such cases with not so hard lens

content are probably the best cases that could be chosen by a

beginner to start learning and practicing the phacotechnique.

- in the posterior cortex (posterior cortical cataract)

or, sometimes, in the region adjacent to the posterior

capsule (posterior subcapsular cataract)

After the lens remnants removal by irrigation–aspiration, the

detaching of the fibers strongly attached to the posterior capsule can

be a goal sometimes difficult to be reached. In certain situations, the

use of the BSS irrigation with a polishing cannula can realize a good

capsular cleaning.

In cases with opacities of the posterior capsule or fine

degenerated lens fibers that still remain attached to the posterior

capsule, for which the complete removal would risk breaking the

capsule, the surgeon should judge whether it is safer to try cleaning

the posterior capsule at any risk, or to perform later the YAG laser

capsulotomy.

- in the entire cortex and nucleous (mature cataract),

usually appearing as “white cataract”.

26

The capsulorrhexis is sometimes difficult because the

degenerated capsule does not have its normal tension and elasticity

and because the red pupillary reflex that allows the visualization of

the capsulorrhexis line is absent.

In my view, the mature cataracts are not the best cases to be

operated by a beginner during the learning curve. These cases

require longer surgeries and laborious maneuvers that can damage

the corneal endothelial population of cells, leading to postoperative

chronic endothelial edema. On the other hand, the risk for capsular

breaks is higher as well as the incidence of consequent

complications, and the surgery can end wrong for the patient but

also for the psychology of the surgeon, who could be discouraged by

the postoperative poor results.

- the entire cortex is opaque and liquefied, while the lens

capsule is degenerated, wrinkled and shrunken

(hypermature cataract)

- the liquefaction of the cortex in a hypermature cataract

allows the free movement of the nucleous in the capsular

bag (morgagnian cataract)

The hypermature and morgagnian cataracts are also, in my

view, not cases suitable for the learning curve due to the complexity

of the intraoperative maneuvers that could be required during the

surgery. The most fair play solution for a beginner would be to defer

the patient to a much more experienced surgeon, or, to perform the

classic extracapsular technique for cataract surgery, if he/she must

perform the operation in any condition.

Clinical picture. The patient complains different

degrees of visual acuity decrease, but, in the absence of

complications, the eye is white, quiet and does not hurt. The

27

pupil is colored not homogeneously in grey in the first

stages, and homogeneous white later, in advanced stages.

The intraocular pressure is not modified by the onset and

the evolution of uncomplicated cataract.

When several complications appear as a result of

the evolution of cataract, the signs and symptoms are

modified:

phacoantigenic uveitis appears when the lens

proteins pass over the severely degenerated lens

capsule inducing a granulomatous immunologic

inflammation, localized especially in the anterior

segment. The eye is red, painful, the anterior segment

is the place of an inflammatory syndrome (corneal

endothelial precipitates, anterior and/or posterior

synechiae, miosis). The intraocular pressure is lower

because of the decreased aqueous humour production

as a result of the ciliary body inflammation. The

phacoantigenic uveitis can be also determined by the

lens remnants left after cataract surgery or in cases

with accidental or surgical lens trauma.

The eye with cataract complicated with phacoantigenic uveitis

in its acute stage should be never operated before trying to quiet the

inflammatory syndrome, because even a perfect surgery will end

wrong. The treatment should start with antiinflammatory drugs

administered systemically and also locally, mydriatic and

cycloplegic drops associated, according to the situation, with

antibiotic therapy, local and sometimes also general.

This decision is to be modulated in cases in which the posterior

segment and the vitreous body are also involved in the inflammatory

reaction (phacoantigenic endophthalmitis), when the pars

28

plana vitrectomy associated to general and local antiinflammatory

therapy should be considered as soon as possible, in order to avoid

losing the eye.

As the phacoantigenic uveitis can be the result of an

incomplete removing of the lens cortex or even nucleous, the

accurate cleaning of the capsular bag during the cataract surgery is

mandatory in order to prevent this postoperatory complication.

In all traumatized cases, the status of the lens should be

carefully checked and a possible trauma of the lens should be

always considered in any ocular trauma because even the capsule

contusion may induce an abnormal passage of the lens proteins in

the aqueous humour, starting an inflammatory phacoantigenic

reaction. Thus, before surgery, when there is no endophthalmitis that

forces the surgical decision as soon as possible, a local and

sometimes also general treatment should try to suppress the

inflammation.

phacomorphic glaucoma is a secondary closure

angle glaucoma caused by an intumescent cataractous

lens that blocks the pupil because of its swelling. A

secondary mechanism for intraocular pressure

increasing is pushing of the entire iris plateau

anteriorly, shallowing the anterior chamber and

blocking the anterior chamber angle. The eye is red

and painful and has a long history of visual acuity

decreasing as a result of the cataract evolution. The

cornea is usually edematous, appearing opaque

because of the subepithelial bubbles caused by the

sudden increase of the intraocular pressure. The pupil

is frequently white as a result of an advanced cataract.

Even if the lens removal is required in order to reverse the

pupillary block and to open the angle, the surgery should not be

performed on an eye with intraocular pressure higher than 20

29

mmHg because of the high risk of suprachoroidal or expulsive

hemorrhage. The intraocular pressure must be decreased, the acute

episode stopped and then, the lens removed.

The major hypotonic medication generally

administrated usually decreases the IOP and prepare the eye for a

safe surgery. If even the general drugs cannot decrease the IOP, the

eye should be approached from the posterior segment, by performing

a pars plana vitrectomy. After depressing the IOP by extracting a

quantity of the vitreous, the lens surgery can continue by choosing an

anterior or posterior approach, according to the decision of the

surgeon.

All cases with high IOP that cannot be decreased

preoperatively by systemic medication are dangerous options for a

beginner during his/her learning curve.

Due to the necessity of the pars plana approach of the

posterior segment, such complex cases are, in my view, surgical

situations that should be operated by experienced surgeons who are

able to perform combined operations, and not by surgeons who

operate in the anterior segment only.

I usually prefer to use intravenous Manitol 20% associated to

systemic Acetazolamide, because Manitol decreases the IOP but also

dehydrate the lens and the vitreous, thus reducing the pupillary block

caused by the swollen lens.

Even if the IOP is decreased preoperatively, even if the eye is

approached from the posterior segment, the risk for expulsive

hemorrhage in these cases still persists because the long ciliary

arteries and possibly also other choroidal or retinal vessels can be

broken by the sudden depression of the intraocular pressure when

the eye is opened. An eye with expulsive hemorrhage is not a priori

lost in the vitreo-retinal surgery era, but the required surgery is

complex and not always followed by very good results, even if it is

performed in time (7-10 days after the onset of the event).

phacolytic glaucoma is an open angle glaucoma in

which the lens proteins leave the lens through a

30

degenerated capsule, usually in mature or

hypermature cataract. The proteins arrive in the

aqueous humour where they are captured by the

macrophages. The proteins – macrophages complexes

block the anterior chamber angle, leading to the

increase of the IOP. On an eye with white pupil due to

the mature or hypermature cataract, the phacolytic

glaucoma has an acute onset with redness and pain,

corneal edema and high IOP. Sometimes, white

flocculent material can be observed in the anterior

chamber, adhering to the lens capsule or to the

trabecular meshwork.

The treatment consist of the lens removal that should be

performed, after the decreasing of the IOP with major hypotonics

(e.g. Manitol intravenous perfusions, Acetazolamide per os or

intravenously).

When the IOP cannot be decreased safely before surgery, the

options are similar to the ones described above.

I usually associate antiinflamatory general and local

medication to the hypotonics preoperatively because in my view, by

quieting the inflammation, the postoperative evolution is better and

the results improved.

“lens particle” glaucoma is also an open angle

glaucoma caused by the occlusion of the anterior

chamber angle with lens particles remained in the

anterior chamber after the incomplete removal of the

lens during cataract surgery, or after YAG

capsulotomy performed on a capsule with retained

lens material. The high IOP, the presence of the lens

31

material in the anterior chamber and the anterior

chamber angle together with different degrees of

anterior segment inflammation establish the positive

diagnosis.

The treatment should be started medically, by administering

generally and locally antiinflammatory drugs aiming to decrease the

inflammation and the IOP, but the surgery is required because the

cause of this complication should be eliminated.

The removal of the lens content as much as completely possible

represents the goal of all cataract operations.

In the context of an opacified lens capsule with a high

quantity of retained cortical material that requires treatment,

instead of Nd:YAG capsulotomy that could expose the eye to “lens

particle” glaucoma or to other complications, I consider that the pars

plana approach and removal of the lens fragments and capsule from

posteriorly, performing a localized vitrectomy, represents the safest

and best option for treatment.

Soft cataracts

The density of the lens nucleous and cortex with

consequences on the cataract surgery plan depends on the

patient age as well as on the lens opacification, as it was

previously described.

Numerous types of secondary cataracts that have the

onset in young and middle age adults can be included in the

“soft cataracts” category, even if their cortex is sometimes

completely opacified as in mature age related cataract. The

main examples of soft cataracts are:

- traumatic cataracts: caused by mechanical injuries –

without intraocular foreign bodies (IOFB) (e.g. cataract

32

after ocular contusion) or with IOFB retention (e.g.

cataract in eyes in which the IOFB traumatizes the lens,

in eyes with metallosis - in which IOFB induces toxic

changes in the adjacent tissues, like iron in siderosis or

copper in chalcosis), cataracts caused by chemicals (e.g.

alkali more than acids), termic injuries, radiation (e.g.

glassblowers cataract produced by infrared radiation,

cataract produced by ultraviolet radiation or by

microwave radiation), or electric shock (e.g.

electrocution cataract).

- metabolic cataracts: observed in diabetes mellitus

(e.g. acute diabetic cataract in which the lens becomes

swollen because it retains water due to an increased

concentration of sugars in the aqueous humour, or

snowflake cataract of young patients with uncontrolled

diabetes), in galactozemia, hypocalcemia, hypoglycemia.

- dermatologic diseases cataracts: atopic dermatitis,

xeroderma pigmentosum, neurodermitis, chronic

eczema, Bureau – Barrière syndrome (in alcoholic

people), Werner syndrome, Rothmund syndrome,

Siemens syndrome, etc.

- neurologic or muscular disorders cataracts:

Steinert myotonic dystrophy, Wilson hepatolenticular

degeneration, type 2 neurofibromatosis.

- drug-induced cataracts: in long term use of

corticosteroids, phenothiazines (Chlorpromazine,

Thioridazine), miotics (Pilocarpine, Echothiopate iodide,

etc), amiodarone, cytostatics, alopurinol, oral

contraceptives, etc.

- cataracts associated with ocular disorders:

uveitis, glaucoma, pseudoexfoliation syndrome, retinal

33

detachment, myopia, intraocular tumors, ocular ischemic

syndromes, chronic ocular hypotony, etc.

Cataracts in combined ocular

pathology

The cataract surgery performed on the eye with

combined pathology of the anterior and posterior segment

should consider possible special situations that could

appear, sometimes requiring particular approaches.

Cataract in glaucomatous eye is a frequent

pathologic association that must be carefully judged by the

cataract surgeon. Sometimes the cataract can be at the

origin of the glaucoma onset, like in the situations described

above, as complications of the age related cataract evolution

or surgery. In other cases, different types of open or closure

angle glaucoma coexist with the cataractogenic process of

the lens.

It should be stressed that the IOP must be always

decreased before opening the anterior chamber in the eyes

in which the cataract is associated with any type of

glaucoma, otherwise, soon or later during or after the

cataract operation, the expulsive hemorrhage can

complicate the surgery and its results.

The decrease of the IOP can be realized in different

ways:

compensation of the glaucoma by topical

medication in cases with chronic primary or

34

secondary open angle glaucoma or with mixed

glaucoma that respond to antiglaucomatous drops

Before starting the cataract surgery, it is safer to wait 2 – 3

weeks of successful topical antiglaucomatous medication that

compensates the IOP, even if the IOP decreased under the level of

20 mmHg. This way, the blood pressure inside of the ocular blood

vessels and the intraocular pressure reaches an equilibrium, the risk

for suprachoroidal hemorrhage being decreased.

In any glaucomatous eye, even if the IOP could be

compensated by administering topic antiglaucomatous drops, the

superior conjunctiva should be preserved by cataract surgeon, in

order to create the conditions for a further filtrating procedure that

could be required by the evolution of the case. Probably the clear

corneal incision is the best approach for cataract surgery in

glaucomatous eyes.

In the glaucomatous eyes compensated by topical

antiglaucomatous drops or by filtrating procedures, but especially in

the eyes with narrow anterior chamber angle, in the morning before

cataract operation, I prefer to administer intravenously a small dose

of Manitol 20%, aiming to further decrease the IOP, to contract the

vitreous gel and to create space for moving the iris backward.

glaucoma surgery performed as separate session

before cataract surgery and including filtrating

procedures in the anterior segment as well as laser

procedures, according to the type of glaucoma

The cataract surgery planned on an eye previously operated

for glaucoma by performing a filtrating procedure should consider

an incision that preserves the conjunctiva adjacent to the

superior and temporal limbus (allowing new filtrating

procedures) and the conjunctiva that covers the site of the

35

previous filtration (e.g. Cairns trabeculectomy, artificial drainage

systems, etc). Clear corneal incision allows a good approach for

cataract surgery phacotechnique in such cases.

In my view, the cataract and glaucoma surgery performed as

separate operations is the best and safest option for a beginner

during his/her learning curve.

administration of major systemic hypotonics (e.g.

Manitol 20% or Acetazolamide as pills or intravenous

solution) before planning a combined procedure –

cataract surgery and filtrating operation for

glaucoma (e.g. cataract surgery combined with Cairns

trabeculectomy)

A plan for combined cataract and glaucoma surgery can be

realized in different ways, according to the surgeon experience and

preferences. However, this complex operation should be avoided by

the beginners in cataract surgery because all sections of this

combined procedures are more difficult than the same techniques

performed separately.

In my opinion, the glaucomatous filtrating operation and

cataract surgery performed as separate sessions, at least 2-3

weeks apart one to the other (first glaucoma surgery and second

cataract surgery) is a better option. The risk for suprachoroidal

hemorrhage is significantly decreased in separate operations.

pars plana approach with eye decompression by

limited anterior vitrectomy or by posterior

pars plana vitrectomy

In consider that such an approach should be considered as an

extreme solution in the cases in which cataract surgery is an

36

emergency and the IOP cannot be lowered by any other means. As I

mentioned previously, I believe that such cases should not be

operated by beginners in cataract surgery and should be deferred to

a surgeon able to operate in the anterior and also in the posterior

segment.

According to the clinical type of glaucoma, the ocular

conditions met by the cataract surgeon during his/her

surgery may widely vary:

- eye with primary open angle glaucoma – on which

filtrating procedures in the anterior segment were

already performed or could be required later

The conjunctiva should be preserved in all these cases for

previous or further filtrating procedures.

In order to obtain the best postoperatory results, the case

must be judged and the surgery planned in the context of the

associated pathology.

- eye with secondary open angle glaucoma – in which the

outflow of the aqueous humour is impeded or blocked by

different mechanisms leading to the IOP increasing. The

associated pathologic conditions in such cases may

increase the difficulty of the cataract surgery steps.

In pseudoexfoliative glaucoma (as well as in almost all

cases with pseudoexfoliation syndrome) the pupil cannot be dilated

very well and the lens capsule is more friable, being easily broken

during lens content cleaning by phacoemulsification or irrigation –

aspiration.

In cases with pseudoexfoliation syndrome with or without

secondary glaucoma I usually perform a smaller capsulorrhexis

37

from the beginning When accidentally the posterior capsule is broken

during different cataract surgery steps, I perform the anterior

vitrectomy until the posterior capsule break and the pupillary area is

relaxed and in the vast majority of cases I implant a multipiece

foldable IOL in the sulcus or an iris-claw lens back to the iris.

The presence of the iris and/or angle neovascularization like

in secondary open angle glaucomas caused by ocular

ischemic disorders can lead to an incomplete dilatation of the

pupil and increase the risk of bleeding during cataract surgery

procedures.

Intravitreal injections with anti-VEGF agents (Bevacizumab

or Ranibizumab) administered a few days before surgery lead to a

rapid regression of neovascular membrane in the anterior and

posterior segment, improving the conditions for cataract surgery

and decreasing the risk for intraoperative bleeding.

When this option is possible, I consider that the posterior

segment pathology leading to the anterior segment

neovascularization should be treated before cataract surgery, in

order to work in the anterior segment in the best conditions during

the lens operation.

When the lens opacification impairs the treatment in the

posterior segment, I consider the combined surgery after intravitreal

anti-VEGF injections as the best surgical treatment for the case –

cataract surgery, pars plana vitrectomy, retinal photocoagulation

and, according to the case, silicone oil tamponade.

In hemorrhagic glaucoma in which the angle is opened but

occluded with blood compounds, in different types of glaucoma after

trauma, in ghost cell glaucoma or in hemolytic glaucoma the

cataract surgery can be necessary to allow the visibility in the

posterior segment for further surgical procedures. If the first step is

cataract operation, the anterior chamber angle should be irrigated in

the order to eliminate the cause of blockage.

38

In cataracts associated with open angle glaucoma due to an

anterior segment inflammatory diseases, the cataract surgery

must be performed after trying the cessation of the anterior segment

inflammation by local as well as general medication. Frequently the

pupil cannot be dilated because of the posterior synechiae, sometimes

requiring iris retractors. The capsulorrhexis can be difficult in eyes

with a history of inflammation and the capsule can be very friable,

with a high risk to be broken during cataract surgery procedures.

Other times the capsule is very thick and cannot be cut unless using

the scissors or the vitrectomy cutter. Taken into account all these

difficulties, the eyes with inflammatory history should be avoided by

beginners in phacotechnique, during their learning curve.

- eyes with primary closure angle glaucoma – the

cataract surgery is frequently difficult on these eyes

because the anterior chamber is shallow; the

manipulation of the instruments is difficult inside of such

an anterior chamber and has a high risk of corneal

damage leading to postoperative corneal

decompensation. As a results of previous closure angle

attacks, the anterior segment is usually the site of chronic

inflammation leading to anterior and posterior

synechiae, permanent constriction of the pupil, different

degrees and areas of iris atrophy.

The eyes with primary closure angle glaucoma must be

compensated from the IOP point of view before cataract surgery.

This goal usually requires different nonconventional maneuvers that

must be adapted to each case. The cataract operation in such cases

is more difficult and should be avoided by beginners in

phacotechnique.

As the thickness of the artificial IOL is lower than that of the

natural lens, after cataract surgery the angle is enlarged and

sometimes the episodes of closure angle are stopped. Sometimes, the

39

surgeon may consider useful a peripheral iridectomy, aiming to

prevent further episodes of angle closure.

- eyes with secondary closure angle glaucoma – the

conditions for surgery in such eyes are difficult, no

matter if the angle is closed by “pulling” (e.g.

contraction of an inflammatory, fibrovascular, epithelial

or endothelial membrane, contraction of anterior

peripheral synechiae) or by “pushing” (e.g. mechanic

force exerted on the iris roof by an intumescent lens,

posterior tumors, cysts, choroidal or retinal detachment)

In some situations, the lens extraction eliminate the cause for

pupillary block and closure angle. In other cases, the cause for

anterior chamber angle closure can be eliminated during the

surgery, by additional maneuvers, otherwise, shortly after cataract

surgery the IOP will increase again and the case will have a bad

postoperative evolution.

Cataract in eyes with vitreo-retinal pathology

is a frequent combination that can be observed in old

patients (age related cataract – age related macular

degeneration), in diabetics (diabetic cataract – diabetic

retinopathy) and trauma (traumatic cataract – retinal

detachment and numerous other vitreo-retinal traumatic

complications). The planning of the cataract surgery in

these cases must be realized taking into account also the

posterior segment disease and that is why the plan should

be made by a cataract surgeon able to operate also in the

posterior segment, or by a team including cataract and

vitreo-retinal surgeons. Sometimes cataract surgery can be

indicated before vitreo-retinal procedures, other time after

40

vitreo-retinal surgery, but frequently, a combined cataract

and vitreo-retinal surgery can be the best and safest option

for these complicated cases.

Cataract in childhood

The presence of the lens opacification at birth is

associated with the term of congenital cataract, while

the development of the lens opacities in the first year of life

with the diagnosis of infantile cataract.

During the first 3 – 4 years of life the visual acuity

progresses from a very low level under the limit of practical

utility at birth, to the normal values of adults. If the

presence of lens opacities interfere with the development of

the visual acuity, on one or both eyes, the cataract surgery

represents an emergency, in order to prevent the amblyopia.

The complete treatment of the cataract in childhood means

also the corrections of aphakia, that nowadays is accepted to

be realized by implantation of an IOL by the majority of the

surgeons.

The congenital cataract surgery in severe bilateral

cases must be performed as soon as possible, preferably

before 3 months of age, in order to prevent the development

of the nystagmus. Because as compared to adults,

children have an enhanced inflammatory and fibrotic

response to cataract surgery, it has been suggested to

separate by 2 weeks the surgeries on the two eyes in

children younger than 2 years and by 1 month in children

older than 2 years.

41

There are few anatomic and physiologic

characteristics in children that have consequences on the

cataract surgery steps:

- the risk for postoperatory subsequent injuries and

endophthalmitis is lower if the incision is made

superiorly in children, beneath a scleral tunnel, and the

incision is sutured at the end of the procedure (even if the

corneal incision as in adults is possible also in children)

- the lens capsule is more elastic in children, the lens

cortex and nucleous tend to be gummy and having a

particular intralenticular pressure, so that the attempt

to perform the capsulorrhexis in the same way as in

adults can fail frequently. The usage of the high-viscosity

cohesive viscoelastic materials and planning of a smaller

anterior capsulorrhexis can help managing these cases. It

is also possible to use vitrectomy cutter for cutting the

hole in the anterior lens capsule while aspirating the lens

cortex passing under the pressure outside of the capsular

bag.

- the lens cortex and nucleous in children have a

particular density and thus, they can be removed by

irrigation-aspiration only, not requiring ultrasounds for

emulsification.

In certain situations, the cataract in children is

associated with other malformations of the anterior and/or

the posterior segment, requiring particular approaches and

attitudes, sometimes a collaboration between anterior and

posterior segment surgeons.

42

The children with cataract require a special attention for

planning the surgery, that is more difficult than the cataract surgery

in adults. The follow-up period of time in these operated cases does

not end soon or later postoperatory, being extended throughout the

life. Taking into account these considerations, the cataract surgery in

children should be avoided by beginners during their learning curve.

43

2. Starting Cataract Surgery by Phaco with

the Main Steps during Wetlabs

If you are a beginner in anterior segment

surgery you must start the main steps on animal eyes. You

should start with cutting the tissues and suturing, miming

different situations that can appear during real operations

on the human eyes. You do not need too many instruments

for these maneuvers. You can start performing if you have:

operating microscope (or, a simple binocular loupe)

device to fix the animal eyes (Fig.5)

fine-tipped tooth forceps

Vannas scissors

blades and knifes

needleholder

10-0 or 9-0 nylon sutures

The first step is to coordinate your hands movements under

the microscope, then to manipulate the instruments in the wanted

direction.

Cut the tissues in different directions and then suture. Try first

with intrerrupted sutures, tied securely in 3-1-1 fashion, as they are

the most frequently used. When you like the way you perform these

simple sutures, you can start training your hands to continue with

the other types of sutures.

Follow other surgeons performing different maneuvers and

then try to repeat the steps during your own training. Your training

during wetlabs will be easier if you follow how other beginners are

performing (see the movie 1 on the DVD).

Do not give up! Every learning curve starts

this way!

44

Did you train yourself for simple maneuvers on animal

eyes and you are happy you succeeded? You can continue

with the next step – cataract surgery by

phacoemulsification.

You also need to train your hands first on dry or

wetlabs because this is the most fair play attitude towards

your patients.

Do not lose any chance to work on the devices for dry

labs at different meetings. Do not be afraid to start using

any phaco machine during the wetlabs you attend. The main

steps of the cataract surgery are the same, no matter which

company provides the devices for phacoemulsification.

Do you have a phaco machine in your department and

you want to start to operate cataract by phaco? You have

nothing else to do than to start doing it!

Fig.5. Performing on animal eyes during wetlabs

- see the movie 1 on the DVD

45

You could organize your first own sessions of

wetlabs in your department, with this minimum set of

instruments:

operating microscope

phaco machine

device to fix the animal eyes

slit knife, angled bevel up

15˚ double bevel stab knife, straight

iris hook

spatula

thin cannula

bent 25- or 30-gauge needle

fine-tipped tooth forceps

Vannas scissors

needleholder

You also need the following materials:

fresh (less than 36 hours) pig eyes

BSS or physiologic salt solution

viscoelastic material

cellulose sponges

10 ml syringes

10-0 nylon sutures

Ask the technicians from the company that provided the phaco

machine in your department to assist you during the first sessions of

your own wetlabs.

Use first the parameters indicated by the technician and, after

learning the steps, adjust the parameters in the most comfortable

way for your hands and movements.

46

You could try the steps described below. No matter if

you perform the steps correctly, try to continue, ending in the best

way the surgery! You need to learn how to finish a surgery

even if some steps do not evolve well!

The cataract surgery by phacoemulsification can use

the coaxial infusion-aspiration-phaco probe that can be

resumed to the following main steps:

I. Anterior chamber paracentesis at 1 and 11 o’clock.

Use the 15˚blade. Do not perform a very large opening at

1 o’clock, to avoid losing the anterior chamber during the next

maneuvers. However, the opening at 11 o’clock should be large

enough to allow you later the manipulation of the needle, in order to

perform the capsulorrhexis.

II. Filling up the anterior chamber with viscoelastic

through one of the two paracenteses.

Fill up the anterior chamber with viscoelastic material in

order to have enough space for the further capsulorrhexis, but also to

protect the corneal endothelial from damages during the maneuvers

in the anterior chamber. However, do not create a too deep anterior

chamber because the iris-lens complex will be pushed towards the

vitreous, such a movement endangering the integrity of the zonula.

III. Capsulorrhexis. Create a continuous circular break in

the anterior lens capsule with the bent angulated needle

(Fig.6). One could also use the forceps for this maneuver

(Fig.7), in this latter case, the opening required by the

introduction of the instrument into the anterior chamber

being larger.

47

In my view, the variant with the needle is easier for beginners

because the depth of the anterior chamber during the capsulorrhexis

could be better controlled. However, each surgeon should choose

his/her personal variant to “control” the lens capsule.

Start in the mid periphery of the anterior capsule observed in

the pupillary field and then continue circularly, clockwise or

counterclockwise. Do not advance towards the periphery. See a

suggestion in the movie 2 on the DVD.

By performing the capsulorrhexis with the needle you will be

able to maintain the anterior chamber deep during the whole

procedure, no matter which viscoelastic you use.

If you are much more comfortable with the forceps, do not

hesitate to choose this technique, but use a cohesive viscoelastic (e.g.

hyaluronic acid) to maintain the depth of the anterior chamber.

Fig.6. Performing capsulorrhexis with the needle.

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IV. Approaching the anterior chamber by performing

a clear corneal incision (Fig.8) or a limbic incision

(Fig.9).

In my view, the easiest and best incision to be used by a

beginner in cataract surgery by phaco is clear corneal incision in 2

steps, because it induces a very small postoperative astigmatism and,

if it is performed correctly, it can be let without suturing (“self-

sealing”).

Introduce first the tip of the angulated blade parallel to the

corneal surface and then orient the tip towards the lens center, until

you penetrate the anterior chamber. The weight of the blade must be

correlated to the dimensions of the probes you use for

phacoemulsification and irrigation-aspiration (e.g. 19 G, 20 G, 23 G).

The weight of the corneal incision should be large enough to allow an

easy manipulation of the probes introduced in the anterior chamber,

but not so large to allow an outflow of the irrigation solution out of

the eye.

Fig.7. Performing capsulorrhexis with the forceps.

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Fig.8. Performing clear corneal incision.

Fig.9. Performing limbic incision.

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V. Extraction of the anterior capsule flap.

The flap obtained after performing the capsulorrhexis should

be extracted from the anterior chamber with a forceps. Apparently,

the maneuver is not important, but in my view it should be always

realized because of two reasons. First of all, you can be sure that you

performed completely the capsulorrhexis in all cases after you

succeed removing this fragment. Secondly, if you let the capsule

there, it can be attached during the next steps on the endothelial

surface and missed there at the end of the surgery. I saw cases in

which the operation evolved wrong, with corneal decompensation

that apparently could not be explained by any reason. When I

opened again the eye and extracted a transparent membrane

attached to the corneal endothelial (the capsule forgotten by the

previous surgeon), the corneal endothelial could be treated. That is

why I have learnt to always remove the flap of the anterior capsule

after capsulorrhexis and I consider that this small step should be

learned during the training on the animal eyes by any beginner.

VI. Hydrodissection and hydrodelineation by using a

thin cannula (Fig.10).

The hydrodissection (injecting BSS between the lens cortex

and its capsule) and hydrodelineation (injecting the BSS between the

cortical layers) are very important steps that make easier the

nucleous phacoemulsification and the cortex removal as well.

If you obtain the “golden ring”, that circular reflex around the

detached nucleous, the maneuver succeeded.

Learn these important steps during your training at wetlabs

and try to maintain the lens content, as much as possible, far away

from the corneal endothelial.

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VII. Nucleous removal by phacoemulsification.

There are numerous ways to divide and remove the

fragments of the lens nucleous that varies according to the

surgeon preference, from the “divide-and-conquer”

technique (Fig.11) to the technique of excavation and

removal from the middle towards the periphery, piece by

piece (Fig.12).

Do not hesitate to choose the technique with which you are the

most comfortable!

You should not work very close to the cornea in order to avoid

the endothelial damage leading to the endothelial edema and corneal

decompensation after surgery. It is safer to work in the pupillary

plane or in the capsular bag (Fig.13), but you should spare the

posterior lens capsule, in order to avoid creating iatrogenic breaks

that may complicate your surgery.

Fig.10. Hydrodissection and hydrodelineation.

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Fig.11. “Divide-and-conquer” technique to

remove the lens nucleous by phaco.

Fig.12. Lens nucleous removal from the

center towards the periphery.

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VIII. Cortical remnants removal by irrigation-

aspiration.

Start this step after cleaning the whole nucleous because the

internal diameter of the aspiration cannula is smaller than the one of

the phacoprobe.

You could help yourself by using the hook needle that divide

the lens remnants agglomerated on the aspiration orifice.

If the capsular bag is not clean and there are still remnants

attached to the capsule, you could irrigate with a thin cannula and

then, aspirate again.

IX. Filling the capsular bag and anterior chamber

with viscoelastic.

If you succeeded not to break the lens capsule, you can implant

the lens in the bag. Start filling the capsular bag, then the anterior

chamber and finally, protect the lips of the corneal wound with a

small quantity of viscoelastic material.

Fig.13. Phacoemulsification inside of the

capsular bag.

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Did you break the posterior capsule but there are still enough

support for the implantation in the sulcus? Fill up the sulcus first, and

then the anterior chamber.

Did you break the posterior capsule and either the

implantation of the lens in sulcus cannot be realized in safe

conditions? No problem! Learn how you should perform anterior

vitrectomy. Learn how to cut the vitreous strands nearby the capsule

margins, but without cutting the capsule! You will surely need this

maneuver for your first surgeries during the learning curve on

human eyes. If you learn the maneuver now, the learning curve on

your patients will be shorter!

Do not give up! Start again the steps on the next animal eye

and pay much more attention to each previous maneuver!

Be patient and trust in you!

X. Implantation of the demo-intraocular lens (IOL)

with the cartridge or forceps.

If you choose the automatic injection of the IOL, try all the

maneuvers outside of the eye and when everything is working well,

introduce and defold the IOL into the animal eye. Follow all the

instructions indicated by the manufacturer and be careful not to

break the foldable IOL.

Did you decide to implant the IOL with the forceps? You will

need to enlarge a bit the incision in order to be able to introduce

easily the folded IOL into the anterior chamber.

If you introduce the first haptic into the established area (bag

or sulcus) and only the second half of the IOL remain to be

manipulated, you will damage less the corneal endothelial.

XI. Removing the viscoelastic remnants from the

anterior chamber and capsular bag.

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Do you have an intact capsular bag and the whole procedures

evolved well? Remove the lens and viscoelastic remnants from the

anterior chamber and capsular bag by irrigation-aspiration with the

irrigation-aspiration probe.

Do you have a break in the posterior capsule? The

introduction of the IOL even in the sulcus area will involve vitreous

strands and induce tractions, even if you performed a good anterior

vitrectomy. I suggest you to remove the lens and viscoelastic

remnants with the vitrectomy cutter. Go with the vitrectomy cutter

tip in the center of the IOL and push a bit the IOL in order to fix it.

Then, cut the vitreous while aspirating. Do not move the vitrectomy

cutter very close to the iris in order to avoid cutting it. Continue to

cut and aspirate until the pupil is relaxed, without any traction.

XII. Reestablishing the intraocular tonus. When the

anterior chamber cannot be maintained after filling it with

BSS to reestablish the intraocular normal tonus, the corneal

or limbic incision must be sutured with 10-0 nylon.

Did you reach the 12th step described above? You won!

Did you have problems during the procedures and you did not

like the way you followed all these steps?

No problem! Try again! Next time will be better!

When you like the way you finalize the surgery on the animal

eyes, you are prepared to start performing phaco technique on your

patients eyes!

Good Luck!

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3. One Way to Start with…

The technique that I like the most in cataract surgery

by phaco includes the following main steps (see the movie 2

on the attached DVD):

I. Anterior chamber paracentesis at 1 and 11 o’clock.

II. Filling up the anterior chamber with viscoelastic.

III. Capsulorrhexis with the bent angulated needle

IV. Approaching the anterior chamber by performing

a clear corneal incision

V. Extraction of the anterior capsule flap.

VI. Hydrodissection and hydrodelineation.

VII. Nucleous removal by phacoemulsification.

VIII. Cortical remnants removal by irrigation-

aspiration.

IX. Filling the capsular bag and anterior chamber

with viscoelastic.

X. Implantation of the demo-intraocular lens (IOL)

with a forceps.

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XI. Removing the viscoelastic remnants from the

anterior chamber and capsular bag.

XII. Reestablishing the intraocular tonus.

You could try this technique! It is easy!