vitrectomytechnique in anterior segment surgery · british journalofophthalmology, 1977, 61,...

British Journal of Ophthalmology, 1977, 61, 209-215

Vitrectomy technique in anterior segment surgeryJ. J. KANSKI AND M. D. P. CRICKFrom Moorfields Eye Hospital, High Holborn, London, WCI

SUMMARY Instruments designed primarily for vitreous surgery were used in 74 anterior segmentoperations. In each case the instrument was introduced into the eye through a limbal incision.This preliminary report shows that this new approach offers several advantages over conventionalmethods in selected cases. It is of particular value in the management of presenile and complicatedcataracts and in the removal of capsulo-lenticular remnants and pupillary membranes. A largernumber of cases and longer follow-up are necessary to define further the specific indications andlimitations of this technique.

The recent development of instruments that willcut and remove ocular tissue through a very smallincision represents a significant departure fromconventional ophthalmic surgical procedures. Mostinstruments consist of 2 metallic tubes (Machemeret al., 1971; Peyman and Dodich, 1971; O'Malleyand Heintz, 1972; Douvas, 1973; Kloti, 1973;Federman et al., 1974). Tissue aspirated into the tipof the outer tube is cut by a shearing action producedby the rotation or oscillation of the inner tube.Evacuation is performed by suction from anaspirating syringe that draws the tissue into theinlet and removes it from the eye. The inflow offluid is controlled by gravity. The instrument canbe introduced into the eye through an incision atthe limbus or pars plana.The purpose of this report is to present a

preliminary analysis of our experience in anteriorsegment surgery using instruments containinginfusion, aspiration, and cutting features as designedfor vitreous surgery.

Patients and methods

During 13-months' period (January 1976 to January1977), 74 anterior segment operations wereperformed with a vitrectomy instrument; 53 wereperformed with the Kloti vitreous stripper and 21with the Keeler-Federman SITE. The patients (31females and 60 males) ranged in age from 6 monthsto 63 years. 8 patients had both eyes operatedon at different times, and a further patient had 2operations on 1 eye and 1 operation on the other eye.

Ocular evaluation included best corrected visualAddress for reprints: J. J. Kanski, FRCS, Moorfields Eye Hospital,High Holborn, London, WCI

acuity, external slit-lamp biomicroscopy, applanationtonometry, and ultrasonography in selected cases.Pre- and postoperative anterior segment photographswere obtained when possible.

Patients were usually admitted to hospital 1 or2 days before the operation and remained 4 to 7days after it. 71 operations were performed undergeneral anaesthetic, 2 under neuroleptic anaesthetic,and 1 under local anaesthetic. After the completionof surgery all eyes were given a subconjunctivalinjection of gentamicin and betamethasone.Mydriatic and antibiotic-steroid drops were instilledfrequently after operation. After discharge, patientswere followed up at 2- to 4-weekly intervals until astable state had been reached.Of the 54 eyes that underwent lensectomy 35 had

cataracts due to chronic anterior uveitis; extensiveposterior synechiae were present in the majority ofthese eyes. Of the 6 eyes with congenital cataracts 2were thought to have been due to maternal rubella.Of the 9 eyes with traumatic cataracts 5 had sufferedpenetrating injuries and 4 blunt trauma. There were3 eyes with presenile cataracts, and one 63-year-oldpatient with a posterior subcapsular cataractunderwent lensectomy during a combinedlensectomy-vitrectomy procedure.Ofthe 16 eyes that had anterior segment reconstruc-

tion for the removal of capsulo-lenticular remnants,pupillary membranes, or pupil enlargement, 2 hadhad previous surgery for traumatic cataracts, 5 forcongenital cataracts, and 9 for complicated cataractsdue to chronic anterior uveitis. In 4 eyes a traumatic-ally subluxated lens was removed.

Operative techniqueA wire lid speculum is inserted and the eye is steadied

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Fig. I Lensec tolmiy of cataractseconclary to chronic anterioruveitis. An oblique stab incisionis made with a Graefe knife at10 o'clock just insi(le the linibuis.The knife is then passed into thelens nucleus

with fixation forceps; traction sutures are notrequired. An oblique incision at 10 o'clock justinside the limbus is made with a Graefe knife(Fig. 1). The hardness of the lens nucleus is thentested. If the knife does not penetrate the nucleuseasily, an alternative method of extraction has tobe used. It is important to avoid damaging theposterior capsule at this stage and not to dislocatethe lens by probing too forcibly at a hard nucleus.If the cataract is suitable for lensectomy the cornealincision is enlarged. An overtight incision may leakpostoperatively owing to stretching of the corneal

tissues, and too large an incision will leak duringthe operation.

After the instrument is introduced into the eye(Fig. 2) as much lens matter as possible is removedworking within the capsular bag (Fig. 3). Thisminimises excessive irrigation of the cornealendothelium. The assistant should wait until hesees the tip of the instrument applied to the lensmatter and then aspirate fairly forcibly so as toengage it into the aspiration port (Fig. 4). Sometimesthe lens fibres will not aspirate immediately, but ifsuction is maintained for a few moments they

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Fig. 2 The incisionI is slightlyenlarged anld the vitrectonmyinlstrument is introduced iitto theanter-ior chaiiiber- alonlg the trackiniade by, the kntife

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Vitrectomy lechnliique inianterior segimient sutrg(ry

Fig. 3 Len)seclou( ), is(omlmel(ice(l bY aspira)tio (1iid('cuttinlg

deform and then aspirate quite suddenly. Whenthis occurs the assistant should stop aspirating soas not to collapse the anterior chamber. Anteriorchamber collapse can be avoided quite easily, andcomputer-controlled infusion and aspiration doesnot appear to be necessary. As much soft lens matteras possible is removed in this way without operatingthe cutting mechanism, though cutting will speedup the process and is necessary for harder lens

material and also for capsule, cyclitic membranes,iris, and vitreous.

After as much lens matter as possible has beenaspirated the anterior capsule is removed and, ifnecessary, the pupil enlarged. The remaining lensmatter is then dislocated from within the capsularbag and drawn into the centre of the pupil or intothe anterior chamber. The posterior and peripherallayers of the lens can be peeled away from the

Fig. 4 Lensectoy, is .earingcompletion. The posteriorcaps:leis still intact in order to preventletns matelial fir falling iilto thevitreous avlit1,'

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Fig. 5 Eye after completion oflensectomy and removal ofposterior capsule

posterior capsule. Allowing the anterior chamber tocollapse slightly at this stage helps to express lensmatter from under the iris into the centre of thepupil. It is important to avoid aspirating the vitreousbase so as not to cause traction and subsequentretinal dialysis. Finally, the posterior capsule isremoved and a shallow anterior vitrectomy per-formed. It is important to remove the posteriorcapsule in eyes with chronic iridocyclitis so as toprevent the formation of postoperative membranes.In eyes with congenital cataracts it is possible to leave

the posterior capsule behind. The instrument is thenremoved from the eye (Fig. 5) and air injected intothe anterior chamber. The bubble should extend asfar as the internal opening of the incision so as to pre-vent the formation of anterior synechiae. No suturesare necessary unless the incision has inadvertentlybeen made too vertical or the air is not retained.

Bleeding during the operation from the iris orvascularised membranes usually stops spontaneously;occasionally it may be necessary to cauterise thebleeding point (Fig. 6).

Fig. 6 Cauterisation of bleedingiris vessels

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Vil reetony feeleihnlique in antlerior seginelilsairgeY'2

Results

Lensefctomy (54 eyes)Accurate assessment in visual acuity was possiblein 45 eyes. It can be seen from Table I that in 40eyes (89 %) the preoperative visual acuity was'counting fingers' or less, and the postoperativevisual acuity of 6/12 or better was achieved in 17eyes (38%). 36 eyes had an improvement in visualacuity, in 7 eyes there was no change owing to pre-existing lesions (retinal detachment in 2 and grossfield loss in 1), and 2 eyes developed retinal detach-ment postoperatively.

In 3 eyes the lensectomy failed as the lens wascalcified. The section was enlarged and the cataractwas removed with a cryoprobe. In another eye onlya partial lensectomy was possible owing to un-expected hardness of the lens. Fortunately, theremaining lens material absorbed spontaneouslyduring the next 8 weeks.

In 6 eyes there was loss of lens material into thevitreous cavity during the operation. In 4 eyes theamount of lens material was very small and in eachcase it absorbed spontaneously. In 2 eyes the wholenucleus was lost. An unsuccessful attempt to retrieveit was made in I eye with the vitrectomy instrument.This resulted in the formation of a retinal tear andsubsequent inoperable retinal detachment. Thenucleus was later removed from the anteriorchamber with the cryoprobe. In another eye aretinal detachment formed 6 weeks after an un-eventful lensectomy. It is thought that this was theresult of excessive traction on the vitreous base bythe vitrectomy instrument resulting in the formationof a dialysis.

Transient striate keratitis occurred in 5 eyes. Ineach case this followed prolonged manipulation oflens material in the anterior chamber of eyes withrelatively hard nuclei. It seems probable that thisresulted in endothelial damage.

Reoperation was necessary in only I eye. Thiswas to remove a pupillary membrane which was thercsult of postoperative bleeding. A bleeding disorder

Table 1 Vi.s al a(l{it ' inl 54 e-)cs /elore(wi d afferlensecfolnl V

Visual acuily No. of,*eyes

Preoperative Post operahi e

6/12 or better 0 176/18-6/24 3 76/36-6/60 2 7Counting fingers 11 3Hand movements 13 5Light perception 16 6Too young to measure 9 9Total 54 54

l' able 2 Complnicalions of le/nectomilln 54 eyes

No. of eyes

Sturgical complications:Partial lens remiioval 1Loss of lens nuLicletis lllo vitreoils 2

Postopciatlive comiiplicationls:Transient st iate kei-atitis 5Formation of pLupillary nembranc IRetinal detachmnent 2

was suspected in this patient. A summniiary of thecomplications is listed in Table 2.On the whole, eyes with chronic uveitis tolerated

lensectomy very well, with no significant re-activation of uveitis durinig the postoperative perioddespite the fact that over 60% of eyes had activeinflamnmationi at the time of surgery.

Aniterior segcment rec(olstrcletionl (16 eyes)Successful removal of capsulo-lenticular remniiants(Fig. 7a, b), pupillary membranes, and pupillary

bFig. 7 (a) Capsulo-lenticluclr rentnants after conventionalcongenital cataract surgery. (b) Appearance afteroperatioll wit/h vitrec'tomny inlstrumlent

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J. J. Kalnski andl M. D. P. Crick

a

bFig. 8 (a) Preoperative appearance of cataract secondaryto chronic anterior uveitis. (b) Postoperative appearance

enlargement with the vitrectomy instrument wasachieved in 14 eyes. In I eye with a very tough post-traumatic membrane, a two-instrument techniqueusing Vanas scissors was necessary in order toachieve a pupillary opening. In another eye with asuspected persistent hyperplastic primary vitreousit was impossible to obtain an opening.Although in the majority of eyes visual improve-

ment was slight owing to pre-existing retinal damage,no serious complications resulted.

Removal of subluxated lens (14 eyes)A traumatically subluxated cataractous lens wassuccessfully removed in 4 eyes. A preliminary anteriorvitrectomy was performed, the incision was enlarged,and the lens was extracted with the cryoprobe.

Discussion

Orn the whole the results of the vitrectomy techniquein anterior segment surgery have been encouraging

and in selected cases appear to be an improvementon conventional methods.

Lensectomy has several advantages over con-ventional intracapsular cataract extraction. The smalllimbal incision, which frequently does not requireto be sutured, allows early ambulation and dischargeof the patient from hospital. It is now becomingapparent, however, that with present-day suturingmethods this is also possible with standard intra-capsular extraction (Galin et al., 1974). The amountof surgically induced astigmatism is small, andpatients can be fitted with their final correctionearlier. The incidence of vitreous loss is negligible.Should vitreous herniate into the anterior chamberit can readily be removed with the vitrectomyinstrument. This is particularly useful in the removalof subluxated lenses. If the lens is too hard forlensectomy then it is possible to do a preliminaryanterior vitrectomy, enlarge the corneal incision,and then remove the lens with the cryoprobe.Lensectomy also has some advantages over

phacoemulsification. It is a cheaper and easiertechnique, which does not require a deep anteriorchamber or a large pupil. The posterior capsule canbe removed during the initial operation and asubsequent capsulotomy is not required. The mainlimitation of lensectomy is that it is not, as yet, asuitable technique for the removal of hard cataracts.Although it is possible to remove posterior sub-capsular cataracts in elderly patients, who do nothave significant nuclear sclerosis, this usuallynecessitates prolonged manipulation of lens materialin the anterior chamber, which increases the risksof endothelial damage and subsequent cornealoedema. Nearly all our severe complications (cornealoedema in 5 eyes and loss of the lens nucleus intothe vitreous cavity in 2 eyes) were the direct resultof underestimating the hardness of the lens. It ishoped that with more experience with this techniquethe incidence of these complications will be reduced.For soft uncomplicated cataracts in children

lensectomy is a very good alternative to aspiration.It offers the additional advantage of not requiringa separate infusion system. It also enables a morecontrolled procedure to be carried out with a morecomplete removal of cortical lens matter and capsule.Lensectomy has a significant advantage over

aspiration in the management of cataracts secondaryto chronic anterior uveitis. These eyes invariablyhave small pupils with extensive posterior synechiae(Fig. 8a), making access to the lens very difficult.With the vitrectomy instrument the pupil can beenlarged and all adhesions can be freed prior tolensectomy (Fig. 8b). Another advantage oflensectomy is for the removal of cataracts in patientsbetween the ages of 30 and 40 years, who are too

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Vit ecaotnv t(ChntIi(que in aniterior seg/iletilsiar,(e2y

a

bFig. 9 (a) Preoperative appearance of cataract in30-year-old patient. (b) Po.stoperative appearance.

The posterior capsule has beeni left intact

old for the nucleus to be aspirated but have a highrisk of vitreouIs loss with convenitional intracapsularextraction (Fig. 9a, b).The vitrectomy tcchnique is very uLsetul in anterior

segment reconstruction. Some have advocated apars plana approach (Peyman and Swartz, 1975) tothese problems. We feel that, althoughl the pars planaapproach may be used in certain cases, we generallyprefer to introduce the instrunient through a limbalincision so as to avoid the possibility of indtucin6gretinal dialyses. Should a tough menibranie betreated with the two-instrumenit technique then apars plana approach may be indicated so as to sparethe endothelium from prolonged exposure to theinfusion stream.

We acknowledge the help and encouragement ofMr J. R. Hudson, and the surgeons and housesuirgeons of Moorfields Eye Hospital, High Holborn.

References

Douvas, N. G. (1973). Transaction.is of ti/ Amer'ican Acadeylmof Op/htlhaltiologv, adl Otolari'ngology. 77, op. 792.

Federman, J. L., et al. (1974). Presented at a meeting of theRetina Society, Montreal, Canada, September 1974.

Galin, M. A., et al. (1974). Transactionls of the AmericanAcadenvmy of Ophtialmnology anid Otolari'vngology, 78, 43.

Kloti, R. (1973). Albrecht v. Gr-aefes Archiv fii Oplhltial-iniologie, 187, 161.

Machemer, R., et al. (1971). Transactions of the American,Academy of Ophthalmology and Otolaryngology, 75, 813.

O'Malley, C., and Heintz, R. M. (1972). Transactiotis of thePacific Coast Oto-Ophithalhiological Society, 53, 121.

Peyman, G. A., and Dodich, N. A. (1971). Alchives ofOphthalmology, 86, 548.

I'eyinan, G. A.. and Swartz, M. (1975). Albrec/t v. Gra/efesArc/ii riir Ophthalmiologie, 195, 1 55.

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vitrectomytechnique in anterior segment surgery · british journalofophthalmology, 1977, 61,...

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