lens for undergraduate student, part 2 2015
TRANSCRIPT
Dr. Abdelmonem HamedFellow of Baylor of College of Medicine, USA
Professor of ophthalmology, Benha University, ARE
LENS
1
حامد المنعم عبد ادبنها جامعة ، العين وجراحة طب استاذ
بأمريكا بيلور طب كلية زميل
LENS
2
حامد المنعم عبد اد ، العين وجراحة طب استاذ
بنها جامعةبأمريكا بيلور طب كلية زميل
Part 2
3
SENILE CATARACT
SENILE CATARACTDefinition:
Gradual,progressive lens opacity, affecting elderly,
who is not suffering from local or systemic disease.
Bilateral,
SENILE CATARACTDefinition:
Gradual,progressive lens opacity, affecting elderly,
who is not suffering from local or systemic disease.
Bilateral,
SENILE CATARACTDefinition:
Gradual,progressive lens opacity, affecting elderly,
who is not suffering from local or systemic disease.
Bilateral,
SENILE CATARACTDefinition:
Gradual,progressive lens opacity, affecting old age people,
who are not suffering from local or systemic disease.
Bilateral,
SENILE CATARACTDefinition:
Gradual,progressive lens opacity, affecting old age people,
who are not suffering from local or systemic disease.
Bilateral,
SENILE CATARACT
Incidence: Age: ˃ 50 years Sex: males = females. Bilateral: It affects both eyes
Etiology: Disturbed capsular permeability. Disturbed Ph. around lens Disrubance of important metabolites ( ↓
vit. C & glutathione) Disturbance of endocrine hormones. Exposure to UV rays .
SENILE CATARACT 4D & 1E
Pathogenesis: Change in water content :
hydration of cortex ; changes in the permeability of lens
capsule water drops go inside cortex which becomes opaque.
sclerosis of nucleus
SENILE CATARACT
V.S i
SENILE CATARACT
how cataract is formed?
Accumulation of lactic acid ↓ pH activation of dormant enzymes (proteases) breakdown of lens proteins & accumulation of amino acids lens opacity (cataract)
Types:1. Cortical2. Nuclear3. corticonuclear
SENILE CATARACT
SENILE CATARACT
I. torchlightII. SlilampIII. Red reflex
Methods of examination:
Senile cortical cataract
Stages of senile cortical cataract
1. Immature cataract Incipient (sectorial opacities
at the periphery). Intumescent.
2. Mature cataract (totally opaque)
3. Hypermature cataract (loses water & shrink)
Immature cataract
Showing Lens is not totally opaque wedge – shaped opacities
appear in the periphery of the lens
progress gradually
Immature cataract
Symptoms:1. Gradual diminution of
vision, as the visual axis is not involved
2. Uni-ocular diplopia, due to sectorial change in the refractive index.
3. Colored halos are seen around light due to light scattering.
من كلهاالمريض
Immature cataract
Signs:Oblique
illumination: Iris shadow
Red reflex: black sectors
against reddish background
من كلهاالطبيب
Immature cataract
Signs:Oblique
illumination: Iris shadow
Red reflex: black sectors
against reddish background
عن كلهاالطبيب
What is the iris shadow? black crescent due to presence of clear interval
between iris and lens opacity.
Intumescent cataract
Hydration of the lens
swelling of the lens shallow AC pupillary block (phacomorphic glaucoma ) Colored halos
Mature cataract
Signs: Entire cortex is opaque. vision is hand movement Iris shadow is absent. R.R. is absent
وبالتالى
Hypermature cataract1. Entire cortex is opaque vision is HM R.R. is
absent2. The lens shrink (thick wrinkled
capsule + cholesterol deposition)
1. Iris shadow may be present. 2. Tremulous iris3. A.C. deep
3. IOP: may be elevated (Phacolytic glaucoma)
وبالتالى
Hypermature cataractComplications Subluxation or dislocation of lens, due
to degeneration of zonules. leakage of lens protein
Phacolytic glaucoma, lens protin is ingested by the phagocytes. Obstruction of angle of AC
Phacotoxic uveitis Morgagnian cataract:
liquefaction of lens matter into a milky fluid, nucleus sinks down by gravity
How to differentiate Immature and Mature Cataract
IMMATURE CATARACT
1. VA is reduced to counting finger.
2. Lens is partially opaque
3. Iris shadow is present
4. Fundus may be visible.
MATURE CATARACT
1. VA reduced to HM or PL
2. Lens is totally opaque
3. No iris shadow4. No fundus details
Prof . Dr. Abdelmonem Hamed
V.S
Senile nuclear cataractDefinition
sclerosis of the central nuclear fibers
EtiologyUV photo – oxidation of amino
acids Formation of brown pigment deposition of abnormal lipoproteins. reduction in glutathione formation. calcium concentration
Senile nuclear cataractDefinition
sclerosis of the central nuclear fibers
EtiologyUV photo – oxidation of amino
acids Formation of brown pigment deposition of abnormal lipoproteins. reduction in glutathione formation. calcium concentration
Senile nuclear cataractDefinition
sclerosis of the central nuclear fibers
EtiologyUV photo – oxidation of amino
acids Formation of brown pigment deposition of abnormal lipoproteins. reduction in glutathione formation. calcium concentration
Senile nuclear cataractDefinition
sclerosis of the central nuclear fibers
EtiologyUV photo – oxidation of amino
acids Formation of brown pigment deposition of abnormal lipoproteins. reduction in glutathione formation. calcium concentration
Incidence: > 40 years of age
Clinical grades (1+ to 4+): due to deposition of melanin pigment derived from amino acids in
the lens The nucleus becomes yellowish, brown,
red & then black Black cataract (cataracta nigra)
Senile nuclear cataract
i
The sclerosis gradually spreads towards the cortex,
then extends up to the capsule , then the entire lens functions as a nucleus (Mature cataract ).
Senile nuclear cataract
PS. Hypermaturity does not occur as the process is very slow
i
Symptom: ↓ VA due to progressive
myopia and central opacity.
Signs: Red reflex : hazy to
black Slit-lamp examination:
nuclear cataract.
Senile nuclear cataract
33
Thank you