CATARACT

CATARACT
DR. SHAHID WAHAB
LEARNING OBJECTIVES
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Describe the anatomy of lens
Identify and classify different types of cataract
Evaluate the patient preoperatively by different investigation
Enlist the types of cataract surgery
Discuss its management, postoperative complications and visual rehabilitation
Any opacity in the lens and its capsule is called a CATARACT
Symptoms depends upon the type of the .cataract
Normal crystalline lens is transparent biconvex structure responsible for approx: 20 Diopters of refractive power. It develops from surface ectoderm:
Capsule.
Zonule.
Lens Epithelium.
Cortex.
Nucleus.
ANATOMY OF LENS
Age related cataract
Morphological classification
1. Sub Capsular.
a)
Anterior.
b)
Posterior.
2. Nuclear.
3. Cortical.
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Immature
Mature
Hyper mature, wrinkling in anterior capsule
Morgagnion, hypermature cataract in which lens liquefies and sinks inferiorly.
NUCLEAR CATARACT
Diabetic snowflake cataract is characteristic, Myotonia dystrophy.
Atopic dermatitis shield like cataract
1.
Vossius ring (iris imprint on anterior capsule).
2.
Direct penetrating injury.
3.
Ionizing radiation to ocular tumor.
Infra red radiation in glass blower industry
1.
Steroids.
2.
Chlorpromazine.
3.
Amiodarone.
4.
Gold salts.
5.
Allopurinall.
6.
Busulphan.
o
o
o
Chronic anterior uveitis.
Acute congestive glaucoma.
High myopia.
o
Retinitis Pigmentosa
.
Indication of Urgery:
1.
2.
3.
Visual improvement.
Medical indication phacolytic glaucoma, phacomorphic glaucoma, diabetic
retinopathy for laser treatment.
Cosmetic indication.
RAPD never occurs due to cataract.
Presence of RAPD means poor
Dacryocystitis, blephritis, conjunctivitis, entropion, ectropion, dry eye may lead to endophthalmitis and are contraindicated for
cataract surgery.
Indicate corneal endothelial decompensation
and surgeon should not attempt for Phaco.
Shallow anterior chamber can render cataract
surgery difficult.
Pseudoexfloation indicate weak zonules.
Poor red reflex makes capsulorhexis difficult and staining of anterior capsule is required.
Nuclear cataract requires more Phaco power.
ARMD and other retinal pathologies should be noted and told to the patient about visual prognosis.:
1.
2.
Keratomatry
3.
IOL
for
calculation
Corneal
formula
curvatures
( A – Constant,
AC
RETRO-BULBAR BLOCK.
1.
Sub-tenon block.
2.
Topical and intracameral anesthesia.
3.
Surface anesthesia.
Extra capsular, cataract extraction (ECCE)
Phacoemulsification.
Phacoaspiration
PHACOEMULSIFATION
TYPES OF IOL:
Anterior chamber
Posterior chamber
•
Cililary body fixation
Ultra Sound “ A “ Scan for
Depth)
axial length
•
Standard P C IOL
•
Foldable IOL
•
Multifocal IOL
COMPLICATIONS:
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OPERATIVE:
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Rupture of posterior capsule.
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Posterior loss of lens fragments.
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Posterior dislocation of IOL.
•
Endothelium damage
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Supra choroidal hemorrhage.
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COMPLICATIONS:
•
POST OPERATIVE :
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Corneal edema.
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Iris prolapse.
•
PCO.
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Induced astigmatism
•
Acute post operative endophthalmitis.
CONGENITAL
CATARACT:
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Occuar in 3 in 10000 live births.
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CAUSES:
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METABOLIC:
•
Galactosemia.
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Galactokinase deficiency.
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Lowe’s syndrome .
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CONGENITAL
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Occuar in 3 in 10000 live births.
CATARACT:
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CAUSES:
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METABOLIC:
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Galactosemia.
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Galactokinase deficiency.
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Lowe’s syndrome .
1.
Cataract if very dense so that examination with
indirect ophthalmoscopy is not possible go for surgery.
If lens opacity is insignificant surgery can be
deferred.
2.
Ocular pathologies associated with congenital
cataract are corneal clouding, microophthalmos,
glaucoma, PHPV, chorioretinitis, rubella.
TORCH Serological test.
Urinalysis for reducing substance after drinking milk (Galactosemia).
FBS, serum calcium and phosphorus level.
Referral to paeds doctor.
TIMING OF SURGERY:
Bilateral dense cataract requires early surgery after six weeks of age to prevent amblyopia
Bilateral partial cataract can be deferred at a later age.
Unilateral dense cataract urgent surgery is needed.
POST OPERATIVE COMPLICATION:
PCO.
Proliferation of lens epithelium.
Glaucoma.
Retinal detachment
Density
.
SPECTACLES very helpful in children with bilateral aphakia.
CONTACT LENS good for unilateral aphakia.
IOL:
Implantation is usually advisable after 3 years of age.
OCCLUSION:
Of good eye for amblyopia treatment
THANK YOU