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Cataract and Implant Surgery. Dominic McHugh MD FRCS London, UK. Cataract Causes. Age Congenital (genetic, metabolic) Trauma Infection Inflammation Surgical Drugs ( eg steroids). Cataract. May be induced by surgical procedure: lens touch; gas; oil. Cataract types. Nuclear sclerosis.
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Cataract and Implant Surgery Dominic McHugh MD FRCSLondon, UK
CataractCauses Age Congenital (genetic, metabolic) Trauma Infection Inflammation Surgical Drugs (eg steroids)
Cataract May be induced by surgical procedure: lens touch; gas; oil
Cataract types Nuclear sclerosis Posterior subscapsular Congenital (rubella) Trauma
ECCE (Extracapsular cataract extraction) But longer wound healing time Management of Cataract
Cataract Surgery Small incisionalPhacoemulsification surgery (Developed by Kelman, USA)
Before IOL implantation was developed • Aphakic spectacles • Contact lenses
Pioneer of intraocular lens implant Sir Harold Ridley FRS FRCS
Harold Ridley collaborated with the Rayner company to develop the IOL John Pike, Rayner Company
Choice of IOL • Insertion through small incision • High biomcompatilbility • Allows good retinal view • Stable centration • Low PCO (posterior capsular opacification) rate
IOL choiceWhy foldable/injectable?Minimise incision size to reduce healing time and astigmatism • PMMA(rigid) : Non-foldable+large incision • Acrylic: Injectable through 2.2-3.2 mm currently.
Preparation for cataract surgery Biometry: The calculation of required IOL power Keratometry (K) (corneal curvature) Axial length (AL) of eye (ultrasound) IOL power= A constant-2.5xAL-0.9K Eg: 118-2.5x 24-0.9x45=17.5dioptres IOL power
Phacoemulsification: surgical sequence • Corneal tunnel • CCC (continuous curvilinear capsulorrhexis • Hydrodissection • Phacoemulsification • Aspiration of cortical lens matter • IOL insertion
Typical injectable IOL Superflex lens: 6.25mm x 12.50mm C-Flex lens 5.75mm x 12.00 mm
Cataract surgery Postoperative management Eye pad overnight Antibiotic+steroid drops for up to one month Change glasses at one month
Complications of cataract surgery (many!) Posterior capsular rupture and vitreous loss Dropped nucleus IOL dislocation Endophthalmitis Retinal detachment