phacoemulsification in long and short eyes dr. memarzadeh md
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DESCRIPTIONIN THE NAME MY GOD . Phacoemulsification in long and short eyes Dr. memarzadeh MD 1387/11/30 1387-11-30 - PowerPoint PPT Presentation
IN THE NAME OF GOD
IN THE NAME MY GOD 1 Phacoemulsification in long
and short eyes
Dr. memarzadeh MD 1387/11/30
Dr memarzadeh MDophthalmologist
4Features of long axial length eyesrelating to phacoemulsifcationDeep ACMore mobility of lensZonular laxityMore liquefied vitreousThin scleraYounger age onset cataractThe degree of maturity of cataract on SLE examination dose not commensurates with the visual loss
Careful SLE and fundus examination specially for macula and peripheral retinal breaks, holes, sever atrophic changes , CNV. 2. In doubtful situations PVA testing may helps 6 Myopic retina
Pre op examination cont IOL power calculation:Long axial length and posterior stapyhloma are of important sources of miss calculation.2. Both A scan and B scan should be done concurrently to obtain the axial length from exact foveal fixation point.3. The best formulas are SRK T and Holladay. 8...Intra operative considerations Anesthesia: Topical anesthesia is performed to decrease the risk of glob laceration but be aware that myopes are more photophobic and so less cooperative there by periocular anesthesia can be another option but be careful of globe laceration. 9Intra operative contWound constriction: Large tunnel incision causes corneal distortion which blurs visibility, hence shorter clear corneal incision (1.5 mm) is preferred.Capsulorhexis: The size of rhexis should be just smaller than optic diameter to minimize PCO but no too small to interfere the view of peripheral retina.
10Intra operative contHydrodisection: Because many myope patients are young there is tenacious corticocapsular adhesions therefore you may need inject multiple small volumes of BSS at various places.11
12Intra operative contNuclear emulsification:1. As myopes have fragile zonula, liquefied vitreous, thin sclera, instruction of probe exerts a sudden positive pressure that pushes the iris peripherally and deepens the AC (breathing pupil phenomena) adjustment of bottle height or positive air pressure can minimize the problem.2. Kelman bent needle is preferred because allows better approach without additional corneal distortion.3. The maturity of cataract can be assessed deceptively soft in SLE hence increments of power is required to minimize stress on zonula and capsule.
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