A 60-year-old man who underwent phacoemulsification surgeryand placement of foldable intraocular lens of left eye a year back has come with complaints of hazy vision now in that eye. There is no associate redness or pain or watering of eye. The most common cause is:
High-Yield Explanation
Ans: (a) Posterior capsular opacificationRef: A.K. Khurana's Comprehensive Ophthalmology, 6th edition, Page 215; Parson's Diseases of the Eye, 22nd edition, Page 285The causes of defective vision after cataract surgery are:Postoperative astigmatism due to surgical incision.Wrong IOL power.Cystoid macular edema.Posterior capsular opacification.Other associated ocular disorders like glaucoma, retinal diseases.Post operative astigmatism and wrong IOL power presents with defective vision from day 1 post operative period.Cystoid macular edema (Irvin Gauss syndrome) presents with defective vision 1 -3 months after surgery till then vision will be good.Similarly, PCO (posterior capsular opacification) usually presents after 1 year.Posterior Capsular Opacification / After Cataract / Secondary CataractCausesResidual lens matter - when all the cortex is not removed completely during cataract extraction.Proliferative type - germinative zone of the anterior lens epithelium proliferate - dysplasia - opaque cells (Waddl cells).TypesWhen the PCO involves the peripheral capsule, it will not cause defective vision. When it involves the visual axis/Central part of the PC, then the patient will have glare and defective vision which is gradual in onset and painless in nature.Membranous - thin/dense.Sommering's Ring - Peripheral ring shaped opacity between anterior and posterior lens capsule. So, visual axis clear - Asymptomatic.Elschnig's Pearls - Soap bubble like appearance migrating towards the visual axis.TreatmentWhen the visual axis is clear - no need of treatment.ND YAG laser capsulotomy (1064 nm wavelength and photodisruption in action),Discission with cystitome.Cystoid Macular Edema (Irvin Gauss syndrome)Usually presents with defective vision 1-3 months after cataract surgery.Etiology: Vitreous disturbances during surgery - Prostaglandin release - Accumulation of fluid in the Henle's layer of macula.On Fundoscopy: Honey Comb appearance.On FFA: Flower Petal appearance.Prevention: Perioperative and post-operative use of topical anti-prostaglandins eyedrops.TreatmentTopical steroids and anti-prostaglandins,Vitrectomy.