On posterior capsule opacification

Abstract

AimsPosterior capsule opacification (PCO) is the most common complication after cataractsurgery. The aim of this study was to increase our knowledge about PCO regardingquantification, treatment effects and how different designs of intraocular lenses(IOLs) influence occurrence.MethodsTo evaluate performed capsulotomy as a measurement of PCO a random sample ofcataract patients who had surgery in 1991 was studied 5 years after their surgery. Tofurther study quantification of PCO visual acuity, morphologic quantification of PCOand self-assessed visual function were compared in 21 patients with PCO. Effectsof treatment of PCO on functional outcome were investigated in 47 patients usingCatquest. In a retrospective study with a 3-year follow up, patients who had receivedan acrylic IOL during cataract surgery were compared with patients who had receivedpolymethylmethacrylate (PMMA) IOLs in terms of need for treatment of PCO. In aprospective clinical study with a 3-year follow up patients who had received siliconeIOLs with two different designs were compared. PCO was evaluated using Evaluationof Posterior Capsule Opacification (EPCO), a morphological method of quantification,and the number of performed capsulotomies was recorded.ResultsThe estimated incidence of PCO 5 years after cataract surgery was 43%, and the untreatedgroup with clinically significant PCO was approximately 9%. The incidence ofperformed capsulotomy was higher in women than in men. The morphological methodof quantifying PCO correlated with visual acuity and self-assessed visual function asmeasured with Catquest. Seventy-seven per cent of the PCO patients benefited fromcapsulotomy according to Catquest. The relative risk of needing capsulotomy was 3.6times higher in the PMMA group than in the acrylic group. Patients with the siliconeIOL with a sharp optic edge had significantly less PCO than patients with a roundedoptic edge IOL. Regression of PCO was noticed in some eyes.ConclusionIn a population without active follow up after cataract surgery, a group of untreatedpatients with PCO was found. They must be considered when using performed capsulotomyas an end-point for PCO. A commonly used method for quantification ofPCO (EPCO) is correlated with visual acuity and self-assessed visual function. Thevast majority of PCO patients benefited from treatment. IOL related factors, specifi-cally IOL design, are important in decreasing PCO occurrence.