OBJECTIVES: Posterior capsular opacification (PCO) results from the growth and abnormal proliferation of lens epithelial cells on the posterior capsule. Severity of PCO is assessed based on the presence or absence of opacification within the visual axis, subjective perception of reduced visual acuity and contrast sensitivity, and assessment of retroillumination images of the posterior capsule. The objective of this review was to identify the methods for quantifying PCO and assess the impact of intraocular lens (IOL) material and design on reported severity scores.

METHODS: A comprehensive literature search was performed for studies published in English between January 1996 and August 2017 in Embase^®, MEDLINE^®, MEDLINE^®-In Process, and Cochrane library. Studies quantifying PCO using different scales were included and impact of lens material and design on the reported severity scores was assessed.

RESULTS: A total of 63 RCTs were included in this review. Among the measurement systems used to assess PCO severity, Automated Quantification of After-cataract scale (AQUA; 20 studies), POCOman (13 studies) and Evaluation of Posterior Capsule Opacification scale (EPCO; 12 studies) were the most common. Other methods identified, included various subjective and objective scoring tools. Irrespective of the measurement system, severity of PCO increased with time and there is a trend in the literature to lower severity scores for eyes implanted with hydrophobic acrylic IOLs compared with IOLs of other materials. Furthermore, higher severity of PCO was observed with round optic edge IOLs compared to sharp optic edge IOLs of the same material.

CONCLUSIONS: There is considerable heterogeneity in terms of the scoring systems used to quantify PCO. However, a trend exists in the available evidence suggesting that the lens material of the implanted IOL impacts on PCO severity. Moreover, sharp edge IOLs appear to provide a better barrier mechanism in preventing PCO than round edge IOLs.