Objective analysis of capsulorrhexis factors and posterior capsular opacification in 420 postmortem eyes.

ABSTRACT

OBJECTIVE: To evaluate the capsulorrhexis structure in postmortem eyes and determine factors associated with posterior capsular opacification (PCO). DESIGN: Experimental study. PARTICIPANTS: Postmortem pseudophakic human eyes (n = 420). METHODS: Postmortem eyes were obtained and examined. Photographs were taken of the eyes in Miyake-Apple view and of the extracted lens-capsule complexes. PCO and Soemmering's ring (SR) were quantified using automated detector opacification software as factors of intensity and area. Miyake-Apple views and ImageJ were used to assess capsulorrhexis diameter, area of anterior capsule-optic overlap, length of the shortest anterior capsular leaflet, and area and angle of capsulorrhexis-optic nonoverlap. Linear regression analysis and Welch's t test were used to determine the relationship of these factors with PCO and SR. All analyses were repeated in sample groups specific to the 5 most common intraocular lens models. RESULTS: Capsule-optic overlap was positively correlated with PCO (P < 0.0001) and SR (P = 0.0016). Capsulorrhexis diameter was negatively correlated with PCO (P < 0.0001) and SR (P = 0.014). Leaflet length was positively correlated with PCO (P = 0.009). Area and angle of capsulorrhexis-optic nonoverlap were not correlated with PCO or SR. Slopes and coefficients of determination were relatively low for all significant results. CONCLUSIONS: The pathogenesis of PCO development after cataract surgery is multifactorial. This study shows that with modern operating technology, capsulorrhexis factors have at best a modest influence on PCO formation. Factors such as time from surgery to death and intraoperative techniques such as laser capsule polishing, posterior capsule vacuuming, and cortical cleanup are likely to play a more significant role.