Quantification and visual outcome analysis with posterior capsular opacification.

摘要

Cataract removal is the most frequently performed surgical procedure in the United Sates. Subsequent development of Posterior Capsular Opacification (PCO) is a common occurrence. With a view to contributing to clinical care and understanding the consequences of PCO, we have studied methods for assessment of PCO severity and examined relationships with vision and on the individual perceptions of reductions in visual abilities.;We developed a set of photographic references for grading PCO severity by clinicians' observations or inspection of photographs. We also developed an image analysis system for quantifying the magnitude of PCO recorded in photographs. All methods show good repeatability, but clinician's gradings by slit lamp examination gave results that are most closely correlated with the magnitude of the adverse visual consequences. The effect of astigmatism and lateral chromatic aberration on visual acuity was evaluated and related to the reported magnitudes of decentration and tilt fount in intra ocular lenses. These aberrations should not be of practical consequence in pseudophakia.;Subjects with pseudophakia, both with and without PCO, were studied. A series of visual acuity tests (high and low contrast and low luminance) and contrast sensitivity tests (large and small letters) were used, both with and without glare. The subjects' perception of their visual disabilities was assessed using a modified Visual Functioning Questionnaire.;All visual acuity and contrast sensitivity measurements showed significant deterioration with the presence of posterior capsular opacification. Multiple regression and discriminability analyses indicated that low contrast visual acuity had the best correlation with PCO severity and was the best indicator of PCO severity, especially if glare is added. On the modified National Eye Institute Visual Function Questionnaire 25 (NEI-VFQ25) scores were lower for the subjects with posterior capsular opacification for the aggregate scores and for scores from most of the subscales. Stronger correlations with PCO severity required combining several aspects of vision or the responses for the more general subscales on the questionnaire.