Correlation of Backward Scattered Light With Intraocular Straylight and Visual Acuity in Patients With Posterior Capsule Opacification

Abstract

Purpose: : To study the correlation of posterior capsule opacification (PCO) with measured intraocular straylight and visual acuity.

Methods: : Visual acuity (logMAR) and intraocular straylight (C-Quant straylight parameter log[s]) were measured under photopic conditions before and 2 weeks after YAG capsulotomy in 20 patients. The eyes with PCO were dilated and photographed at a slit lamp, illuminated with a wide slit beam under an angle of about 50 degrees to document the amount of opacification. Photopic pupil diameter was measured. Three masked observers graded the opacification inside the photopic pupil diameter on the PCO photographs on a scale from 0 to 10.

Results: : The photographs at the slit lamp with a wide slit beam allow the visualization of optical imperfections inside the IOL and deposits on it, the light scattering from the posterior capsule opacification and even vitreous imperfections, some of which are missed with the retroillumination. Regression of visual acuity improvement (post-pre YAG) as function of PCO-Slit lamp grading gave a coefficient of determination (R²) of 0.30. Regression of intraocular straylight improvement as function of PCO-slit lamp grading gave an R² of 0.48.

Conclusions: : PCO-Slit lamp grading, which considers backward light scattering, is weakly correlated with visual acuity and moderately correlated with intraocular straylight measured by the C-Quant.

Keywords: posterior capsular opacification (PCO) • visual acuity • optical properties