Abstract
Purpose: :
To compare retroillumination with slitlamp-derived reflected-light images for posterior capsule opacification grading and determine their correlation with retinal straylight.
Methods: :
Forty-one patients (53 eyes) with PCO prior to YAG capsulotomy treatment at the Centro de Oftalmología Barraquer in Barcelona or the University Eye Clinic, Paracelsus Medical University in Salzburg, were included. Retinal straylight was measured using the C-Quant instrument (Oculus GmbH, Wetzlar, Germany) under photopic condition. Photographs were taken with a digital camera attached to a slit lamp with angles of illumination of 1º (retroillumination) and 45º (reflected-light) to document PCO level. Images were subjectively graded on a scale of 0 to 10 and using the POCOman system.
Results: :
Subjective PCO score on retroillumination images showed a statistically significant correlation with the retinal straylight values (r = 0.414; p = 0.003). A similar correlation was found using the POCOman severity score (r = 0.340; p = 0.013). Subjective PCO score on reflected-light images also correlated with the retinal straylight values (r = 0.403; p = 0.006).
Conclusions: :
The different light scattering pattern in the forward and backward direction may explain the only mild correlation between retinal straylight and PCO scores on retroillumination and reflected-light images. The C-Quant instrument measures light that scatters forward to the retina whereas PCO grading uses light that scatters back from the posterior capsule.
Keywords: posterior capsular opacification (PCO) • imaging/image analysis: clinical • optical properties