Objective quantification of posterior capsule opacification using swept-source AS-OCT

PURPOSE: To objectively quantify posterior capsule opacification (PCO) using swept-source anterior segment optical coherence tomography (SS-AS-OCT) in pseudophakic eyes. SETTING: Zhongshan Ophthalmic Center, Guangzhou, China. DESIGN: Prospective cross-sectional study. METHODS: 180 eyes with PCO (37 multifocal intraocular lenses [mfIOLs] and 143 monofocal intraocular lenses [moIOLs]) were enrolled. The PCO irregular degree (PID), defined to evaluate the surface irregularity of PCO, the average and maximum thickness of PCO (AT-PCO, MT-PCO) were applied to quantify PCO based on SS-AS-OCT (CASIA2) images. Corrected distance visual acuity (CDVA), higher-order aberrations (HOAs), modulation transfer function, and Strehl ratio were recorded. The associations between SS-AS-OCT parameters and visual function parameters were assessed by Spearman correlation analysis. RESULTS: PID, AT-PCO, and MT-PCO showed significant correlations with CDVA, Strehl ratio, and HOAs (CDVA: r = 0.702, 0.741, and 0.736; Strehl ratio: r = -0.746, -0.719, and -0.740; HOAs: r = 0.762, 0.734, and 0.752). The correlations of these 3 parameters with Strehl ratio and HOAs were significantly higher than those of clinical PCO grading with Strehl ratio and HOAs (all P < .05). Particularly, PID demonstrated notable correlations with Strehl ratio and HOAs. In addition, patients with mfIOLs presented worse Strehl ratio and HOAs than those with moIOLs after matching age, PID, AT-PCO, and MT-PCO. CONCLUSIONS: This study provides a new method for objectively quantifying PCO using successive cross-sectional SS-AS-OCT images. AT-PCO, MT-PCO, and PID are presented as new indicators to document PCO severity, with PID offering a unique perspective by considering the irregularity aspect of PCO.