Polarisation-sensitive OCT is useful for evaluating retinal pigment epithelial lesions in patients with neovascular AMD

BACKGROUND/AIMS: To examine the reproducibility of lesion dimensions of the retinal pigment epithelium (RPE) in neovascular age-related macular degeneration (AMD) with polarisation-sensitive optical coherence tomography (PS-OCT), specifically imaging the RPE. METHODS: Twenty-six patients (28 eyes) with neovascular AMD were included in this study, and examined by a PS-OCT prototype. Each patient was scanned five times at a 1-day visit. The PS-OCT B-scan located closest to the macular centre presenting with RPE atrophy was identified, and the longitudinal diameter of the lesion was quantified manually using AutoCAD 2008. This procedure was followed for the identical B-scan position in all five scans per eye and patient. Reproducibility of qualitative changes in PS-OCT was evaluated. Interobserver variability was assessed. Results were compared with intensity-based spectral-domain OCT (SD-OCT) imaging. RESULTS: Mean variability of all atrophy lesion dimensions was 0.10 mm (SD±=0.06 mm). Coefficient of variation (SD±/mean) was 0.06 on average (SD±=0.03). Interobserver variability assessment showed a mean difference of 0.02 mm across all patients regarding RPE lesion size evaluation (paired t test: p=0.38). Spearman correlation coefficient was r=0.98, p<0.001. Results revealed a good overall reproducibility of ∼90%. PS-OCT specifically detected the RPE in all eyes compared with conventional intensity-based SD-OCT that was not capable to clearly identify RPE atrophy in 25 eyes (89.3%, p<0.01). CONCLUSIONS: PS-OCT offers good reproducibility of RPE atrophy assessment in neovascular AMD, and may be suitable for precise RPE evaluation in clinical practice. PS-OCT unambiguously identifies RPE changes in choroidal neovascularisation compared with intensity-based SD-OCT that does not identify the RPE status reliably.