LONGITUDINAL QUANTITATIVE EVALUATION OF OUTER RETINAL LESIONS IN ACUTE POSTERIOR MULTIFOCAL PLACOID PIGMENT EPITHELIOPATHY USING OPTICAL COHERENCE TOMOGRAPHY.

PURPOSE: To quantify the external limiting membrane (ELM) disruption and photoreceptor volume changes in eyes with acute posterior multifocal placoid pigment epitheliopathy (APMPPE) using Spectral Domain Optical Coherence Tomography (SD-OCT) at the acute and resolution phases. METHODS: Retrospective study of 10 eyes of 5 patients with APMPPE. Intact ELM and the Bruch's membrane were manually traced using ImageJ software and their lengths from each scan of the Spectral Domain Optical Coherence Tomography macular volume were summed. The ratio of intact ELM length/Bruch's membrane length was calculated. Also, two-dimensional areas of specific regions of interest were demarcated between the intact ELM and Bruch's Membrane in every cross-sectional B-scan. Total volume of photoreceptors was calculated by multiplying the total area by the distance between B-scans. RESULTS: There was a statistically significant increase in ELM/Bruch's membrane ratio (P value = 0.022), mean photoreceptors volume (P value = 0.028), and a significant linear positive correlation between change of intact ELM/Bruch's membrane ratio and percent change of photoreceptor volume (r = 0.927, P value = 0.001) when comparing baseline and final follow-up visit, independent of total follow-up length. CONCLUSION: Using Spectral Domain-Optical Coherence Tomography, we showed that quantitative evaluation of ELM disruption and the volume of photoreceptor recovery can help us to follow the clinical course of APMPPE.

LOSS OF EXTERNAL LIMITING MEMBRANE INTEGRITY PREDICTS PROGRESSION OF HYDROXYCHLOROQUINE RETINAL TOXICITY AFTER DRUG DISCONTINUATION.

PURPOSE: To quantify external limiting membrane (ELM) disruption and photoreceptor volume over time, using spectral domain optical coherence tomography in eyes with hydroxychloroquine (HCQ) toxic effects after discontinuation. METHODS: We performed a retrospective chart review of patients who were screened for toxic effects of HCQ between January 1, 2009 and August 31, 2014, and identified 10 patients diagnosed as having HCQ retinal toxic effects. Intact ELM and the Bruch membrane were manually traced using ImageJ software and their lengths from each scan of the spectral domain optical coherence tomography macular volume were summed. The ratio of intact ELM length/Bruch membrane length was calculated. We measured the two-dimensional photoreceptor area between the intact ELM and Bruch membrane in every cross-sectional B-scan. We calculated the total volume of photoreceptors in a volumetric OCT by multiplying photoreceptor area by the distance between B-scans. RESULTS: Of the 10 patients (120 eyes), 1 eye was excluded because of the presence of vitreomacular traction. The mean cumulative dose of HCQ was 1,951 g (range, 584-3,650 g). The mean follow-up duration was 34.1 months (range, 11-64 months). Based on the extent of ELM integrity at diagnosis of HCQ toxicity, we classified eyes into 2 groups: 1) 12 eyes showed severe ELM disruption and 2) 7 eyes had intact ELM. All 19 eyes showed characteristic signs of HCQ toxicity on the visual field examination at the baseline. Seven of 12 eyes with ELM disruption showed progressive ELM changes, including 7 eyes that additionally developed progressive photoreceptor volume decline, whereas 5 eyes remained stable. All 7 eyes with intact ELM remained stable over time. CONCLUSION: Intact ELM status at the time of HCQ discontinuation is a good prognostic sign, and ELM status may allow clinicians to predict patients at risk for progression of retinopathy. Quantitative measurements of ELM disruption and photoreceptors volume may provide an objective tool to monitor outer retinal changes due to HCQ.

LONGITUDINAL QUANTITATIVE EVALUATION OF PHOTORECEPTOR VOLUME FOLLOWING REPAIR OF MACULA-OFF RETINAL DETACHMENT.

PURPOSE: To quantify photoreceptor volume changes after successful surgical repair of macula-off retinal detachment and to correlate these volumetric changes to postoperative best-corrected visual acuity (BCVA). METHODS: Retrospective study of 15 eyes of 15 patients with macula-off retinal detachment who underwent successful surgical repair. A minimum of 4 optical coherence tomography scans that straddled the foveal center was used to quantify the central photoreceptor volume (central 1 mm). RESULTS: Mean photoreceptor volume at the first postoperative visit was 0.451 mm, increasing to 0.523 mm at the final postoperative visit (P = 0.004). Mean BCVA improved from 1.13 ± 0.59 logarithm of the minimum angle of resolution units (∼20/270) preoperatively to 0.52 ± 0.42 logarithm of the minimum angle of resolution units (∼20/66) at the final postoperative visit (P = 0.001). Mean photoreceptor volume at either the initial or final visit demonstrated significant correlations with final postoperative BCVA (r = -0.670, P = 0.017 and r = -0.753, P = 0.005, respectively). Shorter time interval from diagnosis to surgery was significantly associated with greater mean final postoperative photoreceptor volume (r = -0.588, P = 0.021) and better mean final postoperative BCVA (r = 0.709, P = 0.003). CONCLUSION: We observed a significant increase in photoreceptor volume after successful retinal detachment repair; photoreceptor volume was positively associated with BCVA and time to surgery. Our series emphasizes the importance of prompt surgical repair and shows that photoreceptor recovery and volumetric improvement correlate significantly with BCVA.