Volumetric SDOCT Imaging of Pigment Epithelial Detachments in the HiPED Study

Abstract

Purpose: : Spectral domain optical coherence tomography (SDOCT) was used to acquire volumetric datasets from a cohort of patients with wet age-related macular degeneration (AMD) and persistent retinal pigment epithelial detachment (PED). We sought to quantify PED metrics and compare their utility as a novel endpoint to established metrics.

Methods: : The High Dose Ranibizumab for Persistent PED in Neovascular AMD (HiPED) study enrolled patients with persistent PED following 6+ previous standard-dose anti-vascular endothelial growth factor intravitreal injections. Visual acuity (VA) at entry ranged from 20/32 - 20/100. Cirrus SD-OCT cube scans were obtained monthly with standard office protocols. Using software version 6.0, an automated algorithm generated segmentations of the ILM, the RPE, and inferred physiologic RPE. Datasets were excluded if the algorithm failed at any time point. Measurements of the central subfield thickness (CST), macular cube volume, average macular cube thickness, and PED area and volume were obtained. Correlations between these metrics and VA were calculated.

Results: : 35 patients received either 2mg intravitreal ranibizumab monthly (Group 1) or 2mg x 3 months followed by PRN therapy for persistent disease activity by SDOCT (Group 2). 7 patient SDOCT datasets (20%) were excluded due to failed segmentation. Baseline characteristics of the remaining 28 patients: CST ranged from 179um to 499um, (mean 271.96um), macular cube volume ranged from 8.40mm³ to 12.70mm³ (mean 9.79 mm³). Within a 5mm of the fovea, PED area ranged from 1.20mm² to 10.50mm² (mean 5.01mm²) and PED volume ranged from 0.06mm³ to 1.68mm³ (mean 0.60mm³). Mean change from baseline for PED area at 6 months (n=9) decreased by 0.94 mm² and PED volume decreased by 0.17 mm³, while VA increased by +7.6 letters. A weak correlation between PED volume and VA was found in these 9 patients (r = -0.15).

Conclusions: : An automated algorithm for SDOCT measurements of PED area and volume in the Cirrus HD-OCT 6.0 software was accurate in 80% of wet AMD patients in the HiPED Study. In this cohort of patients, persistent decrease in PED area and volume as well as macular thickness occurred with repeated 2mg ranibizumab injections, and each was weakly correlated with gradual gain in VA.

Clinical Trial: : http://www.clinicaltrials.gov NCT01189019

Keywords: age-related macular degeneration • imaging/image analysis: clinical • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)