Subretinal Hyperreflective Material seen on Optical Coherence Tomography as a Quantitative Biomarker in Retinal Angiomatous Proliferation treated with Intravitreal Ranibizumab

Abstract

Purpose : Intravitreal ranibizumab can be used as monotherapy for retinal angiomatous proliferation (RAP) in neovascular age related macular degeneration (NVAMD). Subretinal hyperreflective material (SHRM) has been identified as a biomarker in NVAMD. We performed a retrospective evaluation to assess whether SHRM seen on Optical Coherence Tomography (OCT) scans could be quantified to reflect the visual gain and improvement in Central Macular Thickness (CMT); thereby assessing its suitability in use as a quantitative biomarker.

Methods : Retrospective review of electronic case notes and OCT viewer was used. 25 eyes of 21 patients who received ranibizumab monotherapy for RAP over a 12 month period were identified. 3 eyes were excluded due to incomplete data availability. Automated segmentation was used to evaluate the volume of SHRM where 3D OCT was available. Height and length of SHRM were measured using a caliper, and CMT was also recorded. Patients were initially given three loading doses of intravitreal ranibizumab and then on an as needed basis. Two tailed paired t-test was used for statistical analysis.

Results : The average age of patient was 85 years. There were two male and 19 female patients. The average number of injections over 12 months was 7.6 injections. A significant reduction was found in CMT from baseline following intravitreal ranibizumab at 4, 6 and 12 months (p < 0.001). The height and length in SHRM were also decreased significantly at 4, 6 and 12 months, and 4 and 6 months, respectively (p < 0.005). A mean reduction was also found in SHRM volume using automated segmentation function on 3D-OCT in 17 eyes from pre injection (0.9834mm³) to follow up at 4 months (0.3294mm³). Visual gains found in mean LogMar were 0.56 at 4, 0.53 at 6 and 0.65 at 12 months from baseline of 0.66, respectively.

Conclusions : Intravitreal ranibizumab has been shown to be effective in reducing CMT and height and length of SHRM at 4, 6 and 12 months following treatment on a load and PRN regime in this retrospective review. This study has demonstrated that SHRM has the potential to be used as a quantitative marker in monitoring disease process in RAP and further studies could be carried out to support that.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.