Spectral Domain Optical Coherence Tomography Analysis Of Fibrotic Lesions In Neovascular Age-Related Macular Degeneration

Abstract Purpose To describe the spectral-domain optical coherence tomography (SD-OCT) features of fibrotic lesions associated with neovascular age-related macular degeneration (nAMD) and to outline the progression pathways from initial macular neovascular lesions (CNV) to fibrosis. Methods Neovascular AMD patients were retrospectively included when macular subretinal fibrosis was present. Fibrosis was categorized using SD-OCT with respect to retinal pigment epithelium (RPE) in 836 SD-OCT slices from 44 eyes of 39 patients. Additionally, in 47 distinct eyes, 4181 SD-OCT slices were retrospectively reviewed in order to longitudinally assess progression from the initial lesion to the final fibrosis. Results Cross-sectional analysis classified fibrosis on SD-OCT slices, as type A if located underneath the RPE, as type B if located above the RPE and as type C if the remaining RPE was undistinguishable. The longitudinal analysis series revealed 3 progression pathways from the original CNV: 1. Progression to type A, followed by RPE erosion and subretinal hyperreflective material (SHRM), then type B and type C fibroglial lesion (FGL, 17/47 eyes); 2. Progression to type B, then type C FGL (17/47 eyes); 3. Persistence of type A with development of a flat, fibroatrophic lesion (FAL, 13/47 eyes). SHRM, macular haemorrhage or RPE tear occurred in 14/47, 13/47 and 10/47 eyes. Conclusion This SD-OCT analysis identified various patterns of macular fibrosis in eyes with neovascular AMD. Three pathways of progression to fibrosis were described including the well-established pathway of type 2 CNV progression to FGL and the progression of type 1 fibrovascular CNV to FGL or FAL.