Ganglion cell complex thickness and optical coherence tomography findings in stargardt macular dystrophy and retinitis pigmentosa

Abstract

Aim: In this study, we aimed to assess ganglion cell complex (GCC) thickness with spectral domain optical coherence tomography (SD-OCT) and to detect changes in retinal layers in eyes with Stargardt macular dystrophy (SMD) and retinitis pigmentosa (RP) patients. Material and Methods: Fifty-four eyes of 27 patients with RP and 46 eyes of 23 patients with SMD were enrolled. Each subject underwent a complete ophthalmic examination before SD-OCT was obtained. Macular scans were taken with software version 6.0 of the ganglion cell analysis (GCA) algorithm. Patients were divided into 3 grades according to photoreceptor layer integrity. GCC thickness was evaluated automatically as the average, minimum and six sectors by SD-OCT, and parameters were compared between groups. Result: The mean age was 41.66 +/- 19. 77 years in group 1 (RP patients), and 28.00 +/- 10.37 years in group 2 (SMD patients). There were no significant differences in mean age, gender distribution, intraocular pressure and spherical equivalent at imaging between the groups (p>0.05). The mean (+/- SD) GCC thicknesses were evaluated and there were no significant differences between the two groups in each segment (Mann-Whitney U, p>0.05), but there were significant differences between patients in each grade (Kruskal-Wallis, p<0.05). Discussion: This study showed that progressive degeneration and loss of function in the outer retinal layers are accompanied by damage to the inner retinal layers in patients with RP and SMD. However, some of the ganglion cells are protected after photoreceptor cell death, which may point us to the target tissue for future treatment modalities.