Purpose: To describe the morphological macular changes detected by spectral domain optical coherence tomography (SD-OCT) in eyes with retinitis pigmentosa (RP) and to analyze their correlation with the visual function.
Methods: Twenty-two patients (44 eyes) patients affected by RP were recruited. The following structures were evaluated on SD-OCT: outer plexiform layer (OPL), outer nuclear layer (ONL), external limiting membrane (ELM), photoreceptor inner/outer segment (IS/OS) junction, photoreceptor outer segment/retinal pigmented epithelium (OS/RPE) junction, inner limiting membrane thickening (ILMT), ganglion cell complex (GCC), and cystoid macular edema (CME). The relation between each SD-OCT finding and BCVA was evaluated at uni- and multivariate analysis.
Results: Mean age and mean best-corrected visual acuity (BCVA) were 51 ± 17.5 years and 0.4 ± 0.5 LogMAR, respectively. Univariate linear regression model revealed a correlation between BCVA and the absence of ELM, IS/OS, ONL, and OS/RPE layers (R (2) values were, respectively, 0.51, 0.57, 0.48, and 0.68, with p values all <0.0001). At multivariate regression analysis, the absence of OS/RPE and ELM layers remained the only variables independently associated with a decrease of BCVA (R (2) = 0.85, t = 3.49, p = 0.0014).
Conclusions: Data show that in patients afflicted with RP, ELM and OS/RPE layers are independently associated with BCVA on multivariate regression analysis. These results highlight the key-role of external retinal layers in determining the visual function impairment attributable to RP.
Keywords: Retinitis pigmentosa; Spectral domain OCT; Visual acuity.