Outer photoreceptor layer thickness mapping in normal eyes and eyes with various macular diseases using spectral domain optical coherence tomography: A pilot study

Abstract

To obtain a de novo map of outer photoreceptor layer (OPRL) thickness using a semiautomatic segmentation method for commercial spectral-domain optical coherence tomography (SD-OCT) and analyze the features of the resulting OPRL map in normal eyes and eyes with various inactive macular diseases. Forty normal eyes and 50 eyes with various inactive macular diseases such as resolved central serous chorioretinopathy (20 eyes), surgically-repaired macular hole (10 eyes), epiretinal membrane (10 eyes), and reattached rhegmatogenous retinal detachment (10 eyes) were screened. All subjects underwent a 12 radial scan protocol in SD-OCT. The segmentation lines defining the OPRL were modified using built-in software. The diseased eyes were subdivided into two groups (good vision, or intermediate to poor vision) based on a visual acuity better or worse than 20/40. The map of the OPRL thickness was obtained automatically by the embedded software and was presented as the Early Treatment Diabetic Retinopathy Study (ETDRS) style. The mean OPRL thickness in normal eyes in all subfields was 40.37 ± 4.35 μm. The central subfield area showed the greatest mean OPRL thickness in normal eyes. The mean OPRL thickness of diseased eyes with good vision in the central subfield was greater than that of eyes with intermediate to poor vision. The OPRL thickness map showed various patterns according to the type of macular diseases. We suggest that our semiautomated segmentation method using a 12 radial scan protocol is simple, fast, and suitable for producing a reliable OPRL map with ETDRS. This quantitative data could be useful in clinical practice or research of various macular diseases.