Abstract
Introduction: Time-domain optical coherence tomography (OCT) studies report that foveal thickness increases with myopia.1,2 We examined retinal thickness in eyes with refractions ranging from plano to −10.60 D, using a high-resolution Fourier-Domain OCT. Methods: Macular thickness of 20 adult subjects was measured with an Optovue FD-OCT, using twelve 6-mm line scans (each 1020 pixels in length) at 15 deg intervals through the fovea. OCT B-scans were segmented by the Optovue software at the inner limiting membrane, inner plexiform layer and retinal pigment epithelial layer, providing estimates of the full, inner, and outer retinal thickness along each scan. Results: Average foveal thickness over the central 1 mm was 249.25, 177.52 and 71.73 micron in the full, outer and inner retina, respectively. Minimum full retinal thickness at the foveal pit averaged 215.94 micron. The central 1 mm foveal thickness increased significantly with increasing myopia (r=0.56;p=0.01), while the minimum thickness at the foveal pit only tended to increase with myopia (r=0.41;p[[gt]]0.05). The foveal pit depth became significantly shallower with increasing myopia (r=0.46;p=0.04). In the 3–6 mm perifoveal ring, full temporal retina thickness decreased significantly with increasing myopia (r=0.45;p=0.048). Conclusions: The nominal ‘1 mm’ central area may cover a larger and hence thicker retinal area in longer myopic eyes,3,4 since the central 1 mm thickness was more highly correlated with myopia than the minimum foveal thickness. Retinal stretching apparently decreases the perifoveal thickness in myopia; this is unlikely to be a magnification artifact since it was observed only in the temporal retina.
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Supported by NIH grants R24 EY014817 and T35 EY007149.