Spectral- and time-domain optical coherence tomography measurements of macular thickness in young myopic eyes

PURPOSE To evaluate the variation in macular retinal thickness and volume in young Chinese myopic patients using time-domain optical coherence tomography (Stratus TD-OCT) and spectral-domain optical coherence tomography (Cirrus HD-OCT). METHODS Ninety-two eyes of 92 myopic subjects were recruited in this study. Based upon spherical equivalence (SE), subjects were divided into two groups: the low to moderate myopia group (-0.5 D ≤ SE < -6.0 D), and the high myopia group (SE ≥ -6.0 D). Stratus TD-OCT and Cirrus HD-OCT were used to compare macular retinal thickness and volume between the two groups. Bland-Altman analysis and Pearson correlation were used to measure agreement between the two OCT systems. RESULTS Average macular retinal thickness and total macular volume measured by Cirrus HD-OCT and Stratus TD-OCT of the low to moderate myopia group were 283.52 ± 12.14 μm and 245.38 ± 8.55 μm, respectively, and 10.08 ± 0.37 mm3 and 6.85 ± 0.26 mm3, respectively, and the high myopia groups were 269.58 ± 10.72 μm and 235.65 ± 7.54 μm, respectively, and 9.71 ± 0.36 mm3 and 6.52 ± 0.25 mm3, respectively. The measurements of the two OCTs showed that macular retinal thickness of the parafovea was significantly lower in the high myopia group compared with the low to moderate myopia group, except at the fovea (all P-values less than 0.001, except at the fovea). Using the Bland-Altman method and Pearson correlation, measurements of macular thickness in nine macular retinal subfields and total macular volumes showed good agreement between the two OCTs in myopic eyes (all P-values less than 0.001), with better agreement in the low to moderate myopia group than in the high myopia group. CONCLUSIONS The average macular retinal thickness of the fovea did not vary with myopia, while the total volume and retinal thickness of the parafovea were thinner with increasing myopia. There was good agreement between the two OCTs in myopic eyes in all macular subfields, and the Cirrus HD-OCT system provided thicker macular retinal thickness measurements than the Stratus TD-OCT system. VIRTUAL SLIDES The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1683223414107652.