|Title||REFRACTIVE ERROR AND OCULAR PARAMETERS: COMPARISON OF TWO SD-OCT SYSTEMS|
|Author, Co-Author||Jill Yuzuriha, Lisa Ostrin, Christine Wildsoet|
|Abstract|| PURPOSE: Spectral domain optical coherence tomography (SD-OCT) was used to determine if subfoveal retinal and choroidal thickness and scleral canal width are related to refractive error (RE), and to compare measurements using Cirrus and Bioptigen SD-OCT.
METHODS: Eighty eyes from 40 healthy human subjects, ages 18 to 40, were used in this study. Ocular parameters were measured using the IOLMaster. Eyes were dilated and imaged with the Cirrus, using two 6 mm 5-line rasters collapsed into one line: one centered on the fovea and the other bisecting the optic nerve head (ONH). Of the 80 eyes, 72 were also imaged with the Bioptigen, using two 6 mm x 6 mm scans: one centered on the fovea and one on the ONH. Total subfoveal retinal and choroidal thicknesses and scleral canal width were measured using the built-in calipers for each OCT device when resolution allowed.
RESULTS: Average RE was -3.46±4.03 D (range -12.18 to +8.12) and axial length was 24.8±1.89 mm (range 20.79 to 29.17). High myopia correlated with thicker retina and thinner choroid (p<0.05) at the fovea. There was no significant correlation between scleral canal width and RE (p=0.66). Bland-Altman analysis showed that the Bioptigen tended to yield retinal and choroidal thicknesses that were lower than the Cirrus measurements on the same eye (avg difference 5.65 μm and 34.4 μm, resp). The Bioptigen-measured scleral canal widths were lower than the Cirrus measurements on the same eye in high myopes, but higher than the Cirrus measurements otherwise.
CONCLUSIONS: In this study, high myopes tended to have thicker subfoveal retina, in contrast to previous reports. However, in accordance with previous studies, we found correlation with thinner choroid and high myopia. This study suggests that scleral canal width may not be a contributing factor to increased risk of glaucoma in myopes. The lack of agreement between retinal and choroidal thicknesses measured with the Cirrus and the Bioptigen suggests that these instruments are not interchangeable.
|Affiliation of Co-Authors||University of California Berkeley, School of Optometry, University of California Berkeley, School of Optometry|