Abstract
Purpose :
The location of the fovea is key in evaluating and treating a variety of macular diseases. Prior studies suggest that, overall, there is a significant amount of variability in the fovea’s location, but little is known regarding this variability. The purpose of this study is to retrospectively measure the location of the fovea relative to the optic nerve head using spectral domain optical coherence tomography (SD-OCT) to determine individual and population group differences in anatomically normal eyes.
Methods :
Macular SD-OCTs from a single SPECTRALIS® (Heidelberg Engineering) were analyzed retrospectively over a 2-year period. Images were included if the OCT revealed normal anatomy and included the optic disc. Images were excluded if the eye carried any pathology that could cause anatomic distortion. Basic demographic data were obtained including age, sex, race, refractive error and ocular diagnoses. Measurements were performed using the Heidelberg Eye Explorer software. Location of fovea was determined by the foveal depression and ellipsoid line contour in conjunction with the signal corresponding to the foveal light reflex. Distances were measured from the midpoint of the temporal rim of the optic nerve head.
Results :
One hundred nine eyes from 81 patients were included and had a mean age of 56.9 ± 12.5 years. Fifty-four percent were female. Regarding race, 52% and 44% of patients self-identified as black and white, respectively, while 2% self-identified as Hispanic and 2% as Asian. Mean spherical equivalent was -0.26 ± 1.62 in the 101 phakic eyes. On SD-OCT imaging, mean overall distance of fovea from optic disc was 583 ± 310 μm and 3644 ± 239 μm for vertical and horizontal axes, respectively. There was no significant difference in position between eyes in an individual (p > 0.07). For race, mean distance of fovea from optic disc was greater blacks as compared to whites both vertically and horizontally by 160 μm (p = 0.01) and 115 μm (p = 0.01), respectively. No correlation was observed for foveal position with regard to sex or refractive error.
Conclusions :
SD-OCT provides a precise modality to measure the position of the fovea relative to the optic nerve. Significant variability exists regarding location of the fovea in healthy eyes, and differences in foveal location may correlate with race.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.