Abstract
Purpose :
To measure the distance between the optic disc center and fovea and to evaluate its associations with axial length and optic disc area.
Methods :
Using Topcon Maestro2 spectral domain optical coherence tomography (SD-OCT), distance between the fovea and optic disc center (DFD) was measured in healthy, glaucoma suspect, and glaucoma patients during scheduled eye examinations at the Illinois College of Optometry. Estimated axial length (AL) was derived from the reference mirror position of the SD-OCT data capture within ± 1 mm error. DFD was correlated with the derived AL and optic disc area measurements using linear regression before and after ocular magnification correction. Ocular magnification was corrected using a geometric adjustment from a test eye with known distance and AL. Patients with macular conditions or poor-quality scans with inability to identify the fovea were excluded.
Results :
582 eyes of 294 subjects (ages 15.1- 87.8 years) were imaged using a widefield (12x9 mm) OCT scan. Mean corrected DFD (± SD) was 4.68 ± 0.36 mm, mean estimated AL (± SD) was 24.16 ± 1.28 mm with a range from 20.14 to 29.99 mm, and mean disc area (± SD) was 2.44 ± 0.61 mm2. Before correction for optical magnification, DFD increased as AL decreased (R2 = -0.062) and as optic disc area increased (R2 = 0.022). The correlation between DFD and AL reversed after correcting for optical magnification; DFD increased as AL (R2 = 0.265) and optic disc area (R2 = 0.066) increased.
Conclusions :
Distance between the optic disc center and fovea increases with longer axial length and larger disc area. However, caution should be applied when using DFD due to its significant variability. These findings may be of interest for the process of emmetropization and myopia development.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.