The relationship between optic disc-foveal distance with choroidal and retinal nerve fiber thickness.

Background: The optic disc-foveal distance is very important as it is an anatomical measure of the fundus. As this distance increases and the fundus tension, there may be variability in retinal and choroidal thickness. The aim of this study was to determine the relationship between optic disc-foveal distance and choroidal and retinal nerve fiber thickness in healthy subjects.

Materials and methods: A total of 72 people between the ages of 20-36 participated in the study. Optic disc-foveal distance was measured with a fundus camera and choroidal and retinal nerve fiber thicknesses were measured with an OCT (Optical coherence tomography) device. Littmann's formula (t = p × q × s) as modified by Bennett was applied to correct the magnification at the fundus camera imaging stage.

Results: The thickness of the nasal choroid (p=0.005; p=0.006), subfoveal choroid (p=0.004; p < 0.001) and temporal choroid (p=0.001; p=0.001) layers decreased as the DFD (Optic disc-to-foveal distance) increased in both right and left eyes of the individuals participating in the study, which was statistically significant. In addition, it was observed that the RNLF (Retinal nerve fiber layer) increased as the DFD distance increased, but this was not statistically significant.

Conclusion: This study demonstrated that the optic disc-foveal distance, an anatomical measure of the fundus, does not affect RNLF in young and healthy subjects, but choroidal thickness does.