Background: Exact determination of the location of the fovea may be difficult, especially in patients suffering from macular pathology. The purpose of this study was to evaluate whether the distance between the optic nerve head and fovea in healthy eyes may be helpful in such patients.
Patients and methods: We measured the distance between the center of the optic nerve head and the fovea in 165 healthy eyes in a horizontal and vertical direction. Results were correlated to the refractive status.
Results: There was a relatively high deviation between all eyes for the distance between the optic disc and the fovea (15.5 +/- 1.2 degrees [12.8 to 21.3 degrees]). There was a significant relationship between this distance and the refraction (r = 0.353, P < 0.001). Intraindividual deviation between the right and left eyes showed a markedly lower variance (0.67 +/- 0.49 degree [0.05 to 2.3 degrees]).
Conclusion: The distance between the optic nerve head and the fovea does not allow for meaningful determination of the location of the fovea in eyes in which morphological changes have occurred. However, knowledge of this distance from the other eye of the same patient is helpful.