Axial length-related inter-individual variability in the posterior pole morphology of healthy eyes.

Abstract

To evaluate morphological characteristics of optic nerve head (ONH) and fovea (F) related to axial length (AL) in healthy eyes. This is an observational study. A consecutive series of healthy subjects was enrolled. Demographic and clinical parameters were age, gender, eye, intraocular pressure, spherical equivalent, AL. Tomographic parameters were ONH-F distance, ONH-F angle, horizontal and vertical ONH diameters, retinal nerve fiber layer (RNFL) thickness and foveal profile patterns. One hundred six eyes (56 patients) were recruited. A correlation between AL and ONH-F distance was demonstrated (p = 0.0342). Horizontal diameter decreased with increasing AL (p = 0.0003), conferring to ONH a more oval shape. A significant decrease in RNFL thickness was correlated with AL, except for temporal quadrant. Two foveal profile patterns were described: concave and straight patterns. Eyes with concave pattern were longer than eyes with straight pattern. Eye elongation affects the morphology of the ONH, the fovea and the distribution of retinal nerve fibers.