Myopic optic disc tilt and the characteristics of peripapillary retinal nerve fiber layer thickness measured by spectral-domain optical coherence tomography

Purpose: To investigate the correlation between myopic optic disc tilt and the characteristics of peripapillary retinal nerve fiber layer (RNFL) thickness measured by Cirrus HD spectral-domain optical coherence tomography (Cirrus HD OCT; Carl Zeiss Meditec, Dublin, CA). Methods: A total of 255 eyes of 255 healthy young male participants with various degrees of refractive errors (mean spherical equivalent, -3.17±2.40 D; range, -11.00 to 0.00 D) underwent ophthalmic examinations, including refractive error, axial length, and optic disc area measurement. The degree of horizontal/vertical optic disc tilt was evaluated by cross-sectional images obtained by the Cirrus HD OCT. The average, superior, nasal, inferior, and temporal quadrant thickness and superior/inferior peak locations of the peripapillary RNFL were also measured with the Cirrus HD OCT. Results: On the univariate analysis, eyes with more temporally tilted optic discs (horizontal tilt) had higher myopia, greater axial length, a thinner average, superior, nasal, and inferior RNFL, thicker temporal RNFL, and more temporally positioned superior/inferior peak locations (all P values <0.001). The degree of inferior optic disc tilt (vertical tilt) was associated with high myopia and a more temporally positioned inferior peak location (all P values <0.05). On multivariate analysis, eyes with more temporally tilted optic discs had a thicker temporal RNFL and more temporally positioned superior/inferior peak locations. Conclusions: The characteristics of the peripapillary RNFL thickness were associated with the degree of myopic optic disc tilt, especially in the temporal area. The degree of myopic optic disc tilt should be considered when interpreting the RNFL thickness measured by the Cirrus HD OCT.