Abstract
Purpose :
To investigate the relationship 1) between axial length and the deep optic nerve head (ONH) structures 2) between open angle glaucoma (OAG) and deep ONH structures.
Methods :
Candidates for this study were patients with myopic eyes with < -0.5 diopter with and without glaucomatous damage who visited Samsung Medical Center (Seoul, South Korea) between January 2015 and March 2016. We used OCT (Heidelberg Engineering, Heidelberg, Germany) to measure the deep ONH structures related to axial elongation. The deep ONH structures showed the following changes with axial elongation: 1) larger externally oblique border tissue (EOBT) length, 2) greater Bruch’s membrane opening (BMO) diameter, 3) greater optic nerve head (ONH) tilt angle, 4) greater optic canal obliqueness, 5) larger beta zone peripapillary atrophy (PPA). We intended to investigate the relationship between axial elongation and the parameters. In addition, the extent and the location of the parameters were compared between myopic eyes with and without OAG.
Results :
Axial elongation was correlated to EOBT length, BMO diameter, ONH tilt angle, optic canal obliqueness and beta zone PPA (P < 0.001, P < 0.001, P = 0.003, P < 0.001, P < 0.001). The correlations among the parameters were significant (P< 0.001 in all correlations). When logistic regression analysis was performed to evaluate the factors associated with the presence of glaucoma, temporally angular location of maximal EOBT length, maximal BMO diameter, ONH tilt angle and maximal optic canal obliqueness were significant (P = 0.008; P=0.022; P = 0.015; P=0.031). When only glaucoma patients were analyzed to compare the direction of retinal nerve fiber layer (RNFL) defect and each parameter, the location of maximal EOBT, ONH tilt angle, maximal optic canal obliqueness and PPA were significant (P<0.001; P<0.001; P<0.001; P=0.003).
Conclusions :
The present study demonstrated that the parameters of the deep ONH structures are associated with axial elongation. In addition, the parameters seem to be associated with the presence and the location of glaucomatous defect in OAG.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.