Optic disc and peripapillary retinal nerve fiber layer characteristics associated with glaucomatous optic disc in young myopia.

PURPOSE

To explore optic disc and peripapillary retinal nerve fiber layer (RNFL) features associated with glaucomatous optic disc (GOD) in young myopia.

METHODS

Presence of GOD, optic disc tilt, and disc torsion were determined using fundus photographs. If the measured disc tilt ratio was >1.3, the optic disc was classified as tilted. Optic disc torsion was defined as a >15° deviation in the long axis of the optic disc from the vertical meridian. The average and four quadrants RNFL thicknesses were assessed using spectral domain optical coherence tomography (SD-OCT). Logistic regression analyses were performed to identify factors associated with the presence of GOD.

RESULTS

Nine hundred and sixty myopic subjects were recruited from four refractive surgery clinic databases. The mean age was 26.6 ± 5.7 years and spherical equivalent (SE) was -5.5 ± 2.5 diopters. Among 960 eyes, 26 (2.7%) received GOD group classification. Among 934 normal eyes, 290 (31.0%) had titled optic discs. Eighteen eyes (69.2%) in the GOD group had tilted optic discs. When compared to normal eyes, the GOD group had significantly higher tilt ratios (1.4 ± 0.2 vs. 1.2 ± 0.1, p < 0.001) and less SE (-7.8 ± 2.7 vs. -5.4 ± 2.5 diopters, p < 0.001). Greater tilt ratio (odds ratio (OR) = 4.9, p < 0.001), less SE (OR = 0.708, p < 0.001), and thinner average RNFL (OR = 0.910, p = 0.001) were significantly associated with GOD. Among 934 normal eyes, 366 (39.2%) displayed disc torsion, while among 26 glaucomatous eyes, eight (30.8%) displayed disc torsion.

CONCLUSIONS

Optic disc tilt was found in approximately one-third of young myopic eyes and was independently associated with the presence of GOD.