Central Retinal Vessel Trunk Dragging in Highly Myopic Eyes.

PURPOSE: To assess occurrence and associations of central retinal vessel trunk (CRVT) dragging.

DESIGN

Retrospective, population-based cohort study.

METHODS

Using optical coherence tomographic images of the optic disc and macula, taken from the participants of the Beijing Eye Study, we assessed the prevalence of CRVT dragging, defined as an optic disc tissue prominence at the inferior, superior, and nasal, but not the temporal, optic disc border.

RESULTS

The study included 3336 individuals (3336 eyes) (mean age: 64.2 ± 9.6 years; axial length: 23.4 ± 1.2 mm [range: 20.16-30.88 mm]). CRVT dragging prevalence increased from 0/3046 (0%) to 9/173 (5.2%; 95% CI: 2, 9), 9/74 (12.2%; 95% CI: 5, 20), 6/25 (24.0%; 95% CI: 6, 42), and 13/18 (72.2%; 95% CI: 49, 95) in eyes with an axial length of ≤25.0 mm, 25.01 mm to 26.0 mm, 26.01 mm to 27.0 mm, 27.01 mm to 28.0 mm, and >28.0 mm, respectively. A higher CRVT dragging prevalence was associated (multivariable analysis) with a longer optic disc-fovea distance (odds ratio [OR]: 5.82; 95% CI: 2.23, 15.2; P < .001) and a higher prevalence of parapapillary retinoschisis (OR: 8.61; 95% CI: 2.43, 30.5; P < .001), after adjusting for longer axial length (OR: 1.95; 95% CI: 1.25, 3.05; P = .003) and older age (OR: 1.08; 95% CI: 1.02, 1.14; P = 0.008). In eyes with an axial length of ≥25.0 mm, CRVT dragging prevalence increased 5.69-fold (95% CI: 2.30, 14.1) for each millimeter increase in fovea-disc distance. These relationships were complemented by univariate associations between CRVT dragging prevalence and temporal retinal vessel straightening, smaller angle κ, higher myopic macular degeneration stage and prevalence, and larger parapapillary β zone and γ zone.

CONCLUSIONS

CRVT dragging, as a common feature in highly myopic eyes, may be etiologically explained by the myopic axial elongation-related increase in the fovea-disc distance. Influencing the 3-dimensional appearance of the optic nerve head, CRVT dragging may be of importance for the morphologic diagnosis of optic neuropathies in highly myopic eyes.