Perforating scleral vessels in children and myopia-related pattern

To compare prevalence, location and orientation of perforating scleral vessels (PSVs) at the ocular posterior pole between emmetropic and myopic children.

The prospective observational study included children undergoing standardized 20° × 20° enhanced-depth imaging optical coherence tomography (EDI-OCT). PSVs were defined as tubular hypo-reflective structures detectable on macular OCT images and traversing the sclera. Curvature-conforming PSVs were oriented following, and against-curvature PSVs were oriented against the physiological curvature of the sclera.

The study included 102 eyes (51 children; age: 10.3 ± 3.3 years; range: 4-16 years). Total PSV number (mean: 1.8 ± 2.4; median: 1.5; range: 0-8) was significantly higher in the myopic group (n = 52 eyes) than the non-myopic group (n = 50) (3.1 ± 2.6 vs. 1.5 ± 2.3; p = 0.036). Against-curvature PSV number was higher in the myopic group than the non-myopic group (2.4 ± 1.7 vs. 0.3 ± 0.9; p < 0.001), as was the prevalence of eyes containing at least one against-curvature PSV (57.7% vs. 18.0%; p < 0.001). Non-myopic eyes showed a greater number of curvature-conforming PSVs (1.2 ± 1.7 vs. 0.7 ± 0.9; p = 0.04). The PSVs were located significantly more often in the outer inferior sector and outer superior macular sector in the myopic group than in the non-myopic group. In the central sector, PSV prevalence was marginally (p = 0.08) higher in the myopic eyes than in the non-myopic eyes, and correspondingly, PSV prevalence in the outer nasal sector was marginally (p = 0.12) higher in the non-myopic eyes. PSV entry angle was smaller in the myopic eyes than in the non-myopic eyes (38° ± 16° vs. 51° ± 15°; p < 0.001).

Count, location, entry angle and direction of PSVs differed between myopic versus non-myopic eyes. Further longitudinal studies will help clarify the role of this finding in myopic axial elongation.