Posterior eye curvature map in children estimated by widefield OCT

Abstract

Purpose : We studied posterior eye curvature map in children to investigate the relationship between the posterior curvature and myopia.

Methods : Both eyes of ninety three (93) children with ages from 6 to 15 y/o were involved in this cross-sectional study. Axial length ranged from 21.47 mm to 26.92 mm (average 23.78 mm). Posterior OCT images were captured using a 400 kHz widefield (20 mm x 20 mm) swept-source OCT prototype (Topcon, Tokyo, Japan). Axial motion artifacts were corrected using vertical line-scan images as reference. The Bruch’s membrane (BM) line was segmented, and then its optical distortion was corrected to define the posterior shape. Gaussian curvature was used to quantify the local curvature in each location. The resulting two-dimensional curvature map was quantitatively assessed.

Results : One-hundred fifty two (152) images had sufficient quality to calculate the curvature. Figure 1 shows an example of the OCT B-frame and the curvature map. The region around the optic nerve head is excluded from the curvature calculation. The Gaussian curvature in the macular region was smaller than that of peripheral region, indicating that the ocular shape in the macula is relatively flat compared to the periphery. A local maximum point of the curvature around 15–20 degrees temporal region was observed in ~80% of the eyes. The height of this maximum decreased with axial eye length.

Conclusions : Posterior eye curvature maps in children were generated by wide field 3D OCT images and assessed to find the relationship to myopia condition.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.

 

Fig.1 (a) A distortion-corrected OCT B-frame image. (b) Three-dimensional posterior structure from distortion-corrected BM segmentation surface. (c) A Gaussian curvature map. Region around the optic nerve head is excluded from the curvature calculation. The dashed line indicates the location of the B-frame shown in (a). Bar : 3 mm