Changes in Scleral Thickness Following Repeated Anti-vascular Endothelial Growth Factor Injections

Purpose: this cross-sectional study aimed to compare changes in scleral thickness between eyes injected with repeated anti-vascular endothelial growth factor (anti-vegf) drugs and fellow injection naive eyes using optical coherence tomography (oct). methods: a total of 79 patients treated with three intravitreal anti-vegf injections in one eye versus no injections in the fellow eye were included. anterior segment-oct measured scleral thickness in the inferotemporal quadrant 4 mm away from the limbus. results: injected eyes had a mean scleral thickness of 588 ± 95 μm versus 618 ± 85 μm in fellow naïve eyes (p < 0.001). comparing injected eyes to fellow naïve eyes stratified by injection number showed a mean scleral thickness of 585 ± 93 μm versus 615 ± 83 μm in eyes with 3–10 injections (n = 32, p = 0.042); 606 ± 90 μm versus 636 ± 79 μm in eyes with 11–20 injections (n = 24, p = 0.017);and 573 ± 104 μm versus 604 ± 93 μm in eyes with >20 injections (n = 23, p = 0.041). there was no significant correlation between injection number and scleral thickness change (r = –0.07, p = 0.26). when stratified by indication, subjects with retinal vein occlusions showed a statistically significant difference in scleral thickness between injected and fellow naïve eyes (535 ± 94 μm and 598 ± 101 μm, respectively, p = 0.001). conclusion: compared to injection naive eyes, multiple intravitreal injections at the repeated scleral quadrant results in scleral thinning. consideration of multiple injection sites should be considered to avoid these changes.