Anterior scleral thickness in ocular hypertension

Purpose To evaluate anterior scleral thickness (AST) in patients with ocular hypertension (OHT) using anterior segment-optical coherence tomography (AS-OCT). Methods Forty-two eyes of 21 patients with OHT and 40 eyes of 40 healthy participants were included in this cross-sectional study. AST was measured at the level of the scleral spur (SS)(AST-0), 1000 µm posterior of the SS (AST-1), and 2000 µm posterior of the SS (AST-2) in the nasal and temporal quadrants using AS-OCT. Results The mean ages were 58.2 ± 12 (27–78) for OHT group; 54.2 ± 9.8 (21–70) years for control group ( p > 0.05). The mean nasal AST-0, AST-1 and AST-2 were 647 ± 25.7 (592–689), 490.7 ± 16.4 (453–526), 513.6 ± 19.2 (481–554) µm in OHT group; 701.7 ± 44.9 (605–785), 521.7 ± 33.4 (433–579), 535.5 ± 33.3 (449–599) µm in control group, respectively. The mean temporal AST-0, AST-1 and AST-2 were 667 ± 28.9 (620–723), 495.9 ± 18.7 (459–545), 509.3 ± 24 (430–596) µm in OHT group; 718.1 ± 45.9 (618–796), 525.3 ± 29.8 (456–583), 533.4 ± 41 (450–611) µm in control group, respectively. Mean ASTs measured at all three points in OHT group were significantly thinner than in control group in both nasal and temporal quadrants ( p < 0.05). Conclusion We found that the scleral thickness was significantly thinner in OHT patients. It is still unknown whether the sclera plays a role in the OHT pathogenesis by affecting the biomechanical response of the globe to IOP elevation. Or conversely, sclera may undergo structural changes secondary to long-term IOP elevation in OHT. Although there are hints about the relationship between sclera and IOP, the mechanisms are still unclear.