Anterior Scleral Thickness And Anterior Segment Biometrics Measured With Swept Source Ocular Coherence Tomography In High Myopic Eyes With And Without Glaucoma, A Comparative Study

To assess the anterior scleral thickness (AST), Schlemm’s canal diameter (SCD), trabecular meshwork diameter (TMD) and conjunctiva tenon capsule thickness (CTT) in high myopic (HM) subjects and HM subjects with glaucoma (HMG) compared to control eyes.

Hospital Universitario Puerta de Hierro, Department of Ophthalmology, Glaucoma Section

One hundred twenty eyes were included, AST at 0,1,2 and 3 mm from the scleral spur, SCD, TMD and CTT were measured using anterior segment optical coherence tomography (AS-OCT). Associations between axial length (AXL), retinal nerve fibre layer (RNFL), ganglion cell layer (CGL) and AST were also estimated.

The temporal SCD and temporal TMD were significantly longer in the HMG subjects compared to controls (380.0±62 μm vs 316.7±72 μm, p=0.000) and (637.6±113 μm vs 512.1±97 μm, p=0.000), respectively. There were no significant differences between HM and HMG subjects in SCD and TMD (all p> 0.05). compared to HM subjects the temporal AST0 (432.5±79 μm vs 532.8±99 μm, p=0.000), temporal AST1 (383.9±64 μm vs 460.5±80 μm, p=0.003), temporal AST2 (404.0±68 μm vs 464.0±88 μm, p = 0.001) and temporal AST3 (403.0±80 μm vs 458.1±91μm, p = 0.005) were significantly thinner in HMG group. No differences were found between the CTT in the three groups (all p> 0.05). Mild correlation was found between AST0 and CGL measurements (R=0.4, , P<0.05).

AS-OCT allows the identification of anterior-segment structures in HMG. Our data indicate a thinner AST in HMG subjects and no differences in SCD and TMD between HM and HMG subjects.