Impact of age, sex and refractive error on conjunctival and Tenon's capsule thickness dimensions by swept-source optical coherence tomography in a large population.

PURPOSE

To evaluate conjunctival and Tenon's capsule thickness (CTT) in a large healthy population using swept-source optical coherence tomography (SS-OCT), investigating the impact of age, sex and refractive error.

METHODS

630 healthy participants underwent a complete ophthalmological examination. CTT was manually measured in the temporal and nasal quadrants at 0, 1, 2 and 3 mm from the scleral spur using SS-OCT (CTT0, CTT1, CTT2 and CTT3, respectively). These dimensions were then assessed for associations in a multivariate regression model with age, sex, refractive error and anterior scleral thickness (AST). The reproducibility of the CTT measurements was determined in 30 individuals.

RESULTS

CTT dimensions could be measured in 596 cases (94.6%); mean age was 42.6 ± 17.2 years (range 5-86). Mean CTT0 was 199.2 ± 33.8 and 192.9 ± 33.9 µm, mean CTT1 195.4 ± 38.0 µm and 199.9 ± 50.9 µm, mean CTT2 187.0 ± 38.4 and 194.8 ± 48.9 µm, and CTT3 180.5 ± 35.6 µm and 191.8 ± 43.7 µm, for the temporal and nasal quadrants, respectively. No difference in CTT was observed in the nasal versus temporal quadrant (p ≥ 0.106) except for the CTT0 and CTT3 (p = 0.001). Moderate correlation was observed between nasal and temporal CTT (R = 0.472, p < 0.001). In the multivariate model, no influence was observed by sex, refractive error and AST on CTT measurements (p ≥ 0.065). Negative association was observed between age and CTT (p < 0.005). The reproducibility was excellent (intraclass correlation coefficient ≥ 0.908).

CONCLUSIONS

SS-OCT allows for in vivo CTT evaluation. Our data document a wide range of measurements, showing negative association between CTT and age.