Morphometry of the Trabecular Meshwork in Vivo in a Healthy Population Using Fourier-domain Optical Coherence Tomography

Purpose: We measured the length, thickness, and area of the trabecular meshwork (TM) in vivo using Fourier domain optical coherence tomography (FD-OCT) in a Caucasian population of healthy subjects.

Methods: A cross-sectional study was done of 1006 healthy subjects. Left eyes were randomly selected. Age, sex, IOP, and spherical refractive error were noted. The depth and volume of the anterior chamber and the central corneal thickness were measured with Pentacam, while IOL Master was used to measure the axial length. The length, thickness, and area of the TM were measured through FD-OCT RTVue. A study was done to determine the correlation between TM size, and other demographic and ocular parameters. Finally, the reproducibility of the measurements was assessed for a subgroup of 50 eyes from 50 patients.

Results: We were able to measure the TM in 91.1% of the total eyes studied. The mean TM length was 496.99 ± 92.77 μm (range, 275-800), TM thickness was 174.16 ± 28.14 μm (range, 100-276), and TM area was 0.069 ± 0.031 mm(2) (range, 0.023-0.133). No differences were found in terms of length and area for sex, although the TM was slightly thicker in men (P = 0.046). No correlation was observed between the TM measurements and any of the studied demographic or ocular parameters (R < 0.09, P < 0.001). Intra- and interobserver reproducibility of the measurements were good (intraclass correlation coefficient > 0.750, P < 0.001).

Conclusions: The FD-OCT is an effective and reproducible examination technique to measure the length, thickness, and area of the TM in vivo.