Trabecular Meshwork Length in Men and Women by Histological Assessment

Abstract

Purpose: To evaluate the length of the trabecular meshwork (TM) from the scleral spur (SS) to Schwalbe’s line (SL) and assess the detectability of the SS in histopathology specimens.

Methods: This study included 158 angle images from 79 cross-sectional slides derived from eyes enucleated for melanoma. The slides were stained with hematoxylin-eosin (HE) or periodic acid schiff (PAS). Two ophthalmologists evaluated the TM length by using the slides stained with HE to assess the interobserver reproducibility. For intraobserver reproducibility, the first observer assessed 79 images in a different session. Also, 30 images that were randomly selected for PAS stain were evaluated to assess the agreement of the measurements between HE and PAS staining. Interclass correlation coefficients (ICC) were calculated to evaluate reproducibility of measurements. The images were also evaluated for detectability of the scleral spurs.

Results: Among the 79 included subjects, 40 were male and 39 were female. The average trabecular meshwork length was 694.9 ± 109.0 µm in the male group and 713.2 ± 106.9 µm in the female group (p = 0.29). Intraobserver and interobserver ICC were 0.89 and 0.62, respectively. ICC for agreement between HE and PAS was 0.89. Among the 158 angles graded, the first observer graded 40 images (25.3%) and the second observer graded 45 (28.5%) as difficult to identify the scleral spur.

Conclusions: There was no statistically significant difference between the average trabecular meshwork length in men and women. Among the angles evaluated, 25.3–28.5% were graded as difficult to identify the scleral spur.

KEYWORDS::

• Scleral spur
• Schlemm’s canal
• Trabecular meshwork
• Anterior chamber
• Anatomy & histology
• Angle closure glaucoma

Declaration of interest: This study was supported by NIH-NEI EY002162 – Core Grant for Vision Research, Research to Prevent Blindness, and That Man May See, Inc.