Correlation of histopathology of trabecular meshwork with clinical features in primary congenital glaucoma

Abstract

Purpose: To correlate histopathological changes of trabecular meshwork (TM) with clinical features in primary congenital glaucoma (PCG).

Methods: This was a prospective interventional study including 66 eyes of 39 PCG children aged ≤12 months at diagnosis. Corneal clarity, corneal diameter (CD), intraocular pressure (IOP) and cup disc ratio (C:D ratio) were assessed at baseline and at 1-year follow-up. The trabecular meshwork (TM) specimens obtained during primary combined trabeculectomy and trabeculotomy augmented with Mitomycin-C were evaluated on light microscopy to look for eosinophilic membrane (EM), status of trabecular beams and trabecular endothelial cells (TEC), presence of intervening spaces, TM thickness and TEC count which were then correlated with clinical features.

Results: At 1-year follow-up, IOP reduced from 27.96±10.2 to 11.88±5.63 mm Hg, p<0.001, C:D ratio decreased from 0.65±0.34 to 0.49±0.06, p=0.036, and the bleb had a significant tendency to change from well formed (59-46) to flat type (3-6) or thin, cystic type (4-14) (p=0.014). Presence of EM on the cameral surface was associated with a lower baseline IOP. Fused trabecular beams were associated with higher baseline IOP. The TM was significantly thicker in eyes with IOP >20 mm Hg at presentation (1.86±0.7 mm vs 1.3±0.47 mm, p=0.0356). Eyes with IOP ≤14 mm Hg at final follow-up had lower TEC count than eyes with IOP >14 mm Hg (0.92±0.45 cells/mm² vs 1.00±0.74 cells/mm², p=0.0028).

Conclusion: A light microscopic analysis of surgical specimens may guide prognosis of PCG. However, larger studies are required to validate these results.

Keywords: Anterior chamber; Glaucoma.