Ultrastructural Changes in the Trabecular Meshwork of Juvenile Glaucoma

Abstract

Trabeculectomy specimens from 11 patients with juvenile glaucoma were studied by electron microscopy and quantitatively evaluated. In all cases, large amounts of extracellular material arranged in a fingerprint-like pattern, resembling basement-membrane-like material (FBM) was found, similar to that described in steroid-induced glaucoma. This material was found mainly within the inner cribriform and outer corneoscleral regions of the trabecular meshwork, and caused the cribriform layer to be greatly thickened. FBM was also intimately associated with trabecular cells, which frequently appeared activated. In 3 cases, there was also an increase in fine fÍbrillar material which resembled that found in eyes with steroid-induced glaucoma. The amount of sheath-derived plaque material, which is increased in primary open angle glaucoma, was greatly increased in the subendothelial layer adjacent to Schlemm’s canal.

Anatomic Changes in Schlemm's Canal and Collector Channels in Normal and Primary Open-Angle Glaucoma Eyes Using Low and High Perfusion Pressures

“…Increased stiffness and extracellular matrix deposition have been reported in the trabecular meshwork in POAG eyes. 39,40 The loss of outer wall elasticity may explain the same number of nonoccluded CCs found in POAG eyes at 10 and 20 mm Hg, suggesting an inability of POAG eyes to compensate for pressure-induced changes. It is interesting to note that all three POAG patients were on various ocular hypotensive medications, yet none of the POAG eyes had SC and CC dimensions similar to those of normal eyes at low pressure.…”

Clinical and Genetic Characteristics of Primary Juvenile-Onset Open-Angle Glaucoma (JOAG)

“…At the ultra-structural level, trabecular meshwork (TM) specimens from JOAG patients who had undergone trabeculectomy were found to have unusually thick compact tissue and extracellular deposits (Furuyoshi et al, 1997). Nine of the eleven JOAG patients from whom specimens were obtained had no abnormalities on gonioscopy.…”

Glycosaminoglycans of the trabecular meshwork of the eye in primary juvenile glaucoma

“…Proteoglycanes (PG) are complex molecules consisting of covalently bound central protein and polysaccharide chains (glycosaminoglycans; GAG) [7]. Changes in the qualitative composition of GAG were detected in PJG; no relationships between these changes and structural transformations in ocular tissues were detected [6,11].…”