Trabecular meshwork cellularity in primary open-angle glaucoma and nonglaucomatous normals.

Area of Science:

• Ophthalmology
• Cell Biology
• Glaucoma Research

Background:

• Trabecular meshwork (TM) cellularity is crucial for aqueous humor outflow.
• Understanding TM cellularity changes with age and in primary open-angle glaucoma (POAG) is vital for disease mechanisms.
• Previous studies have not fully characterized age-related TM cellularity decline across the lifespan and in POAG.

Purpose of the Study:

• To compare trabecular meshwork cellularity in patients with POAG versus non-glaucomatous (NG) individuals.
• To investigate the pattern of cellularity decline with age in both groups.
• To determine if age-related cellularity loss differs between POAG and NG individuals.

Main Methods:

• Human TM specimens were obtained from NG individuals (n=69, prenatal to 98 years) and POAG patients (n=49, 23-80 years).
• Cellularity was quantified as cells per unit tissue area.
• Specimens were sourced from prenatal samples, postnatal individuals, trabeculectomy, and autopsy.

Main Results:

• Trabecular meshwork cellularity declines rapidly in late fetal and early postnatal life, then linearly thereafter.
• POAG patients consistently showed lower TM cellularity than NG individuals across all ages studied.
• Age-related cellularity decline patterns were parallel between POAG and NG groups, indicating similar aging trajectories.
• Cell loss occurred in a gradient, affecting inner TM tissues more than outer tissues.

Conclusions:

• Trabecular meshwork cellularity decreases significantly with age in both normal and POAG eyes.
• Primary open-angle glaucoma is characterized by reduced TM cellularity compared to normal aging.
• The similar age-related decline patterns suggest that POAG may involve accelerated or superimposed cellular loss on a normal aging process.