ASSOCIATION BETWEEN PLATELET AGGREGATION PARAMETERS AND PRIMARY OPEN ANGLE GLAUCOMA

Abstract

Glaucoma is the leading cause of irreversible blindness in the world. Being a progressive optic neuropathy, understanding multiple mechanisms playing a part in its progression is of vital importance. Among them, vascular theory states that it occurs as a consequence of insufcient blood supply. To know if this insufciency occurs due to thrombosis in the blood vessels, platelet aggregation parameters can be used as a guide. Aims: To compare the association between platelet aggregation parameters in patients with and without primary open angle glaucoma and also to co-relate it with the severity of glaucoma. Design: Randomized, Cross-sectional, hospital-based observational study. Methods: A total 53 consecutive patients with POAG and 53 controls were recruited in the study. The cases were grouped as mild, moderate and severe based on the clinical optic nerve head ndings and mean deviation (MD) value of visual elds. In bilateral cases, the eye with worse MD was selected. Complete blood count was done to assess Platelet count (PLT), Platelet distribution width (PDW), Plateletcrit (PCT), Mean platelet volume (MPV). These platelet aggregation parameters were compared between the two groups. Results: In the POAG group, PDW (16.29±1.10 fL) and MPV (8.48±0.83 fL) values were signicantly higher (p <0.05) than those of the control group (PDW 15.85±0.74 fL, MPV 8.17±0.76 fL). In POAG patients, PLT counts were lower (276.1±43.5) compared to controls (291.2±53.0) though not statistically signicant. MPV (8.80±0.55), PDW (16.65±1.25) was highest in the moderate group but no statistically signicance found. Conclusions: PDW and MPV values were found to be higher in POAG patients, suggesting the possibility of platelet activation and hence increased platelet aggregation leading to insufcient blood supply to the optic nerve head and hence development of POAG. Role of antiplatelet drugs in delaying the development of glaucoma can be considered based on the above evidence.