Erythrocyte deformability in high-tension and normal tension glaucoma.

The exact cause of primary open angle glaucoma is still unknown. Intraocular pressure is a major factor but it is impossible to explain the whole mechanism of glaucomatous optic nerve damage with only increased intraocular pressure. Other factors play important roles in the development of glaucoma. With this point of view, vascular factors have been implicated in the pathogenesis of glaucoma. We tried to determine the etiopathogenetic role of decreased erythrocyte deformability in normal tension glaucoma and high-tension glaucoma. The study group consisted of 16 patients with the diagnosis of normal tension glaucoma, 17 patients with the diagnosis of high-tension glaucoma, and 24 patients as controls. Independent t-tests were used to compare the three groups two by two for age, hematocrit, mean cell volume, plasma protein level, cardiovascular risk factors, and erythrocyte deformability. There was no statistically significant relationship (p>0.05) between the groups concerning the erythrocyte deformability. When we consider all of 57 patients, we found that both increasing age (>60 years) and greater mean cell volume (>84 fl) had a statistically significant relationship with decreased erythrocyte deformability (p<0.05). When we performed Pearson correlation analysis, we found that only mean cell volume and erythrocyte deformability had a statistically significant relationship (r = 0.31, p = 0.02). We conclude that decreased erythrocyte deformability is not a major factor in the ethiopathogenesis of normal tension glaucoma and high-tension glaucoma.