Aparna Nayak1 , Sandhya Somasundaran2 , Bindu Susheela3 , Jyothi Poothatta4
BACKGROUND Corneal endothelial cells are one of the major factors responsible for maintaining corneal transparency. Since they cannot regenerate, the factors which affect them adversely should be looked into. Heredity, increasing age, topical drug use, high intraocular pressures etc., are some of them. Corneal endothelial cells are badly affected in acute and chronic angle closure if the pressures remain high for longer periods. So, we wanted to know whether mild to moderate increase in IOP as in Primary Open Angle Glaucoma (POAG) will affect the corneal endothelial status. If high intra ocular pressure is the sole factor, then the endothelial cells should be normal in Normal Tension Glaucoma (NTG). Hence, a study was undertaken to compare the corneal endothelial status of POAG and NTG. We wanted to study and compare corneal endothelial status in patients with primary open angle and normal tension glaucoma. METHODS The study was conducted in the Glaucoma clinic in a tertiary care hospital in Northern Kerala. It was a facility based comparative cross sectional study. 142 glaucoma patients were included in the study. They were divided into Primary Open Angle Glaucoma (POAG) and Normal Tension Glaucoma (NTG) groups. Endothelial status was studied using specular microscope. Relevant clinical examination, central corneal thickness, IOP measurement and field analysis by HFA was done in all patients. RESULTS Mean age was 54.7 ± 5 years in POAG and 54.65 ± 6.2 years in NTG. Females were more affected by the disease in both groups. Age showed a statistically significant association with endothelial cell density. As age increases by one-year, endothelial cell density decreases by 5.078 cell / mm2 . POAG group had endothelial cell density 160 cell/ mm2 lower than NTG (p value 0.000). Average hexagonality is 3.73 lesser in POAG than NTG (p value 0.005). CONCLUSIONS High intraocular pressure or wide fluctuations can contribute to endothelial cell damage as well as progression of glaucoma. This indicates the importance of achieving target IOP and maintaining it in the treatment of POAG as well as NTG. Anti-glaucoma medications should be selected cautiously in patients with compromised endothelium. Surgical procedures should be done with adequate precautions in glaucoma patients with reduced endothelial count.
