Central corneal thickness and intraocular pressure in primary open angle glaucoma suspects in a south Indian population. Is it time for “corneal anthropology”?

Purpose: To study correlation between central corneal thickness (CCT) and intraocular pressure (IOP) in the primary open angle glaucoma (POAG) suspects and to assess the importance of the local population reference CCT in pachymetry adjusted IOP. Design: Prospective, cross sectional study. Materials and Methods: A total of 100 patients aged 40-70 years of age diagnosed as POAG suspects were included. CCT measurements using ultrasound pachymetry and IOP measurement with Goldmann applanation tonometer (GAT) was done. IOP was corrected to the local south-Indian baseline CCT and also to the International CCT and comparison was done. Results: The study included 100 patients (58 male and 42 female) with mean age of 51.7 ± 6.1 years. The mean CCT was 518.91 ± 24.26 mm, 522.19 ± 21.56 mm among females, males respectively. The mean uncorrected IOP (GAT) was 19.50 mmHg, 20.14 mmHg (right, left sides). Significant, moderate positive correlation between CCT and IOP was observed. The two groups i.e mean IOP corrected for South-Indian CCT (Mean_CX_IOP) versus IOP corrected for CCT international (Mean_CX_INT_IOP) showed significant difference. The mean IOP in Indian CCT corrected group was 19.76 ± 2.81 mmHg and in international CCT group was 21.51 ± 2.83 mmHg. Levene’s test indicated significant difference in mean IOP of 2 groups (p=0.000). Conclusions: CCT is an important parameter in glaucoma management and known to vary in different ethnic groups. Local ethnicity specific CCT should be used in IOP correction with the help of anthropologists. Keywords: Corneal anthropology, Central corneal thickness, Glaucoma suspects, Intraocular pressure.