Exploring the Link Between Intraocular Pressure and Central Corneal Thickness, as Well as the Diurnal Variation of Intraocular Pressure, in the Elderly Population of North Karnataka

Abstract

Purpose The study aimed to understand the relationship between intraocular pressure (IOP) and central corneal thickness (CCT) in older adults living in North Karnataka and the diurnal variation of IOP in the elderly population. Methods This is a population-based cross-sectional study in which 84 eyes of 42 study participants aged over 50 years were examined. A complete ophthalmic examination was done for all subjects. IOP was measured with an iCare IC100 (Icare Finland Oy, Vantaa, Finland) rebound tonometer and CCT with an ultrasound pachymeter. Statistical significance was accepted as p<0.05. Results The mean age of the study participants was 64.42±6.917 years. The mean IOP and CCT at 1 pm were 12.4±2.576 and 509.24±25.379 in the right eye, and 12.45±2.319 and 511.05±24.464 in the left eye. Spearman’s correlation showed that IOP was positively correlated with CCT, with p<0.05. This showed that CCT has the most significant impact on IOP. In our study, the diurnal variation of IOP by paired samples t-test was also crucial in the elderly population, with p<0.05. Conclusion In this study, IOP was reduced as the CCT was reduced, and vice versa, i.e., IOP was positively correlated with CCT. The diurnal variation of IOP in older people was the same as in the young and middle-aged population, i.e., the highest recording of IOP was in the morning, and it gradually reduced as the day passed.