Central corneal thickness and its association with ocular and general parameters in indians. Central India Eye and Medical Study

Purpose To evaluate the distribution of central corneal thickness and its associations in the adult Indian population Methods The Central India Eye and Medical Study is a population‐based study performed in a rural region close to Nagpur in Central India and included 4711 subjects (aged 30+ years) out of 5885 eligible subjects. This study was focused on central corneal thickness (CCT) as measured by sonography and it associations. Intraocular pressure was measured by applanation tonometry. Results CCT measurement data were available for 9370 (99.4%) eyes. Mean CCT was 514±33 mm (median:517 mm; range: 290‐696 mm). In multiple regression analysis, CCT was significantly associated with male gender (P<0.001), higher body mass index (P=0.028), lower age (P<0.001), lower corneal refractive power (P<0.001), and higher anterior chamber depth (P=0.025). CCT was not significantly associated with axial length (P=0.39), lens thickness (P=0.65), refractive error (P=0.12) and cylindrical refractive error (P=0.75). Intraocular pressure readings increased significantly (P<0.001) with higher CCT and higher corneal refractive power Conclusion Indians from rural Central India have markedly thinner corneas than Caucasians or Chinese. As in other populations, CCT is higher in males. It decreased with higher age and lower body mass index. Intraocular pressure readings were falsely high in eyes with thick corneas and steep corneas. Besides corneal thickness, the anterior corneal curvature has to be taken into account in applanation tonometry. It may hold true particularly after corneal refractive surgery.