Impact of pterygium on central corneal thickness measured by optical coherence tomography in older adults

Purpose To measure the central corneal thickness (CCT) using anterior segment optical coherence tomography (AS-OCT) in older adults with and without pterygium from the Brazilian Amazon Region Eye Survey (BARES). Methods BARES is a population-based epidemiological cross-sectional study conducted in Parintins city. Participants were residents >= 45 years of age identified through a door-to-door interview. Eligible participants were invited for a comprehensive eye exam. Pterygium occurrence and severity were assessed by ophthalmologists through slit-lamp examination considering its location (nasal or/and temporal) and severity (lesion with extension <3 mm, >= 3 mm not reaching the pupillary margin or >= 3 mm reaching the pupillary margin). CCTs were obtained and measurements from the more severely affected eye were included. Images were analyzed offline by masked observers. Results A total of 671 subjects, 533 (79.4%) with pterygium in at least one eye and 138 (20.6%) without pterygium in either eye, were examined. The mean CCT evaluated by multiple linear regression and adjusted for demographic variables and pterygium severity was 521 +/- 34 mu m (median = 521; range = 304-665). Decreased CCT was significantly associated with age and pterygium severity. Individuals aged 65-74 years had CCT 7 mu m thinner than those aged 45-54 years (p = 0.044), individuals aged 75 years and older had CCT 15 mu m thinner than those aged 45-54 years (p = 0.001), and eyes with severe pterygium had CCT 33 mu m thinner than eyes without pterygium (p < 0.001). Conclusions The CCT analysis in this population-based sample shows that a thinner cornea is associated with pterygium severity and older age.