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

Abstract

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 μm (median = 521; range = 304–665). Decreased CCT was significantly associated with age and pterygium severity. Individuals aged 65–74 years had CCT 7 μm thinner than those aged 45–54 years ( p = 0.044), individuals aged 75 years and older had CCT 15 μm thinner than those aged 45–54 years ( p = 0.001), and eyes with severe pterygium had CCT 33 μm 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.