Ocular Biometric Features of Eyes With Prior Pterygium

Purpose: Numerous studies have investigated external risk factors for the development of pterygium, such as ultraviolet light exposure. However, relatively little is known about any ocular features associated with pterygium development. This study investigated whether any ocular biometric features are associated with eyes with prior pterygium excision. Methods: This was a retrospective, case–control study. Cases were eyes with prior nasal pterygium excision, whereas controls were eyes without current or prior pterygium. All study eyes had biometry measurements using an ocular biometer, and each case was matched with three controls according to age, sex, and ethnicity. The following measurements were compared between the two groups: axial length, flat K value, steep K value, mean K value, and anterior chamber depth. Results: A total of 101 patients with previous pterygium and 303 control patients were included. There were no significant differences between the two groups in mean age, gender, and ethnic distribution. The mean axial length was 0.41 mm shorter in eyes with prior pterygium compared with controls (23.48 ±1.05 mm vs. 23.89 ±1.29 mm; P = 0.007). In the prior pterygium group, the mean steep K was 0.49 D higher (44.71 ± 1.87 vs. 44.22 ± 1.95; P = 0.016) and mean corneal astigmatism 0.54 D higher (1.58 ± 1.65 vs. 1.04 ± 0.93; P < 0.001) than the control group. There were no statistically significant differences in flat K, mean K, and anterior chamber depth between the two groups. Conclusions: Overall, eyes with prior pterygium had a shorter axial length, higher mean steep keratometry, and increased corneal astigmatism. Multiple mechanisms could account for an association of shorter axial length with pterygium.