Herman Christiaan Izaak Themen , Dennis Ricardo August Mans , Robert Bipat , Denise Judith Doelwijt , Dineshpersad Jiawan , Annemarie Thelma Bueno de Mesquita-Voigt
Background: Loss of elastic properties, the introduction of tractional forces, and shortening of the plica-limbal distanceÂ (the distance between the nasal limbus and the semilunar plica bottom in full abduction) are common anatomical abnormalities in eyes of patients with primary medial pterygium. In this study, we assessed whether, and to which degreeÂ the latter phenomenon correlated with the presence of pterygium.
Methods and findings: Plica-limbal distance was measured using a slit lamp in individuals who came for routine eyeÂ examination, and was related to pterygium size, as well as to patientsâ€™ gender and age. Data were expressed as meansÂ (95% CI). Eighty-three males and 118 females were enrolled in the study. There were 49 eyes from patients with unilateral pterygium, 84 from patients with bilateral pterygium, and 220 from individuals who did not suffer from eitherÂ uni- or bilateral pterygium. The mean plica-limbal distance in eyes with pterygium (7.3 mm, 95% CI: 6.9 â€“ 7.7 mm) wasÂ significantly shorter than that in eyes without pterygium (9.9 mm, 95% CI: 9.7 â€“ 10.1 mm). Plica-limbal distance correlated inversely with pterygium size (r2 = 0.32, p < 0.0001), was not related to gender, but decreased with increasing ageÂ in both individuals with and without pterygium.
Conclusion: Our results suggest that plica-limbal distance correlated inversely with the presence of pterygium. ThisÂ finding may have important consequences for the identification of individuals at risk, as well as for improvement of theÂ treatment of this condition.