Association of blepharoptosis with refractive error in the Korean general population

Abstract

Background/objectives: We investigated the effect of blepharoptosis on refractive errors across different age groups in Korean population.

Subjects/methods: This cross-sectional study was performed with data obtained in the Korea National Health and Nutrition Examination Survey (KNHANES) from 2008 to 2012. A total of 33,103 participants were enroled in our study. Blepharoptosis was defined as a marginal reflex distance 1 (MRD1) less than 2 mm, and was diagnosed in 3,305 (9.98%) participants. Ophthalmic examinations were performed, including measurements of MRD1, spherical equivalent, and degree of astigmatism. The age range was divided into three groups: less than 20 years old; more than 20 years and less than 60 years old; and more than 60 years old.

Results: The mean spherical equivalent were -0.28 ± 2.23 D in the ptotic eyelids and -1.13 ± 2.30 D in the non-ptotic eyelids (p < 0.001, 95% CI: -0.93, -0.77). The mean cylinder dioptre were -1.03 ± 0.87 D and -0.80 ± 0.77 D respectively (p < 0.001, 95% CI: 0.20, 0.26). The association with the eyelid position and refractive error significantly differed according to the age group and body mass index. Increased positive spherical change and increased astigmatism were prominent among ptotic participants aged less than 60 years.

Conclusions: A decrease in MRD1 was associated with a hyperopic shift and higher astigmatism. Mechanical compression of the ptotic eyelid may affect ocular biometry, with the effect being particularly prominent in younger participants who had greater eyelid tension.