Abstract
Purpose: :
Approximately half of contact lens (CL) wearers report dry eye symptoms. As a possible cause of CL-related dry eye, meibomian gland dysfunction has been recognized. We have developed an innovative infrared non-contact meibography, which make possible a quick and thorough examination of the meibomian gland structure. The purpose of this study is to investigate the meibomian gland changes in CL wearers using this meibography.
Methods: :
We observed 121 eyes of 121 CL wearers whose mean ± SD of age were 31.8 ± 8.0 (47 males and 74 females), and 137 eyes of 137 age-matched non-CL-wearers as a control. In 121 CL wearers, 39 were using gas permeable lenses, 82 were using hydrogel lenses. After a clinical questionnaire, following tests were performed: manifest refraction, a slit-lamp examination of eyelids, corneal and conjunctival staining by fluorescein, measurement of tear film breakup time (BUT), tear production by Schirmer I test, and grading of meibomian glands using a non-contact meibography. The partial or complete loss of meibomian glands were scored using subsequent grades (meibo-score) in each eyelid: grade 0 (no loss of meibomian glands), grade 1 (the lost area was less than 1/3 of total area of meibomian glands), grade 2 (the lost area was between 1/3 and 2/3 of total area of meibomian glands), grade 3 (the lost area was over 2/3 of total area of meibomian glands). The meibo-score in upper and lower eyelids were summed for each subject. This study was adhered to the tenets of the Declaration of Helsinki and the informed consent was obtained from all subjects before examinations.
Results: :
In CL wearers, the period of CL wear was 12.3 ± 7.2 years and the spherical equivalent was -5.1 ± 2.7 diopters. BUT was significantly shorter (P<0.0001) in CL wearers (4.8 ± 2.6 seconds) than in the control (6.7 ± 3.7 seconds). The Schirmer value in CL wearers and control group was 20.4 ± 10.1 mm and 20.2 ± 11.2 mm, respectively (p=0.96). The meibo-score was significantly higher (P<0.0001) in CL wearers (mean 1.71; 95% confidence interval 1.48-1.96) than in the control (mean 0.96; 95% confidence interval 0.72-1.20). The average meibo-score of CL wearers was similar to that of 60 to 69-year age group in the normal population. A significant positive correlation was recognized between the length of CL wear and meibo-score (P = 0.0032, R=0.27).
Conclusions: :
CL wearers have significantly higher meibomian gland loss than age-matched non-CL-wearers.
Keywords: cornea: clinical science • cornea: tears/tear film/dry eye • contact lens