Abstract
Purpose :
Cellular level assessment of the cornea using corneal confocal microscopy (CCM) is used widely in ophthalmic research; what affects these measures in health is not well understood. The effect of menstrual cycle, lifestyle factors and dry eye (DE) sign and symptoms on CCM measures in young healthy women was determined.
Methods :
In a prospective observational study, 30 young healthy women with regular, 24 to 32-day menstrual cycles were recruited and attended 3 visits on day 7, 14, 21 ± 1 of their cycle. At baseline, general health and pain sensitivity questionnaires were completed. At each visit, lifestyle questionnaire, DE signs (ocular surface assessment, tear break-up time (TBUT), and phenol red thread (PRT)) and symptoms (Ocular Surface Disease Index) as well as CCM (corneal nerve fibre length (CNFL), fibre density (CNFD), branch density (CNBD), Langerhans cell density (LCD) and epithelial cell density (ECD)) of the central cornea were assessed. Changes in CCM measures over the 3 phases were determined, as well as correlations between CCM measures and DE and lifestyle measures at each phase.
Results :
A total of 26 participants (mean age 22.3±3.7yrs) with an average menstrual cycle of 28±1 days completed 3 visits. Some CCM measures changed over the menstrual cycle; ECD was lower at day 7 than day 14 (5421±635 vs 5673±596 cells/mm2, p<0.05); CNFL was lower at day 14 than day 21 (28±3 vs 30±3mm/mm2, p<0.05). At all visits, ECD correlated with pain sensitivity (r=-0.58, p<0.05). At the follicular phase (day 7), LCD correlated with cosmetics use (r=-0.51, p<0.05). At the ovulation phase (day 14), ECD correlated with exercise intensity (r=-0.51, p<0.05). At the luteal phase (day 21) there were associations between; CNFD and the lifestyle questionnaire (r=-0.41, p<0.05) and TBUT (r=0.43, p<0.05); CNFL and CNFD with poor sleep quality (both r=-0.47, p<0.05); LCD with PRT (r=0.44, p<0.05), and; ECD with corneal staining (r=-0.43, p<0.05). There were no correlations between DE symptoms and CCM measures.
Conclusions :
Menstrual cycle, lifestyle factors and DE signs affect corneal nerves, and epithelial and Langerhans cells in young, healthy women, although the absolute effect on cell densities was modest. The associations between lifestyle factors and DE signs and CCM measures were more pronounced during the luteal phase of the menstrual cycle.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.