Abstract
Purpose: :
We previously reported that meibomian gland physiology changes during the menstrual cycle (ARVO, 2007). In this study, we assessed the meibomian gland physiology in both females and males, then evaluated them in regards to sex-related differences as well as the influence of serum sex steroid hormones.
Methods: :
Six female subjects in their twenties with a regular 28-day menstrual cycle and 6 male subjects from the corresponding age group were recruited for this study, with informed consent being obtained from all subjects prior to enrollment. The volume of meibum by meibometry, fluorescein tear-film breakup time (F-BUT), the diameter of the meibomian gland orifice (MGO) using slit-lamp photography with high magnification, meibomian gland morphology by meibography, and the serum concentration of sex steroid hormones were evaluated every 3-5 days for 5 consecutive weeks.
Results: :
In females, cyclical changes were seen in F-BUT, the volume of meibum, MGO diameter, and meibomian gland morphology during the menstrual cycle. The maximum F-BUT, volume of meibum, and MGO diameter were observed in the first half of the menstrual cycle (average ± S.E.: 6.8 ± 0.9 sec, 0.073 ± 0.014 ODU, 0.174 ± 0.002 mm, respectively). In males, the average F-BUT, volume of meibum and MGO size were 8.6 ± 0.2 sec, 0.117 ± 0.005 ODU, and 0.187 ± 0.002 mm, respectively. In females, the MGO diameter was negatively correlated with the serum concentration of estradiol and progesterone (p<0.005). The volume of meibum and F-BUT in both female and male subjects were positively correlated with the serum concentration of testosterone (p<0.05).
Conclusions: :
Significant sex-related differences were seen in the meibomian gland physiology. Serum levels of sex steroid hormones play an influence on meibomian gland physiology and may exert an impact on evaporative dry eye.
Keywords: cornea: tears/tear film/dry eye • cornea: clinical science