Abstract
Purpose: :
Our aim was to access the changes in corneal biomechanics during various phases of the menstrual cycle (MC) in glaucomatous and age matched healthy eyes.
Methods: :
In this prospective study the corneal parameters of 15 female glaucoma patients (43 ± 5.5 years) of reproductive age were measured by Ocular Response Analyzer (Reichert Ophthalmic instruments, NY, USA) and compared with these of age matched healthy women. The corneal hysteresis (CH) and corneal resistance factor (CRF) were measured at 3 time points in their menstrual cycle, day 1 to 3, at ovulation (approximately day 15) and at day 25 to 28. Ovulation was determined with a test that records the peak of luteinizing hormone in the urine. In addition, corneal thickness (CCT) and intraocular pressure (IOP) were determined.
Results: :
CH in the glaucoma patients was lowest at the beginning of the cycle (mean = 10.0 mmHg), increased statistically significantly at ovulation (mean = 10.7 mmHg, P= 0.033) but not at the end of the cycle (mean = 10.5 mmHg, P=0.45). CRF (11.4 mmHg) stayed at the same level during MC (P=0.101). In comparison of the both groups glaucoma showed a significant lower CH (10.07 mmHg vs. 11.367 mmHg; P=0.024) at the beginning of the cycle. There were no statistically significant differences between the groups in CRF (P=0.55). In addition, CCT and IOPg showed no statistically significant changes. IOPcc changed significantly from 17.3 mmHg to 16.4 mmHg to 16.9 mmHg in the glaucoma group, respectively. There were no differences between the groups. The difference in IOPcc was statistically significant at ovulation (P=0.024) in comparison with the baseline.
Conclusions: :
During the menstrual cycle corneal parameters change in healthy and also in glaucoma. CH but not CRF decrease at the middle of the menstrual cycle. The physiological estrogen level is in this period of MC at the top. Therefore, these results could be secondary to hormonal influences suggesting that reduced estrogen may play a role in glaucoma pathogenesis.
Keywords: cornea: clinical science • clinical (human) or epidemiologic studies: systems/equipment/techniques • clinical (human) or epidemiologic studies: risk factor assessment