Purpose:
There has been conflicting evidence about the efficacy of HRT in the treatment of dry eyes in the medical literature. The aim of this meta-analysis was to determine if HRT is an effective treatment option for DES in postmenopausal women.
Methods:
Searches of PubMed and Embase up to November 2011 yielded 26 clinical trials. Non-English publications (n=4), uncontrolled studies (n=10), case-control studies that used hormones other than a combination of estradiol and medroxyprogesterone acetate (n=4) and studies with insufficient data on the event rate of dry eyes (n=3) were excluded. The remaining 5 case-control studies were included in the meta-analysis. Random effects model with unequal variances was used to average pooled estimates of relative risk (RR) and corresponding 95% confidence intervals (CI). Heterogeneity of the study sample was calculated using Chi² test. Statistical analyses were performed by using RevMan 5 software provided by the Cochrane Collaboration.
Results:
The combined study population of the 5 studies included in the meta-analysis was 268. The average duration of postmenopausal life in this sample population was 9.7±8.6 years. 117 postmenopausal women (mean age=57.5±6.6 years) received HRT at doses of at least 50 mg/day of 17 beta-estradiol and 2.5 mg/day of medroxyprogesterone acetate, for an average of 18 months; while 151 in the control group (mean age=57.3±8.1 years) did not receive any treatment for DES. 47 patients in the HRT group vs. 38 women in the control group had new onset or worsening dry eye symptoms. Quantitative measurement of dry eyes in these studies were performed using either one or a combination of tests such as Schirmer’s test, tear film break up time, corneal thickness, visual analog scale and intra-ocular pressure. HRT was associated with improvement of dry eyes symptoms in postmenopausal women (RR=0.94; 95%CI=0.25 to 3.54) (Chi²=26.47; I²=85%). However, this finding was not statistically significant (Z=0.10; p=0.92).
Conclusions:
HRT (17 beta-estradiol and medroxyprogesterone acetate at a minimum dose of 50 mg/day and 2.5 mg/day respectively) over an average of 18 months does not appear to be an effective treatment modality for DES in postmenopausal women.
Keywords: cornea: tears/tear film/dry eye • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • aging