ABSTRACT
<p><b>BACKGROUND</b>Gender is one of the risk factors accounting for the high prevalence of adolescent myopia. Considerable research results have shown that myopia incidence of female is higher than that of male. This study aimed to analyze the correlation between ocular parameters and serum estrogen level and to investigate the vision changes along with estrogen change in menstrual cycle of adolescent females.</p><p><b>METHODS</b>A total of 120 young females aged between 15 and 16 years, diagnosed with myopia were recruited. Spherical lens, cylindrical lens, axis, interpupillary distance (IPD), and vision in each tested eye of the same subject were measured by automatic optometry and comprehensive optometry, with repetition of all measurements in the menstrual cycle of the 2 nd or 3 rd days, 14 th days, and 28 th days, respectively. Serum estradiol (E 2 ) levels were assayed by chemiluminescence immunoassay at the same three times points of the menstrual cycle mentioned above.</p><p><b>RESULTS</b>In young females with myopia, the spherical lens showed a statistically significant difference among all different time in menstrual cycle (all P < 0.0001). The cylindrical lens, axis, and IPD were changed significantly during the menstrual cycle (P < 0.05). The vision of the three different time points in menstrual cycle had a significant difference (χ2 = 6.35, P = 0.042). The vision during the 14 th and 28 th day was higher compared to that on the 2 nd or 3 rd days (P = 0.021). Serum E 2 levels were significantly different at different time points in menstrual cycle (P < 0.05). E 2 levels reached its maximum value on the 14 th day and the minimum value on the 2 nd or 3 rd day.</p><p><b>CONCLUSIONS</b>In adolescent females, the spherical lens and other related ocular parameters vary sensitively with different levels of E 2 in menstrual cycle. Vision in late menstrual stage is significantly higher than that in premenstrual stage.</p>