Objective: To investigate the effect of intraocular pressure (IOP) on myopia progression in adolescents.Methods: This was a prospective study of 112 myopia subjects (ages 6-18 years old) in Changsha Aier Hospital from July 2014 to December 2015. Depending on the mean IOP at baseline, the subjects were categorized into three groups: High IOP (IOPH, 21 mmHg < mean IOP < 30 mmHg), moderate IOP (IOPM,15 mmHg < mean IOP ≤ 21 mmHg), and low IOP (IOPL, 10 mmHg < mean IOP ≤ 15 mmHg). Regular follow-ups were at 6, 12, and 18 months after baseline. Twenty-four hour IOP, spherical equivalent (SE),axial length (AL), and central corneal thickness were measured at each follow-up visit. Repeated measures analysis of variance and logistic regression analysis were performed to estimate the factors influencing
SE and AL. Results: At last, 103 cases finish the follow-up. The rates of SE progression for each group were determined for the 18-month follow-up period. For the IOPH group, IOPM group, IOPL group, the SE progression rate was -0.87±0.90 diopter (D)/year, -0.59 ± 0.89 D/year, -0.33 ± 0.32 D/year respectively,the rate of change in SE over the study period was significant (F=5.848, P=0.017). The rates of AL change for each group were also determined. For the IOPH group, IOPM group, IOPL group, the rate was 0.40 ± 0.29 mm/year, 0.18 ± 0.31 mm/year, 0.17 ± 0.30 mm/year respectively , the rate of change in AL over the study period was significant (F=5.265, P=0.007). Eyes with higher mean IOPs were likely to have SE progression (OR=0.454, 95%CI=0.317-0.716, P=0.007). Younger subjects were likely to have greater AL
elongation than older subjects (OR=1.433, 95%CI=0.994-1.506, P=0.015). Conclusions: Adolescents with higher mean IOPs are associated with the SE changes that are consistent with the changes in AL elongation.These findings suggest that IOP plays a major role in myopia progression in adolescents.