Association between Myopia, Biometry and Occludable Angle: The Jiangning Eye Study

BACKGROUND: Myopia subjects usually have long axial lengths and are predisposed to deep anterior chamber depths and open angles. Jiangning eye study is a randomized, population based study in Shanghai to determine whether myopia has an effect on the prevalence of occludable angles. METHODS: A total of 2478 residents aged 50 years and over were randomly selected, and 2044 (82.5%) individuals of them participated in ophthalmic examinations between November 2012 and February 2013. Eye examinations included autorefraction, noncontact tonometry, measurement of axial length, anterior chamber depth, lens thickness and spectral domain optical coherence tomography. RESULTS: The crude prevalences of iris trabecular meshwork contact in Jiangning Chinese individuals with myopia, emmetropia, and hyperopia are 1.25%, 6.44%, and 7.43%, respectively. There is also iris trabecular meshwork contact and shallow anterior chamber depth in myopia subjects even with long axial lengths. CONCLUSIONS: The prevalence of iris trabecular meshwork contact in myopia subjects is lower than their emmetropia or hyperopia counterparts. Axial length is an important factor associate with occludable angle.