Prevalence of Glaucoma in Myopic Corneal Refractive Surgery Candidates in Hong Kong China

PURPOSE: To estimate the prevalence of glaucoma in myopic individuals in Hong Kong China seeking corneal refractive surgery and factors associated with the occurrence of glaucoma. METHODS: Six hundred twenty-nine eyes of 315 myopic individuals seeking corneal refractive surgery in a tertiary institution in Hong Kong China, were consecutively recruited. Glaucoma was defined by the presence of abnormal retinal nerve fiber layer (RNFL) and neuroretinal rim measurements obtained with spectral-domain optical coherence tomography, as well as narrowed neuroretinal rim and optic disc excavation observed in color optic disc stereophotographs. Factors associated with glaucoma were analyzed with univariable and multivariable mixed-effects logistic regression analysis. RESULTS: The mean age and spherical equivalent were 36.3 +/- 9.3 years (range: 21.5 to 60.1 years) and -6.59 +/- 2.34 diopters (D) (range: -2.25 to -17.13 D), respectively. Twenty-three eyes of 16 myopic individuals (5.1%; 95% confidence interval [CI]: 3.2% to 8.1%) had glaucoma, of which 10 eyes of 7 myopic individuals (2.2%; 95% CI: 1.1% to 4.5%) also had visual field defects by standard automated perimetry (5 had mild and 5 had moderate visual field loss). None of the myopic individuals were aware of the diagnosis at the time of examination. The inferotemporal sector of the optic disc was the most frequent location where RNFL thinning was found and the superonasal visual field was the most common region where visual field defects were located. The only biometric factor associated with glaucoma was intraocular pressure (odds ratio: 1.77; 95% CI: 1.14 to 2.75). CONCLUSIONS: Glaucoma was present in 5.1% of myopic individuals seeking corneal refractive surgery in Hong Kong China. Corneal refractive surgeons should be watchful in the diagnostic evaluation of glaucoma among myopic corneal refractive surgery candidates.