This study was approved by the institutional review board of Asan Medical Center at the University of Ulsan, College of Medicine, Seoul, Korea. All procedures conformed to the Declaration of Helsinki. Medical records of open-angle glaucoma (OAG) patients were reviewed from March to August 2016 at the glaucoma clinic of Asan Medical Center and Central Seoul Eye Center, Seoul, Korea. All patients underwent a comprehensive ophthalmic examination, including medical history, best-corrected visual acuity (BCVA), Humphrey field analyzer Swedish Interactive Threshold Algorithm (SITA) 24-2 VF testing (Carl Zeiss Meditec, Dublin, CA, USA), stereoscopic optic disc photography, measurement of macular ganglion cell–inner plexiform layer (mGCIPL) thickness by Cirrus HD spectral-domain optical coherence tomography (SD-OCT; Carl Zeiss Meditec), and imaging with a commercial OCTA system (Cirrus HD-OCT Angioplex; Carl Zeiss Meditec). Reliable SITA VF assessment was defined as a VF test with a false-positive error <15%, a false-negative error <15%, and a fixation loss <20%. The second VF test was performed within 2 to 4 weeks after the first test to control for learning effects.
For inclusion in the study, patients had to meet the following criteria: (1) BCVA of 20/30 or better; (2) refractive error within +5 to −10 diopters (D) sphere and ±3 D cylinder; (3) typical glaucomatous ONH appearance regardless of IOP level, that is, focal or generalized narrowing or disappearance of the neuroretinal rim, disc hemorrhage, or cup-to-disc asymmetry >0.2 not explained by optic disc size; (4) open anterior chamber angles on slit-lamp biomicroscopy and gonioscopy in both eyes; and (5) glaucoma hemifield defects corresponding to ONH appearance. All VF findings were confirmed in two consecutive examinations and the second VF data were used in the final analysis. The definition of glaucoma hemifield defects
29 required all of the following: (1) three or more adjacent points with
P < 0.05 on a pattern deviation (PD) probability map, or two or more test points with
P < 0.02 or smaller on a PD probability map in a superior or inferior hemifield; (2) no three-point clusters with
P < 0.05 and no two-point clusters with
P < 0.02 on both the total deviation and PD probability maps of the opposite hemifield; and (3) a glaucoma hemifield test result outside normal limits. Patients were excluded if they had one or more of the following: severe myopic disc and fundus changes impairing adequate ONH/VF evaluation for glaucoma; myopic eyes with spherical equivalent (SE) of less than −10 D to prevent excessive ocular magnification effect; advanced VF loss (mean deviation [MD] ≤ −10 dB) for the purposes of evaluating eyes with early glaucomatous VF damage; intracranial lesion such as pituitary adenoma or craniopharyngioma that can affect VF testing; a history of massive hemorrhage or hemodynamic crisis; a history of other ophthalmic disease that could result in ONH/VF defects; and/or a history of diabetes mellitus or retinal vaso-occlusive diseases, such as RVO or prior eye surgery/laser treatment. One eye per patient was included and if both eyes were eligible, one eye was selected randomly.