Patients with clinically confirmed primary open angle glaucoma (POAG) were included in this study and met the following criteria: (1) untreated IOP of ≥21 mm Hg with typical glaucomatous visual field defects and GON. Visual field defects were defined as a glaucomatous hemifield VF defect in the superior or inferior hemifield according to the Anderson-Patellar criteria,
24 which was confirmed by at least two reliable visual field examinations. GON was defined as a vertical cup-to-disc ratio ≥0.7 (unless explained by a large optic disc), or a cup-to-disc ratio asymmetry >0.2, neuroretinal rim thinning, and RNFL defect; (2) open angle confirmed by gonioscopy; (3) best corrected visual acuity ≥20/30; (4) refractive error (spherical equivalent) >+2.0 diopters (D) or <−6.0 D; (5) axial length <26 mm; (6) could follow up every three months for a period of at least 2 years; and (7) IOP is stable within the range of 10–21 mm-Hg under treatment with IOP-lowering eye drops.
Exclusion criteria were: (1) history of primary angle closure glaucoma, secondary glaucoma (e.g., exfoliative or pigmentary glaucoma), or congenital glaucoma; (2) history of intraocular surgery or laser treatment; (3) other ocular diseases, such as trauma, keratitis, uveitis, cataract, age-related degeneration, diabetic retinopathy, retinal vein occlusion, the retinal anterior membrane, macular edema, etc.; (4) history of cerebrovascular events (e.g., Parkinson's disease, Alzheimer's disease, dementia or history of stroke, etc.) or history of other cardiovascular diseases, diabetes mellitus, hypertension, or with systematic measurements that may influence the final microscopic measurement, such as chloroquine/hydroxychloroquine, glucocorticoid, chlorpromazine, thiolidazine, tamoxifen, canthaxanthin, sildenafil, and niacin; and (5) inability to cooperate with all ophthalmic examinations or poor image quality. Only the right eye of the individuals was included in the study.