This cross-sectional study enrolled 29 consecutive POAG and 37 PACD patients at the glaucoma department of Zhongshan Ophthalmic Center between January 2016 and January 2017. Thirty-four healthy volunteers with no current or previous ophthalmic diseases were also enrolled in this study. All included eyes of healthy volunteers had a best-corrected visual acuity (BCVA) of 6/9 or better, IOP of <21 mm Hg, and a refractive error between −5 and +5 diopters (D) (spherical equivalent, SE). All healthy volunteers had normal visual field (VF) in both eyes. This study was approved by the Ethical Review Committee of Zhongshan Ophthalmic Center and adhered to the tenets of the Declaration of Helsinki. All subjects received comprehensive ocular examinations that included a review of their medical history, BCVA, a slit-lamp examination, and a stereoscopic optic disc examination with a 90-diopter lens. IOP was measured using a noncontact tonometer (NCT; Canon TX-20 Full Auto Tonometer; Canon, Tokyo, Japan). The axial length (AL) was measured using partial optical coherence interferometry (IOL-Master; Carl Zeiss Meditec, La Jolla, CA, USA). A refractive error examination was performed using an auto refractometer (KR-8900 version 1.07; Topcon Corporation, Tokyo, Japan). POAG or PACD was diagnosed in open-angle or angle-closure eyes (by gonioscopy) with characteristic glaucomatous optic neuropathy, diffuse or focal optic rim thinning, cupping, nerve fiber layer defects, and corresponding VF defects, and the diagnoses were based on criteria proposed by Foster et al.
6 The definitions for each subgroup of PACD in the study were as follows. (1) PACS was defined as an eye in which appositional contact between peripheral iris and pigmented trabecular meshwork is greater than or equal to 180° under static gonioscopy; (2) PAC was defined as an eye with adhesive angles (defined as the pigmented trabecular meshwork not seen for at least 180° on indentation gonioscopy in primary position), with peripheral anterior synechiae, elevated IOP, but without glaucomatous optic neuropathy or VF defect; (3) PACG was defined as an eye with PAC together with evidence of glaucomatous optic neuropathy (defined as a vertical cup-to-disc ratio [CDR] > 0.7 and/or CDR asymmetry > 0.2, with glaucoma hemifield test outside normal limits, and with an abnormal pattern standard deviation with
P < 0.05 in the healthy population). POAG was defined as the presence of a normal open angle on gonioscopy and UBM, increased IOP (usually > 21 mm Hg at the clinics), and glaucomatous optic nerve damage with corresponding typical VF defect, as confirmed by at least two reproducible VF tests. Subjects were excluded if they (1) had other ocular diseases (e.g., conjunctivitis, corneal diseases, fundus diseases; or (2) had had previous ocular surgery (e.g., iridectomy/iridotomy, trabeculectomy, cataract surgery).