The goal of this observational study is to examine the anterior segment anatomical parameters associated with the scleral spur and cornea for risk profiling of primary angle-closure glaucoma (PACG). The main question it aims to answer is:

• Are there new anatomical parameters of the anterior segment of the eye that can be used early for risk profiling for PACG? Researchers will compare PACG and narrow angle groups to see if there are some anatomical parameters that can distinguish the two.

We aimed to examine the anterior segment anatomical parameters associated with the scleral spur and cornea for risk profiling of primary angle-closure glaucoma (PACG).

This retrospective study included 84 patients with PACG and 84 patients with narrow angles (NA). We collected parametric measurements obtained using anterior-segment optical coherence tomography and IOLMaster 700. Univariate and multivariate logistic regression models were used to compare the ocular parameters between the NA and PACG groups as well as to identify risk factors for PACG. The predictive performance of each parameter was evaluated using the area under the receiver operating characteristic curve (AUROC) analysis.

Inclusion Criteria:

1. Primary angle-closure glaucoma （PACG) was defined as an occlusion angle with peripheral anterior synechiae and intraocular pressure (IOP) > 21 mmHg or associated with glaucomatous optic neuropathy. The following conditions were identified as possible glaucomatous optic neuropathies, including a vertical cup-to-disc ratio ≥ 0.6, vertical cup-to-disc ratio asymmetry ≥ 0.2, optic disc haemorrhage, and visible retinal nerve fibre layer defect.
2. Participants with narrow angle (NA) were selected from among patients with cataracts. NA was defined as a trabecular-iris angle (TIA) < 15° on anterior segment optical coherence tomography, with the exclusion of glaucomatous optic neuropathy or visual field loss.

Exclusion Criteria:

(1) severe systemic disease, (2) secondary angle-closure glaucoma, (3) other ocular diseases, (4) history of intraocular surgery, and (5) unclear examination images.

Patients with PACG and anterior chamber angle stenosis were enrolled in this study and excluded from other diseases affecting the structure of the anterior segment of the eye, as well as a history of intraocular surgery.