Abstract: Objective To observe the differences of anterior segment biometry parameters between primary angle closure glaucoma(PACG) and primary angle closure glaucoma suspects(PACS). Design Retrospective comparative case series. Participants 58 patients with PACG/PACS who were diagnosed from October, 2019 to Mrach, 2021 at Wuhan Tongji Hospital. Methods Medical records of all patients were reviewed including ultrasound biomicroscopy (UBM). Qualitative and quantitative comparison of biometry parameters between PACG/PACS groups were conducted. Main Outcome Measures  anterior chamber depth (ACD), angle opening distance 500(AOD500), trabecular-iris angle 500(TIA500), trabecular-ciliary process distance 500(TCPD500), trabecular-ciliary process angle(TCA), iris thickness 500 (IT500）, ciliary process length(CPL), ciliary body thickness(CBT). Result Compared with PACS group (n=25), PACG group (n=33) had lower best corrected visual acuity (BCVA) (0.4±0.35, 0.2±0.17), higher baseline intraocular pressure (21.17±6.09, 15.57±3.57 mmHg), shorter ocular axis (22.17±1.22, 22.74±0.88 mm), shallower ACD (1.77±0.27, 1.94±0.25 mm), and AOD500, TIA500, TCPD500 TCA500 is smaller (0.04±0.04, 0.10±0.05 mm; 3.90±4.58, 11.07±4.77 °; 0.51 ± 0.10, 0.58±0.10 mm; 60.55±13.26, 71.54±12.58 °, respectively) and CPL is longer (1.43±0.26, 1.28±0.15 mm). The proportion of iris insertion point at the base of ciliary body (54.5%, 20.0%) and ciliary body pronation (68.0%, 39.4%) in PACG group was greater than that in PACS group (all P<0.05). There was no statistically significant difference in IT500, CBT and proportion of iris angulation and iris convexity between PACG group and PACS group. Conclusion Smaller AL, shallower anterior chamber depth, more significant the anterior rotation and size of the ciliary body, and larger proportion of the basal iris insertion in PACG group than in PACS group were observed, whether these features be risk factors of PACG progression, remains to be determined by long term follow-up observation. (Ophthalmol CHN, 2022, 31: 20-26)

Key words: primary angle closure glaucoma, primary angle closure suspects, ultrasound biomicroscopy