Diagnosis of patients with the angle-closure disease (PACD) had relatively narrow-angle structures measured by swept-source optical coherence tomography (SS-OCT) at 250 μm from the with scleral spur (the very root of the iris) compared to normal subjects with similar shallow anterior chamber depth (ACD), especially along oblique and vertical axes. For a study, the researchers sought to compare ordinary people with PACD patients with similar ACD who had a shallow ACD on slit-lamp examination but did not match the diagnostic criteria for PACD. Patients were recruited from the Ophthalmic Center’s glaucoma clinic. A total of 40 eyes were examined, and CASIA SS-1000 OCT tests were performed on 40 eyes from 29 PACD patients and 40 eyes from 34 normal people. At 0 degrees of the scan, PACD and control eyes were 1:1 matched for ACD. The differences in intraocular pressure and SS-OCT parameters between the 2 groups were compared using a generalized linear model that took into account inter-eye correlation. The Bonferroni procedure was used to adjust P-values for multiple comparisons. The PACD and control groups were similar in age, but the PACD group had a greater intraocular pressure (18.4 vs 14.0 mm Hg, P=0.005). Angle recess area and trabecular iris space area measured at 250 μm along axes of 90, 135, 225, and 315 degrees were significantly smaller in the PACD group than in the control group (adjusted P<0.05). In contrast, most angle parameters at 500 and 750 μm, volume parameters, and anterior chamber parameters were similar (adjusted P>0.05). OCT outcomes evaluated at the iris root 250 μm from the scleral spur, especially in the oblique and vertical axes, including angle recess area and trabecular iris space area, may more closely match gonioscopic outcomes and provided further understanding into mechanisms of PACD in PACD patients compared with normal subjects with similar anterior chamber shallowing.
