Associated factors of acute primary angle closure glaucoma in a sub-group of Chinese people: comparison between attack eyes and normal controls

Abstract

Acute primary angle closure glaucoma (APACG) is an ophthalmic emergency that may lead to irreversible blindness. Although efforts were made to control intraocular pressure, disease progression still existed. Anterior segment optical coherence tomography (AS OCT) may provide a new insight into mechanism of APACG. In order to seek out associated factors by AS OCT, We compared anterior segment parameters between 74 APACG and 48 normal eyes. Analysis of variance, principle component analysis and logistic regression were used. APACG group had more women (75.7% vs 47.9%, p = 0.002), smaller anterior chamber (anterior chamber depth, ACD; anterior chamber area, ACA; all p = 0.001), narrower angle (AOD500, AOD750, angle opening distance at 500um and 750um; TISA500, TISA750, trabecular-iris space area at 500um and 750um; ARA500, ARA750, angle recess area at 500um and 750um; all p < 0.001), thinner iris (iris thickness at 750um, IT750; maximum of iris thickness, ITMAX; all p < 0.001), larger iris area (IA, p < 0.001) and lens vault (LV, p = 0.005). Principle component extracted were AOD500, AOD750, TISA500, TISA750, ARA500, ARA750, IA, PD (pupillary diameter), ACD, ACA and IT750. After adjusting for confounding factors, AOD750 (b = 12.40 ± 2.56, p < 0.001), IT750 (b = 10.50 ± 3.45, p = 0.002) and IA (b = −1.56 ± 0.77, p = 0.044) were significantly associated with occurrence of APACG.

The Iris Thickness in a Healthy Saudi Population

“…We found that the iris is thicker at IT750 compared to IT500 in different settings. This observation concurs with Liu et al findings that report better correlations at 750 µm than 500 µm in ACG cases [ 9 ]. Nongpiur et al also used the 750 µm location in their study and so did Huang et al while evaluating normal individuals [ 1 , 4 ].…”

“…It has been suggested that orbital and ocular parameters could vary with ethnicity [ 7 ]. Therefore, ASOCT measurements of normal anterior segment structures in different populations would be useful in understanding the pathophysiology of diseases such as glaucoma and help us in improving clinical detection of disease or identifying risk factors [ 1 , 8 , 9 ].…”

Morphologic Features of Crystalline Lens in Patients with Primary Angle Closure Disease Observed by CASIA 2 Optical Coherence Tomography

“…Previous studies of lens biometric parameters in PACD produced inconsistent results. There were studies that found that the PACD eyes had a greater iris–lens contact distance by ultrasound biomicroscopy, 22 a more anterior lens position (LP; defined as ACD + 1/2LT) by A-mode applanation ultrasonography, 23 and a greater LV by AS-OCT 24 compared with normal eyes. There was also one study that they did not find any difference of lens position when comparing angle closure eyes with those open angle eyes.…”

Modeling of gonioscopic anterior chamber angle grades based on anterior segment optical coherence tomography

“…The global parameters characterize the morphology of anterior segment as a whole, including anterior chamber width [16], anterior chamber area [17], volume [17], and lens vault [18]. The peripheral parameters characterize the morphology on the ACA especially, including the angle opening distance (AOD) and the trabecular-iris space area (TISA) [19,20]. The AOD is defined as the perpendicular distance between the trabecular meshwork and the iris at 750 μm anterior to scleral spur, which is designated as "AOD750" (Fig.…”