A prospective comparison of chronic primary angle-closure glaucoma versus primary open-angle glaucoma in Singapore

Abstract

the optic disc, visual field and ocular characteristics (such as intraocular pressure [IOP] at presentation, best-corrected visual acuity, sphere equivalent, mean keratometry, axial length, lens thickness, corneal thickness and lens opacity) of a consecutive cohort of Asian patients with CPACG, and to compare them with a similarly enrolled sample of patients with POAG. METHODSThis was a prospective comparative study of new patients with POAG or CPACG, who presented to the National University Health System, a tertiary eye care centre in Singapore, from January 2002 to June 2009. These were newly diagnosed patients, with no previous treatment or laser therapy done. The patients, who presented with unrelated eye conditions, were found to have clinical signs suggestive of glaucoma. They were referred from general ophthalmology clinics and community screening programmes for diabetes mellitus and glaucoma, as they were found to have suspicious discs or raised IOP. Ethics approval was obtained from the institutional review board and the study was conducted in accordance with the Declaration of Helsinki.Written informed consent was obtained from all study participants prior to enrolment in the study. RESULTS 98 patients were enrolled (POAG n = 48; CPACG n = 50). CPACG patients were significantly older (66.5 ± 9.2 years vs. 64.1 ± 13.5 years; p = 0.027) and mostly female (p = 0.004). CPACG eyes had significantly higher intraocular pressure (26.9 ± 6.9 mmHg vs. 24.5 ± 3.3 mmHg; p = 0.03), shorter axial length (22.89 ± 0.97 mm vs. 24.26 ± 1.79 mm; p < 0.001) and shallower anterior chamber depth (2.60 ± 0.25 mm vs. 3.16 ± 0.48 mm; p < 0.001). HVF mean deviation or pattern standard deviation (PSD) did not differ significantly between POAG and CPACG eyes, but the latter had a lower PSD for a given mean deviation. HRT parameters between the two groups were not significantly different. CONCLUSIONIn this study, CPACG eyes had significantly higher presenting intraocular pressure than POAG eyes, but there were no significant differences in optic disc topography. A majority of the patients in both groups had moderate field defects at the time of presentation, followed by severe and then mild defects. The field loss in CPACG eyes was more diffuse than that in POAG eyes.

Objective Assessment of Progression after Acute Primary Angle Closure Using HRT and GDx

“…This result is in contrast with several studies on APAC patients where a reduction in the neuroretinal rim area was recorded [11,12]. For example, Shen SY et al have suggested a decrease in rim area 16 weeks after APAC in a predominantly Chinese population [11], accompanied by a reduction in disc area (10%).…”

“…In this study, however, the ONH assessment was performed using optic disc photography. Similarly, Chai et al, in a case report, documented a reduction in rim area in a 64-year-old man one year after a single episode of APAC (2.15 mm 2 at 1 week, and 2.08 mm 2 at 1 year) [12,13]. The discrepancy with the literature could be due to the use of different imaging techniques for ONH assessment and on different study populations.…”

Clinical Correlates of Computationally Derived Visual Field Defect Archetypes in Patients from a Glaucoma Clinic

“…The few existing studies characterizing VF defect patterns associated with CACG suggest more generalized VF loss and less paracentral VF involvement in CACG than in POAG, as well as increased susceptibility to superior than inferior VF loss. [91][92][93][94][95] There may be particular need for better future characterization of patterns of CACG presentation in racially heterogeneous populations, as most previous research characterizing CACG-related VF defect patterns has focused on Asian patient populations, in whom CACG is known to be highest in prevalence.…”

Rates of Visual Field Loss in Primary Open-Angle Glaucoma and Primary Angle-Closure Glaucoma: Asymmetric Patterns

“…25,26 Previous studies have reported that POAG and PACG have different patterns in visual field (VF) damage. [27][28][29][30][31] The VF damage is more pronounced in the superior hemifield than in the inferior hemifield in both POAG and PACG groups [32][33][34][35] ; however, this tendency is more obvious in POAG eyes. [27][28][29][30] Without doubt, the assessment of the rate of VF loss is very important in the management of glaucoma.Nonetheless, most of the previous studies have investigated the cross-sectional spatial patterns of VF loss.…”