Comparative study of factors associated with the progression of primary open-angle and angle-closure glaucoma

Abstract

To compare the factors associated with the progression of primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG). This prospective study analyses clinical data of POAG and PACG patients followed up for 6 years. The progression of glaucomatous optic neuropathy (GON) was determined using perimetry and spectral optical coherence tomography (OCT). The value of each diagnostic indicator (z-value) was calculated using the Wilcoxon-Mann-Whitney test and the area under the ROC-curve (AUC) to identify the parameters reliably associated with the progression in both groups of patients. According to OCT, 47.3% of PACG patients and 52.46% of POAG patients had GON progressing, while according to perimetry, these figures were 21.8% and 23%, respectively. The common factors associated with progression of these glaucoma forms were age (AUC 0.7, z -1.9 in PACG and AUC 0.7, z -2.9 in POAG) and maximum IOP (0.7; -2.7 in PACG and 0.79; -5.4 in POAG). The progression of PACG is associated with lens size (0.7; -2.4), subfoveal choroidal thickness (AUC 0.8, z -3.3) and peripapillary choroidal thickness (0.79; -3.2), resistive index in the vortex veins (0.81; -3.3) and their end diastolic blood flow velocity (0.83; 3.2). The progression of POAG is associated with a thin peripapillary (0.75; 2.6) and subfoveal choroid (0.74; 2.5), increased resistive index in the posterior short ciliary arteries (0.8; -2.3), and initial retinal nerve fiber layer (RNFL) thickness: 0.69; 2.9. The progression of POAG and PACG has only two common factors - age and maximum IOP. The progression of PACG is mainly related to the lens size, venous dysfunction and the choroid expansion, while the progression of POAG is related to the initial RNFL thickness, reduced arterial blood flow and choroid thinning.