ABSTRACT
Objective:To investigate the association of ocular dominance with the severity of chronic primary angle-closure glaucoma (PACG).Methods:Ocular dominance was assessed via the " hole in card" method.The anatomical symmetry (including anterior chamber depth, lens thickness and axial length) in both eyes was analyzed via A scan ultrasound.The severely glaucomatous eye was determined by the mean defect of visual field.The association of ocular dominance with the severity of chronic PACG was then analyzed.This study followed the Declaration of Helsinki, and the study protocol was approved by the Ethics Committee of Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong.Written informed consent was obtained from all subjects prior to their entering the study cohort.Results:Visual acuity (LogMAR) was 0.39±0.24 in the dominant eye group, and 0.43±0.29 in the non-dominant eye group.Anterior chamber depth was (2.53±0.26)mm in the dominant eye group, and (2.54±0.29)mm in the non-dominant eye group.Lens thickness was (4.96±0.31)mm in the dominant eye group, and (4.92±0.33)mm in the non-dominant eye group.Axial length was (22.58±0.61)mm in the dominant eye group, and (22.73±1.11)mm in the non-dominant eye group.No significant difference was found in visual acuity, anterior chamber depth, lens thickness or axial length between the dominant and non-dominant eye groups ( t=-1.643, -0.797, 1.867, -1.345; all at P>0.05). The vertical cup-disc ratio of the dominant eye group was lower than that of the non-dominant eye group (0.55 [0.40, 0.80] vs. 0.80 [0.63, 0.90]). The mean defect in the visual field of the dominant eye group was lower than that in the non-dominant eye group (-6.54 [-16.70, -3.85]dB vs.-18.77 [-28.19, -8.55]dB), and the intraocular pressure in the dominant eye group was lower than that in the non-dominant eye group (21.00 [17.00, 27.75]mmHg vs. 24.50 [19.00, 36.25]mmHg) (1 mmHg=0.133 kPa). Significant differences were found in mean defect, vertical cup-disc ratio and intraocular pressure between the two groups ( Z=-3.781, -3.528, -2.126; all at P<0.05). The ratio of the severely glaucomatous eye being the non-dominant eye was 84.09%, which was much higher than that of the severely glaucomatous eye being the dominant eye (15.91%). The non-dominant eye was related to the severity of chronic PACG ( χ2=40.909, P<0.001, Pearson contingency coefficient r=0.563). Conclusions:The non-dominant eye is associated with the severity of chronic PACG.