Comparative Study of Accommodative Function and Binocular Vision in Patients With Primary Angle-Closure Disease

The age-related decline in accommodative function after the age of 50 years corresponds with an increasing incidence of primary angle-closure disease (PACD); however, the interaction between this decline and PACD remains unexamined. Additionally, refractive error-accommodation associations in elderly individuals, which are critical for PACD pathophysiology, remain unclear, despite a prior pediatric focus. This study evaluated visual functions (including binocular vision, vergence function, and accommodation function) in patients diagnosed with PACD. A total of 51 patients (102 eyes) were included in this prospective study. The subjects were categorized into the following three groups: primary angle-closure/primary angle-closure glaucoma (PAC/PACG), primary angle-closure suspect (PACS), and a control group. Various parameters, including best-corrected near visual acuity, refractive error, Worth's 4 Dot test results, stereoacuity, vergence facility, accommodative facility (AF), and amplitude of accommodation (AMP), were measured and compared across the groups. A negative correlation was noted between AMP and refractive error (p < 0.001). After controlling for age and refractive error, no significant difference in AMP was detected; however, a statistically significant difference in AF was noted among the groups. PACS (p = 0.002) and PAC/PACG (p = 0.048) emerged as independent predictors of strong AF compared with normal controls. No significant differences in best-corrected near visual acuity, binocular vision, or vergence facility were observed between the groups. This research demonstrated that patients diagnosed with PACS and PAC/PACG exhibited stronger AF compared with the control group. Furthermore, a negative correlation between AMP and refractive error was observed within the elderly population. This research characterizes the correlation between refractive status and accommodative function, while establishing a link between accommodative function and PACD. Future studies on PACD pathogenesis and clinical management should prioritize accommodative function as a key research focus.