Comparison of Near Point of Accommodation and Near Point of Convergence with Positive Fusional Vergence among Young Adults, Bengaluru

Abstract

Background: When encountered with mass screening and increased walk-in patients in outpatient departments (OPD), evaluating complete binocular vision assessment becomes time-consuming. Consequently, there is a need to streamline the testing process. This study also aims to explore if there are any correlations between Near Point of Accommodation (NPA) and Near Point of Convergence (NPC) with Positive Fusional Vergence (PFV). Methodology: A retrospective study was carried out at Sankara Eye Hospital in Bangalore. Data from patients aged 18 to 35, who underwent binocular vision assessment between 2016 and 2020, were included. Out of 101,896 patients who visited the hospital during this period, 3,449 attended the vision therapy clinic. Among them, 1708 patients met the criteria for inclusion, while 1,741 were excluded. Results: Out of 1708 subjects, 759 are females and 949 are males. The relationship between Near Point of Accommodation (NPA), Near Point of Convergence (NPC), and Positive Fusional Vergence (PFV) blur and break values were analysed. A positive correlation was observed between NPA and PFV blur (Spearman's rho = 0.069, p=0.004) and a negative correlation between NPC and PFV break (Spearman's rho = -0.370, p<0.001). There was a significant difference between NPA and PFV blur, as well as NPC and PFV break (p=0.000), emphasizing the importance of incorporating all three tests in a binocular vision assessment. Conclusion: These results emphasize the necessity for complete binocular vision assessment to effectively diagnose and manage binocular vision anomalies. By accounting for the various parameters involved in this investigation, clinicians can enhance the precision and quality of their assessments and plan for appropriate treatment strategies for patients with binocular vision anomalies.