Evaluation of Visual Functions in Children Using Manifest Refraction: Effect of Age and Refractive Error

It remains unclear whether positive relative accommodation (PRA), negative relative accommodation (NRA), or binocular cross cylinder (BCC) values present differently when manifest refraction (MR) is performed before or after drug-induced mydriasis. This study aimed to compare visual functions in children as measured by refraction and MR after the administration of mydriatics. A total of 483 children (4–18 years old) were categorized into three groups based on MR performed at three visit points: initial MR, refraction after rapid pupil dilation (RRP), and refraction after slow pupil dilation (RSP). The investigated subjects included PRA, NRA, and BCC values. No significant differences in the PRA (P = 0.120), NRA (P = 0.492), and BCC (P = 0.240) values were detected among the MR, RRP, and RSP groups. When the PRA values among different groups were stratified by age, no significant differences were detected. Although there were no statistically significant differences in the NRA values among groups for children aged 4–6 years (P = 0.077) and 7–11 years (P = 0.865), there was a significant difference in the NRA values among groups for children aged 12–18 years (P =0.044). In addition, the BCC values among groups for children aged 7–11 years (P = 0.044) also showed significant differences. Meanwhile, the differences between PRA (P <0.001) and NRA (P = 0.016) among emmetropes, pseudomyopes, myopes, and hyperopes were statistically significant, while the refractive error was not affected by MR assessed with BCC (P = 0.380). Performing MR after pupil dilation could replace MR before mydriasis in children aged 4–6 years, while MR before mydriasis could be omitted for children aged 4–6 years.