Long-term Evaluation of the Anisohypermetropic Children: What Happens to Visual Acuity, Binocular Vision and Refraction?

Objective: Refractive errors and their inappropriate correction may not only lead to deterioration visual acuity (VA) but also deteriorate binocular functions and then lead to strabismus since the binocular single vision (BOV) and VA are important in ensuring the parallelism of the eyes. In this study, we evaluated the changes in best corrected visual acuity (BCVA), BOV and refraction in anisohypermetropic children.
Methods: The records of anisohypermetropic children who were followed up between January 1999 and June 2019 were retrospectively reviewed. Detailed ophthalmological examination findings of the initial and last control with at least one year follow-up were obtained. BCVA was determined by the Snellen-chart letters and transformed to the logarithm of the minimum angle of resolution (logMAR). Binocular vision functions were evaluated using the Titmus and Worth 4-dot tests. The changes in BCVA, BOV and refraction were evaluated.
Results: Seventy-one patients were included in the study. While 39 patients were male, 32 patients were female. The mean age of patients was 74.31±40.51 (24-180) months at the first admission, the mean follow-up time was 67.75±47.8 (12-204) months. Amblyopia was seen in 68 (95.77%) eyes with higher refractive error and 38 (53.52%) eyes with lower refractive error at the first examination. The median BCVA of the eye with higher refractive error was 0.52 logMAR at the first examination and 0.10 logMAR for the last control (p<0.001). The median BCVA of the eye with lower refractive error was 0.10 logMAR at the first examination and 0.00 logMAR at the last control (p<0.001). BOV was detected in 7 patients (9.9%) at the first examination, while BOV vision was detected in 22 (31%) patients at the last examination (p<0.001).
Conclusion: The results show the importance of close follow-up and early treatment in anisometropic cases because of the negative influence of anisometropia on visual functions.