This article published in Kosin Medical Journal [4] compared the visual function of patients with simple esotropia and those with esotropia accompanied by ptosis, building upon previous research by the same group that compared visual acuity and stereopsis between patients with simple exotropia and those with exotropia accompanied by ptosis [5]. These two studies found that in patients with esotropia, ptosis did not affect visual function, including stereopsis, whereas in those with exotropia, ptosis led to a reduction in distance stereopsis and suppression. However, it is important to note that factors such as the timing of strabismus onset and the duration of the condition can influence the development of visual function [6]. Therefore, standardizing the onset, angle, and duration of strabismus is essential for drawing definitive conclusions. In this current study on esotropia, a sub-analysis was conducted based on the degree of ptosis (0<marginal reflex distance 1 [MRD1]≤1 and 1<MRD1≤2). Mild ptosis did not affect stereopsis. However, the study did not differentiate between distance and near vision, which could limit the findings since convergence at near distances might have a lesser impact on the development of stereopsis. Additionally, the study did not differentiate between various subtypes of esotropia, such as accommodative esotropia, non-accommodative esotropia, and congenital esotropia. This omission makes it challenging to generalize the results to all forms of esotropia.

Nevertheless, ongoing research, including this study, is likely to contribute to the understanding of visual acuity and visual function development in patients with simple esotropia and those with esotropia accompanied by ptosis. Despite several limitations—including its retrospective nature, small sample size, lack of data on post-surgical binocular function, absence of lateralization analysis of ptosis, and no consideration of esotropia types—this study provides valuable suggestions for future research. Nonetheless, the strength of this research lies in its quantitative assessment of binocular function in esotropia patients with congenital ptosis compared to esotropia-only patients.

To enhance the quality and reliability of data, future research should focus on conducting prospective studies and expanding the sample size through multicenter, large-scale studies to improve statistical power and generalizability. Additionally, it is crucial to investigate potential improvements in binocular function following ptosis surgery, particularly if reductions in visual functions, including stereopsis, are observed across various degrees of ptosis. It is also important to perform lateralization analyses to compare visual outcomes between affected and unaffected eyes. Finally, investigating the effects of different types of esotropia on visual acuity and stereoacuity will provide a more comprehensive understanding of the condition.

In conclusion, this study highlights the importance of understanding the development of visual function in patients with esotropia and ptosis. Despite its limitations, the research offers valuable insights and proposes directions for future studies.