Prevalence of Near-Vision-Related Symptoms in a University Population

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This present study investigated the prevalence of visual symptoms and accommodative dysfunction in the academic population, which comprise of students, professors and researchers. While this is a diverse population, the authors concluded that the high prevalence of symptoms and accommodative dysfunction are related to the higher visual demands and length of time that is spent in performing near vision tasks. Numerous studies have investigated asthenopic symptoms related to near visual activities in students. The wide age range may explain the effect of age in some of the symptoms, as some of the participants may be presbyopic. It is interesting that the effect of age was not reflected on the CISS scores, but the authors did not discuss about it. The methodology of the survey and techniques used in evaluating accommodation were not adequately explained. How does a mean CISS score of 18.7 in the academic population compare with the general population? Was there an effect of age in the accommodative tests too? Why only 40% of the symptomatic participants had accommodative dysfunction? The authors did not explain how the participants were randomised and how they were selected for further evaluation to diagnose the accommodative dysfunction. In the discussion section, the authors mentioned the observation of "much time spent on near visual tasks" but did not report the actual amount of time in the results section. The authors mentioned a high prevalence of accommodative dysfunction compared to general adult population, but did not state the actual numbers. Participants who wore glasses had higher scores for some of the symptoms than those who did not wear glasses, but the authors did not comment on the rest of the symptoms that did not have high scores. The authors should also discuss the strengths and weaknesses of their study. Why didn’t the authors examine vergence? Did the authors check if the habitual spectacles were appropriately prescribed or up-to-date? Minor comments: CISS should be spelt in full on line 9. Only one decimal place is sufficient for age and CISS score.

Comments on the Quality of English Language

Need to check on grammar and past/present tense. 

Author Response

We would like to thank the reviewer for the efforts and valuable time to evaluate our manuscript. The points addressed by reviewer allowed us to improve our work.

The wide age range may explain the effect of age in some of the symptoms, as some of the participants may be presbyopic. It is interesting that the effect of age was not reflected on the CISS scores, but the authors did not discuss about it.

The number of presbyopic subjects is small (39 subjects) and did not affect the mean CISS score. Information about this was added to the manuscript.

The methodology of the survey and techniques used in evaluating accommodation were not adequately explained.

Information about the survey and the techniques used to assess accommodation were described in the manuscript.

How does a mean CISS score of 18.7 in the academic population compare with the general population?

The discussion was improved by comparing our results with the general population.

Was there an effect of age in the accommodative tests too?

Age did not affect the accommodative tests, as presbyopic subjects were not included in this part of the study.

Why only 40% of the symptomatic participants had accommodative dysfunction?

This is discussed in the discussion section. Other symptomatic subjects may have other conditions, such as vergence dysfunction or poor ergonomics for near tasks.

The authors did not explain how the participants were randomised and how they were selected for further evaluation to diagnose the accommodative dysfunction. 

After the questionnaire, the non-presbyopic subjects were invited to the second part of the study, which included an eye examination. Unfortunately, as the questionnaire was distributed during the COVID-19 pandemic, as mentioned in the discussion, many subjects were not available to participate in this second part, which justifies the reduced number of subjects compared to those who completed the questionnaire.

In the discussion section, the authors mentioned the observation of "much time spent on near visual tasks" but did not report the actual amount of time in the results section.

Information added to the results section.

The authors mentioned a high prevalence of accommodative dysfunction compared to general adult population, but did not state the actual numbers.

The discussion has been improved and the actual numbers was added to this section.

Participants who wore glasses had higher scores for some of the symptoms than those who did not wear glasses, but the authors did not comment on the rest of the symptoms that did not have high scores. 

We did not consider important to discuss symptoms with low scores, but if the reviewer considers it important, we can discuss about it and add it to the discussion section.

The authors should also discuss the strengths and weaknesses of their study.

We agree that weaknesses should be discussed. This was added to the discussion section.

Why didn’t the authors examine vergence?

We assessed vergence at distance and near for all participants who had an eye examination. We did not include this because the focus of this study was only on accommodative dysfunction. However, if the reviewer considers it is necessary to include this, we can add this information to the manuscript.

Did the authors check if the habitual spectacles were appropriately prescribed or up-to-date?

Yes, we have checked this and we agree that this information is important to discuss the symptoms found.

Compared to their habitual spectacle refraction, 15.2% were overcorrected and 9.5% were undercorrected. Of those who were overcorrected, 87.5% were myopes who wore a more negative refraction than they actually needed, and of those who were undercorrected, 20% were myopes who wore less than they needed.

This was added to the results section.

CISS should be spelt in full on line 9. Only one decimal place is sufficient for age and CISS score.

Alterations were made in accordance with the review comments.

Reviewer 2 Report

Comments and Suggestions for Authors

In this research, the authors assessed near-vision-related symptoms and the prevalence of accommodative dysfunctions in a university population. By highlighting the significance of evaluating symptomatology, accommodation, binocular vision and workplace ergonomics during clinical exams in academic populations, this work is comprehensive in explaining this phenomenon.

 

1.     In the background section, please provide more information about the Convergence Insufficiency Symptom Survey.

2.     The full name of CISS needs to be given before the abbreviation in the abstract.  

3.     There are some mistakes in the manuscript. For example, “Considering symptomatic with a score more or equal to 21, 38%”, “reading/doing close work, with 91,7% having this symptom”, and “41,2%, 6,7%” in table 4.

4.     Please provide a higher quality of figure 1 since some of the information is not clear.

5.     There should be existing blank between the unit and value (like “Monocular accommodative facility ≤ 6cpm and binocular ≤ 3cpm” in table1，“The mean age of the subjects was 28.79±11.36years, 62.3% reported wearing glasses and 13 spending 7.20±2.92hours/day in near vision”.)

6.     More related literatures (VIEW 2023, 4, 20220059; VIEW 2023, 4, 20220070) should be included and discussed to enhance the scope of this work.

7.     The format of manuscript should be uniform. Such as “score = 16.85; hours/day = 7.11) and 135 without (score = 17.77; h/day = 7.69)”. Please carefully check the format of manuscript and revise the possible problems.

Comments on the Quality of English Language

/

Author Response

We would like to thank the reviewer for the efforts and valuable time to evaluate our manuscript. The points addressed by reviewer allowed us to improve our work.

1. In the background section, please provide more information about the Convergence Insufficiency Symptom Survey.

Information added to the manuscript.

2. The full name of CISS needs to be given before the abbreviation in the abstract. 

Information added to the manuscript.

3. There are some mistakes in the manuscript. For example, “Considering symptomatic with a score more or equal to 21, 38%”, “reading/doing close work, with 91,7% having this symptom”, and “41,2%, 6,7%” in table 4.

All errors were corrected in the manuscript.

4. Please provide a higher quality of figure 1 since some of the information is not clear.

We uploaded a higher quality image.

5. There should be existing blank between the unit and value (like “Monocular accommodative facility ≤ 6cpm and binocular ≤ 3cpm” in table1，“The mean age of the subjects was 28.79±11.36years, 62.3% reported wearing glasses and 13 spending 7.20±2.92hours/day in near vision”.)

Alteration made in accordance with the review comment.

6. More related literatures (VIEW 2023, 4, 20220059; VIEW 2023, 4, 20220070) should be included and discussed to enhance the scope of this work.

We added more literature to the manuscript to improve the introduction and discussion, but we did not understand the references given by the reviewer. Please, provide more information about the literature you consider we should include.

7. The format of manuscript should be uniform. Such as “score = 16.85; hours/day = 7.11) and 135 without (score = 17.77; h/day = 7.69)”. Please carefully check the format of manuscript and revise the possible problems.

We have taken the reviewer's comment into account and the manuscript is now consistent.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have addressed the reviewer comments adequately, but it will be better to explain why vergence results is omitted in the manuscript. This is because the symptoms associated with accommodative dysfunction tends to be similar to those experienced with vergence disorders, such as convergence insufficiency. Did the authors use only spherical equivalent in the refraction findings? The authors did not mention about astigmatism in the refraction results, but it will be important to report or minimally mention this as a study limitation because the severity of astigmatism is known to influence accommodative response and is often linked to poor visual development, such as amblyopia (Please refer to:  https://iovs.arvojournals.org/article.aspx?articleid=2766009). Kindly address these concerns in the manuscript. 

Author Response

The prevalence of binocular dysfunctions found was very low and we considered this does not add valuable information to the manuscript. However, we have added the data we measured about phoria and fusional vergences for distance and near vision, as well as the prevalence of binocular dysfunction we found. The methods and discussion sections were adapt according to the new data.
We agree with the reviewer that the information about astigmatism is missing. The astigmatism has been measured and added to the manuscript.

We have also added the suggested reference.

Round 3

Reviewer 1 Report

Comments and Suggestions for Authors

The authors has addressed all the concerns. Well done!