Author's response to reviews Title:Hyperopia: a meta-analysis of prevalence and a review of associated factors among school-aged children Authors:

the objective of the study has been made clearer in the Background. The methodology has been completed including the study of meta-analysis and the conclusion was improved and expanded. 2. Background section, line 3. Please provide a reference to the statement “....presence or absence of associated accommodative and binocular dysfunctions”. Reference [1] has been added, the first paragraph of which indicates the importance of accommodative and binocular dysfunctions in sequelae: “Hyperopia in childhood, particularly when severe and/or associated with accommodative and binocular dysfunctions may be a precursor of visual motor and sensory sequelae.[1]” 3. Discussion. In the section relating to ethnic differences: “The particularly low hyperopia prevalence could be partly explained by ethnicity, as in Durban, South Africa [27], where the majority of the population are black followed by Asian people. Regarding ocular components, both African and Asians have an axial length larger than white individuals. Since the study was Majorly based in the black ethnicity, it is important to consider that the hyperopic error might be underestimated due to a smaller cycloplegic action in eyes with dark irises.[27, 60]” Further clarification is needed. Given that hyperopia is associated with shorter axial length and myopia with longer axial length, we should also expect higher rates of myopia in South Africa. However, this is clearly not the case (2.9-4.0% Naidoo et al). It seems unlikely that in the report by Naidoo et al (and other RESC studies) incomplete cycloplegia could under-estimate hyperopia as a strict protocol for pharmacological dilation was used, and pupil diameter was assessed. The article mentions that low hyperopia prevalence is partially explained by ethnicity. The explanation in relation to darker irises has been removed from the text since we agree with the reviewer’s argument. 4. Tables 1& 2 seem to have a lot of duplication of data – the authors could consider condensing the two tables into one. Table 1 & 2 have been combined into one table (Table 1) and the number of eyes examined has been included (by eye or by child) and which examination was performed (cycloplegic autorefraction or cycloplegic retinoscopy). Table 3 was renumbered as Table 2. Minor Essential Revisions 5. Results. In the sentence: “...prevalence of hyperopia at age of 7 years ranges from 2.8%[27] to 28.9%[28]. Even excluding outliers, the prevalence ranges from 4.0% [29] to 10.7% [30].”, please elaborate or clarify what is meant by “excluding outliers”. Meta-analysis of hyperopia prevalence by specific age has been undertaken, resulting in a comprehensive modification of the results description (Results: fifth and sixth paragraphs). 6. Discussion. The sentence “On the other hand, females have greater acceptance and participation in studies, trials and interviews with scientific purpose that could lead to positive selection bias” should be referenced, or else another explanation provided, as in these paediatric studies, consent is not accepted from the child participants, but from the parents. Although parental consent is needed, children’s consent and collaboration is also needed. In places where there are no barriers to girls’ participation, girls usually collaborate more. (Ref: Ostadimoghaddam H, Fotouhi A, Hashemi H, Yekta A, Heravian J, Rezvan F, Ghadimi H, Rezvan B, Khabazkhoob M: Prevalence of the refractive errors by age and gender: the Mashhad eye study of Iran. Clin Experiment Ophthalmol 2011, 39(8):743-751). Minor Comments not for publication 7. Please ensure consistency in number of decimal places for statistics within the manuscript. Eg. In Abstract, line 8 and line 9, change 4% to 4.0%, and 7% to 7.0%.