Dear editor,
We would like to share our ideas on the publication “Refractive and Vision Status in Down Syndrome: A Comparative Study.”1 Hashemi et al.1 concluded that “In DS patients, the prevalence rates of refractive errors, amblyopia, and visual impairment are higher than those in non-DS individuals.” Regarding DS and refractive/vision problems, there should be a hypothesis for the clinical association. How DS might contribute to ocular problems should be proposed. In a recent report, the possible mechanism was cerebral visual impairment, not an intraocular problem.2 This might not be concluded based on the findings of the present study. An important concern is about the control group. The control group is only a group of non-DS cases but not healthy controls. For example, “candidates for refractive surgery” must have an ocular problem. Additionally, Hashemi et al.1 mentioned “age- and gender-matched normal controls,” but there were unequal numbers of subjects in the patient and control groups. Hence, there might be a methodological flaw and bias.
Peer-review: Internally peer reviewed.
Authorship Contributions
Concept: P.S., V.W., Design: P.S., V.W., Data Collection or Processing: P.S., V.W., Analysis or Interpretation: P.S., V.W., Literature Search: P.S., V.W., Writing: P.S., V.W.
Conflict of Interest: No conflict of interest was declared by the authors.
Financial Disclosure: The authors declared that this study received no financial support.