Rohan Kumar Ochani  ( 3rd Year Student, Dow Medical College,Karachi,Paksitan )
Asim Shaikh  ( 3rd Year Student, Dow Medical College,Karachi,Paksitan )
Simran Batra  ( 2nd Year Student, Dow Medical College,Karachi,Paksitan )

Madam, active trachoma is one of the leading causes of preventable blindness in children,¹ therefore, the efforts of Khokar et al² in determining prevalence of active trachoma in children is to be applauded. However, there are some considerable limitations to the methodological domain of the study that have not been discussed, which brings the interpretation of its results into question. Firstly, it states “maximum trachoma cases were reported in month of January (n=24), February (n=24) which showed winter season has relation with trachoma prevalence”. The authors have suggested a relationship exists, however, only arithmetic percentages have been used, hence, the existence of any relationships cannot be stated as no statistical tests have been applied in this study.³ Secondly, it states “the trachoma prevalence was high among infants (1-5 year) and more prevalent among female children 82 vs 75”. Once again, the authors seem to suggest that gender and age are, perhaps, linked to presence of active trachoma, however,  without checking whether these are statistically significant factors, no such relationships can be suggested.³ Finally, limitations of the study and ways of reduction of biases have not been mentioned. The absence of limitations hinders further research efforts on the subject as it does not provide ways in whichproblems faced by the study can be tackled in the future.⁴ On the other hand, it is the authors duty to employ procedures that limit biases, so the interpretation of results can be done with confidence.⁵
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References

1. Alemayehu W, Melese M, Fredlander E, Worku A, Courtright P. Active trachoma in children in central Ethopia: Association with land. Trans R Soc Trop Med Hyg. 2005; 99: 840-43.
2. Khokhar AR, Sabar S, Lateef N. Active trachoma among children of District Dera Ghazi Khan, Punjab, Pakistan: A cross sectional study. J Pak Med Assoc 2018; 68: 1300-3.
3. Nayak BK, Hazra A. How to choose the right statistical test? Indian J Ophthalmol 2011; 59: 85-6.
4. Puhan MA, Akl EA, Bryant D, Xie F, Apolone G, Riet G ter. Discussing study limitations in reports of biomedical studies- the need for more transparency. Health and Quality of Life Outcomes. 2012; 10:23. doi:10.1186/1477-7525-10-23.
5. Pannucci CJ, Wilkins EG. Identifying and avoiding bias in research. Plast Reconstr Surg 2010; 126: 619-25.