Thank you for your comment. In our manuscript, we did not use the mean and the standard deviation but used each patient's raw data for the analyses. Further, as written in the methods section, we only used unpaired Student's t test (parametric test) for the comparison between the two groups and paired Student's t test (parametric test) for the comparison between the baseline and each follow-up point.

Conflict of Interest:

None declared

Dear editor,

We have read with great interest the article by Unoki N et al Randomised controlled clinical trial of sub-tenon triamcinolone as an adjunct to panretinal photocoagulation for the treatment of diabetic retinopathy 1. We wish to make few comments. The p value of the primary outcome as documented is 0.04. But if calculated from the results documented, applying parametric tests as used in the study it comes out to be highly significant 0.001. We would like to know whether authors might have used a non-parametric test for the analysis. In the retinal thickness analysis, the p values mentioned are significant for the foveal and perifoveal thickness. Again we calculated the p values applying the parametric tests and it came out to be without statistically significant difference. We feel the use of non-parametric test for the analysis could have been more appropriate because the data especially of that of retinal thickness is a continuous variable.

References 1. N Unoki, K Nishijima, M Kita, K Suzuma, D Watanabe, H Oh, T Kimura, A Sakamoto and N Yoshimura. Randomised controlled trial of posterior sub- Tenon triamcinolone as adjunct to panretinal photocoagulation for treatment of diabetic retinopathy. Br. J. Ophthalmol. 2009; 93; 765-770.

2. Techniques for scatter and local photocoagulation treatment of diabetic retinopathy: Early Treatment Diabetic Retinopathy Study Report no. 3. The Early Treatment Diabetic Retinopathy Study Research Group. Int Ophthalmol Clin, 1987 Winter;27(4):254-64.

Competing Interest: None