Authors' reply

Hemanta Kumar Kar, Lipy Gupta

 Department of Dermatology, STD and Leprosy, Dr. RML Hospital and PGIMER, Baba Kharak Singh Marg, New Delhi, India

Correspondence Address:
Hemanta Kumar Kar
Department of Dermatology, STD and Leprosy, Dr. RML Hospital and PGIMER, Baba Kharak Singh Marg, New Delhi - 110 001
India

Sir,

We thank the authors ^[1] who have shown interest in our study entitled "1064 nm Q Switched Nd: YAG Laser treatment of Nevus of Ota: An Indian open label prospective study of 50 patients." ^[2] We would like to answer the queries put forth by the authors in the letter to the editor.

The quartile scoring system has been used previously in many studies. All of us are well aware that an objective scoring system has clear advantages over a subjective scoring system. A scoring system similar to the MASI score, which is used for melasma, would have been better for evaluating the improvement in Nevus of Ota. But, even after the drawbacks of the quartile score, it has been used widely in many previous studies and hence was also used by us.

We have shown percentage improvement versus number of sessions in [Table 1]. It is a good suggestion that Pearsons coefficient of correlation could have been used. The results with bilateral Nevus of Ota have been included separately in the discussion. We did not exclude these patients in [Table 1] due to a less number of overall cases. Moreover, in the materials and methods section, the goal was to continue treatment sessions till complete improvement or 15 sessions, but 36/50 patients did not achieve this goal at the time of evaluation. However, we had included patients who had completed a minimum of five sessions. When we compare the number of sessions versus, improvement what we want to emphasise is that there is no added advantage after 10 sessions, although the number of patients to support this inference are few in our study.

A Mexameter/Derma Spectrometer would have been better to determine the color change in Nevus in Ota, which was not available with us, and hence we were unable to include this in our study design. Because we had no patient with Type I/II skin, we could not comment that the response is faster in the type I/II skin type. The results in type IV-VI skin are inferior when compared with type I/II skin.

We still would like to say that despite the low overall improvement rates, 1064 nm Q Switched Nd: YAG Laser is a safe, easy and effective treatment modality for Nevus of Ota. We acknowledge your suggestion that combination lasers (QS 532-nm Nd: YAG laser with QS 1,064-nm Nd: YAG laser and an ablative laser followed by the QS ruby laser) would have been better and would like to try the same in the future. Use of QS ruby laser in Nevus of Ota in Indian patients is an alternative option worthy of trial.

There is a definite risk of recurrence after laser treatment. The point that QS Nd: YAG laser is a safe modality and provides reasonable improvement is true where there is no monetary consideration. But, where money is a factor, the benefit versus cost of treatment must be taken into consideration.

1.	Sardana K, Chugh S, Garg V. Are Q switched lasers for Nevus of Ota really effective in pigmented skin? Indian J Dermatol Venereol Leprol 2012;78:187-9. [Google Scholar]
2.	Kar HK, Gupta L. 1064 nm Q switched Nd: YAG laser treatment of nevus of Ota: An Indian open label prospective study of 50 patients. Indian J Dermatol Venereol Leprol 2011;77:565-70. [Google Scholar]