A Clinical Study Looking At The Influence Factors Of Curative Effect About Laser Treatment Of Nevus Of Ota And The Occurence Of Hypopigmentation

Ota is a common type of dermal melanin granule increased disease that commonly affects the Oriental people. It is presented as bluish hyperpigmentation along the distribution of the trigeminal nerve. There still no effective and efficient method on the treatment of Ota. Traditional treatments including cryotherapy, dermabrasion, skin grafting, chemistry desquamation skill and so on, all can cause obvious scarring or texture change. With the development of laser treatment in recent years, the treatment of Ota has entering into a brand new period. People pursue beauty and focus on the modern medical conditions Which make the study of the efficacy and complications of laser treatment of Ota an important task. Laser treatment clear the granules of melanin in the skin through selective photothermolysis. It has mild tissue damage, and has definite curative effect, which make laser treatment be the preferred method. But after years of clinical practice, we found that laser treatment also could bring complications, and has opposite aside in curative effect and patient satisfaction.Objectives:This study focuses on discussing the efficacy of Ota patients treated by QS Nd:YAG and QS Ruby laser. And we also described the complication of Hypopigmentation and its Risk factors.Materials and Methods:266Ota patients were chosen who were treated with QS Nd:YAG and QS Ruby laser, and followed up. All related clinical information of the patients were gathered. Two doctors who did not involved in the treatment and the patients evaluated the efficacy together. Each clinical features were analysed for statistical data with SPSS system. We chose one typical patient with hypopigmentation and took the tissues of hypopigmentation spot and the Ota tissue around it by surgery excision. HE staining and chemical immunohistochemical staining was adopted and analysed.RESULT:①Follow-up results:After4to13times laser treatments, all266Ota patients reached mild improvement or much more improvement. Among all of them,80patients were totally complete clearing (30.07%of the total);151patients were significantly improved (56.77%), and35patients were moderately improved (13.165%). Besides,40people were affected hypopigmentation during the treatment with an incidence rate of15.04%.②Statistical results:After the statistical analysis, we found that the fluence of lasers\the first treatment age. the size of the injury and the sex may be risk factors related to hypopigmentation.③Pathological analysis results:HE staining showed that the melanin granule were mainly cleared away in spots of the hypopigmentation, but they still exist in the surrounding Ota cutaneous. Chemical immunohistochemical staining showed that there were no significant difference in melanophore numbers between spots of the hypopigmentation and surrounding Ota cutaneous.CONCLUSION:Laser treatment shows many advantages in Ota, such as easy operation and therapeutic confirmatory. Because of different depth of the melanin granule, we could use lasers of different wavelengths. While laser treating, the type of laser instruments and the fluence of lasers should be directly estimated according to the response of the treatment area, the experience of the doctors and the therapeutic part. Although laser treatment of Ota patients has its safety, there still are several complications in few people because of many kinds of factors’combined action. The complications are hypopigmentation, hyperpigementation, scars, skin texture changes and so on. The hypopigmentation is the most unacceptable complication. We found that the fluence of lasers, the first treatment age and the size of the injury have an affect on the happening of hypopigmentation, and they might be risk factors related to hypopigmentation. With the growing of the ages and the times, the curative effect are better, while this increase the danger of the occurrence of hypopigment. So, when we are pursuing better effect, the complication should be paid attention too. Conservative fluence should be chosen while treating according to the actual reaction. Tissue staining showed that compared to the surrounding Ota tissue, the spot of hypopigmentation has fewer melanin granule, but the melanocytes has no obvious change. So, whether the laser treatment can do permanent injure to the metabolism of melanocytes still need further study and discussion.