# Quantitative Evaluation of the Clinical Evolution of Traumatic Onycholysis after Laser Treatment
## 4 Discussion  
Laser therapy is considered a potential treatment for nail disorders because it is a rapid, easily applied treatment and presents no problems of pharmacological treatments such as side effects or interactions with other drugs [9; 10; 11]. The study's principal objective was to measure the efficacy of applying Nd:YAG 1064 nm laser to treat 10 nails with onycholysis, which were treated homogeneously and clinically evaluated using objective  
Figure 2: Same patient before and after treatment (**A**,**B**). Clinical improvement is observed, with a reduction in the affected area of the longitudinal axis from 68.57% to 20.00%. Another patient before and after treatment (**C**,**D**), showing clinically meaningful changes with a reduction in the affected area of the longitudinal axis from 41.94% to 28%. criteria. The laser treatment achieved clinical improvement in the nails of all participants, although none showed complete remission of symptoms during the study period. These findings agree with the results of other new studies contributing to the advancement of laser treatment in nail disorders that concluded there is no scientific evidence about the efficacy of treatment for infections. However, patients experienced evident clinical improvement in their nails [12; 13; 14; 15; 16; 17; 18; 19]. The FDA, therefore, does not recommend laser as first-line therapy for onychomycosis [3]. However, [PERSON] et al. (2016) observed structural nail keratin by Raman spectroscopy in three clinical cases. They described structural changes in nail keratin after applying Nd:YAG 1064 nm laser in onychomycosis treatment [15]. Our results support the idea of laser treatment's beneficial action in the pathologies treated even though they are not due to onychomycosis. In the literature consulted, we found only descriptions of clinical cases and a pilot study addressing the application of Nd:YAG 1064 nm laser in disorders other than onychomycosis and psoriasis, such as chronic paronychia, longitudinal melanonychia, and other idiopathic nails disorders [16; 17; 18; 19]. The clinical symptoms improved, but the authors concluded that laser could be a nonsurgical alternative with a good aesthetic outcome, and more research is needed on this topic. These works did not treat traumatic onycholysis, each case followed a different protocol, and the clinical evaluation was by clinical observation with no objective measurement method. However, the present work was carried out following the same therapeutic protocol in all cases, photographs were collected of the treated nails showing a qualitative improvement in the appearance of nails with traumatic onycholysis, and improvement was quantified using the method of the affected percentage of the axis. Statistical analysis confirmed that the improvement observed is objective and significant (\(p<0.006\)). Although the rejuvenation or remodeling mechanism of laser action is unclear, we found clinical improvement in 100% of nails. These results agree with the data in the literature consulted [13; 16; 17; 18; 19], indicating that the mechanism of laser action should be researched in future studies. We considered this protocol appropriate because we focused on the progression of the affected area from proximal to distal for the clinical evaluation, based on the nail growth theory [20] and the OSI and NAPSI methods [21; 22]. These approaches highlight the importance of evaluating the proximity of the lesion to the nail matrix rather than focusing solely on the affected area. The authors of the NAPSI method proposed a modification after detecting that the nail began healthy regeneration, but the affected area remained unchanged [23]. In this study, the main anatomical landmarks selected to measure the axis (onychocorneal band and hyponymium) prevents changes in the results due to nail trimming if the pathology is located mainly in the distal nail plate. Further studies should allow a more extended follow-up period until complete renewal of the nail, to entirely rule out recurrence.