Introduction & Objective: Chronic ulcer is a significant problem in patients referring to dermatologists and plastic surgeons. Diabetes delays or impairs wound healing. Fifteen percent of diabetic patients have lower extremities ulcer with high morbidity. Retinoic acid is a vitamin A derivative which has significant effect on cellular proliferation and connective tissue extra cellular proteins differentiation. Our purpose in this study was to observe the effects of tretinoin on wound healing.

Materials & Methods: This study was a case-control study performed on 48 Wister male rats. The rats were made diabetic and then divided into two groups. We induced a full thickness wound on back of all rats. The wounds were treated with 0.1% tretinoin lotion once daily in the case group and with normal saline in the control group. Both groups were examined macroscopically and histological on the 5th, 10th, and 15th days. At last, the data was analyzed by ANOVA and t- student statistical tests.

Results: In the macroscopic evaluation on the 5th and 10th days, wounds that were tretinoin treated, healed more rapidly than that of the control (P=0.002, P=0.001), but on the 15th day, this effect was not significant (P=0.212). At the histological level on the 5th day an increase was observed in the granulation tissue ,epidermal thickness and collagen density but it was not significant(P=0.417, P=0.999, P=0.470). On the 10th day, this increase was rather observable, but not significant (P=0.400, P=0.999, P=0.999).

Conclusion: According to our findings, topical tretinoin treatment improves wound healing in diabetic ulcers.