ORIGINAL PAPER Evaluation of antimitotic and antiangiogenic effect of preoperative subconjunctival application of mitomycin C in primary pterygium: a randomized trial Thiago Gonc¸alves dos Santos Martins . Ana Luiza Fontes de Azevedo Costa . Karina Mie Furuzawa . Roger Chammas . Milton Ruiz Alves Received: 25 September 2018 / Accepted: 28 January 2019 Ó Springer Nature B.V. 2019 Abstract Purpose To evaluate the influence of preoperative mitomycin C (MMC) on the proliferative behavior of fibroblasts and fibrovascular tissue derived from the primary pterygium using the immunohistochemical method (Ki67 and CD34). Design Randomized clinical trial. Subjects, participants and/or controls Sixty-five patients with primary pterygium were randomly selected and divided into one of three groups. The control group had 29 patients that were only submitted to pterygium removal. The group that received the MMC injection a month before surgery had 16 patients, and the group that received the MMC 2 weeks before surgery had 20 patients. Each patient only had one eye operated on. Methods Sixty-five patients were selected to undergo pterygium excision surgery. We randomly placed the patients into three groups: one without MMC (n = 29), one with MMC application 1 month before surgery (n = 16) and another with MMC application 2 weeks before surgery (n = 20). Subcon- junctival injection was applied with 0.1 ml of 0.02% MMC in the pterygium body, and patients were followed for 2 years. Main outcome measures Proliferative behavior of fibroblasts and fibrovascular tissue using the immuno- histochemical method (Ki67 and CD34) comparing the three groups. Results Of the total 29 patients (44.6%) in the control group (without MMC application), 11 cases had recurrence (37.9%), of which seven (63.6%) were within 3 months of follow-up and four (36.3%) within 6 months of follow-up. The mean proliferation index of the recurrent cases was 4.5%, and of the cases without recurrence, it was 6.1%. There were 16 patients (24.6%) in the MMC application group 1 month before surgery, in which one case (6.25%) recurred at 6 months. In the group with MMC application 2 weeks before surgery, of the total of 20 patients (30.7%), there was one case of recurrence (5%) at 6 months. The proliferation index of the group that had MMC administered and did not have a recurrence was 7.2%, and in the group with recur- rence, it was 6.4%. The CD34-labeled cell count was 5.8% among cases with recurrence and 5.6% in cases without recurrence. No side effects of MMC applica- tion were reported during the study follow-up period. Conclusion MMC was efficient to reduce the recur- rence index despite the absence of a direct relation with its antimitotic and antiangiogenic effect in the samples that were analyzed. T. G. dos Santos Martins (&) Federal University of Sa˜o Paulo (UNIFESP), Botucatu Street, 821 Vila Clementino, Sa˜o Paulo 04023-062, Brazil e-mail: thiagogsmartins@yahoo.com.br T. G. dos Santos Martins Á A. L. F. de Azevedo Costa Á K. M. Furuzawa Á R. Chammas Á M. R. Alves University of Sa˜o Paulo (USP), Sa˜o Paulo, Brazil 123 Int Ophthalmol https://doi.org/10.1007/s10792-019-01081-0