Morteza Entezari, Alireza Ramezani, Hamid Ahmadieh, Pejman Bakhtiari, Mehdi Yaseri (Ophthalmic Research Center, Shaheed Beheshti University of Medical Sciences, Tehran, Iran)

Advantages:

To present the disadvantages of cryotherapy of sclerotomy sites in prevention of late (after 4 weeks) post-vitrectomy diabetic hemorrhage. There is a hypothesis that cryotherapy of sclerotomy sites by preventing fibrovascular ingrowth may decrease the rate of post-vitrectomy diabetic hemorrhage. Based on a clinical tr ial, however, we reached to an opposite conclusion.

Methods:

After closure of the sclerotomy sites at the end of the vitreous surgery, we applied two cryotherapy spots at each sclerotomy site. The duration for each spot was up to 3 seconds after formation of the ice ball.

Effectiveness / Safety:

In a clinical trial comparing this procedure with no treatment, we found not only the ineffectiveness of this method but also its risky effect. The rate of vitreous hemorrhage up to 6 months was significantly higher in the eyes receiving cryotherapy (29.4%) compared to the controls (9.1%) (P=0.035). Fibrovascular ingrowth, detected by ultrasound biomicroscopy, was noticed in 46% and 30% of the cases and controls, respectively (P=0.4). Take home message: Cryotherapy of sclerotomy sites is not helpful for prevention of late post-vitrectomy diabetic hemorrhage and it may even increase the risk.