Cryotherapy of the Anterior Retina and Sclerotomy Sites in Diabetic Vitrectomy to Prevent Recurrent Vitreous Hemorrhage: An Ultrasound Biomicroscopy Study

To evaluate the role of cryotherapy of the anterior retina and sclerotomy sites in the prevention of fibrovascular ingrowth (FVIG) at sclerotomy sites and postoperative recurrent vitreous hemorrhage in patients undergoing pars plana vitrectomy (PPV) for proliferative diabetic retinopathy (PDR). Design. Retrospective, nonrandomized, observational case series. Participants. Eighty-one eyes in 71 patients who had undergone PPV for complications of PDR in the previous 2 years, with postoperative retinal reattachment for at least 3 months. Methods. Cases were divided into 3 groups: (1) having panretinal or supplementary endophotocoagulation; (2) having anterior peripheral retinal cryotherapy ( ARC) in addition to panretinal endolaser treatment; and (3) having endophotocoagulation, ARC, and cryotherapy on the 3 sclerotomy sites added . Ultrasound biomicroscopy (UBM) examination of the 3 sclerotomy sites was performed ≥2 months after surgery. The UBM findings were separated into 4 categories: well-healed, gap, vitreous incarceration, and FVIG. History and management of recurrent vitreous hemorrhage were recorded. Main Outcome Measures. Ultrasound biomicroscopy findings and the percentage of recurrent vitreous hemorrhage in the 3 groups were compared to determine the effectiveness of the adjunct cryotherapy in inhibiting FVIG and preventing recurrent vitreous hemorrhage . Results. The recurrent vitreous hemorrhage rates in groups 1, 2, and 3 were 12 of 32 ( 37.5%), 3 of 26 (11.5%), and 1 of 23 (4.3%), respectively (P = 0.0004). In each group , different sclerotomy sites had similar distributions of the 4 UBM categories. Among the 3 groups, gap was found in 9 .4%, 20.5%, and 52.2% of eyes, respectively (P<0.001), whereas FVIG was found in 36.5%, 15 .4%, and 0% of eyes (P<0. 001). Fibrovascular ingrowth was noted in 87.5% (14/16) of all eyes experiencing recurrent vitreous hemorrhage. Of those with rebleeding but no FVIG (2 eyes), 1 had vitreous lavage combined with additional cryotherapy, and 1 had no treatment. Of those with FVIG (14 eyes), 5 needed ≥2 operations. Conclusions. The presence of FVIG had good correlation with the development of recurrent postoperative vitreous hemorrhage. Anterior peripheral retinal cryotherapy combined with cryotherapy of sclerotomy sites might be helpful adjunct procedures in diabetic vitrectomy for inhibition of FVIG and prevention of recurrent vitreous hemorrhage.