Ultrasound biomicroscopy of sclerotomy sites after pars plana vitrectomy for diabetic vitreous hemorrhage

OBJECTIVE: This study was aimed at assessing changes at the sclerotomy site using the ultrasound biomicroscope (UBM) in eyes that underwent primary pars plana vitrectomy for complications of proliferative diabetic retinopathy. DESIGN: Prospective, observational case series. PARTICIPANTS: Eighty-six eyes of 84 patients with vitreous hemorrhage caused by proliferative diabetic retinopathy. INTERVENTION: Three-port pars plana vitrectomy followed by UBM evaluation of all sclerotomy sites between 6 and 8 weeks after surgery. Correlation with intraoperative findings done in case of reoperations. Forty-one eyes had repeat UBM at 6 months. MAIN OUTCOME MEASURES: The changes at the sclerotomy site were classified into six groups: well healed, gape, plaque, vitreous incarceration, fibrovascular proliferation, and anterior hyaloidal fibrovascular proliferation (AHFVP). The UBM characteristics of each of the groups were defined. The findings at 6 months were compared with those at 6 to 8 weeks. RESULTS: At 6 to 8 weeks after surgery, most sclerotomies were well healed or had either moderate to high reflective plaques bridging the site. Wound gape was seen in 22.1% of active ports, 32.6% of light ports, and 25.6% of infusion ports. Vitreous incarceration was seen most often at the infusion port (18. 6% of eyes). Fibrovascular proliferation was seen in 9.3% of active ports, 12.8% of light ports, and 15.1% of infusion ports. Thirteen eyes had recurrent vitreous hemorrhage 6 to 8 weeks after surgery. Cases with rebleeding and no fibrovascular proliferation at the sclerotomy on UBM did well with outpatient fluid-air exchange (two eyes) or observation only (three eyes). Those with fibrovascular proliferation on UBM (eight eyes) required more extensive surgery. CONCLUSIONS: UBM is helpful in detecting complications at the sclerotomy sites after pars plana vitrectomy and is an invaluable tool in the assessment of the patient before reoperation.