Intravitreal gas injection for the treatment of experimental vitreous hemorrhage in rabbits

PURPOSE: To determine the effectiveness of intravitreous gas injection in the management and clearing of experimental vitreous hemorrhage. METHODS: A total of ten New Zealand white rabbits received an injection of 0.4 ml of autologous blood into the vitreous of the right eye. After 24 hours of the vitreous hemorrhage simulation, six eyes were randomly assigned for treatment with na intravitreous injection of 0.2 ml of 100% perfluoropropane gas (C3F8) (group A), while four eyes received a control injection of an equivalent volume of balanced salt solution (group B). The persistence of vitreous opacification, which was graded at pre-established time points during 32 days of follow-up, was evaluated on the basis of visibility of retinal details in each of the four quadrants. RESULTS: In the gas-treated group (A), a partial view of the retina in the four quadrants was possible at 15 days, while at 32 days, the vitreous cavity was completely free of blood in all eyes, allowing unobstructed observation of the fundus. No retinal details could be observed in the control group after 32 days of follow-up. CONCLUSIONS: Gas injection proved effective in the treatment of experimental vitreous hemorrhage. It was significantly better than the injection of balanced salt solution, according to criteria of extension, intensity, and clearing time. Its technical facility, lack of complications, and low cost encourage additional research into gas injection to add knowledge to this initial study and to clarify its potential usefulness to treat persistent vitreous hemorrhage as well as to elucidate some unique pathophysiology features of blood catabolism in the vitreous.