Quantitative effect of intravitreally injected tissue plasminogen activator and gas on subretinal hemorrhage

Purpose: To quantify the effect of intravitreally injected tissue plasminog en activator (TPA) and an expanding gas on freshly formed subretinal hemorr hage (SRH). Patients and Methods: Thirteen patients with acute (1 week or less) SRH due to age-related macular degeneration (ARMD) were treated with an intravitre al injection of 50 mug TPA, and 24 hours later, with an expanding gas. Fund us photographs taken before and 24 hours after each injection were digitize d and calibrated. Area, geometric center, and shift of the SRH were measure d at each time point using NIH image analysis software. Elevation of the SR H was assessed by echography. Results: Compared to the preoperative size, SRH enlarged significantly 24 h ours after TPA injection (P < 0.001). A significant shift of the geometric center toward the inferior retinal periphery out of the macula was found af ter gas injection (P < 0.001). Significant horizontal displacement of the S RH was not noted after TPA or gas injection. More elevated subretinal blood clots showed a larger increase in size after TPA injection than flat clots (P < 0.05). Conclusion: Enlargement of SRH in a gravity-dependent manner indicates subr etinal liquefaction of the clot after TPA treatment. An intravitreal inject ion of gas 24 hours later can significantly displace the SRH inferiorly.