Abstract
Abstract: :
Purpose: To evaluate objectively the therapeutic effect of Laser-induced Chorioretinal Venous Anastomosis(CRVA) for Retinal Vein Occlusion(RVO) by means of Indocynine Green Angiography(ICGA) and oscillatory potentials(OPs). Methods: The study included 18 patients(18 eyes) with nonischemic retinal vein occlusion, which were treated with the krypton red or green laser to induce CRVA. The site for the attempt at anastomosis creation was chosen at least two to three disc diameters away from the optic disc in central RVO or one disc diameter peripheral to the occlusion site in eyes with branch RVO, and enlarged underlying choroidal vein could be shown by ICGA. Power of 800 to 1000mw, 0.1 second duration and 50µ spot size were applied to the selected location. The adjacent Bruch's membrane were disrupted at first, followed by the edge of vein itself. Signs of presumed rupture of Bruch's membrane were vaporization bubble and occasionally a small intravitreal stream of hemorrhage from the adjacent retinal vein. All the patients were followed up for more than five months after treatment.ICGA and OPs were recorded to monitor the state of retinal circulation. A controlled nonischemic RVO group were compared with the treated group. Results: Twelve cases(66.67%) in the treated group developed a chorioretinal anastomosis within 2 to 4 weeks(the mean 3 weeks) by the monitor of ICGA. Amplitudes of OPs in the cases with successfully created anastomosis increased with statistically significance compared with control group(P<0.01), and visual acuity improved in 10 cases. None of case in successfully created anastomosis developed to ischemic state. Conclusion: Laser-induced CRVA would relieve the venous obstruction, restore retinal circulation and improve retinal function. ICGA can be used to guide creation anastomosis so as to improve the successful incidence and OPs can be used to monitor retinal functional prognosis for a successful CRVA.The results suggest CRVA is a relatively feasible and safe therapeutic method for RVO, especially for controlling conversion from nonischemic type to ischemic type.
Keywords: 454 laser • 432 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • 395 electroretinography: clinical