RESTORATION OF RETINAL BLOOD FLOW VIA TRANSLUMENAL Nd:YAG EMBOLYSIS/EMBOLECTOMY (TYL/E) FOR CENTRAL AND BRANCH RETINAL ARTERY OCCLUSION

Abstract

Central retinal artery occlusion (CRAO) and branch retinal artery occlusion (BRAO) may be a result of platelet-fibrin emboli, cholesterol plaques, or calcific emboli that typically lodge at the bifurcation of retinal arterioles or at a location as the vessel narrows. Hollenhorst plaques (cholesterol emboli) can often be seen at the site of vessel obstruction. Obstruction of blood flow results in partial or complete retinal ischemia and sudden loss of vision. There is no effective therapy for CRAO and BRAO. The authors employed the Nd:YAG laser to photodisrupt emboli within the central retinal artery (CRA) and branch retinal arteries (BRA) to achieve rapid reperfusion of the retina. Translumenal Nd:YAG embolysis (TYL) or embolectomy (TYE) was performed on 19 patients with sight-threatening CRAO or BRAO. All patients had a visible embolus within the CRA or BRA. A fundus contact lens was used to focus the Nd:YAG laser on the embolus within the retinal arteriole. Laser applications were delivered directly to the embolus with increasing energy until the embolus was either fragmented within the lumen (embolysis) or was observed to pass into the vitreous through a small opening in the arteriole (embolectomy). TYL/E was achieved in all 19 patients. In 8 patients the emboli was fragmented (embolysis) and in 11 the embolus was transplaced into the vitreous (embolectomy). Reperfusion of the retina was observed in all patients as determined by fundus examination, fundus photography, and fluorescein angiography. Snellen visual acuity improved by an average of 4.7 lines (range, 1-11 lines) in 17/19 (89%) patients. Eleven of the patients (58%) gained greater than 4 lines. One patient had no improvement and another lost one line due to a persistent vitreous hemorrhage. Vitreous hemorrhage (VH) occurred in seven patients, and subhyaloid hemorrhage (SH) occurred in one patient. In five of the patients an early vitrectomy was performed to allow clinical assessment and documentation of the successful TYL/E. Photodisruption of an embolus within an occluded CRA or BRA can be achieved via TYL/E. Rapid reperfusion of the retina is associated with anatomic and visual acuity improvement. Translumenal Nd:YAG embolysis or embolectomy of a visible embolus in patients with CRAO or BRAO can be achieved resulting in restoration of retinal blood flow and improved visual function.