Vitreous Surgery for Central Retinal Artery Occlusion

Central retinal artery (CRA) occlusion is a devastating disease for which conventional therapies are often relatively ineffective.¹ Since CRA occlusion is usually caused by a physical obstruction in the CRA, we propose a mechanical means of relieving the obstruction. We postulate that cannulation of the CRA with a stylet during vitreous surgery may disrupt the obstructive agent and restore blood flow.²

A 68-year-old man with diabetes developed CRA occlusion in his left eye. On initial examination, his best-corrected visual acuity was counting fingers at 0.5 m OS. Funduscopy revealed a cherry red spot and severely narrowed retinal arteries. At approximately 30 hours after the onset of vision loss, conventional treatments had still resulted in no improvement in vision. The patient declined the option of selective thrombolysis. The option of vitrectomy with vessel cannulation and thrombus disruption under local anesthesia was then offered. The patient understood the experimental nature of this treatment and gave his informed consent.

After vitrectomy, one of us (W.M.T.) used a microvitreoretinal blade to penetrate the arterial wall at the central bifurcation of the retinal artery (Figure 1). No notable hemorrhage was noted. A 50-gauge flexible stylet made of nickel titanium was extended from a 19-gauge support shaft and used to cannulate the CRA through the arteriotomy site. Cannulation was confirmed by the ease of passage of the stylet into the CRA. Approximately 3.5 mm of the stylet entered the CRA. The stylet was moved using forward, backward, and circular motions, and then withdrawn. A small amount of semiclotted blood emerged from the arteriotomy site. The caliber of the superior retinal arteries increased partially after cannulation; however, the inferior retinal arteries remained severely narrowed. Because it was unclear how the procedure might affect the risk of ocular neovascularization, peripheral endophotocoagulation was performed prophylactically to minimize the risk.

Postoperatively, the patient was given oral aspirin, 325 mg daily. Examination findings on day 2 showed a visual acuity of counting fingers at 1.8 m. The appearance of the retinal vessels had not changed significantly since the procedure. By the next examination on day 10, the caliber of the retinal vessels had returned to normal (Figure 2). Angiographic images revealed a normal retinal circulation time. The latest follow-up examination findings at 4 months showed a corrected visual acuity of 20/25 OS. The cherry-red spot had disappeared. A laboratory evaluation revealed an atheromatous plaque in the thoracic aorta.

Cannulation of the CRA is a novel surgical approach that allows direct mechanical access to the site of obstruction. This method presents the advantage of avoiding the risk of neurological complications associated with selective thrombolysis.^2-4 In this case, immediate improvement in blood flow was modest. It seemed that the thrombus was only partially disrupted. In the future, to relieve the obstruction more completely, one might consider using a longer stylet or an infusion cannula to deliver thrombolytic agents into the CRA. The excellent recovery of vision in this case suggests that the restoration of blood flow may lead to functional improvement.

We do not have any commercial or proprietary interest in any product or instrument discussed in this article.

We thank Janice M. Burke, PhD, for providing eyebank tissue for laboratory testing with the support of core grant P30 EY01931 from the National Eye Institute, Bethesda, Md.

Reprints: William M. Tang, MD, Department of Ophthalmology, Boston University, 715 Albany St, Boston, MA 02118-2526 (e-mail: wtang@bu.edu).