Radial optic neurotomy plus triamcinolone considered for central retinal vein occlusion

Columbus, OH-Performing radial optic neurotomy with adjunctive intraocular triamcinolone seems to be a feasible procedure for treating patients with central retinal vein occlusion (CRVO). The clinical resolution of the CRVO and the improved vision were similar when compared with the outcomes in patients who underwent radial optic neurotomy alone, according to E. Mitchel Opremcak, MD.

Dr. Opremcak, associate clinical professor, department of ophthalmology, Ohio State University, Columbus, and colleagues had previously reported their experience with 117 consecutive patients with severe CRVO who underwent radial optic neurotomy alone. The investigators found that the anatomic and visual outcomes compared favorably with the natural course of the disease 19 months after the surgery.

"However, we found that the macular function often was limited by persistent cystoid macular edema (CME) or the development of macular pigmentation," Dr. Opremcak said at the American Society of Retina Specialists meeting in Montréal. "Optical coherence tomography has taught us that there is substantial submacular fluid that often leads to macular pigmentation with the resolution of the central retinal macular edema and fluid. When we conducted subgroup analysis, we found that CME and macular pigmentation were correlated with worse visual acuity."

All 63 patients who underwent the combined procedure were similar to those who had undergone radial optic neurotomy alone. The patients in both groups were all older than 40 (average age, 65 years). All were followed for 9 to 11 months after the procedure, and only 5% were lost to follow-up. One difference between the studies was that in the first study more of the CRVO was perfused and in the second study more was indeterminate.

Differences in two studies

The rates of intraoperative hemorrhage also differed between the studies, with a rate of 18% in the first study and 8% in the second study; this difference, according to Dr. Opremcak, may have been the result of a surgeon learning curve and the CRVO blade. There was one case of endophthalmitis in the combination procedure group. The increases in IOP also differed, in that in the group that underwent radial optic neurotomy alone, 1% of patients had an IOP increase, while 25% of patients that underwent the combination procedure had an increase in IOP.

"In the patients who underwent the combination procedure, we found that about 95% had anatomic resolution of the CRVO," he reported. "In addition, 17% of patients in both studies still had persistent CME at the end of the study. Macular pigmentation was seen in 22% of patients in the first study and 28% in the second study. About 7% of patients developed anterior segment neovascularization after the combination procedure."

All patients had 20/200 or worse vision before surgery. Postoperatively, 28% in the first study and 34% in the second study had vision that exceeded 20/200; 18% in the first study and 15% in the second study achieved 20/80 vision.

"Most of the patients (94% in the first study and 98% in the second study) had vision that was equal to or better than the preoperative level; 71% in the first study and 68% in the second study gained one line of vision; 41% in the first and 39% in the second study gained three or more lines of vision; and 24% in the first and 20% in the second study gained four or more lines of vision," Dr. Opremcak reported.

"Surgical decompression of CRVO is technically feasible and safe in our hands. Both radial optic neurotomy and radial optic neurotomy with intraocular triamcinolone compared favorably with the natural history studies. The combined procedure paralleled the results of radial optic neurotomy alone, but there was a higher incidence of increases in IOP and a case of endophthalmitis with the combined procedure," he said.

He also noted that over the past year, the surgeries have been performed with a 50% air bubble and the requirement that patients maintain a face-down position for 1 day postoperatively. This is done, he explained, to displace pneumatically the submacular lipo-proteinaceous fluid that causes the macular pigmentation.

In addition, he suggested consideration of using intraocular 100% oxygen bubble rescues for certain diseases such as anterior ischemic optic neuropathy and recalcitrant and recurrent anaerobic endophthalmitis.