In his letter, Dr Hayreh raises a number of interesting points related to our article, “Radial Optic Neurotomy for Management of Hemicentral Retinal Vein Occlusion,”1 based on his extensive research and clinical studies over the last several decades.
As described by Hayreh and Hayreh2 in an article on the natural history of 41 patients with HCRVO, around 16 (40%) of the cases had retinociliary collateral vessels at the time the condition was diagnosed and 29 (75%) showed collateral vessels during follow-up. Nevertheless, Hayreh and Hayreh do not specify the time of evolution of HCRVO at the initial examination; hence, some of the patients might have had visual symptoms for several months before the initial evaluation. Fuller et al3 found that cilioretinal collateral vessels appear spontaneously at around 6.7 months in patients with CRVO. In our experience of 20 cases of HCRVO1 diagnosed among 232 retinal vein occlusions, no patients had retinochoroidal anastomoses at the initial evaluation whereas 6 (46%) of the 13 patients with HCRVO who underwent surgery developed chorioretinal anastomoses following the procedure. The anastomotic vessels were at the site of the nasal neurotomy as early as 3 weeks postoperatively. In contrast, only 1 of the 7 patients who remained under observation showed chorioretinal anastomosis at the 6-month follow-up visit. In addition, the group of patients with retinochoroidal anastomoses in our series showed a tendency toward achieving a better mean final visual acuity (VA) than those without collateral vessels, although the differences were not statistically significant (P>.05).
García-Arumí J, Boixadera A, Martínez-Castillo V. Radial Optic Neurotomy for Management of Hemicentral Retinal Vein Occlusion—Reply. Arch Ophthalmol. 2006;124(12):1799-1800. doi:10.1001/archopht.124.12.1799