Colour Doppler Imaging for monitoring radial optic neurotomy in central vein occlusion

Purpose: Surgical decompression of central retinal vein occlusion(CRVO) has been proposed for a rapid reperfusion of the retina together with visual improvement. This procedure is still controversial. To evaluate the efficacy and role of transvitreal radial optic neurotomy, we monitored and studied with Colour Doppler imaging the flows of central retinal vein and artery before and after surgery.
Material and Methods: Nine eyes with severe central retinal vein occlusion were considered. Patients's mean age: 64.4 (range: 45–87). Mean duration of CRVO before surgery: 2 to 16 months. Transvitreal radial optic neurotomy was performed in all eyes with a standard technique. Complete ocular examination, visual acuity, macular OCT examination and Eco–Colour–Doppler examination were performed in all eyes before surgery, and one week and every months during the post–surgical follow–up. Mean follow–up was 4.7 ± 2.2 months (range: 1–6).
Results: Before surgery, medium central retinal venous flow was 4.2 ± 1.5 cm/sec (range: 2.6 – 7.4), mean visual acuity: 0.09 ± 0.1 (range: 0.001 – 0.3), and retinal thickness: 600 ± 97 µ (range: 491–755). After surgery, medium central venous flow was 4.2 ± 1.4 cm/sec (range: 3 – 6.6), mean visual acuity: 0.2 ± 0.2 (range: 0.002 – 0.8), and retinal thickness: 486 ± 114 µ (286–614 µ). A peripapillary nasal pucker developed in one case after surgery, successfully re–operated.
Conclusions: Our results, even if in a limited experience, showed a stabilization or slight improvement of central vein venous flow after surgery. Visual acuity was stable or improved. OCT showed a great variability in the macular thickness in the follow–up.