Evaluation of radial optic neurotomy for central retinal vein occlusion by indocyanine green videoangiography and image analysis.
OBJECTIVE
To evaluate the effects of radial optic neurotomy (RON) on retinal circulation in patients with central retinal vein occlusion (CRVO) by indocyanine green (ICG) videoangiography and a computer-assisted image analysis.


METHODS
An interventional case series.


METHODS
RON was performed in 15 eyes of 15 patients with CRVO. Within 72 hours before the surgery and at 3 months after the surgery, ICG videoangiography was performed with a scanning laser ophthalmoscope, and the images were transferred to a computer. Two measurement points were selected, one on a main retinal artery close to the optic disk and the other on the corresponding retinal vein. At each point, fluorescence intensities were serially measured, and dye dilution curves were obtained. Retinal circulation times (DeltaT(50)) before and after the surgery were calculated.


RESULTS
Mean preoperative DeltaT(50) was 6.46 +/- 1.36 seconds, and mean postoperative DeltaT(50) was 6.80 +/- 2.50 seconds. In 8 of 15 eyes, T(50) decreased by 6.8% to 29.6% after the surgery. In the seven eyes that developed chorioretinal anastomosis (CRA) at the site of RON, DeltaT(50) decreased after the surgery. In contrast, DeltaT(50) decreased postoperatively in only one of the eight eyes without CRA. Best-corrected visual acuity improved significantly after the surgery in the group of eyes with improvement in DeltaT(50), but not in the group of eyes without improvement in DeltaT(50).


CONCLUSIONS
Some degree of retinal circulation improvement occurred in approximately half of these eyes, which appears to be correlated with the development of CRA.
Department of Ophthalmology, Kagawa University School of Medicine, Kagawa, Japan. nomoto@med.kagawa-u.ac.jp <nomoto@med.kagawa-u.ac.jp>
Hiroyuki
H
Nomoto
Fumio
F
Shiraga
Hidetaka
H
Yamaji
Mitsuyo
M
Kageyama
Hirokazu
H
Takenaka
Tetsuya
T
Baba
Yozo
Y
Tsuchida
D000368:Aged; D001775:Blood Circulation; D004396:Coloring Agents; D005260:Female; D005451:Fluorescein Angiography / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007208:Indocyanine Green; D008297:Male; D008875:Middle Aged; D009898:Optic Disk / Q000098:blood supply; D009900:Optic Nerve / Q000601:surgery*; D012170:Retinal Vein Occlusion / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D012171:Retinal Vessels / Q000503:physiopathology
D004396:Coloring Agents; D007208:Indocyanine Green