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Hirokazu Sakaguchi

Publications and source records attributed to Hirokazu Sakaguchi.

21 records · Page 2Linked to original sources
PubMedDate not supplied

Electrical stimulation with a needle-type electrode inserted into the optic nerve in rabbit eyes.

PURPOSE: To investigate whether electrical stimulation of the optic nerve can elicit an electrical evoked potential (EEP) in rabbits and to determine whether such stimulation is a useful approach for the placement of a visual prosthesis. METHODS: Two needle-type electrodes were inserted into the optic nerve using a transvitreal approach. For electrical stimulation, monophasic and biphasic pulses were used. By stimulating the optic nerve, the EEP was elicited. After evaluation of the EEP, a histological study was carried out. RESULTS: When electrical stimulation was applied, the EEP could be recorded. The threshold with monophasic and biphasic stimulation was 10 +/- 0 microA and 20 +/- 8.2 microA, respectively. Histological examination revealed no major complications, such as bleeding or degeneration, which might have resulted from the insertion of electrodes or the electrical stimulation. CONCLUSIONS: Electrical stimulation of the optic nerve can elicit an EEP, suggesting that this approach may be useful for a visual prosthesis system.

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PubMedDate not supplied

Radial optic neurotomy for the management of hemicentral retinal vein occlusion: long-term follow-up study.

PURPOSE: To assess the efficacy of radial optic neurotomy (RON) for hemicentral retinal vein occlusion (hemi-CRVO) in patients with follow-up of >12 months. METHODS: Five consecutive patients with hemi-CRVO were enrolled in the study and underwent vitrectomy with RON. The effects of this treatment were assessed by visual acuity, optical coherence tomography, indocyanine green angiography, and kinetic visual field testing. RESULTS: The median and mean visual acuities improved from 20/250 to 20/50 and from 20/286 to 20/51, respectively. Four patients (80%) had visual acuity improvement of > or =3 lines; visual acuity in 1 patient (20%) remained the same. Visual acuity in all four eyes with preoperative visual acuity of <20/200 improved to >20/200 12 months after surgery. Foveal thickness was gradually reduced during the follow-up period. Chorioretinal anastomosis was detected by indocyanine green angiography in 3 eyes (60%). A temporal visual field defect was found in two eyes. No neovascularization on the iris, angle, optic disk, or retina was detected postoperatively. CONCLUSION: Visual acuity may improve more with RON compared with the natural history of the disease, and no neovascular formation may occur after RON, suggesting that this procedure may be an effective treatment for hemi-CRVO.

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