Abstract
Purpose: :
The electrical stimulation of neural tissues seems to have a neuro-protective effect; this study describes the effect of Transcorneal Electrical Stimulation (TES) with a non conventional biphasic bipolar waveform in central retinal artery occlusion with onset of more than 3 months.
Methods: :
In four patients 5 eyes were chosen with diagnosis of central artery occlusion (CRAO) and were treated with TES. Complete clinical evaluations, best corrected visual acuity (masked examination) and fluorescein angiography were performed. The TES was delivered by a monopolar contact lens electrode 3 times for 30 minutes every 3 weeks with a novel prototype system (10 minutes at 200mV/11.8 Hz, 10 minutes at 250mV/23.6Hz, and 10 minutes at 300mV/11.8Hz). The follow-up visits were at 1, 7, 15 days after stimulation; the clinical course was evaluated by BCVA, standardized electroretinogram and ophthalmic examination.
Results: :
This waveform model induced phosphenes in patients with CRAO. Electroretinogram reported an increase in the b wave amplitude (p<0.05). BCVA increased in three of the eyes from 5/350 to 10/300; 10/600 to 10/225 and from light perception to hand movement, respectively.
Conclusions: :
The phosphenes reported by the patients, and the visual acuity improvements suggest that the signal applied can stimulate retinal tissue and can increase retinal function. The registered response in this study is similar to previous reports.
Clinical Trial: :
www.clinicaltrials.gov NCT00802698
Keywords: neuroprotection • electroretinography: clinical • visual acuity