Materials and methods
retinal edema, painless, CRAO
SEVERE VISUAL IMPAIRMENT, RETINAL EDEMA
This exploratory clinical trial was an investigator-led, prospective, non-randomized, open-label, uncontrolled multicenter trial conducted at Chiba University Hospital, Kobe University Hospital, and Nagoya City University Hospital in Japan. This was a 12 weeks trial consisting of six TdES treatments in patients with CRAO. TdES was applied every 2 weeks for 6 weeks, as in our previous trial on patients with RP [The diagnosis of CRAO was made based on a history of sudden and painless unilateral severe visual impairment and ophthalmoscopic findings, such as retinal edema (ischemic retinal whitening) and cherry red spot sign (due to underlying normal choroidal circulation) in the macula, as well as normal appearance of the optic disc.Delay in retinal arterial filling, arteriovenous transit time, and normal choroidal vascular filling were confirmed by fluorescein angiography in the acute phase in all cases. Only patients with CRAO 6 months or longer after the onset were enrolled, as visual function may improve spontaneously more than 30 days after the onset [The patients underwent TdES consisting of 10-ms biphasic pulses at 20 Hz for 30 min. Only the affected eye was simultaneously stimulated with 1.0-mA pulses in all patients by physicians. One electrode was placed on the lower eyelid lateral to the midline of the affected eye, and the other was placed at the center of the forehead. Electrical pulses were obtained from the same equipment used in a previous clinical trials jointly developed by Mayo Co., Ltd. (Aichi, Japan).