Effect of Electrical Stimulation on Ocular Cells: A Means for Improving Ocular Tissue Engineering and Treatments of Eye Diseases

Table 2

A list of clinical trials on the effect of ES on ocular diseases.

NCT number	Conditions understudy	Interventions	(age)	Outcome		Status	Start date
NCT01600300	MD	Two period treatment with Tesmac device, twice/day for 5 days, with a two-day interval	40 (≥50)	NA	NA	Completed	2002
NCT01282827	Visual impairment	Repeated tACS (2 to 9 pulses, <1000 μA)	40 (18-75)	(i) Significant improvement of a VF detection deficit; (ii) Significant improvement of VA; (iii) EEG: increased synchronization in posterior brain regions; (iv) Patients’ visual improvements were stable for almost two months	Germany	Completed	2006
NCT00804102	RP, macula off, POAG, hereditary MD, treated retina detachment, retinal artery occlusion, retinal vein occlusion, nonarthritic-anterior-ischemic optic-neuropathy, hereditary autosomal dominant optic atrophy, dry AMD, ischemic ME	Transcorneal ES (Dawson-Trick-Litzkow electrode attached to patient eye)	80 (≥18)	(i) Safety of TES for RP patients.; (ii) VF area and scotopic b-wave amplitude were reached statistically significant; (iii) A larger sample size was needed for further investigations	Germany	Completed	2008
NCT01280877	Optic nerve diseases; Optic nerve injuries; Optic neuropathies	tACS (8 to 14 pulses, <1000 μA), 1 pulse per minute during 25-35 min	90 (≥18)	(i) VF improved in the rtACS-treated patients.; (ii) EEG: signs of neuromodulation (suggested as probable brain plasticity modulation); (iii) rtACS was reported as a safe and effective therapy for restoring vision	Germany	Completed	2010
NCT01630291	Dry eye	Electrode device for lacrimal gland stimulation	4 (≥18)	NA	Mexico	Completed	2012
NCT01835002	RP	Weekly ES using Okustim® device for a period of 30 min for 6 months	105 (18-80)	(i) Transient dry eye symptoms; (ii) No other serious adverse events post TES.; (iii) The safety profile of TES	Germany, UK, the Netherlands, Italy, Denmark, and Norway	Completed	2012
NCT01847365	RP	Weakly transcorneal ES using Okustim® device for a period of 30 min for 6 months	14 (≥18)	(i) Safety and well tolerance of TES application; (ii) No significant difference in visual function improvement	United Kingdom	Completed	2013
NCT02019927	NAION, trauma, MS	Transcorneal ES using the OkuVision device	97 (≥18)	NA	United States	Completed	2013
NCT04008589	Stroke	Repetitive transorbital AC stimulation combination of transcranial direct current stimulation and rtACS	45 (18-75)	NA	Germany	Completed	2014
NCT02086890	RP	Electro-acupuncture; Laser acupuncture transcorneal ES	21 (≥18)	(i) TES caused significant improvement in VA and VF; (ii) TES reduced RP visual dysfunctions; (iii) TES induced retinal blood flow.; (iv) TES improved visual function; (v) MVF regulated visual function	United States	Active, not recruiting	2014
NCT02405143	Stroke, infarction; posterior cerebral artery, hemianopsia	Active tACS using DC-stimulator MC	50 (18-75)	NA	Finland	Unknown status	2015
NCT02495935	Amblyopia	OkuStim®	40 (≥18)	NA	United States	Recruiting	2015
NCT02699216	Dry MD	ES of the retina	0 (≥50)	NA	NA	Withdrawn	2016
NCT03239418	Blepharoptosis; Lagophthalmos	Neuromuscular ES	60 (≥19)	NA	United States	Unknown status	2017
NCT02548572	RP	Transcorneal ES using Okustim device	0 (22-80)	NA	United States	Withdrawn	2019
NCT04042363	MS, optic neuritis	Transorbital ES (eyetronic next wave 1.1)	45 (18-60)	NA	France	Recruiting	2019
NCT04010994	Glaucoma	Transorbital ES	50 (≥18)	NA	Germany	Enrolling by invitation	2019
NCT04017234	Myopia	Frequency following response, eye exercise, and transcutaneous	27 (6-13)	NA	Taiwan	Recruiting	2019
NCT02540148	Dry AMD	Nova oculus™ microcurrent ES	60 (≥50)	NA	Canada	Recruiting	2019
NCT04634383	Ocular injury; Optic nerve diseases; Photoreceptor degeneration; Blindness, acquired	WFMA—wireless floating microelectrode array	5 (18-65)	NA	United States	Recruiting	2020
NCT04648085	Dry eye; Neuropathic pain; Eye pain	Transcutaneous ES	42 (>18)	NA	Mexico	Recruiting	2021

AMD: age-related macular degeneration; EEG: electroencephalogram; ES: electrical stimulation; : location; MD: macular degeneration; ME: macula edema; MS: multiple sclerosis; : number of patients; NAION: nonarteritic anterior ischemic optic neuropathy; NA: not available; POAG: primary open angle glaucoma; RP: retinitis pigmentosa; rtACS: repeated transcranial alternating current stimulation; VA: visual acuity; VF: visual field.