PurposeThe aim of this article is to investigate the effect of transcorneal electrical stimulation (TES) on chorioretinal blood flow in healthy human subjects.MethodsThe chorioretinal blood flow of 10 healthy subjects was measured before and after TES by laser speckle flowgraphy and expressed as the square blur rate (SBR). The chorioretinal blood flow was determined before and immediately after TES and 0.5, 1, 1.5, 2, 2.5, 3, 24, and 40 h after TES in three different areas: the margin of the optic disc, a point located midway between the optic disc and macula, and the macula area. The SBR of the stimulated eye is expressed relative to the value of the fellow eye. The mean standardized blur ratio was calculated as the ratio of the standardized SBR to the baseline SBR. The changes of intraocular pressure (IOP), blood pressure (BP), and pulse rate (PR) were determined after each measurement of the SBR. The ocular perfusion pressure (OPP) was calculated from BP and IOP.ResultsThe mean standardized blur ratio at the optic disc did not change significantly throughout the course of the experiment. However, the mean standardized blur ratio midway between the optic disc and macula and at the macula area were significantly higher after TES than that after sham stimulation at 3 and 24 h (P < 0.05, P < 0.01, respectively). At all times, the mean BP, PR, IOP, and OPP were not significantly different from the prestimulation values.ConclusionsTES increases the chorioretinal blood flow in normal subjects with minimal effects on the systemic blood circulation and the IOP. The increase in chorioretinal blood flow may be one of the beneficial effects that TES has on ischemic retinal diseases.

Purpose:To investigate the effects of transcorneal electrical stimulation (TES) on eyes that have a branch retinal artery occlusion (BRAO).Subjects and method:We studied two eyes having a BRAO, with an interval between the onset of symptoms and the beginning of treatment of >16 weeks (longstanding cases), and in three eyes with an interval of <16 weeks (fresh cases). The visual functions of the eyes were assessed by the best-corrected visual acuity (BCVA), multifocal electroretinograms (mfERGs), and automated static perimetry with the Humphrey field analyzer (HFA). The mfERGs were recorded before and 1 month after the TES, and perimetry with the HFA was done before and at 1 and 3 months after the TES. The amplitudes and implicit times of the N1, P1, and N2 components of the mfERGs were analyzed.Results:TES did not alter the BCVA significantly in all eyes, but it led to a significant increase in the amplitude of the N2 wave of the mfERGs (P < 0.01). The amplitude of the N1–P1 was also increased but not significantly. The implicit times of N1 (P < 0.01) and P1 (P < 0.05) were significantly shorter than that before the TES. The mean deviation of the HFA was increased after the TES but only in the longstanding cases.Conclusion:Our results indicate that TES improves the visual function in eyes with BRAO, mainly in longstanding cases.