Vitreous composition modification after transpalpebral electrical stimulation of the eye: Biochemical analysis

Transcorneal Electrical Stimulation Modulates Visual Pathway Function in Mice

Due to its ability to modulate neuronal activity, electrical stimulation of the eye may be a promising therapy for preserving or restoring vision. To investigate how electrical currents can influence visual function, Transcorneal Electrical Stimulation (TES) was tested on both female and male C57BL/6 mice to evaluate its neuromodulatory effect from the retina to the cerebral cortex through visual evoked potential (VEP) and electroretinogram (ERG) recording. VEP or ERG was acquired before (baseline), immediately (t0), after 5 min (t5), and 10 min (t10) of sham (i.e., no stimulation) or TES applied on the eye of anesthetized C57BL/6 mice. Notably, TES affected neuronal activity in the visual pathway since a significant increase in VEP and ERG amplitude was detected and persisted 10 min after TES. The amplitude increase induced by TES could underlie an enhancement of neuronal excitability that may ameliorate retinal-genicular-cortical function in diseases involving the visual system.

Managing Retinitis Pigmentosa: A Literature Review of Current Non-Surgical Approaches

Retinitis pigmentosa (RP) is a heterogeneous group of inherited retinal diseases characterized by the progressive loss of photoreceptor function, visual impairment, and, ultimately, blindness. While gene therapy has emerged as a promising therapy, it is currently available only for the RPE65 gene mutation, leaving many patients without targeted genetic treatments. Non-surgical interventions may help in managing the progression of RP and improving patients' quality of life. Visual training and rehabilitation, maximizing residual vision, have shown potential in improving mobility and patients' ability to perform daily activities. Visual aids enhance visual function. Moreover, photo-protection demonstrated effectiveness in mitigating light-induced damage and improving visual comfort. Alternative therapies (i.e., electrostimulation, acupuncture, and ozone therapy) are being explored to preserve retinal function and reduce disease progression. Pharmacological interventions supported by nutritional and psychological counseling play a role in slowing retinal degeneration while managing the emotional burden of progressive vision loss. Although for these interventions, further validation is required, their potential benefits make them valuable additions to care for RP patients. The integration of these interventions into a multidisciplinary care approach-including ophthalmologists, orthoptist, dietitians, and psychologists-is essential for providing comprehensive, personalized care to RP patients while awaiting more widespread gene therapy solutions.

Evaluation of visual acuity in dry AMD patients after microcurrent electrical stimulation

BACKGROUND

To assess micro current to improve vision for dry age-related macular degeneration. Dry age-related macular degeneration is a major cause of blindness, disability, and severe erosion of quality of life, throughout the world. Beyond nutritional supplementation, there is no approved therapy.

METHODS

This was a prospective randomized sham controlled clinical trial for participants with confirmed dry AMD with documented visual loss. Participants were randomized three to one, to receive transpalpebral external micro current electrical stimulation with the MacuMira device. The Treatment group received four treatments in the first two weeks, and two further treatments at weeks 14 and 26. Differences in BCVA and contrast sensitivity (CS) were estimated with mixed-effects repeated measures analysis of variance.

RESULTS

Change of visual acuity with ETDRS assessment of number of letters read (NLR) and contrast sensitivity at week 4 and 30, compared to the first visit, between 43 treatment and 19 sham control participants. The Sham Control group had NLR of 24.2 (SD 7.1) at baseline, 24.2 (SD 7.2) at 4 weeks, and 22.1 (SD7.4) at 30 weeks. The Treatment group had NLR of 19.6 (SD 8.9) at baseline, 27.6 (SD 9.1) at 4 weeks, and 27.8 (SD 8.4) at 30 weeks. The change in NLR from baseline in the Treatment compared to the Sham control group was 7.7 (95% CI 5.7, 9.7, p < 0.001) at 4 weeks and 10.4 (95% CI 7.8, 13.1, p < 0.001) at 30 weeks. There were similar benefits in CS.

CONCLUSIONS

This pilot study of transpalpebral microcurrent demonstrated improved visual measures and is very encouraging as a potential treatment for dry AMD.

TRIAL REGISTRATION

NCT02540148, ClinicalTrials.gov.

Electrical neurostimulation in glaucoma with progressive vision loss

Background

The retrospective study provides real-world evidence for long-term clinical efficacy of electrical optic nerve stimulation (ONS) in glaucoma with progressive vision loss.

Methods

Seventy glaucoma patients (45 to 86 y) with progressive vision loss despite therapeutic reduction of intraocular pressure (IOP) underwent electrical ONS. Closed eyes were separately stimulated by bipolar rectangular pulses with stimulus intensities up to 1.2 mA sufficient to provoke phosphenes. Ten daily stimulation sessions within 2 weeks lasted about 80 min each. Right before ONS at baseline (PRE), vision loss was documented by static threshold perimetry and compared to the same assessment approximately 1 year afterwards (POST). Mean defect (MD) was defined as primary outcome parameter. Perimetries with a reliability factor (RF) of max. 20% were considered.

Results

Perimetry follow-up of 101 eyes in 70 patients fulfilled the criterion of a max. 20% RF. Follow-up was performed on average 362.2 days after ONS. MD significantly decreased from PRE 14.0 dB (median) to POST 13.4 dB (p < 0.01). 64 eyes in 49 patients showed constant or reduced MD as compared to baseline (PRE 13.4 dB vs. POST 11.2 dB). In 37 eyes of 30 patients, MD increased from PRE 14.9 dB to POST 15.6 dB.

Conclusions

Innovative treatments that preserve visual function through mechanisms other than lowering IOP are required for glaucoma with progressive vision loss. The present long-term data document progression halt in more than 63% of affected eyes after ONS and, thus, extend existing evidence from clinical trials.