Electrical stimulation--a therapeutic strategy for retinal and optic nerve disease?

The Use of Electrotherapeutics in Ophthalmology

PURPOSE

To present a perspective on the use of electrotherapeutics in the history of ophthalmology along with the development of novel contemporary ophthalmic instrumentation.

DESIGN

Perspective study.

METHODS

We reviewed historical journals, articles, and books discussing the use of electricity and electrotherapeutics in ophthalmology.

RESULTS

Electrotherapeutic applications have been researched and used to treat ocular diseases as far back as the 18th century. By the 20th century, research in electrotherapeutics in ophthalmology had caught the eye of Edward Jackson, the first president of the American Academy of Ophthalmology and Otolaryngology and first editor of the present (third) series American Journal of Ophthalmology. Edward Jackson published an extensive review on this topic and reported a variety of modalities used to treat ocular diseases.

CONCLUSIONS

While many early therapeutic uses of electricity did not produce effective and replicable results, studies on electrical stimulation of the eye provided the foundation for the development of clinically significant vision enhancing and restoring instrumentation.

Microcurrent stimulation in the treatment of dry and wet macular degeneration

Purpose

To determine the safety and efficacy of the application of transcutaneous (transpalpebral) microcurrent stimulation to slow progression of dry and wet macular degeneration or improve vision in dry and wet macular degeneration.

Methods

Seventeen patients aged between 67 and 95 years with an average age of 83 years were selected to participate in the study over a period of 3 months in two eye care centers. There were 25 eyes with dry age-related macular degeneration (DAMD) and six eyes with wet age-related macular degeneration (WAMD). Frequency-specific microcurrent stimulation was applied in a transpalpebral manner, using two programmable dual channel microcurrent units delivering pulsed microcurrent at 150 µA for 35 minutes once a week. The frequency pairs selected were based on targeting tissues, which are typically affected by the disease combined with frequencies that target disease processes. Early Treatment Diabetic Retinopathy Study or Snellen visual acuity (VA) was measured before and after each treatment session. All treatment was administered in a clinical setting.

Results

Significant increases were seen in VA in DAMD (P=0.012, Wilcoxon one-sample test), but in WAMD, improvements did not reach statistical significance (P=0.059). In DAMD eyes, twice as many patients showed increase in VA (52%) compared to those showing deterioration (26%), with improvements being often sizeable, whereas deteriorations were usually very slight. In WAMD eyes, five of six (83%) patients showed an increase and none showed deterioration.

Conclusion

The substantial changes observed over this period, combined with continued improvement for patients who continued treatment once a month, are encouraging for future studies. The changes observed indicate the potential efficacy of microcurrent to delay degeneration and possibly improve age-related macular degeneration, both wet and dry. However, this study has no control arm, so results should be treated with caution. Randomized double-blind controlled studies are needed to determine long-term effects.