Clinical Trials of our Technologies

 

Non-Damaging retinal laser therapy

            Despite the broad use of lasers in retinal therapy, the mechanisms leading to clinical benefits of the photocoagulation in the macula have never been understood. Assuming that these pathways are associated with cellular response to hyperthermia rather than with cell death, we measured the extent of tissue response below damage threshold. This included acute expression of heat shock protein (HSP70) in the retinal pigment epithelium, which activates native repair pathways, and longer-term activation of Müller cells. To ensure that the temperature rise is above the response threshold but below the damage threshold in every patient, we developed a quantitative model of tissue response to hyperthermia and a titration algorithm (EndPoint Management), which relates laser settings from observable titration lesion to non-damaging therapeutic settings. Lack of tissue damage allows (a) high density treatment to boost the therapeutic response, (b) treatment in the foveal areas, (c) periodic retreatments for chronic diseases or in cases of insufficient response.
            In clinical testing, we observed powerful therapeutic effect of such non-damaging retinal laser therapy (NRT) in chronic Central Serous Chorioretinopathy (CSCR), and early indications of the clinical efficacy in Macular Telangiectasia (MacTel), Diabetic Macular Edema (DME) and Branch Retinal Vein Occlusion (BRVO). NRT resulted in resolution of sub-retinal fluid and improvement in visual acuity in all treated patients with chronic CSCR. In MacTel patients, it not only stabilized the disease in all treated eyes, but also induced partial restoration of the photoreceptor layer – a result never seen before. Clinical success in CSCR, MacTel and other macular disorders suggests that NRT activates multiple endogenous tissue repair mechanisms, and might be applicable to other macular diseases, including retinal degenerations.

We are starting prospective, randimized clinical trials for the following macular disorders:
photovoltaic restoration of sight

            Retinal degenerative diseases can lead to blindness due to loss of photoreceptors, while inner retinal neurons are relatively well-preserved. Electrical stimulation of the inner retinal neurons allows reintroducing information into the visual system, thereby enabling restoration of sight. We developed a high-resolution photovoltaic retinal prosthetic system, and successfully tested it ex-vivo and in-vivo. In this system, processed images from video camera are displayed on video goggles, and projected through the eye optics onto the retina using pulsed near-infrared (880nm) light. Each pixel in the subretinal photovoltaic array converts light into electric current, which stimulates the nearby neurons. NIR light does not affect remaining photoreceptors and thus allows full utilization of the residual peripheral vision. Optical transmission of information to all pixels simultaneously allows for scaling up the number of electrodes to thousands. Lack of any wiring greatly simplifies the surgery and allows implanting multiple modules via small retinotomy to tile a large visual field. Optical projection of the images into the eye preserves the natural link between eye movements and visual information. We have demonstrated that arrays with 75 and 55 um pixels can restore sight in rats blinded by retinal degeneration, with spatial resolution matching the pixel pitch, indicating that smaller pixels may provide even higher visual acuity.

            In collaboration with Pixium Vision, we commercialized this system (PRIMA). The first clinical trial in patients who lost central vision due to age-related macular degeneration started in January 2018 in the Quinze-Vingts National Eye Hospital in Paris, under supervision of professor Jose Sahel. Initial results demonstrate that prosthetic visual acuity can closely match the pixel size (100um) in the current version of the implant.

electronic stimulation of tear secretion

            Millions of patients suffer from Dry Eye Disease – a debilitating condition with no effective treatment. Insufficient tear volume on the ocular surface caused by deficient tear production or excessive tear evaporation leads to tear hyperosmolarity, causing inflammation and nerve damage. We have demonstrated that electrical stimulation of lacrimal gland results in a dramatic increase in tear production.

           We developed neural stimulator (TrueTear, now manufactured by Allergan) which demonstrated excellent initial results in clinical tests, and is now approved for clinical use world-wide. Post-approval clinical trails are now starting to evaluate its benefits for patients with various forms of Dry Eye syndrome.
Smartphone-based Near Vision Testing System

           Smartphones enable frequent assessment of vision and enhanced automated analysis of the changes in visual functions. Easy access to the data by designated physicians may allow optimizing the treatment regimen for each patient. Home monitoring of the visual functions may help optimize the timing of anti-VEGF injections and avoid vision loss due to under-treatment and unnecessary office visits.

           DigiSight is conducting several clinical trials of the smarphone-based tests we developed for assessment of the visual functions in patients with various retinal diseases. Tests include visual acuity, contrast sensitivity, low-light acuity and metamorphopsia.