Wearable Eye Technologies

Bionic Eye Technology: A Promising Device for Patients With Age-Related Macular Degeneration

Thomas A. Finley, MD

Technological solutions are being applied to challenging eye conditions in hopes of providing better outcomes to patients. Oculenz AR Wear glasses (Ocutrx Technologies; Figure 1) are a perfect example.

Known by some as a bionic eye, these augmented reality (AR) glasses address a variety of concerns for patients with age-related macular degeneration (AMD), including blurry or dark/blind spots and distorted shapes and colors that can make the activities of daily living such as reading, writing, and recognizing faces difficult or impossible. A technological solution that addresses the visual side effects of this condition could have a giant impact on the care and quality of life of individuals with AMD.

DESIGN

The Oculenz AR Wear was unveiled at the Mobile World Congress in 2019. The product’s lightweight structure (< 200 g) and floating lens design provide a new visual-assistance option for those with AMD. An eye-tracking camera housed in the nosepiece helps direct computer-mediated video to line up with the user’s natural gaze. The camera works at a speed of 200 Hz, which helps keep the image properly stabilized and in line with the scotoma.

The Oculenz AR Wear is the only technology that can address a scotoma without using magnification. Most visual-assistance devices for individuals with AMD magnify or adjust the image around the scotoma, which leaves a defect in the patient’s vision. These glasses measure and track the size of the scotoma and use AR technology to fill in the missing visual to display a full field of vision to the retina, giving the patient a more complete picture. This is particularly valuable for reading because words or letters are often left out with magnification, whereas they are visually filled in with the Oculenz AR Wear (Figure 2).

WHY AR?

AR makes sense for holistic patient care. This technology overlays graphics on the natural environment, whereas virtual reality solutions involve wearing a large headset that blocks peripheral vision.

Virtual reality can create immersive experiences, but it also obstructs input from the user’s surroundings. With the AR technology of the Oculenz AR Wear, the wearer can walk around and participate in normal activities while receiving visual assistance.

Another notable feature of the Oculenz AR Wear is that it offers a visual field test for at-home patient care. The test takes about 5 minutes to complete per eye. Patients take the test with the headset on to help identify the location of a defect. This allows the glasses to identify which areas require pixel manipulation.

The Oculenz AR Wear is a connected device, so it can alert the patient’s physician if self-directed visual field testing indicates that the size of a scotoma has increased significantly. This facilitates earlier detection of AMD progression and earlier care and treatment.

CONCLUSION

The Oculenz AR Wear has the potential to improve care for individuals with AMD. Patients can benefit from this technology in their real-world environment.

Mojo’s Electronic Contact Lens for Patients With Low Vision

Jeffrey Sonsino, OD, FAAO

In early 2020, I visited the Mojo headquarters in Silicon Valley. The team had just finished building a prototype of their electronic smart contact lens, and I was to be the first person from outside the company to wear it. This novel scleral lens projects AR images onto the retina using an image sensor facing out and a projector facing in. Mojo has an all-star team; one of its founders invented dial-up for early internet access, and a team leader worked on the original iPhone (Apple). At the time of my visit, the company had raised more than $100 million. Its latest contact lens technology is well positioned for success.

PREPARATIONS

An impression of my ocular surface had been taken a month in advance of my visit using a process developed by scleral lens manufacturer EyePrint Prosthetics. In this painless process, a plastic tray is filled with an amalgam that is similar to dental impression material and is placed on the ocular surface. The impression is sent for conversion into a computer-aided design (CAD) image (Figure 3).

Once a CAD image is generated, a custom scleral lens can be manufactured that offers complete rotational stability. The hassle of trial-and-error fitting is avoided. Rotational stability is necessary to ensure the correct orientation of images projected onto the retina.

TECHNOLOGICAL CHALLENGES

The technical hurdles of creating an electronic contact lens were complex. The microelectronic components were novel and therefore had to be custom fabricated. A scleral lens base had never before housed electronics, so a redesign was required. The Mojo team had to devise a way to transmit an adequate amount of oxygen through a lens that had to be thicker than the standard 200 to 400 µm.

They created an air-gap design (Figure 4) that provides ample oxygenation of the cornea and sclera. This was demonstrated in their unpublished studies with Joe Benjamin, OD, PhD.

Figures 3 and 4 courtesy of Jeffrey Sonsino, OD, FAAO

EXPERIENCE

Wearing the prototype was a life-changing experience that showed me what the future holds for humans. Engineers projected text and images into my central field of view in real time while I viewed the world around me. The purpose of the Mojo lens is to create a true AR experience for the user. My experience with the technology was fun and interesting, but the first application of real clinical benefit (and for FDA clearance) will be to aid people who are visually impaired.

I have worked with children who are visually impaired for the past 19 years, most recently at the Smokey Powell Center at Georgia Academy for the Blind. Once the Mojo lens has been proven safe and effective for adults, I believe children with visual impairments will readily adopt an AR contact lens designed to assist them with orientation and mobility and enhance contrast; this generation is so accepting of technology. Providers such as myself were once limited to prescribing optical devices for patients. Now, we can use technology to help solve problems such as magnification. The potential for AR contact lenses to increase magnification, enhance contrast, and label borders for orientation and mobility may occur with the next software update.

Technology such as this has the potential to provide significant benefits to patients. The ultimate goal is to create an AR scleral lens that can be used as a mass-market consumer electronic solution. This could attract more patients to eye care providers than ever before.^1,2 In the process, optometrists and ophthalmologists would have an opportunity to diagnose and treat ocular pathology at an earlier stage, which could dramatically decrease vision loss.

1. Liao Y, Bang D, Cosgrove S, et al. Surveillance of health status in minority communities---racial and ethnic approaches to community health across the U.S. (Reach U.S.) risk factor survey, United States, 2009. Center for Disease Control. Morbidity and Mortality Weekly Report. May 20, 2011;60(SS06):1-41.

2. Vision Health Initiative. Fast facts of common eye disorders. Centers for Disease Control and Prevention. Reviewed June 9, 2020. Accessed May 26, 2021. www.cdc.gov/visionhealth/basics/ced/fastfacts.htm

OcuMedic Freedom Lenses: Drug-Releasing Bandage Contact Lenses for Drop-Free Postoperative Treatment

Mark E. Byrne, PhD, FAIMBE

The topical therapy regimen required after cataract surgery is widely acknowledged to be the biggest negative of what is otherwise a straightforward and elegant procedure. One study found problems with compliance in more than 90% of patients.¹ Even if compliance is perfect (ie, drops are administered correctly and on schedule), poor bioavailability due to quick tear turnover and barriers to ocular transport can significantly limit the effectiveness of topical eye drops.² A drop-free treatment strategy has the potential to increase the efficacy and convenience of therapy.

Contact lenses are noninvasive and well accepted by patients, and these devices have a strong safety record. It is not surprising, therefore, that the controlled release of drugs from contact lenses has been a subject of investigation for more than 60 years. No such technology has made it to market³ because of poorly controlled drug release and inadequate commercial physiochemical lens properties. Freedom silicone hydrogel lenses (OcuMedic) has overcome these obstacles. (See video below.)

DRUG-ELUTING LENS TECHNOLOGY

The drug of choice in OcuMedic’s patented technology is noncovalently linked with the monomer building blocks of the polymer contact lens network during synthesis. This creates a lens polymeric network with small pores or macromolecular memory, unique for each drug, while maintaining all of the lens’ commercial properties. The patented technology enhances the chosen drug’s affinity to the polymer and allows a high payload without preservatives. The rate at which a drug is released from the lens can thus be controlled as the drug moves from one memory site to the next and is released from the lens. The goal is a stable, therapeutic concentration of drug for the duration of lens wear (Figure 5).

Courtesy of Mark E. Byrne, PhD

In preclinical studies, OcuMedic’s lenses have demonstrated sustained drug release with a constant ocular concentration of drug for the duration of wear, ranging from daily (1 day) to weeklong (7 days), compared to commercial topical drops. Bioavailability was more than 25 times higher than for topical drops currently on the market. Complete ophthalmic examinations and ocular tissue histology performed before and after wear showed that the lenses were safe and well tolerated.

OcuMedic’s lenses can be manufactured in afocal, multifocal, or other vision-correcting models or in plano or bandage models that offer no vision correction. Preclinical studies have shown that these lenses can provide combination therapy by releasing multiple drugs, each at a tailored rate (data on file, OcuMedic). As a platform technology, lenses have been produced for use with certain agents, including steroids, NSAIDs, antibiotics, IOP-lowering drugs, antihistamines, and lubricating agents.

A NEW PARADIGM

Freedom silicone hydrogel bandage lenses are designed to release an NSAID (bromfenac) over the course of 1 week with continuous wear. The constant dosing rate can facilitate compliance, provide more effective therapy, and offer greater convenience compared to therapy with topical drops. After cataract surgery, a new contact lens is placed each week and the amount of drug delivered may be increased or decreased on lens replacement over a 2- to 6-week period. Over 6 weeks, six lenses can replace up to 84 drops. After refractive surgery, one or two lenses can replace seven to 14 drops.

The primary treatment strategy after cataract surgery involves the placement of a Freedom bandage lens that releases a first-line NSAID (bromfenac) and the single-dose injection of a broad-spectrum antibiotic (moxifloxacin) via intracameral irrigation intraoperatively at the conclusion of cataract surgery. Intracameral antibiotics have been found to reduce the risk of endophthalmitis six- to sevenfold compared to topical antibiotic eye drops.⁴ An appropriate dose of moxifloxacin accounts for aqueous turnover. Potential benefits of this drop-free approach utilizing the bromfenac releasing lens and injection for endophthalmitis prophylaxis⁵ include more control of inflammation without compromising corneal endothelial regeneration/function or increasing IOP and the risk of pseudophakic cystoid macular edema.⁶

OcuMedic has met with the FDA and is planning human clinical trials of the technology. This is expected to begin soon.