Retinal disease care at Mayo Clinic


Mayo Clinic ophthalmologists, eye surgeons, pediatric ophthalmologists, neuro-ophthalmologists and others work together to diagnose and treat adults and children with retinal diseases. Retinal experts collaborate with other specialists to provide care for the whole person. For example, if you have diabetic retinopathy, your eye doctor can consult with Mayo Clinic diabetes specialists to provide exactly the care you need.

The goal is to improve your quality of life by preserving as much eyesight as possible and preventing further vision loss. And when you need help dealing with vision loss, you can work with Mayo's low-vision experts.

The latest techniques and technology

Mayo Clinic doctors have expertise treating retinal diseases with medications, surgery, laser therapy and other options. Mayo Clinic offers an option called retinal prosthesis, which may help some people with severe vision loss or blindness owing to retinal disease.


Mayo Clinic physicians conduct retinal disease research and share knowledge to help advance care for people everywhere. Mayo Clinic's research activities include national studies that investigate innovative ways to preserve, rejuvenate and restore vision. You may have the opportunity to participate in clinical trials.

Bionic eye offers hope of restoring vision

Allen Zderad: I want to walk through the center of the door without any assistance.

Dennis Douda: The next step Allen Zderad takes will be one of the greatest strides forward in his life.

Allen Zderad: Right there.

Dennis Douda: One that allows him to see his future in an entirely new way.

Allen Zderad: Oh, yes!


Raymond Iezzi: You just saw your first sunshine.

Raymond Iezzi, Jr., M.D., Ophthalmology, Mayo Clinic: So, Mr. Zderad has a condition called retinitis pigmentosa. It's an inherited disease that involves the degeneration of a cell type in the retina called photoreceptors.

Dennis Douda: Mayo Clinic ophthalmologist and retinal surgeon Raymond Iezzi has made it his life's mission to try to restore vision - even artificial vision - for people like Allen.

Dr. Iezzi: The retina in these patients is relatively healthy except for the photoreceptors and so what we're trying to do is replace the function of these lost photoreceptors with the retinal prosthesis.

Dennis Douda: The prosthesis is basically a bionic eye. While decades of research have convinced Dr. Iezzi it's possible, this next moment convinces him that it's also essential.

Technician: There!

Allen Zderad: YEAH!

Technician: What do you see?

[Laughter. Clapping.]

Dennis Douda: With family members in tears, Allen is given his first glimpse of his wife Carmen in more than 10 years.

Technician: This is what his camera is capturing right now. This is the frame.

Dennis Douda: While the bionic system's interpretation of what Allen looks at may seem rough and pixilated to others, for Allen, it is literally an eye-opening revelation.

Allen Zderad: Oh, okay, it's going to take, yes, it is going to take interpretation of the shape of the light that's flashing. Okay. Because, it's a pulsing light. It's not like regular vision where it's constant. It's the flash and I've gotta be able to interpret the changes in that shape.

[Laughter. Clapping.]

Mrs. Carmen Zderad: Okay. Let's do it again, okay?

Allen Zderad: Yes! [Laughter] I picked you up! Oh! [Laughter] It's crude, but it's significant. You know, it'll work.

Dennis Douda: Allen knew his restored vision would be limited. While a sighted person would see this hallway like this, Allen's bionic eye converts the scene into flashes of light.

Dr. Iezzi: These small flashes of light are sort of like the points of light on a scoreboard at a baseball game.

Dennis Douda: To try to imagine how it might look to Allen, Dr. Iezzi says to picture contrasting light and dark blocks on a grid.

Dr. Iezzi: But by moving his head and using his visual memory and all of his cognitive skills and his remarkable capacity to get around, Mr. Zderad can reconstruct a scene.

Dennis Douda: How it works is a bio-engineering marvel, starting with the half-centimeter-wide electronic strip Dr. Iezzi placed inside Allen's eye.

Dr. Iezzi: It's a very delicate device and it's an array of electrodes that actually have to lay on a curved surface in the back of the eye where the retina is. And basically, we place an electronics package around the eye, fixate that electronics package and then we enter through the eyewall, through the white part of the eye. So there's actually a portion of the device that's outside of the eye and a portion of the device that's inside of the eye on the retinal surface.

Dennis Douda: Called the Argus II, the system is designed by Second Sight. Animation shows how 60 electrodes on a tiny grid stimulate the retina's cells with patterns of pulses, thus sending signals to brain.

Allen Zderad: Right here in the center over the bridge is where the camera is that's picking up the images. The front piece is a radio frequency antenna and the back piece is part of a video processing unit.

Dennis Douda: Several weeks after his operation, Allen says his ability to interpret the system's visual images is continually improving.

Allen Zderad: I feel more confident in being able to navigate around furniture items, chairs and tables.

Dennis Douda: Allen says moments of new found appreciation often surprise him, even during routine tasks, such as assembling his favorite breakfast egg sandwich.

Allen Zderad: The revelation as it were, was the fact that when I turned to look at the frying pan, I could tell that the eggs had turned white as a result of the cooking. And that was a very new experience for me.

Carmen Zderad: I think it'll help him to navigate better and just to enjoy a whole lot more in life. I mean, not that he doesn't enjoy life now, but this is just really cool.

Dennis Douda: Back to that morning when Allen's bionic eye was first activated, he wasn't the only one inspired by its potential. So was another one of Dr. Iezzi's retinitis pigmentosa patients, a teenage boy named Caleb, who also happens to be Allen's grandson. Should Caleb ever need it, the doctor says, the technology will only get better.

Dr. Iezzi: While Mr. Zderad has 60 points of stimulation, if we were able to increase that number to several hundred points of stimulation, I think we could extend the technology so that patients could recognize faces and perhaps even read.

Allen Zderad: So, I hope it's an encouragement to him to realize that I think that's a pretty exciting thing about the future for him.

Dennis Douda: Legally blind for most of his life, Allen says he adapted extremely well as the last rays of light gradually faded to darkness. But, he admits, this day was definitely the answer to a prayer.

Allen Zderad: There's always that desire to say, what would it be like if I could be more independent? If I could appreciate more of the things that are in my environment and enjoy participating more fully, because part of the issue is that you lose contact with the world around you.

Dennis Douda: One step at a time, Allen says he can't wait to see what's ahead.

Allen Zderad: Whoo, I can see with my eyes closed! It's gonna be an exciting journey.

Dennis Douda: For the Mayo Clinic News Network, I'm Dennis Douda.

Expertise and rankings


Each year, Mayo Clinic eye disease specialists, called ophthalmologists, treat thousands of people for all types of retinal conditions. These highly skilled specialists have advanced diagnostic tools and offer the latest treatments in an effort to restore, preserve or improve vision or to slow or stop diseases.

Nationally recognized expertise

Mayo Clinic ophthalmologists are widely respected for their expertise in rapidly evolving treatment options for retinal diseases, including many that are rare or complex. They regularly hold seminars for other physicians to share advances. And Mayo Clinic offers a retinal and vitreous surgery fellowship. This means doctors from throughout the United States who want to specialize in retinal diseases seek advanced training at Mayo Clinic.

Mayo Clinic in Rochester, Minnesota, is ranked high performing for ophthalmology by U.S. News & World Report.

Learn more about Mayo Clinic's Department of Ophthalmology expertise and rankings.

Locations, travel and lodging

Mayo Clinic has major campuses in Phoenix and Scottsdale, Arizona; Jacksonville, Florida; and Rochester, Minnesota. The Mayo Clinic Health System has dozens of locations in several states.

For more information on visiting Mayo Clinic, choose your location below:

Costs and insurance

Mayo Clinic works with hundreds of insurance companies and is an in-network provider for millions of people.

In most cases, Mayo Clinic doesn't require a physician referral. Some insurers require referrals or may have additional requirements for certain medical care. All appointments are prioritized on the basis of medical need.

Learn more about appointments at Mayo Clinic.

Please contact your insurance company to verify medical coverage and to obtain any needed authorization prior to your visit. Often, your insurer's customer service number is printed on the back of your insurance card.

More information about billing and insurance:

Mayo Clinic in Arizona, Florida and Minnesota

Mayo Clinic Health System

March 08, 2024


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