Do Both Eyes Get Gene Therapy, and What Happens When They Treat the Second One?
Gene Therapy for Both Eyes, at a Glance
Yes. When gene therapy is the right choice for an inherited retinal disease caused by the RPE65 gene, both eyes can be treated, but not on the same day. Each eye is treated separately, in two visits at least six days apart.1 The second eye receives the same kind of procedure as the first. This page explains what that second surgery involves, why the eyes are spaced apart, and what to expect from treating them one at a time.
Treating one eye at a time is deliberate, not a delay. It lets your surgical team focus fully on each eye and watch how the first one settles before moving to the second. Each eye undergoes its own procedure in the operating room, and the two are done at least one week apart.2 Spacing the surgeries also spreads out the recovery, so you are never healing from both eyes at once.
This is not a routine clinic procedure. It is carried out at a small number of specialized centers by a retina surgeon working with a genetics team. Because the therapy targets one specific genetic cause of vision loss, genetic testing and a detailed eye evaluation come first. If the patient is a young child, the same team guides the family through each step and each eye.
What This Gene Therapy Is and the Disease It Treats
The RPE65 gene helps the retina turn light into the signals your brain reads as vision. When both copies of this gene carry a fault, the retina cannot do that job well, and vision, especially in dim light, fades over years. Faults in the RPE65 gene cause forms of retinitis pigmentosa and Leber congenital amaurosis, in which light-detecting cells in the retina break down over time.3 These are inherited conditions, present from birth in the genes even when symptoms come later.
The treatment does not remove the faulty gene. It adds a working copy. A single injection delivers a healthy copy of the RPE65 gene to the retina and restores the retina's ability to respond to light.3 The healthy gene is carried into the retinal cells by a harmless, modified virus used only as a delivery vehicle. Once inside, the cells can make the protein they were missing.
This therapy is not a cure, and it does not rebuild a retina that has already been lost. It works by giving still-living cells the instructions they were missing. Given early enough after diagnosis, it can improve night vision and help people better navigate in low-light conditions.3 How much any one person gains varies, which is why the team frames results as realistic improvement rather than a promise of normal sight.
How the Treatment Works in Each Eye
The healthy gene has to reach the layer of cells at the very back of the eye. Luxturna is delivered as a subretinal injection in the operating room while the patient is under anesthesia.2 A retina surgeon places a tiny amount of fluid, carrying the gene, gently beneath the retina, where it can spread to the target cells. The vector carrying the gene is injected beneath the retina by a surgeon.1
The plan is the same for each eye, just carried out on two different days. Patients undergo two separate procedures, one for each eye, at least one week apart.2 The second surgery repeats the first: the same subretinal injection, the same surgical team, the same care afterward. Because the eyes are treated on separate dates, you go through the process twice rather than recovering from both at once.
A short course of medicine calms the eye's response to the new gene. Oral steroids are started before the injection and continued for a time afterward.1 This same steroid plan is used around each eye, so the second eye gets its own course. Your team will tell you exactly when to start the tablets and how to taper them down.
Who Is a Candidate for Treatment in Both Eyes
The therapy is matched to one specific genetic cause, so a genetic diagnosis comes first. It is only for patients who have a mutation in both copies of the RPE65 gene.3 A general diagnosis of retinitis pigmentosa is not enough on its own. The exact gene must be confirmed by testing before treatment is considered for either eye.
Adding a working gene only helps if there are still cells alive to use it. A complete clinical evaluation and testing are needed to determine whether enough cells remain in the retina to receive the treatment.2 This is checked in each eye. An eye with too little surviving retina may gain little, even when the gene fault is the right one.
Both children and adults can be candidates. Children over 12 months of age and adults with genetically confirmed mutations in both copies of the RPE65 gene may be candidates for gene therapy.2 Because the retina keeps losing cells over time, being evaluated sooner rather than later gives each eye its best chance to benefit.
The Consultation and Testing Before You Decide
The first step is confirming the gene, usually with a blood test. Genetic test results showing mutations inherited from both parents in the RPE65 gene are part of the evaluation.2 Sometimes parents are tested too, to show that one faulty copy came from each side. This confirmation is what makes the therapy appropriate, because it treats this gene and no other.
Alongside the genetics, each eye is examined in detail to map how much working retina remains. This tells the team whether one or both eyes are likely to benefit, and it sets a baseline to compare against after treatment. The evaluation is where the plan for treating the second eye, and the spacing between the two surgeries, is worked out with you.
A good consultation is a two-way conversation. Expect to discuss what improvement is realistic for each eye, the risks of surgery, the steroid course, and the schedule for both eyes. If the patient is a child, the team will explain how anesthesia and recovery are handled for a young patient. This is the moment to raise every question before any date is set.
When Gene Therapy Is Not the Right Option
This therapy is built for one gene. It is not for retinal disease caused by other genes, only for a confirmed mutation in both copies of RPE65.3 Many inherited retinal diseases are caused by other genes, and for those this specific treatment does not apply. Genetic testing is what separates the two, which is why it is required first.
If the retina no longer has enough living cells, adding a healthy gene has little to work with. Whether enough retinal cells remain is judged by a full clinical evaluation and testing, done for each eye.2 An eye that has degenerated too far may not be offered treatment, even when the gene fault matches. This is decided eye by eye, so the two eyes can differ.
Ordinary surgical caution still applies. An active eye infection, another eye problem that needs attention first, or a medical reason that makes anesthesia unsafe can all delay a procedure. These are usually reasons to wait and treat later, not permanent barriers. Your team will tell you what needs to be settled before each eye's surgery goes ahead.
Recovery After Each Eye
Recovery is handled one eye at a time, which keeps it manageable. The treatment does not usually require an overnight hospital stay.1 You go home the same day and take the steroid tablets as directed. Some soreness, redness, or light sensitivity in the treated eye is common early on, and your team will explain how to care for the eye while it settles.
Close follow-up matters after each injection. Follow-up visits occur at about one week, one month, and five months after treatment.1 These checks confirm the eye is healing and track any early change in vision. Keep every appointment, even if the eye feels fine, because some issues are easier to catch on an exam than to feel.
Because the eyes are treated on separate days, you go through recovery twice, with its own steroid course and follow-up for the second eye. The upside is that you are never healing from both eyes at the same time, so one eye is always further along. Many people find the second recovery more predictable, having been through it once already.
Risks, Results, and the Long-Term Outlook
Results are real but vary from person to person. In the main study, 27 of 29 treated patients, about 93 of every 100, improved enough to navigate a maze in low to moderate light.4 The clearest gains tend to be in dim-light vision and moving around safely, rather than in reading fine print. Your own results depend on how much healthy retina each eye still had going in.
Any eye surgery carries some risk, and this one is no exception. Because the gene is placed under the retina in the operating room, possible problems include eye inflammation, raised eye pressure, a tear or thinning of the retina, and, rarely, a change that reduces rather than improves vision. These are uncommon, and the surgical team watches for them at each follow-up. Weigh them against the vision the eye stands to gain, eye by eye, with your surgeon.
The healthy gene is meant to keep working in the cells it reached, and each treated eye is followed over time to see how the benefit holds. Treating both eyes aims to help vision on both sides, not just one. Long-term monitoring continues after the second eye, because this is still a relatively new therapy and the team wants to track both eyes for years, not months.
When to Call Your Doctor
Most recovery is smooth, but some changes need prompt attention. Call your eye team the same day, or seek urgent care, if a treated eye develops increasing pain, growing redness, new or worsening vision loss, a curtain or shadow across your sight, or a sudden shower of new floaters or flashes. These can signal a problem such as infection, raised pressure, or a retinal issue that is easier to treat early. Do not wait for your next scheduled visit if these appear.
Between any warning signs, keep the planned follow-up visits after each eye. Ongoing care belongs with the retina specialist and center that carried out the treatment, working with your genetics team. If you also see a general eye doctor, let them know you have had this therapy so your records stay complete. Bring your questions to each visit, especially as you plan or recover from the second eye.
Common Questions About Treating Both Eyes
Yes, both eyes can be treated when each one qualifies. Each eye is evaluated on its own, and each receives its own subretinal injection on a separate day. The two surgeries are spaced at least six days to a week apart. Treating both eyes is common, but the decision is still made eye by eye, based on how much healthy retina each one has.
The eyes are treated on separate days so the team can focus fully on each eye and watch how the first heals before treating the second. Spacing the surgeries also spreads out your recovery, so you are not healing from both eyes at once. The gap is a safety and recovery choice, and it is at least six days, sometimes a week or more, between the two procedures.
The two procedures are done at least six days apart, and often about a week or slightly more, depending on your team's plan and how the first eye is doing. There is no fixed maximum that applies to everyone; the timing is set for you during your evaluation. Your care team will give you the two dates and explain the schedule for the steroid tablets around each one.
No, the second surgery repeats the first. It uses the same subretinal injection, the same surgical team, and the same steroid course and follow-up afterward. What differs is mainly your experience: many people feel more prepared the second time, having already been through it. Each eye is still assessed on its own findings before its surgery goes ahead.
Yes. The steroid course is used around each eye, so the second eye gets its own course, started before that injection and tapered afterward. The steroids calm the eye's response to the new gene. Your team will give you a clear schedule for each eye and explain how to take and reduce the tablets, so the two courses do not run together.
Treating both eyes aims to help vision on both sides rather than only one, which matters for everyday tasks that use both eyes together, such as moving around in dim light. How much the second eye gains depends on how much healthy retina it still has, just as with the first. Your team can give you a realistic picture for each eye from its evaluation.
More Questions About the Second Eye and Beyond
That can happen, because each eye is judged on its own. If one eye has too little surviving retina or another problem, the team may treat only the eye likely to benefit. This does not rule out watching the other eye over time. The evaluation is done eye by eye precisely so the right decision can be made for each side.
No. It is not a cure and does not restore normal vision or rebuild a retina that has already been lost. It gives still-living retinal cells a working copy of the gene they were missing, which can improve dim-light vision and navigation. The goal is meaningful, realistic improvement, and the amount varies from person to person and from eye to eye.
Yes. Children over 12 months of age can be candidates, and each eye is treated in its own procedure under anesthesia, on separate days, just as for adults. The team explains how a young child's anesthesia, comfort, and recovery are managed. Treating sooner can matter, because the retina keeps losing cells over time, so an early evaluation is worthwhile.
This therapy is offered at a small number of specialized centers with a retina surgeon and a genetics team, not at a routine eye clinic. Your eye doctor can refer you for an evaluation. The center confirms the gene, checks each eye, and plans the schedule for both eyes. Ask how many of these procedures the center has done and who will follow you afterward.
- Is my exact genetic diagnosis confirmed as an RPE65 mutation in both copies?
- Does each of my eyes have enough surviving retina to benefit?
- How many days apart will my two surgeries be, and why?
- What improvement is realistic for each eye, and what are the main risks?
- How will the steroid course and follow-up work for each eye?
- Who will monitor both eyes over the long term?
- Boston Children's Hospital (2024). Luxturna Gene Therapy for Inherited Retinal Disorders.
- Children's Hospital of Philadelphia (2024). Gene Therapy for Inherited Retinal Dystrophy (Luxturna).
- American Academy of Ophthalmology (EyeSmart) (2024). New Treatments for Retinitis Pigmentosa (Luxturna Gene Therapy).
- American Academy of Ophthalmology (EyeSmart) (2024). Gene Therapy May Be a Game-Changer for People With Inherited Retinal Disease.