Combined Cataract and Vitrectomy Surgery for Diabetic Retinopathy: One Operation or Two?
Combined Cataract and Vitrectomy Surgery at a Glance
You can have the cataract and the retina fixed in one sitting, or one at a time. Both plans are in wide use. Both help most people see better. Your surgeon chooses based on how cloudy your lens is, how well the retina can be seen through it, and how many operating-room trips suit your life.
A cloudy lens blocks the surgeon's view of the retina. If it blocks too much, the lens has to come out first or at the same sitting. In a large national database, about 50 of every 100 eyes that still had their own lens had cataract surgery within one year of a vitrectomy, and about 86 of every 100 by five years1. For many people the question is when the cataract comes out, not whether.
Neither plan is a rescue for sight that is already lost. Surgery clears blood and scar tissue and gives light a clear path again. How much vision returns depends on the retina underneath.
Three things drive the choice. First, the view: a dense lens makes retina work slower and less exact, so taking it out can be part of the job.
The second is the retina itself. The usual reasons to operate in diabetic retinopathy are a bleed into the gel that will not clear, scar tissue pulling the retina off in a way that involves the central reading area, and a detachment that combines pulling with a tear2. The third is you: your other eye, your work, and how well you could lie face down if a gas bubble is used.
What Each Operation Does Inside the Eye
Cataract surgery takes out the clouded natural lens and puts a clear plastic lens in its place. The usual method, phacoemulsification, uses sound waves to break the lens into pieces small enough to draw out. In a diabetic eye the cataract both blurs your sight and hides the retina from the people watching it.
The trade is that operating on a diabetic eye stirs up the retina. A pooled analysis of 143 studies found swelling at the center of the retina after routine cataract surgery in about 5 of every 100 eyes, and 19 studies found it roughly three times as common in people with diabetes3. That is why retina specialists want a plan for the macula before the lens comes out.
A vitrectomy removes the clear gel that fills the back of the eye. The surgeon takes out the gel and replaces it with a salt water solution, or with a gas or silicone oil bubble that holds the retina in place while it heals4. In diabetic eyes the same operation washes out old blood, peels away the scar sheets that tug on the retina, and lays flat any retina that has lifted.
Taking out the gel also removes the scaffolding that abnormal vessels grow along. Laser is often applied in the same sitting.
A combined operation, sometimes called phacovitrectomy, does both jobs in one anesthetic session. The surgeon usually takes out the cataract first and implants the lens, then works at the back of the eye through separate tiny openings. You are sedated once and recover once.
Because the front and back of the eye are both worked on in one sitting, more inflammation is stirred up. In a single-surgeon comparison of eyes with proliferative diabetic retinopathy, a fibrin film formed in the front of the eye in 9 of 29 combined eyes and in none of the 12 staged eyes5. Fibrin usually clears with drops over days to weeks.
In a staged plan the two jobs are separated, usually by weeks to months. If the cataract is why the retina cannot be seen or lasered, the lens comes out first. If the retina problem is urgent and the lens is only mildly cloudy, the vitrectomy goes first.
The cost of staging is a second anesthetic, a second recovery, and blurred vision in between.
One Operation or Two: How the Two Plans Compare
These figures come from one single-center review.
| What is compared | One combined operation | Two staged operations |
|---|---|---|
| Anesthetic sessions | One | Two |
| Average total operating room time | About 121 minutes | About 161 minutes |
| Direct cost | Lower | Higher |
| Time to reach best recorded vision | Reached sooner | Reached later |
In that review of 81 eyes, combined surgery averaged about 121 minutes in the operating room against about 161 minutes for the staged plan, cost less, and reached best recorded vision about 449 days sooner6. Those were one center's records, not a randomized trial, so treat the gap as an estimate.
On vision the two plans have looked broadly similar.
| Measured outcome | Combined (29 eyes) | Staged (12 eyes) |
|---|---|---|
| Vision better by two lines or more | 18 of 29 | 7 of 12 |
| Fibrin film in the front of the eye | 9 of 29 | 0 of 12 |
| Repeat bleeding into the gel cavity | 3 of 29 | 1 of 12 |
| Neovascular glaucoma | 1 of 29 | 1 of 12 |
In that series the vision difference between the two plans was not statistically significant, while the fibrin difference was5. These are small groups, and small groups can miss real differences.
Surgeons lean toward combining when the cataract blocks the retina view and the patient wants to be done in one go. They lean toward staging when the retina emergency is the whole story, when the lens is still fairly clear, or when the eye is already inflamed. What matters is that the reason is said out loud.
Who Is a Good Candidate, and What to Settle at the Consultation
The combined plan fits people whose two problems are both ready to be treated.
- Your cataract is dense enough that your retina cannot be examined or lasered through it.
- You are over about 50, so the lens is likely to cloud after a vitrectomy anyway.
- Getting to the surgical center is hard, and one trip beats two.
- Your retina problem is serious, but not so urgent that hours count.
Staging is often the safer sequence in a difficult eye.
- The lens is still clear, and you are young enough that it may stay that way.
- The retina is detached in a way that will take a long operation on its own.
- The front of the eye is inflamed, or new vessels are growing on the iris.
- Silicone oil is planned, since oil changes the lens calculation and the later plan.
The power of the implanted lens is chosen from measurements taken before surgery, and those measurements assume the eye keeps the shape it had. A vitrectomy, and especially a gas bubble, changes where the new lens finally settles.
In a review of 104 eyes, the gap between the predicted and the actual prescription averaged about 0.08 diopters after cataract surgery alone and about 0.59 diopters in the short-sighted direction after combined surgery with gas, so the authors suggested shifting the target by roughly 0.5 to 0.8 diopters when gas is planned7. That is one center's experience. Ask your surgeon what correction they apply, and expect the final number to differ a little from the prediction.
Many retina surgeons give an anti-VEGF injection in the days before a diabetic vitrectomy, to shrink the fragile new vessels so they bleed less when cut. A Cochrane review of 28 randomized trials in 1,914 eyes found that an injection before surgery lowers the chance of bleeding back into the gel cavity afterwards, and lowers the chance of retinal breaks during the operation8. Timing is a judgment call, since waiting too long can tighten scar tissue.
Bring every bottle or a printed list. Blood thinners, diabetes medicines, and prostate medicines that affect the pupil all change the surgical plan. Do not stop or change anything on your own. Ask the prescriber, then tell the surgical team what they said.
Steady blood sugar and blood pressure around the date give the retina a calmer place to heal, and nobody expects perfect numbers from you.
Recovery After a Combined Operation
Expect the eye to be patched at first and to feel scratchy once the patch is off. A gritty, sandy sensation, as if something is in the eye, is a normal part of recovery after this surgery4. Vision is usually poor at first and improves unevenly, not in a straight line.
You will be on several drops: an antibiotic, a steroid, and often an anti-inflammatory. After combined surgery the steroid course is often heavier, because the front of the eye has more inflammation to settle. Keep to the schedule even when the eye feels fine.
A gas bubble presses the retina into position while it seals. You may be asked to keep your head face down or turned to one side for a set period, and you cannot fly, go up into the mountains, or dive until the bubble is gone4. Altitude makes the bubble expand and the pressure inside the eye rise. That is why the rule is absolute.
The bubble shrinks on its own over days to weeks. While it is there, vision in that eye is dark and wobbly at the top or bottom. That is expected, not a sign of failure.
Most surgeons wait until the eye is quiet and any gas has gone before writing a glasses prescription, often four to twelve weeks. Sight can keep improving for months in eyes that had a lot of blood or swelling.
How far it improves depends on the retina, not on which plan you chose. A clear window will not undo damage already done to the macula. Ask what your imaging shows there.
Risks, Complications, and a Realistic Outlook
The consistent finding is more early inflammation at the front of the eye after the combined plan. It shows up as a fibrin film across the pupil, sticking of the iris to the lens implant, and a slower start to visual recovery. Fibrin formed in 9 of 29 combined eyes and in none of 12 staged eyes in one comparison, though the groups ended up with similar vision5. Most of it settles with steroid drops and leaves no lasting harm.
Some complications belong to diabetic retina surgery itself, not to the choice of plan. One series followed 104 diabetic eyes for six months after combined surgery.
- About 64 of every 100 eyes had at least one complication9.
- Swelling at the center of the retina affected about 26 of every 100 eyes with proliferative disease9.
- Lasting pressure elevation affected about 14 of every 100 eyes9.
- Repeat bleeding into the gel cavity affected about 10 of every 100 eyes9.
- Neovascular glaucoma affected about 4 of every 100 eyes9.
Most are treatable when found early, which is what follow-up visits are for. Across a national database, at least one complication during the operation was recorded in about 8 of every 100 vitrectomies, most often a small tear made in the retina1. Your surgeon can treat such a tear during the same operation.
Infection inside the eye is the complication everyone plans around. It is rare, and it moves fast. In a series of 111,876 vitrectomy operations, culture-positive infection inside the eye followed about 2 of every 10,000 operations10. For cataract surgery, a systematic review and meta-analysis found infection inside the eye after about 26 of every 10,000 operations in people with diabetes, against about 24 of every 10,000 in people without, and it is sight-threatening and needs prompt treatment11.
Put the other way round: well over 99 of every 100 people never get it, and it is treated as an emergency when it is found. Retinal detachment, a large repeat bleed, and pressure that stays high are the other serious ones. Each has a treatment, and each is caught faster by a patient who knows the warning signs.
Published series report vision improving or holding steady in most eyes with either plan. Vision improved by two lines or more in 18 of 29 combined eyes and 7 of 12 staged eyes in one comparison, and held steady in most of the rest5. These are averages from small groups, describing a room full of patients rather than your eye.
Your own outlook depends on how long the blood was there, whether the macula was detached or swollen, and how well the diabetes is controlled from here.
When to Call Your Surgeon After Either Operation
Some changes after eye surgery are expected. These are not. Call your surgeon's office the same day, using the after-hours number if needed.
- Pain that is getting worse rather than better, especially deep aching pain.
- Vision that is getting worse after it had started to improve.
- Redness that is spreading, or thick discharge from the eye.
- A curtain or shadow moving across your field of view.
- A sudden shower of new floaters or flashing lights.
- Severe sickness or vomiting with eye pain, which can mean the pressure has risen.
Calling early is the whole point. Infection and detachment are both treatable, and both do better the sooner they are found.
Plenty of odd sensations are normal at first. A gritty feeling, fading redness, watering, and blurred vision that is slowly clearing are all ordinary. So is seeing the edge of the gas bubble wobble as you move your head.
Note anything that puzzles you and bring it to your next appointment. If you are unsure, call and describe it.
You need two kinds of follow-up afterwards. Your retina specialist watches the retina and decides whether more laser or injections are needed. Your optometrist or ophthalmologist handles the glasses, the pressure checks, and the yearly diabetic eye examination.
Diabetic retinopathy does not end with an operation, and that ongoing care protects the vision the surgery gave back.
Questions Patients Ask About Combining Cataract and Retina Surgery
Not in terms of final vision, based on the comparisons published so far. The combined plan does bring more early inflammation at the front of the eye, most visibly a fibrin film, and that needs more drops and closer follow-up. Serious problems such as repeat bleeding and neovascular glaucoma have looked similar. The trade is early inflammation against fewer anesthetics.
Most likely yes, if you are middle-aged or older and still have your own lens. In a large national database, about 50 of every 100 such eyes had cataract surgery within a year of a vitrectomy, and about 86 of every 100 within five years1. Younger eyes cloud more slowly. That expectation is much of why combining is offered.
Plan on a longer day than a standard cataract operation. In one center's records, operating room time averaged about two hours for the combined plan, against nearly three hours across both visits of a staged plan6. Your own time depends on how much scar tissue must be peeled.
Usually you are sedated but not fully asleep, with the eye numbed by drops or an injection. You may be aware of lights, movement, and voices without feeling pain. General anesthesia is used when a case is expected to be long, or when lying still is hard. That is settled beforehand.
Most retina surgeons advise against multifocal implants in eyes with diabetic retinopathy. These lenses split light between distance and near, which lowers contrast, and a diabetic retina needs all the contrast it can get. Raise it directly, because the choice is permanent.
Eyes are done one at a time. That way you keep usable vision in one eye while the other recovers, and your team can see how the first eye responded. The gap is typically several weeks, and longer if a gas bubble was used. Which eye goes first is decided by which is more urgent.
More Questions About Recovery, Vision, and Everyday Life
It depends on the vision in your other eye and on whether a gas bubble was placed. With a bubble, the operated eye is not usefully clear until the gas absorbs, which takes days to weeks. Your surgeon will say when the eye is safe to rely on, and local licensing rules set the legal standard. Do not drive until you are cleared.
A gas bubble floats upward inside the eye. Positioning your head aims that floating pressure at the part of the retina that needs support while it seals. Not every operation needs it, and the time ranges from a day to a couple of weeks. Ask for the position and duration in writing.
The underlying disease continues, so new vessel growth and swelling can return. Surgery removes what is already there and gives laser and injections a clear field to work in. About 10 of every 100 eyes in one series bled again into the gel cavity within six months of combined surgery9, and that is treatable when caught. Blood sugar control and kept appointments hold the gains.
In the United States both parts are medically necessary and are generally covered, though your deductible, co-insurance, and facility fees still apply. One center's analysis found the combined plan cost less overall than staging6, largely from the single anesthetic and facility visit. Ask the billing office for a written estimate.
Bring this list to your consultation and write the answers down.
- Why are you recommending one operation rather than two for my eye?
- How much of my blurred vision is from the cataract, and how much from the retina?
- Is a gas bubble planned, and for how long would I hold a head position?
- What glasses prescription are you aiming for, and how confident are you in it?
- Will I need an injection before surgery, and how many days before?
- What does my macula look like on imaging, and what does that mean for my outlook?
- What are the warning signs that should make me call you the same day, and on what number?
- Eye (London), via PubMed Central (2013). United Kingdom National Ophthalmology Database Study of Vitreoretinal Surgery: Report 1; case mix, complications, and cataract.
- American Academy of Ophthalmology (2024). Diabetic Retinopathy Preferred Practice Pattern (2024).
- Cureus, via PubMed Central (2025). Risk Factors and Cumulative Incidence of Cystoid Macular Edema After Simple Cataract Surgery: A Systematic Review and Meta-Analysis.
- American Academy of Ophthalmology, EyeSmart (2026). What Is a Vitrectomy?.
- PLoS ONE, via PubMed Central (2014). Comparison of Combined and Sequential Surgery for Proliferative Diabetic Retinopathy: A Single Surgeon Study.
- Graefe's Archive for Clinical and Experimental Ophthalmology, via PubMed (2021). Combined phaco-vitrectomy provides lower costs and greater area under the curve vision gains than sequential vitrectomy and phacoemulsification.
- Ophthalmology and Therapy, via PubMed Central (2024). Evaluation of the Accuracy of Intraocular Lens Power Calculation Formulas in Phacovitrectomy.
- Cochrane Database of Systematic Reviews, via PubMed Central (2023). Anti-vascular endothelial growth factors in combination with vitrectomy for complications of proliferative diabetic retinopathy.
- Therapeutic Advances in Ophthalmology, via PubMed Central (2022). Postoperative complications of combined phacoemulsification and pars plana vitrectomy in diabetic retinopathy patients.
- PLoS ONE, via PubMed Central (2018). Incidence, microbiology, and outcomes of endophthalmitis after 111,876 pars plana vitrectomies at a single, tertiary eye care hospital.
- Journal of Ophthalmic Inflammation and Infection, via PubMed Central (2025). Do people with diabetes have a higher risk of developing postoperative endophthalmitis after cataract surgery? A systematic review and meta-analysis.