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Blog
October 31, 2026
PRP laser and anti-VEGF injections both protect vision in proliferative diabetic retinopathy (PDR), with similar vision after 5 years in the Protocol S trial [1]. Injections spared more side vision and caused less macular swelling but needed far more visits [1]. PRP holds up better if visits are missed, so the right choice depends on macular edema, your ability to return and your priorities [2].
Key takeaways
In this article
This article is general education, not a treatment plan. Diabetic retinopathy may cause no symptoms at first, and advanced stages need prompt treatment. Do not delay treatment your retina specialist recommends [6].
PDR can bleed or pull on the retina without warning. Get care fast for sudden changes in vision. After an injection, call your eye doctor right away about pain or worsening vision.
Call 911
Go to your eye doctor or an emergency room right away
Call your eye doctor the same day
Our guide to urgent vision changes covers other warning signs.
Proliferative diabetic retinopathy is the advanced stage of diabetic eye disease. Damaged retinal blood vessels close off, and the eye grows fragile new vessels to make up for them. These new vessels can bleed into the eye. Scar tissue can then pull the retina away from the back of the eye [6].
The retina is the light-sensitive layer at the back of the eye. When scars pull it loose, this is called tractional retinal detachment. Abnormal vessels can also block fluid drainage and cause neovascular glaucoma [6].
Diabetic retinopathy may cause no symptoms at first. That is why treatment timing follows the eye exam, not how well you see. Treatment can stop vision from getting worse, but it won't undo damage that has already happened [6].
See our guide to the four stages of diabetic retinopathy and our diabetic retinopathy overview for the bigger picture.
PRP places many small laser burns across the side (peripheral) retina. This improves oxygen supply to the rest of the retina, which helps abnormal vessels shrink. Anti-VEGF injections block VEGF, a protein that drives abnormal vessel growth and leakage. Injections usually start monthly and are then spaced out [9,10,11].
PRP is done in the eye doctor's office. Numbing drops are used, and you may see flashes and feel stinging or discomfort. Vision is blurry for the rest of the day, so you need a ride home. More than one session may be needed [11]. In Protocol S, the first PRP course was completed in 1 to 3 visits [4].
PRP can cause loss of side vision, color vision and night vision [11]. It can also worsen macular edema. Newer multispot lasers have reduced these problems but not removed them [10].
The eye is numbed and cleaned, and the medicine is given with a very small needle. Short-term irritation and floating air bubbles are common and usually clear in a day or two [9]. Serious eye infection is rare: about 3 in 10,000 office injections in a large pooled analysis [12].
As of October 2026, FDA labels list diabetic retinopathy as an approved use for ranibizumab (Lucentis) and aflibercept (Eylea and Eylea HD) [13,14,15]. Faricimab (Vabysmo) is approved for diabetic macular edema, but not for diabetic retinopathy alone [16].
Bevacizumab (Avastin) is also commonly used in the eye [9]. Its FDA label covers cancers, not eye disease, so eye use is off-label [17].
Neither treatment is best for everyone. Over 5 years, vision results were similar. Injections spared more side vision and prevented more macular edema. PRP needed fewer visits and gave better protection when people missed appointments. The table sums up the trade-offs [1,2].
| Factor | PRP laser | Anti-VEGF injections |
|---|---|---|
| How it works | Laser burns in the side retina help new vessels shrink | Medicine blocks the VEGF signal that drives new vessels |
| Treatment visits | 1 to 3 laser visits at first, more if needed; in Protocol S, PRP-group eyes also averaged about 5 injections over 5 years, as either group could get injections for macular edema | About 19 injections over 5 years in Protocol S, plus regular checks |
| Vision at 5 years (Protocol S) | About 20/25 on average | About 20/25 on average |
| Side (peripheral) vision | More loss | Less loss, though some loss still occurred over time |
| Vision-impairing macular edema by 5 years | 38% | 22% |
| Vitrectomy surgery by 2 years | 15% | 4% |
| If visits are missed | Longer-lasting protection | Higher risk of vision loss and retinal detachment |
| Main side effects | Loss of side, night and color vision; possible worsening of macular edema | Short-term irritation; rare serious infection |
Sources for the table: Protocol S results [1,4,18], follow-up data [2] and side effect information [9,10,11].
Protocol S compared PRP with ranibizumab injections in 394 eyes of 305 US adults with PDR. At 2 years, injections were not worse than laser for vision. At 5 years, average vision was about 20/25 in both groups, but the injection group had less side-vision loss and less vision-impairing macular edema [1,4].
The trial was run by the DRCR Retina Network at 55 US sites. Both groups could receive ranibizumab for macular edema [4].
Vision is measured in letters read on an eye chart. Five letters equal one line.
The authors concluded that both treatments are viable. They advised weighing expected visit attendance, cost and visit frequency for each patient [1].
CLARITY was a UK trial of 232 adults with active PDR. It compared aflibercept injections with PRP for 1 year. Vision was about 4 letters better with aflibercept, a little less than one eye-chart line. Because it lasted only 52 weeks, it cannot show long-term results [5].
The trial ran at 22 UK eye centers. Aflibercept was given at the start, 4 weeks and 8 weeks, then as needed at 4-week reviews. The optometrists who measured vision did not know which treatment each person had, but patients and treating doctors did. No safety concerns were found [5].
Together, Protocol S and CLARITY show that injections are a valid first treatment for PDR. They do not show that injections are right for every eye.
An injection's effect fades over time, so abnormal vessels can return if treatment stops. One study followed eyes that missed more than 6 months of care. Eyes treated only with injections lost more vision and had more retinal detachments than eyes treated with PRP [2].
In that study of 76 eyes, 10 injection-only eyes had tractional retinal detachment at the final visit, compared with 1 PRP eye [2].
Lapses are common even in trials. In Protocol S, 55% of people assigned to injections had at least one gap of 8 weeks or more past a scheduled visit. By 5 years, 29% had dropped out. Among those who finished 5 years, people with a gap had a median change of minus 2 letters, versus plus 5 letters without one [19].
Real-world numbers can be higher. At one US city hospital, 61% of 418 people treated for PDR were lost to follow-up over about 4 years. Risk factors included a primary language other than English, older age, many other health problems and missed non-eye appointments [20].
In that hospital, people treated only with PRP were more likely to be lost to follow-up than people treated only with injections [20]. So PRP is not a reason to skip visits. New vessels, swelling or bleeding can still appear after laser.
Tell your clinic early about barriers such as transport, work, dialysis, caregiving or cost. If you must miss a visit, call to reschedule as soon as possible.
Yes. Many eyes receive both, at the same time or one after the other. Injections can make new vessels shrink and also treat macular edema, while PRP adds longer-lasting protection. Protocol S allowed both treatments in either group. The best order is still being studied [4,18,21].
A 2024 study using a large health-records network compared 1,377 matched patients in each group. Starting with injections and adding PRP was linked with fewer later vitrectomies, fewer bleeds and fewer detachments than starting with PRP. This was not a randomized trial, so it cannot prove which order is better [21].
If blood already fills the gel inside the eye (vitreous hemorrhage), the choice changes. In the DRCR Protocol AB trial, vision at 2 years was similar, about 20/40, with aflibercept injections or with vitrectomy surgery plus PRP. Surgery cleared vision faster, and about one-third of injection eyes later had surgery [22].
If you also have swelling in the center of the retina, read our guide to diabetic macular edema treatment. Our article on diabetic retinopathy injections, laser and surgery explains each procedure, including vitrectomy.
Choose with your retina specialist, based on your eyes and your daily life. Key factors include macular edema, your ability to attend frequent visits for years, and how much you rely on side and night vision. Cost and whether both eyes need treatment matter too. Protocol S researchers stressed visit attendance, cost and visit frequency [1].
Eye treatment works alongside diabetes care. Keep working on blood sugar, blood pressure and cholesterol [6]. Our guide to preventing diabetic vision loss explains these steps. Keep your scheduled dilated eye exams and scans too.
Netra Restoration Therapy (NRT) is offered as adjunctive care, meaning support alongside your retina specialist's treatment. NRT has not been tested in controlled trials for diabetic retinopathy. It does not treat, reverse or cure PDR, and it cannot replace PRP, anti-VEGF injections or surgery.
If you use NRT, keep every retina appointment and injection visit. Do not delay standard care. You can read what Netra Restoration Therapy involves and what is known about its effectiveness.
Not for everyone. In the Protocol S trial, vision after 5 years was about the same with either treatment. Injections caused less side-vision loss and less macular edema, but they required many more visits. PRP may suit people who cannot reliably return for frequent visits.
PRP can reduce side vision, night vision and color vision, and it can worsen macular swelling in some eyes. These effects are weighed against its benefit, because PRP cuts the risk of severe vision loss from PDR by half or more. Newer laser systems have lowered these side effects but not removed them.
It varies from person to person. In Protocol S, eyes treated with ranibizumab received about 19 injections on average over 5 years. Injections usually start about monthly and are spaced out over time, but some people need them long term.
Abnormal vessels can grow back as the medicine wears off. In one study, injection-only eyes that missed more than 6 months of care had worse vision and more retinal detachments than eyes treated with PRP. If you must miss a visit, call your clinic right away to reschedule.
Yes. Many eyes receive both. Injections can shrink new vessels and treat macular edema, while PRP adds longer-lasting protection. Your retina specialist will decide the order and timing based on your eye.
During PRP, you may see bright flashes, and your eye may sting or feel uncomfortable. Numbing drops are used. Vision is usually blurry for the rest of the day, so you need a ride home, and some people need more than one session.
As of October 2026, FDA labels list diabetic retinopathy as an approved use for ranibizumab (Lucentis) and aflibercept (Eylea and Eylea HD). Faricimab (Vabysmo) is approved for diabetic macular edema but not for diabetic retinopathy alone. Bevacizumab (Avastin) is also used in the eye, but off-label.
Treatment aims to stop vision from getting worse, and it usually cannot undo damage that has already happened. In Protocol S, average vision stayed near 20/25 in eyes that completed 5 years. Vision lost to bleeding inside the eye may improve once the blood clears or is removed with surgery.
Sources checked October 31, 2026.
This article provides general education and does not replace an individual eye examination, diagnosis or treatment plan. A sudden shower of floaters, a shadow or curtain over your vision, sudden vision loss, or pain or worsening vision after an eye injection needs same-day eye care.
