Patient Education
Panretinal Photocoagulation (PRP)
In-office · 20–40 minutes, often split across sessions
Panretinal photocoagulation, also called scatter laser, treats the peripheral retina to stop abnormal blood vessel growth. When large areas of retina are starved of oxygen, they release a signal called VEGF that triggers fragile new vessels — vessels that bleed into the eye, pull on the retina, and can cause a severe form of glaucoma.
Panretinal photocoagulation, also called scatter laser, treats the peripheral retina to stop abnormal blood vessel growth. When large areas of retina are starved of oxygen, they release a signal called VEGF that triggers fragile new vessels — vessels that bleed into the eye, pull on the retina, and can cause a severe form of glaucoma. PRP places hundreds to thousands of laser spots across the peripheral retina, reducing its oxygen demand and shutting that signal down. It deliberately trades some peripheral and night vision to protect central vision.
What It Treats
- Proliferative diabetic retinopathy
- Ischemic retinal vein occlusion
- Neovascular glaucoma
- Ocular ischemic syndrome
What to Expect
Before
Your eye is dilated and numbed. Because PRP is more uncomfortable than other laser treatments, an anesthetic injection around the eye is sometimes used, and treatment is often divided across two to four sessions rather than done all at once.
During
A contact lens is placed on the numbed eye and a rapid series of bright flashes is delivered across the peripheral retina. Many patients feel a pinching or deep aching sensation, strongest when treating far forward where the nerves are denser. Pattern-scanning lasers deliver many spots in a fraction of a second and are generally much better tolerated.
After
Significant glare and afterimages for an hour or more, and commonly a dull ache or headache for the rest of the day. The eye is often mildly inflamed for a day or two.
Recovery & Restrictions
- A driver is required.
- Blurred vision for a day or two is expected, and the macula can swell mildly after treatment, blurring vision for a couple of weeks.
- Expect some permanent changes: reduced night vision and some loss of side vision. This is the intended trade-off, not a complication.
- Abnormal vessels regress over weeks, and bleeding can still occur during that time. Follow-up appointments are not optional.
- Tell your doctor if you drive at night or professionally — very extensive treatment can affect the visual field standards required for a license.
Risks & Side Effects
Loss of peripheral and night vision
This is expected. The peripheral retina being treated is already failing, but the laser makes the loss definite. Most patients adapt; some find night driving becomes difficult or impossible.
Worsening macular swelling
PRP can aggravate swelling in the center of the retina, blurring vision temporarily. This is common enough that an injection is often given alongside the laser to prevent it.
Pain during and after treatment
More than any other retinal laser. Tell your doctor if it is too much — sessions can be shortened and more anesthetic given.
Bleeding into the eye
Fragile vessels can still bleed while they are regressing. A sudden shower of dark floaters or a curtain of haze should be reported.
Uncommon complications
Fluid collecting under the retina, angle closure, and inadvertent treatment of the center of vision are all rare.
Every procedure carries risk, and this list is not exhaustive. Your doctor will discuss the risks that apply to your eye and your circumstances before you decide.