PostOp Eyes

SLT Laser (Selective Laser Trabeculoplasty) Recovery: What to Expect

Illustration for SLT laser treatment recovery

General information about typical recovery, not medical advice. Every eye and every surgery is different, and your surgeon's instructions override anything on this page. Read our full disclaimer.

Selective laser trabeculoplasty, usually just called SLT, is a quick outpatient laser treatment for open-angle glaucoma and high eye pressure. The Glaucoma Research Foundation describes SLT as using low levels of laser light on the eye's natural drainage tissue to help fluid leave the eye more easily. The American Academy of Ophthalmology explains that in open-angle glaucoma the fluid inside the eye does not drain the way it should, pressure builds, and that pressure damages the optic nerve. SLT is aimed at that drainage problem, not at the lens, the retina, or your glasses prescription.

The visit itself is short. The Academy says the laser part takes less than 10 minutes, and the Glaucoma Research Foundation puts the treatment at roughly 5 to 10 minutes. Your eye is numbed with drops and a special contact lens is placed on the eye to guide the laser. Most people describe it as nearly painless. The Glaucoma Research Foundation says you may feel a slight tingling, and the Academy says you may feel a stinging sensation while the laser is used.

The most important thing to know is that SLT does not work right away. The Academy says it can take about 6 to 8 weeks for laser trabeculoplasty to fully lower your eye pressure, and the Glaucoma Research Foundation says it may take 1 to 3 months for the results to appear. So the weeks after your laser are mostly about waiting and getting your pressure rechecked, not about healing from a wound. Published expectations for pressure lowering are roughly 20 to 30 percent per the Academy, and the Glaucoma Research Foundation reports about 30 percent when SLT is used as initial therapy.

SLT is a pressure treatment, not a vision treatment. The Academy states that glaucoma damage is permanent and cannot be reversed, and that no treatment can fix damage already done to the optic nerve. SLT is meant to help prevent further damage. If your eyesight was already reduced by glaucoma before the laser, SLT is not expected to bring it back. Everything below is general expectation-setting from published sources. Your ophthalmologist knows your eye, your pressure targets, and your medication list, and their instructions override everything here.

The typical timeline

Typical full recovery: 1-2 days of comfort recovery; 6-8 weeks for the pressure effect. Ranges below are what published guidance describes for most people; your surgeon may set different limits for your eye.

StageWhat to expectRestrictions
The same dayDay 0The laser itself is short, generally under 10 minutes, and the eye is numbed with drops first. Afterward the contact lens comes off, the eye is rinsed, and your pressure is rechecked before you leave. Published patient guidance says your vision may be blurry for a couple of hours and the eye may feel a bit irritated. Some people have a temporary spike in eye pressure shortly after the procedure, which is why the recheck happens the same day.Plan to have someone drive you home. Many surgeons start an anti-inflammatory eye drop the same day. Do not rub the treated eye. Follow whatever drop schedule your ophthalmologist gives you, including your usual glaucoma drops unless you are told otherwise.
The first few daysDays 1-3This is the short comfort-recovery window. The Glaucoma Research Foundation says post-operative inflammation is common but generally mild, and that the vast majority of complications from SLT are mild and self-limiting. Mild soreness, light sensitivity, and some redness in the first day or two are the usual reports. Vision is typically back to your baseline once the same-day blur clears.The Glaucoma Research Foundation suggests taking it easy for a day or two and then returning to your daily routine. Its laser surgery overview says people can generally resume their normal routine the next day. Anti-inflammatory drops are typically used for a couple of days. Do not stop your regular glaucoma medications on your own.
The pressure-check stretchWeeks 1-8Nothing dramatic happens visually, but this is when the treatment is actually doing its job. The Academy says it can take about 6 to 8 weeks for laser trabeculoplasty to fully lower eye pressure, and the Glaucoma Research Foundation says results may take 1 to 3 months to appear. Most patients are scheduled for a return visit within a few weeks so the pressure can be re-evaluated. You will not be able to feel whether it is working. Only a measured pressure reading tells you that.No physical restrictions are described in published patient guidance for this stretch beyond returning to normal activity. The real requirement is showing up for the pressure checks and continuing any prescribed glaucoma drops until your ophthalmologist tells you to change them.
Ongoing follow-up3 months and beyondThe Academy notes that three months after the procedure, if your pressure is still too high, you may need more treatment. The Glaucoma Research Foundation reports that the pressure-lowering effect typically lasts between 1 and 5 years, and in some cases longer, and that SLT can be repeated if it worked the first time, though a repeat may not lower pressure as much. Glaucoma remains a lifelong condition that needs monitoring regardless of how well the laser worked.Keep your long-term glaucoma appointments. The Glaucoma Research Foundation notes that in most cases medications are still necessary to control and maintain eye pressure, though laser may lessen the amount of medication needed. Any change to your drops should come from your ophthalmologist.

When can I...

Is this normal?

Common questions

Does SLT hurt afterward?
Usually not much. The Glaucoma Research Foundation says SLT is typically painless or results only in minor discomfort, and that the vast majority of complications are mild and self-limiting. BrightFocus Foundation gives the same description and mentions occasional pinprick sensations during the treatment itself, while the American Academy of Ophthalmology notes you may feel a stinging sensation as the laser is used. Afterward, mild soreness, irritation, and light sensitivity in the first day or two are consistent with the post-operative inflammation the Glaucoma Research Foundation calls common but generally mild, which is why anti-inflammatory eye drops are typically prescribed for a couple of days. Severe or worsening pain is a different story. The American Academy of Ophthalmology lists eye pain among possible complications and describes severe eye pain with headache, nausea, blurry vision, or halos as a true eye emergency requiring an immediate call to your ophthalmologist.
When will I know if the SLT worked?
Not for several weeks, and not from how your eye feels. The American Academy of Ophthalmology says it can take about 6 to 8 weeks for laser trabeculoplasty to fully lower your eye pressure, and the Glaucoma Research Foundation says it may take 1 to 3 months for the results to appear. Most patients are scheduled for a return visit within a few weeks so pressure can be re-evaluated. The published expectation is roughly a 20 to 30 percent drop in pressure per the American Academy of Ophthalmology, and about 30 percent when SLT is used as initial therapy per the Glaucoma Research Foundation. BrightFocus Foundation reports a success rate of about 60 to 70 percent for lowering pressure by 20 percent. The American Academy of Ophthalmology also notes that three months after the procedure, if your pressure is still too high, you may need more treatment. Only a measured pressure reading answers this question, so keep those appointments.
Do I keep taking my glaucoma eye drops after SLT?
Usually yes, unless your ophthalmologist tells you otherwise. The Glaucoma Research Foundation states that in most cases medications are still necessary to control and maintain eye pressure, although laser may lessen the amount of medication needed. BrightFocus Foundation similarly says the procedure can either eliminate the need for eye drops or reduce the number of eye drops. Separately from your regular glaucoma drops, the Glaucoma Research Foundation and BrightFocus Foundation both note that patients are typically treated with anti-inflammatory eye drops for a couple of days after the laser. Because SLT takes weeks to reach its full effect, stopping your pressure-lowering medication on your own during that window leaves your eye unprotected. Any change to your drop regimen should come from the ophthalmologist who treated you.
How long does SLT last?
It varies, and the effect does fade. The Glaucoma Research Foundation says the pressure-lowering effect of SLT typically persists between 1 and 5 years, and in some cases longer than that. Its laser surgery overview and BrightFocus Foundation both note that the effect of the laser can wear off over time. StatPearls similarly states that the effect of laser trabeculoplasty decreases gradually over time. The good news is that SLT is repeatable. The Glaucoma Research Foundation says the procedure can be repeated if it was effective initially, though repeat treatments may or may not lower pressure as much as the first. BrightFocus Foundation explains that because SLT leaves portions of the drainage meshwork intact, the procedure may be repeated. Ongoing glaucoma monitoring stays necessary either way.

Sources