Patient Education
Focal & Grid Laser
In-office · about 10–20 minutes
Focal and grid laser treat leaking blood vessels in the macula, the center of the retina. Focal laser targets specific leaking points — usually microaneurysms mapped out on a fluorescein angiogram — while grid laser applies a light, evenly spaced pattern across an area of more diffuse leakage.
Focal and grid laser treat leaking blood vessels in the macula, the center of the retina. Focal laser targets specific leaking points — usually microaneurysms mapped out on a fluorescein angiogram — while grid laser applies a light, evenly spaced pattern across an area of more diffuse leakage. Both work by sealing leakage and shifting the retina's fluid balance so swelling can resolve. Injections have become first-line for most macular swelling, but focal laser remains useful for well-defined leaks, for reducing long-term injection burden, and for chronic central serous retinopathy.
What It Treats
- Diabetic macular edema
- Swelling from branch retinal vein occlusion
- Chronic central serous retinopathy
- Leaking retinal macroaneurysms
What to Expect
Before
You will usually have an OCT scan and often a fluorescein angiogram first, so the doctor has a map of exactly where the leakage is coming from. Your eye is then dilated and numbed with drops.
During
You sit at the slit lamp with a contact lens on the numbed eye and hold your gaze steady while a series of brief, bright flashes are delivered. This is considerably more comfortable than scatter laser — most patients feel little or nothing beyond the brightness. Far fewer and much lighter spots are used than in panretinal treatment.
After
Spotty afterimages for up to an hour. Swelling does not resolve immediately — the retina dries gradually over weeks to a few months, which is measured on follow-up OCT scans rather than by how you feel.
Recovery & Restrictions
- A driver is recommended because of the dilation, though the treatment itself is undemanding.
- There are generally no activity restrictions — most people return to their normal routine the same day.
- Vision may be unchanged or slightly blurrier at first. Improvement, when it comes, is gradual.
- The usual goal is to stabilize vision and dry the retina rather than to sharpen vision. Holding ground is a good outcome in a disease that otherwise progresses.
- Repeat treatment is sometimes needed, generally no sooner than three to four months later.
Risks & Side Effects
Small permanent blind spots
Each treated spot leaves a tiny scar. Patients occasionally notice these as small gaps when reading, which is why treatment very close to the center of vision is avoided or done with much lighter settings.
Scar enlargement over time
Laser scars can slowly expand over years, more so with the heavier settings used historically. Modern lighter and subthreshold techniques substantially reduce this.
Accidental treatment of the center
Rare, but the reason you are asked to hold your gaze completely still and to tell the doctor before you need to move or blink.
Abnormal vessel growth at a scar
Uncommon, and usually treatable, but a recognized late effect of laser scars in the macula.
Incomplete response
Some swelling does not resolve with laser alone and needs injections, or both together.
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.