Does one eye laser treatment lower pressure in the other eye for OHT?
For ocular hypertension (OHT), selective laser trabeculoplasty (SLT) is a treatment that can lower eye pressure. A common question is whether treating one eye with SLT can also lower pressure in the other, untreated eye. This effect is called the contralateral response. Research shows that unilateral SLT does produce a small but significant pressure reduction in the fellow eye.
What the research says
A 2024 meta-analysis pooled data from 9 studies (478 eyes) and found that after unilateral SLT, the untreated eye experienced a mean intraocular pressure (IOP) reduction of 1.85 mmHg at 3-6 months 4. This effect was seen whether the laser treated 180 degrees or 360 degrees of the trabecular meshwork, with no significant difference between the two 4. The same analysis also found a moderate positive correlation between the pressure drop in the treated eye and the drop in the untreated eye 4. The exact mechanism is not fully understood, but it may involve a neural or inflammatory signal that travels to the other eye. Other sources confirm that SLT is a safe and effective treatment for OHT 67, though they do not specifically address the contralateral effect. The contralateral reduction is modest compared to the effect in the treated eye, but it may be clinically relevant for some patients.
What to ask your doctor
- Could unilateral SLT help lower pressure in both of my eyes, or would I need treatment in each eye?
- How much of a pressure drop in the untreated eye is typical after SLT?
- Are there any risks or side effects of SLT that I should consider?
- How long does the contralateral effect last, and would I still need eye drops?
This question is drawn from common patient questions about Ophthalmology and answered using cited medical research. We do not provide individualized advice.