IOP drop in first eye after SLT may predict drop in fellow eye

Arch Ophthalmol. 2011;129(6):699-702.

For patients treated with selective laser trabeculoplasty, IOP reduction percentages in the first eye at 3 months may predict responses in the fellow eye for up to 30 months for those with ocular hypertension and up to 9 months for those with primary open-angle glaucoma, a study found.

The retrospective study reviewed medical records from postoperative exams for 80 eyes at 2 weeks and 3, 6, 9, 12, 18 and 30 months. Patients were excluded if they used an ocular hypotensive medication, had an intraocular procedure performed during the 30 months of follow-up or had a history of selective laser trabeculoplasty or argon laser trabeculoplasty.

For those with ocular hypertension (65%), 3-month IOP reduction percentages in the first eye correlated strongly (Pearson product moment correlation > 0.652) with long-term IOP reduction in the fellow eye. For those with primary open-angle glaucoma (35%), the correlation was moderate (Pearson product moment correlation > 0.367) for up to 9 months.

While the well-known IOP-lowering effect of selective laser trabeculoplasty in the contralateral eye was a potential confounder, the study authors said that this effect has been shown to be minimal beyond 12 months. Moreover, the mean intervals between treatment of the first and fellow eyes were 154.9 days for patients with ocular hypertension and 150.7 days for patients with primary open-angle glaucoma, allowing time to lessen this effect.