Researchers develop predictive rule for estimating treatment success after SLT

The effectiveness of selective laser trabeculoplasty is positively associated with IOP elevation before treatment is initiated, suggesting that efficacy may be related to the timing of treatment, a retrospective observational study found. However, the efficacy of the procedure also appears to be adversely associated with the maximum IOP ever recorded in a patient's history.

In order to produce a prediction rule to estimate the probability of acceptable IOP reduction after SLT, Alexander J. Mao, MD, OD, MPH, and colleagues reviewed medical records for 268 eyes of 158 patients with ocular hypertension, open-angle glaucoma or normal tension glaucoma who underwent SLT.

For analysis, the investigators considered an IOP reduction of 20% or more at 6-month follow-up indicative of treatment success.

After controlling for sex, diagnosis, anterior chamber pigmentation and washout of eye drops, multivariate logistic regression analyses identified presurgical IOP and maximum IOP as independent predictors of treatment success at 6 months, the authors reported.

The area under receiver operator characteristic curve was 0.716, which showed good agreement between predicted and observed probabilities of acceptable IOP reduction.

Assuming a 50% or greater probability of acceptable IOP reduction is used as the minimal clinical threshold for consideration of the procedure, the developed IOP prediction rule had a sensitivity of 91.3% and a specificity of 30.4%, the authors noted.

"This prediction rule should be further validated with a comparable prospective clinical study cohort," the study authors said in the September issue of Journal of Glaucoma.