Predictive factors of success in selective laser trabeculoplasty (SLT) treatment

Glaucoma is a progressive optic neuropathy that may lead to blindness. Reducing intraocular pressure (IOP) is the only known treatment to slow progression in glaucoma. IOP can be reduced by pharmaceutical treatment, laser and surgery. The aim of the present study was to assess predictive factors of success after selective laser trabeculoplasty (SLT) treatment.

We used a retrospective chart review of eyes that underwent SLT between January 1, 2005 and December 31, 2005. The dependent variable was time to failure after SLT treatment. Failure after SLT was defined as any changes in the medical treatment, and/or a new SLT treatment was performed and/or the patient was sent for surgery. All patients were treated with 90° SLT. A multivariate regression analysis was performed to assess correlation between time to failure after SLT and age, gender, IOP before treatment, number of medications used, SLT number, amount of spots, laser energy used, grade of angle, pigmentation and diagnosis.

120 eyes of 120 patients were identified. The average time to failure after SLT was 18 months. The predictive factors identified were: age, IOP before SLT and dose.

Predictive factors identified in our study were high baseline IOP, age and amount of laser energy used. Our study confirms previous results about baseline IOP as a predictive factor.