Nancy A. Melville

May 16, 2014

ORLANDO, Florida — Afro-Caribbean patients with open-angle glaucoma show significant improvements in intraocular pressure (IOP) after only 1 treatment session with selective laser trabeculoplasty (SLT) monotherapy, according to a new study.

"We can conclude from this preliminary study that selective laser trabeculoplasty can be safely performed in people of African descent," said lead author Tony Realini, MD, associate professor of ophthalmology at the West Virginia University Eye Institute in Morgantown.

"It lowers IOP by an amount that would reasonably be expected to favorably alter the clinical course of glaucoma in this under- or untreated population," he said. "This actually has the potential to bend the blindness curve in the Afro-Caribbean world."

Results from the prospective interventional study were presented here at the Association for Research in Vision and Ophthalmology 2014 Annual Meeting.

Dr. Realini and his colleagues evaluated 61 patients with open-angle glaucoma in St. Lucia who were taking no more than 1 medication before treatment with bilateral 360-degree SLT.

Average age of the cohort was 62 years. Approximately two-thirds of the patients were taking beta-blockers; the remaining third were taking prostaglandin analogs.

At enrolment, average IOP was 17.3 mm Hg in the right eyes and 17.5 mm Hg in the left eyes. After a 30-day washout period, average baseline IOP had increased to 21.4 mm Hg and 21.1 mm Hg, respectively.

This actually has the potential to bend the blindness curve in the Afro-Caribbean world.

Patients received 1 SLT treatment and were then screened regularly for a period of 36 months.

At 36 months, in the 40 (66%) patients who had a sustained reduction in IOP of at least 10%, average IOP was 13 mm Hg.

In this cohort of 40 patients, 93% had at least a 20% reduction in IOP, 63% had at least a 30% reduction, 35% had at least a 40% reduction, and 18% had at least a 50% reduction.

Three eyes had IOP spikes greater than 5 mm Hg, which is consistent with what has been seen in other studies, and many patients experienced photophobia after treatment, Dr. Realini reported.

"Brief but intense photophobia was ubiquitous among the patients; this is not typical in Caucasian patients," he added.

Dr. Realini said the team hopes to conduct a randomized controlled trial comparing SLT with medical therapy.

"Eventually, we'd like to establish a pan-Caribbean glaucoma laser program or glaucoma care program," he said.

The biggest challenge related to addressing glaucoma in the region is the sheer burden of disease, which well exceeds the estimated prevalence of about 1.9% in the United States. "A conservative estimate of prevalence of glaucoma in St. Lucia is around 9%, but a more realistic estimate likely approaches 15% of people older than 30," Dr. Realini told Medscape Medical News.

Because healthcare resources in the region are limited and because "glaucoma doesn't kill anyone, it is not a high priority," he explained.

"The goal of our work in the Caribbean is not to evaluate first-world treatments in developing-world populations per se, but rather to identify a care process that balances efficacy and safety with the primary driver of availability, which is cost."

This is not the first study to show improvement with SLT as monotherapy, said Robert Fechtner, MD, director of the glaucoma division at the New Jersey Medical School, Rutgers University, in Newark.

However, "I believe many physicians will be initially surprised by the magnitude of the IOP reduction, as SLT laser is often used as an adjunct to medication rather than as monotherapy," he told Medscape Medical News.

"We should not be too quick to generalize from this study, but it is intriguing," said Dr. Fechtner. "Even though the study is an uncontrolled cohort study, the long-term consistency of IOP makes it highly unlikely that a phenomenon such as regression to the mean could explain these substantial and sustained IOP reductions."

Although the cost-effectiveness of the treatment in the developing world needs to be much better understood, SLT could be a promising alternative to existing treatments, he pointed out.

"The alternative to SLT in the study population is generic timolol," said Dr. Fechtner. "Certainly the initial cost of performing SLT is higher, but SLT offers benefits that may not be immediately obvious, such as eliminating compliance challenges, likely better diurnal and nocturnal IOP control, and no systemic adverse effects," he explained.

"The longer SLT efficacy persists, the better it looks as a first-line intervention to lower IOP and reduce preventable blindness in a cost-effective manner for the developing world," he added.

Dr. Realini said he agrees. "The overall better quality and consistency of IOP reduction with SLT may well translate into lower disease progression rates over time," he said.

"And if SLT is better at preventing blindness than beta-blockers, the long-term cost savings to society, in terms of preservation of the patient's ability to function in and contribute to society, rather than become a burden and cost to society, may well make the economics favor first-line SLT as the optimal care process for glaucoma in this region," Dr. Realini explained.

Dr. Realini reports a financial relationship with Lumenis. Dr. Fechtner has disclosed no relevant financial relationships.

Association for Research in Vision and Ophthalmology (ARVO) 2014 Annual Meeting: Abstract 821. Presented May 5, 2014.


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