SLT comparable with glaucoma therapy

Selective laser trabeculoplasty (SLT) is comparable to medical treatment as the initial therapy for open-angle glaucoma (OAG) or ocular hypertension, according to results of a study presented at the American Academy of Ophthalmology annual meeting, last year in Las Vegas.

L. Jay Katz, MD, professor of ophthalmology, Thomas Jefferson University and director of glaucoma, Wills Eye Institute, Philadelphia, USA spoke of the added benefits of SLT. Particularly, it may be associated with fewer side effects and less expense for patients and third-party payers, and importantly, patient adherence is not an issue.

Therapy adherence not an issue

With a chronic disease such as glaucoma, patient adherence to medical therapy is a challenge, he said. Because the early to moderate stages of glaucoma generally are asymptomatic, therapy nonadherence does not result in any negative effects that are apparent to the patient. In fact, Dr Katz said, the patient may feel better because of the elimination of any ocular or systemic side effects from the drug that was discontinued.

A previously conducted multicentre trial, the Glaucoma Laser Trial, showed the comparable effectiveness of initial ALT with medical treatment. The limitations of that study included a lack of laser repeatability and an antiquated medical stepping regimen that used eyes instead of patients for randomization.

To participate in the study, patients had to be aged between 25 and 82 years, have bilateral visual acuity of 20/70 or higher and have IOP ranging from ≥24 mmHg to <31 mmHg in the more severely affected eye and an IOP ≥20 mmHg in the less severely affected eye.

Additionally, patients had to have received a diagnosis of primary OAG, pseudoexfoliation, or a mixed mechanism or ocular hypertension, with a central corneal thickness of less than 600 µm. The angle structures had to be adequately visualized.

Patients could not have undergone a previous ocular surgery in one or both eyes, with the exception of laser iridotomy. Furthermore, patients could not have been taking any other medication known to increase IOP, such as steroids.

The target IOP was established using a formula from the Collaborative Initial Glaucoma Treatment Study based on starting IOP and an objective visual aid score. The primary aim of the study was to determine whether SLT is equivalent to medical therapy in its initial IOP-lowering effect based on target IOP levels. Patients were followed up to one year.