Selective laser trabeculoplasty treatment for medication-refractory open angle glaucoma

Background: Selective laser trabeculoplasty (SLT) is a new method to reduce intraocular pressure in eyes with primary open angle glaucoma. The laser parameters are set to selectively target pigmented trabecular meshwork (TM) cells without damage to the adjacent non-pigmented tissue. Purpose: A clinical retrospective study was conducted to evaluate the 12 months results of SLT in the treatment of medically uncontrolled open angle glaucoma. Patients and methods: During the period March to September 2004, the authors performed a SLT in 50 patients (50 eyes) with open angle glaucoma uncontrolled on maximally tolerated medical therapy. Treatment was carried out with a frequency-doubled, Q-switched Nd:YAG laser 532 nm.(Selectra 7000 Laser Coherent, Inc., Palo Alto,CA). Approximately 85 to 90 non-overlapping laser spots were placed over 180 degrees of the trabecular meshwork at energy levels ranging from 0.6 to 1.4 ml per pulse. In patients who required additional SLT therapy, the untreated 180° was treated. During the follow-up period, patients were treated with antiglaucoma medications as required. The success rates were defined as decreases in intraocular pressure (IOP) of 3 mmHg or more with no additional medications, laser, or glaucoma surgery. Results: The mean IOP reduction from baseline 6 months after treatment was 21% and 20% after 12 months. The success rates were 66% after 6 months and 55% after 12 months. Four eyes (8%) did not respond to SLT. One hour after SLT, an increase in IOP of more than 5 mm Hg was detected in 5 eyes (10%). Seven patients (14%) required additional SLT. Conclusions: SLT is efficient in lowering IOP in medication-refractory open angle glaucoma. It should be considered in such patients when surgery is contraindicated or refused.