The goal of this study is to show the efficacy and safety of an innovative surgical procedure regarding the treatment of open-angle and juvenile glaucoma known as sclerothalamotomy ab interno (STT ab interno).
Patients and Methods
Between February and July 2002 surgery was performed in 58 eyes of 58 consecutive patients, of which 53 were diagnosed with open-angle and 5 with juvenile glaucoma. The procedure was performed with the assistance of a custom-made high-frequency dissection probe (19 gauge with a tip of 0.3×1 mm), which applies a bipolar current of 500 kHz frequency. The probe penetrates approximately 1 mm into the nasal sclera (ab interno) and through the trabecular meshwork and Schlemm's canal, thus forming a deep sclerotomy or “thalami” of 0.3 mm height and 0.6 mm width.
The average baseline intraocular pressure (IOP) was 25.6±2.3 mm Hg (range: 18–48 mm Hg) for the open-angle glaucoma group and 39.6±2.3 mm Hg (range: 34–46 mm Hg) for the juvenile glaucoma group. All patients had a minimum follow-up of 72 months. The mean IOP for the stated period was 14.7±1.8 mm Hg for the open-angle glaucoma group and 13.2±1.3 mm Hg for the juvenile group. The IOP after surgery was statistically significantly lower than the baseline IOP at all measured intervals (P<0.001). After 72 months only 11 eyes accounted for a 20.8% continuous antiglaucoma therapy. With regard to the procedure no serious complication was documented.
Sclerothalamotomy ab interno is a minimally invasive, safe, and efficient surgical technique for lowering the IOP in open-angle and juvenile glaucoma.