Abstract
Purpose:
To evaluate whether direct trans-scleral application of SLT irradiation to the perilimbal area is effective in reducing Intraocular Pressure (IOP), eliminating the need for gonioscopy during the procedure.
Methods:
A randomized, masked, controlled trial was performed on open angle and pseudoexfoliative glaucoma patients. The control group underwent conventional SLT delivering 100 laser spots through a gonioscope for 360 degrees directly on the trabecular meshwork (TM). The trial group underwent irradiation by the same laser at the same irradiation parameters. A similar number of applications were administered all around the limbus on the sclera overlying the TM. Topical glaucoma therapy was not changed during the 6 months trial.
Results:
In the trial group (N=16), IOP decrease from an average of 20.21 mmHg before treatment to 15.50 at 6 months. The corresponding numbers for the control group (n=16), were 21.14 mmHg and 15.00. There was no statistical difference between the two groups in IOP reduction. Complications rate was significantly higher in the control group (p<0.0001, OR 6.881, 95% CI 1.676/28.248). Anterior chamber inflammation and superficial punctate keratitis rates were significantly higher in the control group and compared to the study group (p=0.006).
Conclusions:
Laser coherency, lost in tissue transmission, is not required for the therapeutic effect and the mechanism of action of the external laser irradiation studied is probably similar to that of the conventional one. It seems that gonioscopy is not necessary for SLT. The novel method may simplify and shorten the SLT procedure considerably, eliminate the corneal and gonioscopy-induced side effects and perhaps enable treatment of angle closure glaucoma.
Keywords: 578 laser •
568 intraocular pressure •
735 trabecular meshwork