Comparison of Transpupillary and Transscleral Diode Laser Cyclophotocoagulation

ABSTRACT

Transscleral and transpupillary diode lasers are methods of cyclophotocoagulation used to lower intraocular pressure by reducing aqueous humor production through ciliary ablation. When compared with the neodymium[Nd]-YAG, the diode laser has characteristics of lower transmission rate through the sclera and more absorption by pigment or melanin in the ciliary body, therefore the transpupillary method might be more effective in Asians who have greater ciliary body pigmentation than caucasian. We compared the efficacy of diode laser transpupillary and transscleral cyclophotocoagulation on lowering of the intraocular pressure in Asian patients. We performed transpupillary[group 2, n=9]and transscleral [group 1, n=21]diode laser cyclophotocoagulation in medically uncontrolled glaucoma patients. Preoperative mean intraocular pressures were 35.0 +/-13.1 millimeters of mercury[group 1]and 31.8 +/-9.8 millimeters of mercury[group 2], respectively. Postoperative mean pressure were 23.0 +/-14.8 millimeters of mercury[group 1]and 24.8 +/-9.9 millimeters of mercury [group 2], respectively. The intraocular pressure decreased in both groups[p=0.002 group 1, p=0.025 group 2]with statistical significance. Complications were phthisis, bullous keratopathy[group 1]and corneal edema[group 2]. Both transscleral and transpupillary diode laser cyclophoto-coagulation may be performed safely to decrease intraocular pressure. Retrospective studies and long term follow up are further needed to determine the safety of laser cyclophotocoagulation.