J Korean Ophthalmol Soc.  1988 Apr;29(2):353-362.

The Effect of Combined Application of Argon and Nd-YAG Laser on Iridectomy in Rabbits

• Park C
• Rhee SW

Abstract

Recently iridectomy using argon or Nd-YAG laser to treat narrow angle glaucoma has become popular, and is now a procedure of choice over the standard surgical technique. However, shock wave of Nd-YAG laser causes hemorrhage in almost all cases and high energy level of Nd-YAG laser, which is required for iridectomy, causes injuries to the lens and cornea. Furthermore, there is a tendency toward closure of the iridectomy site after argon laser application. We performed iridectomies by combined application of argon and Nd-YAG laser in pigmented rabbits to improve iris bleeding, iridectomy patency, and lens and corneal damage. The iridectomy patency and the lens and corneal damage were examined with scanning electron microscope. The rabbits that underwent laser iridectomies with only Nd-YAG laser were used as a control group. The following results were obtained: 1. The bleeding rate of the iridectomy in the combined application group was 2.4% and in the control group 98.8% proving the combined application of both lasers to be higly effective. 2. In the experimental group, the patency rate of iridectomy was 33.3% at the energy level of 1 mJ, 66.6% at 2 mJ, 83.3% at 4 mJ, and 6 mJ, respectively. In the control group, the patency rate of iridectomy was 33.3% at the energy level of 4 mJ, 63.6% at 6 mJ, 83.3% at 8 mJ, respecively. At the same energy level, the experimental group showed a higher rate of patency than the control group. 3. In both experimental and control groups, the lens damage was noted at the energy level of 6 mJ or higher. The lens was not affected by lower energy Nd-YAG laser. 4. In the experimental and control groups, the corneal damage was observed at the energy level of 8 mJ or higher. The cornea was not affected by low energy Nd-YAG laser. Based on the above results, it can be concluded that laser iridectomy by combined application of argon and Nd-YAG lasers results in a lower rate of bleeding, a higher rate of patency, and less damage to the lens and cornea as compared with iridectomy performed by Nd-YAG laser only.

MeSH Terms

Argon*
Cornea
Glaucoma
Hemorrhage
Iridectomy*
Iris
Lasers, Solid-State*
Rabbits*
Shock
Argon