J Korean Ophthalmol Soc.  1986 Jun;27(3):351-361.

Changes in the Rate of Flow by Quantitative Analysis of Aqueous Humor after Argon Laser Trabeculoplasty in Rabbits

• Kwak HW
• Kim SM

Abstract

The measurement of the rate of flow of aqueous humor is very important for the investigation of the physiology in the aqueous humor and maintenance of the intraocular pressure. Argon laser trabeculoplasty apears to be effective in lowering intraocular pressure with much advantage over standard filtering operation but despite the, widespread use of argon laser traheculoplasty in medically unresponsive open angle glaucoma, the exact mechanism by which it reduce outflow resistance remains unknown and so the study of the mechanism and the most suitable site are required due to the associated complication and less effectiveness during long term evaluation. We studied the changes in the rate of constant, the rate of flow for 2 weeks, intraocular pressure and C-value for 4 weeks, histopathologic changes for 36 days after argon laser trabeculoplasty in 25 rabbits(21 white and 4 black). The normal control group of 20 rabbits was also measured for intraocular pressure and C-value and the rate of constant, the rate of flow. In trabeculoplasty, we used the Britt 900 argon laser photocoagulator(pulse wave) with 50~60 burns at a setting of 700~800 mW, 0.2 seconds duration, 50 micro beam diameter in 360 degrees portion at the site between scleral spur and trabecularmeshwork. The results were as follows; 1) In control group of 20 rabbits. 1. The mean normal intraocular pressure was 18.5 +/- 2.0mmHg. 2. The mean normal C-value was 0.385 +/- 0.072 cumm/min/mmHg. 3. The mean normal rate of constant was 0.0114 +/- 0.0021min(-1). 4. The mean normal rate of flow was 3.980 +/- 0.735 micro l/min. 5. The relationship between rate of flow and C-value was high. 2) In rabbits after argon laser trabeculoplasty. 1. The white and black rabbits showed a statistically significant decrease of intraocular pressure for 4 weeks and elevation of rate of flow for 2 weeks after argon laser trabeculoplasty (p<0.001). 2. The changes of post-laser intraocular pressure was related with changes of C-value after argon laser trabeculoplasty for 4 weeks. 3. The changes of the mean IOP and C-value for post-laser 4 weeks showed no significant differences between white group and black group. 4. In histopathologic changes for 36 days, inflammtory change was not seen for post-laser period, fibrosis and edema in trabecular meshwork was more prominent at the 8th day, edema and fibrosis was regressed as normal at the post-laser 27th day.

MeSH Terms

Aqueous Humor*
Argon*
Burns
Edema
Fibrosis
Glaucoma, Open-Angle
Intraocular Pressure
Physiology
Rabbits*
Trabecular Meshwork
Trabeculectomy*
Argon