Abstract
Abstract: :
Purpose: To determine histologic findings after successful laser trabeculoplasty in eyes with POAG and PEX glaucoma. Previous studies have examined eyes in which laser did not lower IOP, or examined only the region of the laser burn itself. Methods: 20 autopsy eyes from donors with either POAG or PEX glaucoma and had undergone laser trabeculoplasty during life were studied. Clinical records were used to determine the success of laser in lowering IOP. An additional 49 glaucomatous eyes which had not undergone laser, and 73 normal eyes, were studied as control eyes. Histologic sections from every quadrant of each eye were studied by light microscopy, selecting regions between laser spots when the spots were visible. Results: Meshworks from lasered eyes often had an expanded and loose-appearing juxtacanalicular region (JCT), with numerous superimposed giant vacuoles. This change could extend into Schlemm's canal, reminiscent of the "herniations" described in lasered monkey eyes by Melamed and Epstein (Arch Ophth 1986). This finding was more common in eyes fixed by perfusion, occurring in 80% (8/10) of lasered eyes, while it was found in only 33% (3/15; p=0.003) of glaucomatous control eyes and 25% (15/59; p=0.001) of normal eyes. In contrast, in eyes fixed by immersion the finding was less common, occurring in 20% (2/10) of lasered eyes, and only 9% (3/34) of glaucomatous control eyes and 7% (1/14) of normal eyes had these changes. Downgrowth of Descemet's membrane over the meshwork was observed in portions of 2 of the 20 lasered eyes. Conclusion: Successful laser trabeculoplasty appears to cause a remodeling of the JCT region of the meshwork. Downgrowth of Descemet's membrane over the meshwork was uncommon.
Keywords: 317 anterior chamber • 454 laser • 601 trabecular meshwork