Abstract
Purpose::
Investigation of dynamic vessel behaviour of arteries and veins in open-angle glaucoma pre and post-trabeculectomy.
Methods::
In 17 patients with POAG the reaction of retinal vessels on flicker provocation was investigated with the Dynamic Retinal Vessel Analyzer (Imedos, Jena) before and after trabeculectomy with MMC. The measurement procedure consisted of a 50 sec baseline measurement and a 20 sec flicker provocation and a resting period of 80sec. The procedure was repeated three times and mean values were calculated.
Results::
We found two groups. In group 1 (n: 12/17; age: 63,4 ± 4,0) arteries and veins showed a significantly increased dilatation postoperative in comparison to preoperative situation (Arteries: Pre.: 1,4% ± 0,4 Post.: 3,8% ± 0,5; Veins: Pre.: 3,1% ± 0,4 Post.: 4,6% ± 0,6). In group 2 (n: 5/17; age: 60,0 ± 5,1) there was no significant difference of vessel behaviour before and after operation (Arteries: Pre.: 6,7% ± 1,5 Post.: 6,3% ± 0,5; Veins Pre.: 7,7% ± 1,8; Post.: 7,2% ± 1,0). In comparison to normal values (Arteries: 6,9% ± 2,8; Veins 6,5% ± 2,5) patients in group 2 showed an adequate reaction of vessels during the flicker procedure even before trabeculectomy.
Conclusions::
Dynamic vessel analysis showed in some patients with POAG a significantly reduced vessel reaction. In these patients lowering IOP by trabeculectomy increases the dilation capacity of retinal vessels. This implies that lowering IOP in patients with reduced vascular dynamics improves the perfusion and supply of retinal nerve fibres. Further studies have to show if dynamic vessel analysis might advance the indication for trabeculectomy.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • intraocular pressure • neuro-ophthalmology: optic nerve