Quantification of Focal Outflow Enhancement Using Differential Canalograms

摘要： PURPOSE. To quantify regional changes of conventional out?ow caused by ab interno trabeculectomy (AIT). METHODS. Gonioscopic, plasma-mediated AIT was established in enucleated pig eyes. We developed a program to automatically quantify out?ow changes (R, package eye-canalogram, github.com) using a ?uorescent tracer reperfusion technique. Trabecular meshwork (TM) ablation was demonstrated with ?uorescent spheres in six eyes before formal out?ow quanti?cation with two-dye reperfusion canalograms in six additional eyes. Eyes were perfused with a central, intracameral needle at 15 mm Hg. Canalograms and histology were correlated for each eye. RESULTS. The pig eye provided a model with high similarity to AIT in human patients. Histology indicated ablation of TM and unroo?ng of most Schlemm’s canal segments. Spheres highlighted additional circumferential and radial out?ow beyond the immediate area of ablation. Differential canalograms showed that AIT caused an increase of out?ow of 17 6 5-fold inferonasally, 14 6 3-fold superonasally, and also an increase in the opposite quadrants with a 2 6 1-fold increase superotemporally, and 3 6 3 inferotemporally. Perilimbal speci?c ?ow image analysis showed an accelerated nasal ?lling with an additional perilimbal ?ow direction into adjacent quadrants. CONCLUSIONS. A quantitative, differential canalography technique was developed that allows us to quantify supraphysiological out?ow enhancement by AIT.