Purpose
The purpose is to identify potential markers associated with one-year clinical outcomes in patients who had angle surgery with intraoperative fluorescein canalograms (IFC). We hypothesize that favorable outcomes are associated with structural markers of the conventional outflow pathway from trabecular meshwork (TM), Schlemm’s canal (SC), and the downstream venous system.
Methods
This study is a retrospective review of patients who had IFC performed during canaloplasty or trabeculotomy. The data reviewed includes: demographics, diagnoses, lasers, surgeries, medications, glaucoma severity index, intraocular pressure (IOP), surgical complications, blood reflux into the anterior chamber, and post-surgery interventions. High-definition videos (HDV) were recorded with a custom cobalt blue filter in the surgical microscope during the IFC. The HDV have been digitally processed using ImageJ to quantify flow characteristics: (i) retrograde flow from SC through the TM and into the anterior chamber, (ii) anterograde flow along SC, (iii) anterograde flow from SC, collector channels, and into episcleral vessels, and (iv) anterograde flow from SC, collector channels, and into intrascleral vessels. This dynamic data will be correlated with one-year outcomes.
Results
There were 16 eyes from 13 patients (62±20.5 yrs; range 15-83 yrs) who met study criteria with glaucoma diagnoses of primary open-angle, secondary, uveitic, normal tension, or juvenile. These eyes had 68 procedures averaging 4.3±1.9 including prior glaucoma, cataract, corneal, and/or retinal surgeries with average follow up 14±2.2 months. Among successful cases (n=12), the IOP outcome was 11±2.1 mmHg at last visit compared to 17±5.1 mmHg pre-operatively. The medication count dropped from 2.3 pre-operatively to 1.6 at last post-operative visit. Complications included transient hematoma with Descemet’s detachment (n=1). Post-surgery interventions included laser goniopuncture (n=5) and laser suture lysis (n=2). There was no correlation between IOP outcome and hyphema. Preliminary analyses of the IFC HDV show variation in flow characteristics.
Conclusions
This small case series shows: 1) canaloplasty is possible after prior surgeries; 2) hyphema does not correlate with outcome; 3) preliminary analyses of IFC HDV indicate that flow characteristics through the episcleral and intrascleral veins may be key markers of angle surgery outcomes.
Keywords: 462 clinical (human) or epidemiologic studies: outcomes/complications •
568 intraocular pressure •
633 outflow: trabecular meshwork