Glaucoma is a leading cause of blindness in numerous species; however, little is known about the distal conventional aqueous humor outflow pathways in the canine eye. The aim of this work was to develop a diagnostic technique to allow for tailored therapeutic treatment options for canine glaucoma. The studies described herein validate the use of a clinically applicable in vivo imaging technique using intracameral indocyanine green dye in normal and ADAMTS10-open angle glaucoma (ADAMTS10-OAG) dogs. These findings were compared to intravenous scleral angiography (SA) to verify outflow of fluorescent dye from the anterior chamber through to the angular aqueous plexus. The initial technique was refined for in vivo aqueous angiography (AA) and subsequently performed via a single intracameral injection technique in normal eyes of sedated dogs. After a recovery period, SA of the same eyes was performed for comparative purposes. SA followed by AA was repeated in ADAMTS10-OAG dogs with elevated intraocular pressure. Identical scleral sectors were imaged in all groups using the Heidelberg Spectralis® Confocal Scanning Laser Ophthalmoscope. Intrascleral vessel depth and lumen diameters were measured in all eyes using optical coherence tomography and computer software. Sectoral and dynamic outflow patterns were observed. The use of AA provides the foundation for improved visualization of post-trabecular conventional aqueous humor outflow pathways in normal and ADAMTS10-OAG dogs, as compared to intravenous SA.
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