For the glaucoma patient, trabecular-targeted minimally invasive glaucoma surgeries (MIGS) are commonly used to help lower IOP. Trabecular MIGS can undoubtedly lower IOP, but variable results hinder wider adoption. Dr Huang explained that many hypotheses exist, and one is that the surgery has to be placed in the correct location in the eye.
“Previously suspected, aqueous angiography has confirmed that aqueous humour outflow is segmental,” Dr Huang said. “In other words, outflow through the trabecular meshwork and Schlemm’s Canal is not 360° uniform radiating away from the limbus. Instead, outflow is usually (but not always) heavier in the nasal part of each eye, with every individual and every eye showing potentially different patterns.
“Early work with aqueous angiography in the lab has demonstrated that trabecular bypass in regions with lesser initial angiographic flow can be improved or rescued,” he continued. “Therefore, it is possible that targeting trabecular-MIGS toward these locations might provide greater and more predictable IOP lowering. Alternatively, placing the trabecular-MIGS next to regions of greater flow (also as assessed by aqueous angiography) in order to access these known flow pathways might be better as well. Future experiments will tell.”
Therefore, with aqueous angiographic information, individualised MIGS placement may become possible.