BMO-MRW optimal parameter for glaucoma detection and management

Bruch’s membrane opening minimum rim width (BMO-MRW) will be the pre-eminent optical coherence tomography (OCT) disc parameter for glaucoma in the future, ESCRS Glaucoma Day 2015 in Barcelona has heard.
During a session examining evolving imagining in glaucoma management, Nick Strouthidis MD, UK, explained that the disc margin is essential for quantification, as it defines the outmost limit of the neuroretinal rim. “If we know exactly where the disc margin is on an image, then we can have accurate, reproducible rim measurements,” he explained.
However, detailed OCT studies have failed to identify a consistent anatomical basis for the disc margin, he told the meeting, adding that the “true” outer limit of the disc’s neural tissue is therefore invisible to the clinician. 
There is now a solution, he said – BMO represents the narrowest canal opening for the neural tissue, and is a consistent and easily detected landmark, consistent with spectral domain-optical coherence tomography (SD-OCT), which is faster and has better penetration of the disc compared to other, older OCT technologies.
“BMO relates to a consistent aperture that the neural tissue must traverse,” Dr Strouthidis said.
He quoted a number of studies highlighting the promise of BMO-MRW, showing it is potentially better for phenotyping than other methods, has great potential for glaucoma progression monitoring, and large ethnic-specific population databases have already been published. The parameter is also easily generated in other OCT platforms.
Concluding, he said that information from the macula and retinal nerve fibre layer thickness also remain important.