At optometric conferences and in the academic literature, speculation about the connection between intraocular pressure (IOP) and cerebrospinal fluid (CSF) has been building in recent years. Researchers, such as John Berdahl, MD, suspect that the CSF holds the key to understanding glaucoma.1 Investigators in that camp are now emboldened by new evidence that shows, for the first time, that CSF’s entry into the optic nerve subarachnoid space is impeded in glaucomatous eyes.2
The mouse-model research included eight subjects with glaucoma for 10 months and another nine with glaucoma for only two months.2 The investigators discovered the CSF flowed more into the areas around the optic nerve of the two-month-old glaucoma cohort than the 10-month-old cohort.2 The researchers used a CFF-injected tracer dye to track the flow.2 The tracer was found in the vessels around the eye in six out of nine of the two-month cohort.2 However, when the same test was run on the 10-month-cohort, only three of the eight mice showed the tracer anywhere in the subarachnoid space.2 For comparison, eight age-controlled mice without glaucoma all showed the tracer.2 Simply put, glaucoma is gumming up the cerebrospinal works, especially as it progresses.
“This finding suggests an association between CSF flow obstruction and axon pathology in this glaucoma model, although a causative relationship cannot be concluded,” the authors note.2
1. Berdahl J, Allingham R, Johnson D. Cerebrospinal fluid pressure is decreased in primary open-angle glaucoma. Ophthalmol. 2008;115(5):763-8.
2. Mathieu E, Gupta N, Paczka-Giorgi L, et al. Reduced cerebrospinal fluid inflow to the optic nerve in glaucoma. IOVS. 59(15):5876–5884