Re: Fast circulation of cerebrospinal fluid: an alternative perspective on the protective role of high intracranial pressure in ocular hypertension.

Trans-lamina cribrosa pressure difference (ΔP = intraocular pressure – intracranial pressure) is a widely accepted mechanism in the pathogenesis of glaucoma. We reply to a recent review postulatjng that the protective effect of higher intracranial pressure could be due to a pressure-independent mechanism, namely faster cerebrospinal fluid production and clearance of potentially toxic molecules. We point out that experimental and epidemiological evidences do not seem to support this view. However, the role of cerebrospinal fluid clearance in glaucoma, which moves in the emerging field of brain waste molecules removal, remains very attractive. In this context, it could be interesting to study the association between glaucoma and the expanding world of cerebrospinal fluid clearance failure conditions.