Abstract: Body mass index (BMI) can influence intraocular pressure (IOP) and cerebrospinal fluid pressure (CSFP), modulating the trans-laminar cribrosa pressure difference (TLCPD), and thereby contributing to the development of pressure-related neuro-ophthalmic diseases. High BMI elevates both IOP and CSFP. BMI is inversely correlated with TLCPD. Low BMI primarily lowers CSFP, leading to a compensatory increase in TLCPD, making it an independent risk factor for primary open-angle glaucoma, especially normal-tension glaucoma. Increasing BMI to within the normal range may be protective against glaucoma. However, the revesed cranio-ocular pressure gradient caused by high BMI underlies the core pathophysiology of idiopathic intracranial hypertension and spaceflight-associated neuro-ocular syndrome.Based on the evidence and possible mechanisms of the impact of BMI on intraocular pressure, CSFP, and TLCPD, clinical management should shift from a single intraocular pressure or CSFP indicator to a TLCPD perspective to achieve more accurate risk prediction and clinical management. At the same time, elucidating how adipokines and inflammatory molecules influence TLCPD, particularly in populations with low BMI, is a worthwhile direction for future research.

Key words: Trans-laminar cribrosa pressure difference, Body mass index, Intraocular pressure, Intracranial pressure