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Berdahl et al. performed a retrospective study to assess the relation between body mass index (BMI) and cerebrospinal fluid opening pressure (CSFP) on lumber puncture (LP). The recent findings of an inverse relation between BMI and primary open-angle glaucoma (POAG), particularly among women, motivated this study. The authors exhaustively research the literature on the topic of BMI and its relation to POAG and do point out that there is not 100% consensus on this score. They are to be congratulated for exploring a novel potential link between BMI and POAG that might involve CFSP, as the optic nerve is a 50 mm white matter tract bathed in cerebrospinal fluid. The authors found a positive linear correlation between BMI and CSFP. Within the BMI range of 18 and 25 kg/m2, men had higher CSFP than women (p < 0.001) and the test for interaction between BMI and gender showed a trend in the statistically significant direction (p for interaction = 0.065). While the sample size is impressive (n = 4235), the study may have been underpowered to find a statistically significant p for interaction term. The authors comment that gender and BMI were independent determinants of CSFP although they do not show the actual results of the multivariable model. These are intriguing findings that support the work of the Nurses Health Study and the Rotterdam Study showing an inverse relation between BMI and POAG among women. More importantly, they underscore the emerging importance of CSFP in POAG pathogenesis. Nonetheless, the results should be viewed conservatively as they are derived from a special population of patients who required LP because of serious neurological indications. Furthermore, the authors do not adjust their results for age, ancestry and a host of other covariates that could confound the association between BMI and CSFP.