Abstract
Purpose:
To delineate the possible relationship between glaucoma and normal pressure hydrocephalus (NPH) based on disease prevalence, uncovering an underlying susceptibility of neural pathways to compressive damage intrinsic to the extracellular matrix, cytoskeleton, or impediment of axonal transport. Given an underlying discrepancy in the susceptibility of their neuronal pathways to pressure, then there should be elevated rates of such diseases as well as worse disease severity in this target population.
Methods:
This IRB-approved study was a retrospective analysis of all patients diagnosed with NPH at a major medical center between January 1997 and November 2013. Using an electronic research tool, Clinical Looking Glass (CLG), all patients with an ICD-9 coded diagnosis of NPH were identified and then confirmed upon chart review looking at neuroimaging, lumbar puncture results, and clinical notes. Two age-matched control groups were generated by searching CLG for: 1) patients who received a diagnosis of hydrocephalus based on ICD-9 codes, and 2) patients who had neuroimaging performed (MRI or CT scan) whose reports indicated evidence of dilated ventricles (but no NPH diagnosis). Using ICD-9 codes all three groups were searched for patients who received a diagnosis of glaucoma, constricting the diagnoses to include only open-angle variants. Chi-square tests were used to compare disease rates between groups.
Results:
There were 182 patients with NPH identified, of which 24 were also held glaucoma diagnoses (13.2%). In the age-matched hydrocephalus group, 7.1% of patients were diagnosed with glaucoma (p=0.056). In the age-matched dilated ventricle group 9.9% of patients were diagnosed with glaucoma (p=0.32). The average ages in years for the three groups were 73.3 ± 13.2, 73.8 ± 11.9, and 72.8 ± 15.4, respectively.
Conclusions:
There is a trend of elevated rates of glaucoma in patients with NPH compared with control groups, with the comparison of the hydrocephalus group to the NPH group showing near statistical significance. This appears to indicate an underlying susceptibility of neurons to barometric insult in this patient population. Further comparison of disease severity between these patient groups needs to be assessed.
Keywords: 463 clinical (human) or epidemiologic studies: prevalence/incidence •
629 optic nerve •
627 optic disc