Normal tension glaucoma in CSF-shunted normal pressure hydrocephalus patients. An extended follow-up

According to the trans-lamina cribrosa gradient hypothesis, intracranial hypotension and intracranial hypertension are risk and protective factors, respectively, for normal tension glaucoma (NTG). This prediction was tested in patients with normal pressure hydrocephalus (NPH) who received CSF shunting to reduce their intracranial pressure. We previously reported on 22 of such patients who had been evaluated for NTG in 2016. By that time, nine patients (41%) had developed NTG, while 13 had not. Here we report the extended follow-up to monitor the possible occurrence of NTG among the patients of our initial cohort who were still free from NTG. NTG occurred at an approximately steady rate suggesting that it may be a common fate among shunted NPH patients. Particularly, survival analysis suggested that three quarters of such patients will be diagnosed with NTG within approximately 10 years from shunting, assuming they survive long enough. In addition, four of 11 non-NTG patients experienced a worsening of their ophthalmological parameters that may suggest a possible future diagnosis of NTG.