Intracranial pressure in primary open angle glaucoma, normal tension glaucoma, and ocular hypertension: a case-control study

Abstract

Purpose: To compare intracranial pressure (ICP) in subjects with primary open-angle glaucoma (POAG), normal-tension glaucoma (NTG; subset of POAG), and ocular hypertension (OHT) with that in subjects with no glaucoma.

Methods: The study was a retrospective review of medical records of 62,468 subjects who had lumbar puncture between 1985 and 2007 at the Mayo Clinic. Of these, 57 POAG subjects, 11 NTG subjects (subset of POAG), 27 OHT subjects, and 105 control subjects met the criteria and were analyzed. A masked comparison of the relationship between ICP and other ocular and nonocular variables was performed by using univariate and multivariate analyses.

Results: ICP was significantly lower in POAG compared with age-matched control subjects with no glaucoma (9.1 +/- 0.77 mm Hg vs. 11.8 +/- 0.71 mm Hg; P < 0.0001). Subjects with NTG also had reduced ICP compared with the control subjects (8.7 +/- 1.16 mm Hg vs. 11.8 +/- 0.71 mm Hg; P < 0.01). ICP was higher in OHT than in age-matched control subjects (12.6 +/- 0.85 mm Hg vs. 10.6 +/- 0.81 mm Hg; P < 0.05).

Conclusions: ICP is lower in POAG and NTG and elevated in OHT. ICP may play an important role in the development of POAG and NTG and in preventing the progression of OHT to POAG. Further prospective and experimental studies are warranted to determine whether ICP has a fundamental role in the pathogenesis of glaucoma.

Figures

FIGURE 1

(A) Uncorrected intracranial pressure in all groups. (B) After correction of the mean ICP of each group for variables predictive of ICP, the significant difference between POAG, the NTG subset and controls persisted and a significant difference between OHT and the control became apparent.

FIGURE 2

The translaminar pressure difference (TLPD) was higher in POAG, the NTG subset, and OHT. TLPD was calculated by subtracting ICP from maximum IOP (A) and by subtracting ICP from IOP (B) near the time of LP.

FIGURE 3

(A) ICP comparison in the current dataset. (B) ICPs in the current dataset (1985–1996) compared with those in the previous dataset (1996–2007).