HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: iovs.09-3668v1 51/2/882    most recent Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Renard, E. Articles by Romanet, J.-P. PubMed PubMed Citation Articles by Renard, E. Articles by Romanet, J.-P.

Twenty-four Hour (Nyctohemeral) Rhythm of Intraocular Pressure and Ocular Perfusion Pressure in Normal-Tension Glaucoma

From the ¹Department of Ophthalmology, Platform of Chronobiology and Flowmetry, University Hospital of Grenoble, and ³HP2 (Hypoxia/ Pathophysiology) Laboratory, INSERM (Institut National de la Santé et de la Recherche Médicale), ERI 0017 EA 3745, Joseph Fourier University, Grenoble, France; ²Pole Tête et Cou, Chirurgie Réparatrice, and ⁵Pole Rééducation et Physiologie, University Hospital, Grenoble, France; and the ⁴Department of Chronobiology, Stem Cell and Brain Research Institute, INSERM, U846, Bron, France.

Corresponding author: Jean-Paul Romanet, Department of Ophthalmology, Platform of Chronobiology and Flowmetry, University Hospital of Grenoble, Joseph Fourier University, BP 217 38043 Grenoble cedex 09, France; jean-paul.romanet{at}ujf-grenoble.fr.

Purpose. To characterize the nyctohemeral rhythm of intraocular pressure (IOP) and ocular perfusion pressure (OPP) in patients with newly diagnosed, untreated normal tension glaucoma (NTG).

Methods. Twenty-seven patients with suspected NTG were prospectively included and underwent 24-hour monitoring of IOP and blood pressure (BP), polysomnography, and nailfold capillaropathy. The nyctohemeral rhythms of IOP, BP, and OPP were modeled with a nonlinear least-squares, dual-harmonic regression procedure, studying the mean value, the acrophase, the nadir and the amplitude of each rhythm. Nonparametric tests were used to study the relationship between the rhythm of IOP and vascular, sleep, and visual field parameters.

Results. Five patients were excluded from the analysis after the 24-hour curve of IOP, (IOP > 21 mm Hg during nighttime [n = 1] or daytime [n = 4]). Twenty-two (81%) patients received a diagnosis of NTG (IOP < 22 mm Hg over 24 hours). They exhibited a diurnal acrophase (54.5%), or a nocturnal acrophase (36.4%) of IOP. The remaining patients (9.1%) with NTG had no nyctohemeral rhythm. A significantly higher proportion of patients with capillaropathy and a higher nyctohemeral fluctuation of IOP characterized the IOP group with diurnal acrophase. A rhythm of OPP was found in all patients, (diurnal [58%] or nocturnal [42%]) acrophase) equally distributed between the two groups of IOP. Amplitude of OPP was not significantly associated with the severity or progression of glaucoma.

Conclusions. A nyctohemeral rhythm of IOP exists in most of the patients with NTG, either with a nocturnal acrophase or a diurnal acrophase. The rhythm of OPP did not correlate with the IOP rhythm.