Control glaucomatous progression with diurnal IOP control

MAUI, Hawaii — Diurnal fluctuations in IOP must be considered in managing well-controlled glaucoma patients, according to Sanjay Asrani, MD.

The beneficial effect of lowering the mean IOP is well known, as is the higher risk factor for glaucomatous progression for IOP peaks above the normal range. Dr. Asrani showed that these previous studies, however, did not separate the effect of the level of IOP from the diurnal variation.

Dr. Asrani told attendees here at Hawaii 2003: the Royal Hawaiian Eye Meeting that large diurnal fluctuations in IOP are an independent risk factor in glaucoma patients.

“The relative risk of progression if a patient has a diurnal IOP of 5.4 mm Hg is six times more than if a patient has a diurnal IOP of 3.1 mm Hg,” he said.

Dr. Asrani’s study assessed fluctuation within the normal range of IOP, accounting for known risk factors. Multi-day monitoring of the IOP was performed on open-angle glaucoma patients who were able to successfully perform home tonometry. IOP was measured each day for 5 days at waking, noon, mid-afternoon, dinnertime and bedtime. The charts of two glaucoma specialists were also reviewed for the date of a definite statement of visual field progression, as well as the date of the last visual field, if no progression was noted.

The study concluded that in patients with office-measured IOP in the normal range, large fluctuations in diurnal IOP are a significant risk factor for progression. Therefore, Dr. Asrani said, fluctuations in IOP must be considered in managing well-controlled glaucoma patients, and a lack of IOP variation will reassure both the patient and the clinician.