Diurnal IOP curves have limited value in patients with POAG

Diurnal IOP curves have limited value in clinical practice for patients with primary open-angle glaucoma (POAG), according to a study newly published in Ophthalmology. A single curve poorly characterizes fluctuations in IOP, and patterns cannot be reproduced from month to month, researchers say.

French researchers conducted a database study of 92 patients who had POAG. The patients had their diurnal IOP curve measurements taken 4 times, 6 months apart. Goldmann applanation tonometry had been recorded with patients in the sitting position at 9 am, 10 am, 11 am, noon, 2 pm, 3 pm, 4 pm and 5 pm. Intraclass correlation coefficients (ICCs) were used to measure intervisit agreement of IOP by time point and of diurnal IOP curve parameters, including mean, standard deviation, range, maximum, maximum hour, minimum and minimum hour.

The researchers found generally poor agreement of between-visit agreement of IOP values at each time point. ICCs were 0.26 to 0.77 in all patients. Also, using the first diurnal IOP curve to predict the risk of IOP fluctuations during the 3 subsequent curves was of limited value. "Only 6.4% of the patients with an IOP range ≥30% of the mean IOP on the first curve presented similar fluctuations on the 3 subsequent curves; 77.1% of the patients who did not have an IOP range ≥30% of the mean IOP on the first curve had an IOP range ≥30% of the mean IOP on at least 1 of the 3 subsequent curves," they wrote.

To read an abstract of the study, click here.