Abstract
Purpose::
To evaluate the effect of travoprost on variations in intraocular pressure over a 24 hour period.
Methods::
Patients with a diagnosis of glaucoma or ocular hypertension were subjected to a medication washout period of 4 weeks prior to the start of the study. Patients were examined mid-way through the washout period to ensure that they were still under control. After the 4 week period patients were admitted to a sleep laboratory and monitored over a 24 hour period. The following measurements were made at 6 different time points during the 24 hour evaluation: IOP (Goldmann), Rim volume (HRT), Retinal Nerve Fibre Layer Thickness (OCT), and Visual Field (FDT). In addition, standard sleep laboratory measurements were made throughout the 24 hour period.Travoprost was dispensed and patients were instructed to use it daily at 8 p.m. After 30 days of travoprost treatment, patients were readmitted to the sleep laboratory and all measurements were repeated in a similar manner as at baseline.
Results::
17 Patients completed the study. One patient withdrew following a traumatic abrasion unrelated to the study. The mean IOP over 24 hours pre-treatment was 17.04 mm Hg. After 30 days of treatment with travoprost, the mean IOP decreased to 14.18 mm Hg, a decrease of 16.8 % (p<0.0001). The range of IOP pre-treatment was 7.25 mm Hg. The amplitude of the IOP fluctuations was found to correlate with glaucomatous progression. After 30 days of treatment with travoprost, the range of IOP fluctuation decreased to 4.68 mm Hg. This decrease of 2.57 mm Hg was found to be highly significant (p = 0.0053). The only significant change observed in the other ocular measurements was that of mean defect as determined by FDT, where the baseline mean defect was shown to improve from -2.68 to -0.98. The increase of 1.70 was significant (p<0.0001). An interesting observation was that 7 of the 18 patients who underwent the baseline 24 hour evaluation (38.8%), were shown to exhibit moderate to severe sleep apnea.
Conclusions::
This study confirmed the large fluctuation in IOP over a 24 hour period reported in several similar studies. Travoprost was found to decrease the amplitude of the IOP fluctuation.
Keywords: intraocular pressure • drug toxicity/drug effects