The authors report on a subgroup of patients who participated in the ARGOS-02 trial a prospective, open-label, single arm, multi-center observational study assessing the safety and performance of the Eyemate-IO system in patients with primary open-angle glaucoma (POAG). This involved the insertion of an intraocular telemetric sensor at the time of cataract surgery which is read with a handheld reading device. Patients were instructed to self-measure their IOP as often as desired, but at least four times daily. The aim of this study was to examine weekday and seasonal IOP variations.
Twenty-two patients with mild to moderate glaucoma were evaluated. The mean age was 67.8 years and 34% were female. Patients formed a heterogeneous group consisting of two patients who had had glaucoma surgery and 6 drops. In total 15811 measurement days were analyzed. All measurements were used to calculate daily and monthly IOP patterns.
For weekly IOP, there was a statistically significant difference (p = 0.040) in daily mean IOPs but not for mean peak IOPs (p = 0.33). The mean daily IOPs were highest on Wednesday at 19.89 mmHg and lowest on Friday at 18.76 mmHg. The mean daily peak IOPs was highest on Wednesday at 30.54 mmHg and lowest on Saturday at 28.62 mmHg.
This study is unique in terms of the substantial amount of IOP data obtained over a long period of time and so more closely mimics real life values
Seasonal IOP variations were observed. Between mid-winter months (December-January) and mid-summer months (June-July), there was a reduction in mean IOP of 8.1%. The lowest monthly IOP was measured in June at 17.43 mmHg and the highest in March at 20.02 mmHg.
The authors acknowledge that similar patterns have previously been reported. However, this study is unique in terms of the substantial amount of IOP data obtained over a long period of time and so more closely mimics real life values in a cohort of patients with glaucoma.The precise mechanism underlying these observations remains elusive.
However, as the authors suggest it is likely that a better understanding of the mechanism(s) responsible for these variations of IOP may enhance glaucoma management in the future.