Continual Intraocular Pressure Monitoring Needed for Open-Angle Glaucoma Patients

Kawek Mansouri, MD, MPH

Regular monitoring of intraocular pressure (IOP) could be beneficial for patients with open-angle glaucoma.

A team, led by Kawek Mansouri, MD, MPH, Glaucoma Research Center, Montchoisi Clinic, Swiss Visio Network, evaluated the short- and long-term variability of intraocular pressure in the eyes of individuals with primary open-angle glaucoma.

The study included 22 patients who had previously been implanted with a sulcus based intraocular pressure sensor. The investigators requested at least 4 IOP measurements per participant per day.

The mean age of the patient population was 67.8 ± 6.8 years, while 36.4% of the study participants were females. The mean follow-up duration of patients was 19.2 ± 21.3 months.

The researchers then groups the data according to the eye and medication, meaning an eye treated with a particular medication was considered as 1 group and the same eye treated with a different medication during the observation period was considered as a different group.

The team divided the day into 7 periods—Night' Midnight to 5:59am, 'early' 6-7:59 am, 'morning' 8-10:59 am, 'noon' 11 am to 1:59 pm, 'afternoon' 2-5:59 pm, 'evening' 6-8:59 pm, and 'late' 9-11:59 pm.

The investigators defined short-term variability at a particular period as the variability in IOP measurements obtained during that period on different days within 3 months of each other and long-term variability was defined as the variability in IOP measurements obtained during a particular period on different days over a time period at least 1 year.

Variability was assessed using intraclass correlation coefficients.

Overall, the team gathered 92,860 IOP measurements over 15,811 measurement days during the study period, with the number of measurements obtained from each eye ranging from 1-277 per day.

Intraclass correlation coefficients for short-term variability among the 7 periods during the day ranged from 0.52 in the morning period to 0.66 in the early period and long-term ICCs ranged from 0.29 at night to 0.51 during the late period.

“Continual IOP monitoring shows that IOP has moderate short-term and high long-term variability in glaucoma patients,” the authors wrote. “These findings demonstrate that single IOP measurements do not characterize day to day variations in IOP. Moreover, they show the importance of continual IOP monitoring in glaucoma patients.”

In 2019, investigators found that latanoprost .005% without the preservative benzalkonium chloride (BAK-free latanoprost) appears to be safe and well tolerated for chronic use as a treatment for open-angle glaucoma or ocular hypertension.

Latanoprost .005% ophthalmic solution with .02% benzalkonium chloride as a preservative can cause decreased ocular epithelial cell integrity, conjunctival scarring, and eye irritation.

Investigators found that treatment with BAK-free latanoprost helped patients maintain lower intraocular pressure and that incident rates, in terms of treatment-emergent adverse events, were similar between patients who had received latanoprost with and without BAK in a prior study.

The study, “Short-Term and Long-Term Variability of Intraocular Pressure Measured with an Intraocular Telemetry Sensor in Patients with Glaucoma,” was published online in Ophthalmology.