Effect of CPAP Therapy on 24-Hour Intraocular Pressure-Related Pattern From Contact Lens Sensors in Obstructive Sleep Apnea Syndrome

Abstract

Purpose: To evaluate the effect of continuous positive airway pressure (CPAP) therapy on 24-hour intraocular pressure (IOP)-related pattern from contact lens sensors (CLS) in obstructive sleep apnea syndrome (OSAS).

Methods: Prospective, observational, case series study. Twenty-two eyes of 22 newly diagnosed patients with severe OSAS were included. A first 24-hour CLS measurement was performed before CPAP therapy was started, and a second 24-hour CLS monitoring was performed after beginning CPAP. We analyzed the amplitude and the maximum and minimum IOP-related values (m Veq). We also analyzed IOP-related measurements at five-minute intervals throughout the first hour of nocturnal acrophase, starting from when the patient fell asleep.

Results: The baseline measurements showed significant fluctuations in the IOP, with the highest IOP readings being recorded at night (nocturnal acrophase) in 17 of 22 patients (77.27%). Nocturnal acrophase began when the patients laid down to sleep. During CPAP therapy, the patients showed a more marked increase in IOP in the initial phase of nocturnal acrophase, with significant differences at 20, 25, 30, and 55 minutes (P < 0.05).

Conclusions: Most of patients with severe OSAS exhibited a nocturnal acrophase and the highest IOP readings at night. CPAP was associated with additional increase in IOP-related pattern for at least the first hour of CPAP use.

Translational relevance: Our results suggest that CPAP was associated with additional increase in IOP during the initial phase of nocturnal acrophase. This effect could be important in the management of patients with OSAS and glaucomatous progression.

Figure 1.

Population pattern of the circadian rhythm before continuous positive airway pressure treatment in severe OSAS patients (n = 22). CLS, contact lens sensor measures in m V eq. An acrophase was observed at 5:03 a.m.

Figure 2.

Twenty-four-hour intraocular pressure (IOP) monitoring with a contact lens sensor. This example was obtained from the monitoring of the IOP over 24 hours, as measured using a contact lens sensor. The patient's sleep period is indicated at the bottom. This patient showed a significant increase in nocturnal IOP associated with a nocturnal acrophase while patients were in bed compared with their result during daytime. We observed an increase in IOP which started when a patient lay on the bed.

Figure 3.

Population pattern of circadian rhythms before and during continuous positive airway pressure (CPAP) treatment in patients with severe obstructive sleep apnea syndrome. The use of CPAP did not modify the circadian pattern. It was showed the presence of nocturnal patterns in patients both before starting CPAP therapy and during CPAP. CLS, contact lens sensor measures in m Veq.

Figure 4.

Two examples (A and B) of two patients for whom we compared the early phase of nocturnal acrophase both without (top graph) and with (lower graph) continuous positive airway pressure (CPAP), based on individualized analyses. A marked increase in nocturnal acrophase was observed after starting CPAP use (arrow). The patient's sleep period is indicated at the bottom of each graph.

Figure 5.

Intraocular pressure (IOP)–related differences at five-minute intervals during the first hour of nocturnal acrophase, both with and without continuous positive airway pressure (CPAP) therapy. Note: statistically significant differences (P < 0.05) are indicated with an asterisk in the graph. It was observed that the increase in IOP during the initiation of the nocturnal acrophase was faster with than without CPAP, with significant differences at 20, 25, 30, and 55 minutes.