The Effect of Body Posture on Intraocular Pressure in Progressive Glaucoma

University of Toronto20 enrolled

Overview

Glaucoma is a condition where the optic nerve (the nerve responsible for sight) shows progressive damage with characteristic loss of visual field. Glaucoma is very commonly associated with raised pressure in the eye (intraocular pressure \[IOP\]). IOP has been shown to increase when lying down in normal subjects as well as patients with glaucoma. It is possible that this effect can make glaucoma worse. This study is designed to investigate the effect of body posture (particularly when sleeping) on the IOP fluctuation in the eye. Each patient will be required to attend for 2 separate 24 hour visits. On one visit the patient will be required to sleep flat and on the other visit at a 30° head up sleeping position. During this time the patient will be required to wear a soft contact lens (SENSIMED Triggerfish®) which has a special sensor on it that monitors the IOP continuously. The IOP measurements are wirelessly transmitted to a recorder.

Study Type

OBSERVATIONAL

Enrollment

Conditions

Glaucoma

Eligibility

Sex: ALLMin age: 18 YearsMax age: 85 Years

Medical Language ↔ Plain English

Inclusion Criteria: * signed informed consent * diagnosis of primary open angle glaucoma (POAG) or normal tension glaucoma (NTG) that is progressing based on recent or recurrent optic disc hemorrhage * age 18-85 years * not more than 4 diopters of spherical equivalent or 2 diopters of cylinder equivalent in study eye * stable anti-glaucoma treatment for 4 weeks before first session * for women of childbearing potential, adequate contraception Exclusion Criteria: * unwilling or unable to sleep in a flat or 30 degrees head up position * ocular surgery in previous 3 months * corneal or conjunctival abnormality * wear of full frame metallic glasses during monitoring session * severe dry eye * secondary forms of glaucoma * allergy to corneal anaesthesia * patients with contraindications for contact lens wear * pregnancy and lactation * patients unable to understand the character and individual consequences of the investigation * simultaneous participation in other research

Outcomes

Primary Outcomes

Intraocular pressure changes that occur during sleep and with changes in body posture

The intraocular pressure will be continuously monitored with a wireless contact lens sensor device over a 24 hour period

Time frame: 24 hours

Secondary Outcomes

Incidence of side effects or adverse effects that occur while subjects are wearing the contact lens device

Patients will be monitored for contact lens related side effects or adverse effects that occur during the monitoring session.