Clinical trial NCT02713152: Prevalence of Obstructive Sleep Apnoea in Glaucoma
Official title: POSAG: Prevalence of Obstructive Sleep Apnoea in Glaucoma
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Obstructive Sleep Apnoea
Open Angle Glaucoma
Lead sponsor: Papworth Hospital NHS Foundation Trust
Sponsor class: OTHER_GOV
Collaborators: name: Anglia Ruskin University
name: Hinchingbrooke Healthcare NHS Trust
First posted: 2016-03-18
Enrollment: 403
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: CASE_CONTROL
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Patients and healthy volunteers

Brief summary: This study aims to investigate a potential link between Obstructive Sleep Apnoea (OSA) and Open Angle Glaucoma (OAG); initially by determining whether the prevalence of OSA is higher in patients with OAG in comparison to people without glaucoma and if OSA is an independent risk factor for OAG. It will comprehensively phenotype glaucoma patients for variables that may be associated with both OSA and OAG.

Detailed description: Open Angle Glaucoma (OAG) is an eye disease which can lead to irreversible loss of vision caused by damage to the optic nerve at the back of the eye. It is often associated with raised fluid pressure in the eye and treated by lowering this pressure. However, despite treatment, some patients continue to lose vision and it is suspected that other factors are contributing to the optic nerve damage. Among them is Obstructive Sleep Apnoea (OSA), though the link between OAG and OSA is controversial.

This study aims to determine whether the prevalence of OSA is higher in patients with OAG in comparison to people without glaucoma. In addition, it will establish whether OSA is an independent risk factor for OAG and whether a future randomised controlled trial assessing the impact of OSA treatment with Continues Positive Airway Pressure (CPAP) on OAG outcomes would be acceptable and feasible in this population. The usefulness of OSA screening tools, including oximetry and questionnaires will also be determined. We comprehensively phenotype glaucoma patients using novel techniques, which include angiographic ocular coherence tomography and retinal oximetry. Ocular perfusion pressure will be calculated based on central retinal vein pressure measured by ophthalmodynamometry.

The study is a collaborative project between sleep specialists at Papworth Hospital and ophthalmologists at Hinchingbrooke Hospital and will involve patients attending glaucoma clinic and their relatives who will act as a control group. Two study visits will be required on consecutive days. Participants will undergo a comprehensive ocular examination and a sleep study in the form of respiratory polysomnography (respiratory PSG) at home. A brief medical history focused on cardiovascular and metabolic co-morbidities will be taken.

Eligibility criteria: Inclusion Criteria:

Glaucoma patients:

1. Open angle glaucoma (including primary open angle glaucoma, normal tension glaucoma and pseudoexfoliation glaucoma) in either eye.
2. Age ≥18 years
3. Able to give informed consent and attend at the required frequency for the duration of the study.

Control group:

1. Age ≥18 years
2. Able to give informed consent and attend at the required frequency for the duration of the study.

Exclusion Criteria:

Glaucoma patients:

1. Unable to perform reliable visual field testing (\>15% false positives, \>20% fixation losses. However, if fixation losses are \>20%, the eye tracker may be used to assess reliability)
2. Known or suspected pregnancy.
3. Tracheostomy
4. Use of nocturnal oxygen for indications other than sleep related breathing disorders (SBD).

Control group:

1. Known or suspected pregnancy
2. Known or suspected glaucoma (participants with glaucoma diagnosed during screening ophthalmic examination and newly identified glaucoma 'suspects' will also be excluded)
3. Inability to undergo screening ophthalmic examination
4. Tracheostomy
5. Use of nocturnal oxygen for indications other than sleep related breathing disorders (SBD).

Primary outcomes:
measure: Diagnosis of OSA
timeFrame: Within 24 hours of recruitment on to study (cross-sectional)
Secondary outcomes:
measure: OSA severity
timeFrame: 24 hours
measure: Glaucoma severity
timeFrame: 24 hours
measure: Ocular perfusion pressure (OPP)
timeFrame: 24 hours
measure: Postural changes in intraocular pressure (IOP)
timeFrame: 24 hours
measure: Optic nerve head perfusion
timeFrame: 24 hours
measure: Structural changes of the optic nerve
timeFrame: 24 hours
measure: Stop-Bang questionnaire as screening tool
timeFrame: 24 hours
measure: Nocturnal oximetry as screening tool
timeFrame: 24 hours
measure: Diagnosis of obstructive sleep apnoea syndrome (OSAS)
timeFrame: 24 hours
Other outcomes:
Locations:
city: Huntingdon
country: United Kingdom
facility: Hinchingbrooke Hospital NHS Foundation Trust
state: Cambridgeshire
Study officials:
References: