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Angle Closure (Glaucoma) in Caucasians

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified February 2014 by Maastricht University Medical Center.
Recruitment status was:  Not yet recruiting
Information provided by (Responsible Party):
Maastricht University Medical Center Identifier:
First received: January 30, 2014
Last updated: February 3, 2014
Last verified: February 2014

Rationale: Primary angle closure glaucoma (PACG) causes high rates of blindness, either by means of a painful attack of acute angle closure glaucoma or unnoticed over a period of many years. Patients with angle closure are particularly at risk but can be detected during an ophthalmological examination and sent for early preventive (laser) intervention. Current practice shows that patients at risk of PACG are frequently missed during routine examinations. Moreover, new imaging techniques like swept source optical coherence tomography (SS-OCT), are emerging with which the angle of the anterior chamber can be imaged in great detail with no burden for the patient. These techniques are already used in clinical practice and replace and complete part of the ophthalmic examination. However, in Caucasians, it is not yet known to what extent angle closure is detected in regular care and can be detected with this OCT device. There are few published data concerning angle closure and PACG in Caucasians and its characteristics.

Objective: To quantify the presence of angle closure by gonioscopy in patients at risk of angle closure on SS-OCT. Secondary objectives are to quantify the presence of an increased intra-ocular pressure during the day or after dark provocation, to quantify morphometric details of the anterior chamber, structural changes, and corneal endothelial cells and to quantify the functional changes of the visual field.

Study design: prospective, observational, descriptive study. Study population: Caucasian patients, presenting at the outpatient clinic of the University Eye Clinic Maastricht, aged 40 to 80 years, who are diagnosed with angle closure on SS-OCT.

Intervention (if applicable): Not applicable. Main study parameters/endpoints: The main study parameter is assessment of the anterior chamber angle according to gonioscopy. Secondary study parameters are the presence of an increased intra-ocular pressure (IOP) (>21 mmHg) during the day or after dark provocation (IOP rise from baseline), morphometric details of the anterior chamber, structural changes of the retinal nerve fiber layer, number of corneal endothelial cells and functional changes of the visual field Hypothesis: It is hypothesised that, based on its resolution and ease of use, SS-OCT is a suitable imaging technique to identify patients with or at risk of angle closure. It will be of value as an additional diagnostic instrument and may even replace gonioscopy.

Glaucoma, Angle-Closure

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Cross-Sectional
Official Title: Structural and Functional Parameters in Caucasian Patients With Angle Closure on SS-OCT

Resource links provided by NLM:

Further study details as provided by Maastricht University Medical Center:

Primary Outcome Measures:
  • Angle closure on gonioscopy [ Time Frame: 3 weeks ] [ Designated as safety issue: No ]
    The percentage of subjects with angle closure on gonioscopy compared with angle closure on SS-OCT.

Secondary Outcome Measures:
  • intra-ocular pressure (IOP) [ Time Frame: 3 weeks ] [ Designated as safety issue: No ]
    The secondary outcome measure is the percentage of patients with presence of an increased intra-ocular pressure (>21 mmHg) during the day or after dark provocation (IOP rise from baseline)

Other Outcome Measures:
  • Visual field loss [ Time Frame: 3 weeks ] [ Designated as safety issue: No ]
    The percentage of patients with visual field loss on the HFA visual field.

  • Retinal nerve fiber layer thickness [ Time Frame: 3 weeks ] [ Designated as safety issue: No ]
    The mean RNFL thickness will be measured.

  • Number of corneal endothelial cells [ Time Frame: 3 weeks ] [ Designated as safety issue: No ]
    The mean number of corneal endothelial cells will be measured

  • Axial length [ Time Frame: 3 weeks ] [ Designated as safety issue: No ]
    The mean axial length will be measured.

  • Anterior chamber angle parameters [ Time Frame: 3 weeks ] [ Designated as safety issue: No ]

    Parameters analysed from SS-OCT images to determine the morphometric details of the anterior chamber will be measured and means will be calculated.

    For example AOD500, AOD750, TISA500, TISA750, ARA500, ARA750,TIA500, TIA750, ACD, LV

Estimated Enrollment: 100
Study Start Date: April 2014
Estimated Study Completion Date: October 2015
Estimated Primary Completion Date: April 2015 (Final data collection date for primary outcome measure)
angle closure


Ages Eligible for Study:   40 Years to 80 Years   (Adult, Senior)
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Sampling Method:   Probability Sample
Study Population
This study will consist of Caucasian patients, aged 40-80 years. Patients will be recruited at the University Eye Clinic Maastricht, the Netherlands. All study participants are derived from the study 'Caucasian patients with angle closure on SS-OCT', METC 13-4-108.

Inclusion Criteria:

  1. Caucasian race
  2. 40-80 years
  3. Willing and able to comply with scheduled visits and other study procedures
  4. Signed informed consent
  5. Participants derived from the study 'Caucasian patients with angle closure on SS-OCT' AND 1 or more of the following:

    • Irido-trabecular contact (ITC) in ≥2 quadrants as seen with SS-OCT in darkened conditions
    • Scleral spur angle (SSA) <20˚ (in 0 and 180º) AND anterior chamber depth (ACD) < 2.5 mm as seen with SS-OCT in darkened conditions
    • The fellow, non-treated eye in a patient after an acute primary angle closure (APAC) attack in the other eye. APAC is defined as an abrupt onset of symptomatic elevation of IOP resulting from total closure of the angle which is typically not self-limiting (although acute attacks can rarely resolve spontaneously).

Exclusion Criteria:

  1. Any condition including (previous) intraocular laser/incisional surgery or medical procedure or treatment in ophthalmology
  2. Any eye condition/abnormality that will affect the acquisition/reliability of measurement (results), (e.g. vitreous haemorrhage, uveitis, intraocular trauma, significant corneal opacity)
  3. Unable to communicate properly or to understand instructions
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT02054403

University Eye Clinic Maastricht
Maastricht, Netherlands, 6202AZ
Sponsors and Collaborators
Maastricht University Medical Center
  More Information

Responsible Party: Maastricht University Medical Center Identifier: NCT02054403     History of Changes
Other Study ID Numbers: NL47347.068.13/METC 13-2-060 
Study First Received: January 30, 2014
Last Updated: February 3, 2014
Health Authority: Netherlands: Medical Ethics Review Committee (METC)

Additional relevant MeSH terms:
Glaucoma, Angle-Closure
Ocular Hypertension
Eye Diseases processed this record on December 07, 2016