Overview

This trial is active, not recruiting.

Condition fabry disease
Treatments contrast sensitivity measurement, slit lamp assessment and intra-ocular pressure measurement, visual field testing, oxygen flow at the optic nerve head measurement, tropicamide, osome
Sponsor Université de Montréal
Collaborator Genzyme, a Sanofi Company
Start date August 2014
End date December 2016
Trial size 8 participants
Trial identifier NCT02023086, GZ-2012-10918

Summary

This study aims to evaluate blood oxygenation at the optic nerve head in relation with visual field losses observed in many Fabry patients. Data collected will allow to evaluate if there is a link between these two entities.

Study will last up to 2 years during which a limited number of Fabry patients will be compared to a control group to confirm any relationship between blood flow and field losses, and to see if these results vary over time.

HYPOTHESIS

1. Fabry patients will present significant differences in visual fields compared to control 2 There will be variability of the visual field defects on the long term but not on the short term 3 Blood oxygenation will be higher for Fabry patients 4 Blood volume at the optic nerve head will be the same for both groups.

United States No locations recruiting
Other Countries No locations recruiting

Study Design

Observational model case control
Time perspective prospective
Arm
contrast sensitivity measurement slit lamp assessment and intra-ocular pressure measurement ocular coherence tomography at the optic nerve head visual field testing OSOME (oxygen flow at the optic nerve head measurement) Tropicamide
contrast sensitivity measurement
Contrast sensitivity test is made with targets alternating black and white lines. The larger the lines are, easier it is to see them. Targets are distributed in 5 rows, each oriented at a different angle. Contrast sensitivity level is determined by the smallest target seen by the participant, line by line. This test is done under dim lightning with the habitual visual correction worn.
slit lamp assessment and intra-ocular pressure measurement
Slit lamp is used to assess the presence of significant lens opacities known as Fabry cataracts. In fact, these opacities can induced a bias on the contrast sensitivity measurement and can increase the symptoms felt by the patient. A grade 2 (CFDI grading chart) of lens opacities is considered clinically significant and this will become an exclusion criteria for the following of the study. Intra-ocular pressure will be measured with a non contact tonometer (air pulsed) (Ocular Response Analyser, Reichert Instrumentation.)
visual field testing
Visual field will be assessed with an automated perimeter (Humphrey, Texas) using a threshold strategy. This implies that the subject has to identify not only if he perceives the visual stimulus but the minimal level of this stimulus (in decibels), to be seen, is also recorded. Visual field will be tested up to 30 degrees from the central point of fixation. In order to measure immediate variability of the visual testing among Fabry subjects, this test will be done at the beginning of the testing session (in the morning) and another time 1h00 later.
oxygen flow at the optic nerve head measurement OSOME
Pupils will be dilated with 1 drop of 1% tropicamide. The procedure is similar to the one used for taking a photo of the retina. Each measurement session represents a continuous recording of 20 simultaneous functions of reflectometry from the optic nerve area during 10 seconds. During all recording sessions, the systemic arterial oxygen saturation will be also monitored at the right index finger using a pulse oximeter (Escort M10, Invivo, Orlando, USA). Arterial blood pressure will be also monitored before and after the testing using a manual sphygmomanometer.
tropicamide Mydriacyl® Mydriatic Tropicamide 1% Ophthalmic Drops
Used to dilate patient's pupil during testing
osome (O.S.O.M.E., US patent # 5,919,132;)
The OSOME system is the only technology able to perform on line and real time capillaries blood oxygenation measurement in the eye. The system operates with 1200 discreet wavelengths between 400 nm to 700 nm with 500 millisecond integration times. It is not invasive, functioning just like a fundus camera.
contrast sensitivity measurement slit lamp assessment and intra-ocular pressure measurement ocular coherence tomography at the optic nerve head visual field testing oxygen flow at the optic nerve head measurement (OSOME) Under tropicamide
contrast sensitivity measurement
Contrast sensitivity test is made with targets alternating black and white lines. The larger the lines are, easier it is to see them. Targets are distributed in 5 rows, each oriented at a different angle. Contrast sensitivity level is determined by the smallest target seen by the participant, line by line. This test is done under dim lightning with the habitual visual correction worn.
slit lamp assessment and intra-ocular pressure measurement
Slit lamp is used to assess the presence of significant lens opacities known as Fabry cataracts. In fact, these opacities can induced a bias on the contrast sensitivity measurement and can increase the symptoms felt by the patient. A grade 2 (CFDI grading chart) of lens opacities is considered clinically significant and this will become an exclusion criteria for the following of the study. Intra-ocular pressure will be measured with a non contact tonometer (air pulsed) (Ocular Response Analyser, Reichert Instrumentation.)
visual field testing
Visual field will be assessed with an automated perimeter (Humphrey, Texas) using a threshold strategy. This implies that the subject has to identify not only if he perceives the visual stimulus but the minimal level of this stimulus (in decibels), to be seen, is also recorded. Visual field will be tested up to 30 degrees from the central point of fixation. In order to measure immediate variability of the visual testing among Fabry subjects, this test will be done at the beginning of the testing session (in the morning) and another time 1h00 later.
oxygen flow at the optic nerve head measurement OSOME
Pupils will be dilated with 1 drop of 1% tropicamide. The procedure is similar to the one used for taking a photo of the retina. Each measurement session represents a continuous recording of 20 simultaneous functions of reflectometry from the optic nerve area during 10 seconds. During all recording sessions, the systemic arterial oxygen saturation will be also monitored at the right index finger using a pulse oximeter (Escort M10, Invivo, Orlando, USA). Arterial blood pressure will be also monitored before and after the testing using a manual sphygmomanometer.
tropicamide Mydriacyl® Mydriatic Tropicamide 1% Ophthalmic Drops
Used to dilate patient's pupil during testing
osome (O.S.O.M.E., US patent # 5,919,132;)
The OSOME system is the only technology able to perform on line and real time capillaries blood oxygenation measurement in the eye. The system operates with 1200 discreet wavelengths between 400 nm to 700 nm with 500 millisecond integration times. It is not invasive, functioning just like a fundus camera.

Primary Outcomes

Measure
Blood oxygenation at the optic nerve head
time frame: up to 2 years

Secondary Outcomes

Measure
Origin of visual field defect in Fabry patients
time frame: up to 2 years

Eligibility Criteria

Male or female participants at least 18 years old.

Inclusion Criteria: Inclusion criteria (Fabry group): - Aged over 18 years old - Being diagnosed with Fabry disease - 3 subjects will be under enzyme replacement treatment for the treatment of Fabry disease. - 3 subjects will not receive enzyme replacement treatment - Is fit to give legal consent. - Is available for a period of 2 years Inclusion criteria (CONTROL group): - Matched for age and sex with group A - 6 participants - Being healthy, with no known chronic systemic disease nor acute disease at the moment of the recruitment - Is fit to give legal consent. - Is available for a period of 2 years Exclusion Criteria:( both groups): - Presents with an active pathological ocular condition - Presence of an abnormal optic nerve (congenital or acquired) - Usage of topical ocular drug(s) at the time of selection - To have known allergy to topical diagnostic drugs used in this study - Usage of systemic medication with known effect on the visual field

Additional Information

Official title Clinical Investigation on the Blood Oxygenation at the Optic Nerve Head in Relation With Visual Field Loss in Fabry Patients
Principal investigator Langis Michaud, OD M.Sc.
Description The first subjects who meet the following criteria will be enrolled in the study. Inclusion criteria (Fabry group ): - Aged over 18 years old - Being diagnosed with Fabry disease - 3 subjects will be under enzyme replacement treatment for the treatment of Fabry disease. - 3 subjects will not receive enzyme replacement treatment - Is fit to give legal consent. - Is available for a period of 2 years Inclusion criteria (CONTROL group ): - Matched for age and sex with group A - 6 participants - Being healthy, with no known chronic systemic disease nor acute disease at the moment of the recruitment - Is fit to give legal consent. - Is available for a period of 2 years Exclusion criteria (Both groups): - Presents with an active pathological ocular condition - Presence of an abnormal optic nerve (congenital or acquired) - Usage of topical ocular drug(s) at the time of selection - To have known allergy to topical diagnostic drugs used in this study - Usage of systemic medication with known effect on the visual field
Trial information was received from ClinicalTrials.gov and was last updated in June 2015.
Information provided to ClinicalTrials.gov by Université de Montréal.