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Performance of Rigid Gas Permeable (RGP) Scleral Contact Lenses With a Passive Artificial Iris (RGPIRIS_PA)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details.
 
ClinicalTrials.gov Identifier: NCT04040790
Recruitment Status : Not yet recruiting
First Posted : August 1, 2019
Last Update Posted : August 1, 2019
Sponsor:
Information provided by (Responsible Party):
University Ghent

Brief Summary:
Data from 15 healthy subjects will be recorded in two testing sessions spread on two days, using three lens designs (A, B and C). Before the measuring days, each subject will undergo an extra fitting session of a large-diameter scleral contact lens on the dominant eye, assessed by an experienced practitioner. The fitting data will be used to custom-make the three lens designs for each subject, thus ensuring their comfort and safety during the days of the experiments. During the experiment days baseline measurements will be obtained before and after pupil dilation and contact lens wear. During the first testing session data from the lens design A (reference lens without artificial iris) will be recorded. During the second testing session data from the lens designs B and C (lenses with artificial iris with different transmittances) will be recorded. In each testing session, contrast sensitivity and visual acuity will be evaluated and non-invasive imaging measurements will be undertaken (optical coherence tomography and slit lamp). A specific questionnaire will be given to the subject to assess comfort, light sensitivity, the horizontal visual angle and overall experience of the scleral lens and in combination with a pair of sunglasses category 3-4.

Condition or disease Intervention/treatment Phase
Low Vision Device: Scleral contact lens without a passive artificial iris Device: Scleral contact lens with a passive artificial iris with low contrast (<1:5) Device: Scleral contact lens with a passive artificial iris with high contrast (>1:5) Drug: Tropicamide and phenylephrine Not Applicable

Detailed Description:
First, the participant will be subjected to an RGP scleral contact lens fitting session, then during the second and third visits the participant will be subjected to several non-invasive procedures specific to the study in order to assess contrast sensitivity and visual acuity using the fitted and uniquely fabricated investigational medical devices. The tests will be performed after eye drops are supplied to dilate the pupil of the subjects (eye drops: tropicamide and phenylephrine). Besides the clinical experiments, the participant will be given a specific questionnaire in order to assess comfort, light sensitivity, horizontal visual angle and overall experience of the investigational medical device and in combination with a pair of sunglasses category 3-4. The investigators will document the occurrence of any adverse events and specific side effects during Day 2 and 3 (testing sessions with the investigational devices) in order to effectively assess their safety.

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 15 participants
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Evaluation of Light Sensitivity and Visual Acuity Changes as Consequence of Rigid Gas Permeable (RGP) Scleral Contact Lenses With a Passive Artificial Iris
Estimated Study Start Date : July 2019
Estimated Primary Completion Date : December 2019
Estimated Study Completion Date : December 2019

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Allergy Eye Wear

Arm Intervention/treatment
Experimental: Healthy volunteers
15 healthy volunteers for trials with passive artificial iris
Device: Scleral contact lens without a passive artificial iris
Participants wear a scleral contact lens without a passive artificial iris (Design A) on the dominant eye to perform the baseline visual performance assessment
Other Name: Control lens Design A

Device: Scleral contact lens with a passive artificial iris with low contrast (<1:5)
Participants wear a scleral contact lens with a low contrast (<1:5) passive artificial iris (Design B) on the dominant eye to perform the baseline visual performance assessment
Other Name: Test lens Design B

Device: Scleral contact lens with a passive artificial iris with high contrast (>1:5)
Participants wear a scleral contact lens with a low contrast (<1:5) passive artificial iris (Design B) on the dominant eye to perform the baseline visual performance assessment

Drug: Tropicamide and phenylephrine
Participants receive pupil dilation eye drops on the dominant eye, after baseline measurement and before wearing the scleral contact lenses (Designs A, B and C)
Other Name: Pupil dilation eye drops




Primary Outcome Measures :
  1. Visual acuity assessment and comparison between Designs A, B and C by means of logMAR or equivalent value [ Time Frame: 5 months from fitting session ]
    Compare visual acuity values obtained with different designs

  2. Contrast sensitivity assessment and comparison between Designs A, B and C by means of threshold percentage or equivalent value [ Time Frame: 5 months from fitting session ]
    Compare contrast sensitivity values obtained with different designs


Secondary Outcome Measures :
  1. Device safety by comparing eventual adverse events with those found in scleral contact lenses [ Time Frame: 5 months from fitting session ]
    Comparing adverse event of similar devices

  2. Correct fitting [ Time Frame: 5 months from fitting session ]
    Taking and analyzing ocular coherence tomography (OCT) images and slit lamp observations to estimate the clearance

  3. Contact lens wear comfort, as assessed by subject data from questionnaires Rasch analyzed using a 4-Andrich ration scale model [ Time Frame: 5 months from fitting session ]
    The subjective assessment will be carried out by means of questions on 3 content areas: lens comfort (3 questions), visual quality (4 questions) and general satisfaction with the lenses (3 questions).

  4. Visual acuity assessment and comparison between Designs B (low contrast) and C (high contrast) by means of logMAR or equivalent value [ Time Frame: 5 months from fitting session ]
    Comparing visual acuity between Designs B and C

  5. Contrast sensitivity assessment and comparison between Designs B (low contrast) and C (high contrast) by means of threshold percentage or equivalent value [ Time Frame: 5 months from fitting session ]
    Comparing contrast sensitivity between Designs B and C

  6. Horizontal visual angle [ Time Frame: 5 months from fitting session ]
    Angle at which the volunteer can see his fingers move when extending the arm (same side as dominant eye), 0°=arm extended to the side; 90°=arm straight ahead



Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 45 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

- Age between 18 and 45 years old

Exclusion Criteria:

  • Iris disorders (i.e. ocular albinism, coloboma, aniridia).
  • Known disease-related ocular surface problem (i.e. microbial keratitis).
  • Known ocular pathologies (except refractive disorders).
  • Coexistent ocular diseases impeding contact lens correction (i.e. glaucoma, previous ocular surgery).
  • Corneal scarring.
  • Low corneal endothelial cell count (< 1500 cells per mm2), with potential of corneal hypoxia-induced corneal edema induced by contact lens wear.
  • Wearing of contact lenses in the last 24 hours (prior to the interventions).

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04040790


Contacts
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Contact: Elke Kreps, MD +32-9-332.64.97 Elke.Kreps@UGent.be
Contact: Andres F Vasquez Quintero, Professor +32-9264.66.24 AndresVasquez@UGent.be

Locations
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Belgium
University Hospital Ghent (UZGent)
Ghent, Belgium, 9000
Sponsors and Collaborators
University Ghent
Investigators
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Study Chair: Andres F Vasquez Quintero, Professor University Ghent

Publications:
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Responsible Party: University Ghent
ClinicalTrials.gov Identifier: NCT04040790    
Other Study ID Numbers: RGPIRIS_PA
First Posted: August 1, 2019    Key Record Dates
Last Update Posted: August 1, 2019
Last Verified: July 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by University Ghent:
visual acuity
contrast sensitivity
scleral contact lens
artificial iris
Additional relevant MeSH terms:
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Vision, Low
Vision Disorders
Sensation Disorders
Neurologic Manifestations
Nervous System Diseases
Eye Diseases
Signs and Symptoms
Phenylephrine
Ophthalmic Solutions
Tropicamide
Pharmaceutical Solutions
Cardiotonic Agents
Mydriatics
Autonomic Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Sympathomimetics
Vasoconstrictor Agents
Nasal Decongestants
Respiratory System Agents
Adrenergic alpha-1 Receptor Agonists
Adrenergic alpha-Agonists
Adrenergic Agonists
Adrenergic Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Protective Agents
Muscarinic Antagonists
Cholinergic Antagonists
Cholinergic Agents