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Low VisionRGPIRIS_PANCT04040790

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

A study testing Scleral contact lens without a passive artificial iris, Scleral contact lens with a passive artificial iris with low contrast (<1:5) and Scleral contact lens with a passive artificial iris with high contrast (>1:5) in people with Low Vision, run by University Ghent at 1 site in Belgium.

Terminated

Stopped early. The study ended before it was planned to and will not resume.

Official record
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Trial 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. Read more about this study

Who is it for?
Ages 18 to 45 yearsHealthy volunteers can take part
Conditions the study is for
Low Vision
What is being tested?
Scleral contact lens without a passive artificial iris, Scleral contact lens with a passive artificial iris with low contrast (<1:5) and Scleral contact lens with a passive artificial iris with high contrast (>1:5)
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
10 participants
Where
1 siteBelgium
Study dates
16 Sep 2019to 22 Jun 2021
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 45 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Age between 18 and 45 years old

Who cannot join

  • 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).

Trial locations and contacts

1 site in 1 country.

Belgium1 site

  • University Hospital Ghent (UZGent)

    Ghent, 9000

Other trials in Belgium

About this study

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

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.

Read the 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.

Conditions
Low Vision
Being tested
Scleral contact lens without a passive artificial iris, Scleral contact lens with a passive artificial iris with low contrast (<1:5), Scleral contact lens with a passive artificial iris with high contrast (>1:5), Tropicamide and phenylephrine
Keywords
visual acuity, contrast sensitivity, scleral contact lens, artificial iris
Medical subject headings
Vision, Low

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Scleral contact lens without a passive artificial irisDevice

    Also called Control lens Design A

    Participants wear a scleral contact lens without a passive artificial iris (Design A) on the dominant eye to perform the baseline visual performance assessment

  • Scleral contact lens with a passive artificial iris with low contrast (<1:5)Device

    Also called Test lens Design B

    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

  • Scleral contact lens with a passive artificial iris with high contrast (>1:5)Device

    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

  • Tropicamide and phenylephrineDrug

    Also called Pupil dilation eye drops

    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)

Study groups in NCT04040790
Study groupRoleWhat they receive
Healthy volunteersExperimental15 healthy volunteers for trials with passive artificial iris
Receives: 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

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Visual acuity assessment and comparison between Designs A, B and C by means of logMAR or equivalent value

    Compare visual acuity values obtained with different designs

    Measured: 5 months from fitting session

  2. Contrast sensitivity assessment and comparison between Designs A, B and C by means of threshold percentage or equivalent value

    Compare contrast sensitivity values obtained with different designs

    Measured: 5 months from fitting session

Secondary outcomes (6)

  1. Device safety by comparing eventual adverse events with those found in scleral contact lenses

    Comparing adverse event of similar devices

    Measured: 5 months from fitting session

  2. Correct fitting

    Taking and analyzing ocular coherence tomography (OCT) images and slit lamp observations to estimate the clearance

    Measured: 5 months from fitting session

  3. Contact lens wear comfort, as assessed by subject data from questionnaires Rasch analyzed using a 4-Andrich ration scale model

    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).

    Measured: 5 months from fitting session

  4. Visual acuity assessment and comparison between Designs B (low contrast) and C (high contrast) by means of logMAR or equivalent value

    Comparing visual acuity between Designs B and C

    Measured: 5 months from fitting session

  5. Contrast sensitivity assessment and comparison between Designs B (low contrast) and C (high contrast) by means of threshold percentage or equivalent value

    Comparing contrast sensitivity between Designs B and C

    Measured: 5 months from fitting session

  6. Horizontal visual angle

    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

    Measured: 5 months from fitting session

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted1 Aug 2019
  2. Study start16 Sep 2019
  3. Primary completion22 Jun 2021
  4. Study completion22 Jun 2021

Why it stopped: Several reasons: Financing ended before all study assessments were performed, covid-19 delayed design, production and shipment of IMD, experience gained during the study made it clear that lens design should be changed

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
10 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04040790
Sponsor's protocol ID
RGPIRIS_PA
Acronym
RGPIRIS_PA
Status last verified
Nov 2021
First submitted
13 Jun 2019
Last updated
27 Apr 2022
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Garcia-Lazaro S, Ferrer-Blasco T, Radhakrishnan H, Cervino A, Charman WN, Montes-Mico R. Visual function through 4 contact lens-based pinhole systems for presbyopia. J Cataract Refract Surg. 2012 May;38(5):858-65. doi: 10.1016/j.jcrs.2011.11.042. Epub 2012 Mar 16.

    PubMed 22424803

  • Pepose JS. Small-aperture contact lenses for presbyopia. J Cataract Refract Surg. 2012 Nov;38(11):2060-1; author reply 2062-4. doi: 10.1016/j.jcrs.2012.08.041. No abstract available.

    PubMed 23079328

  • Xu R, Gil D, Dibas M, Hare W, Bradley A. The Effect of Light Level and Small Pupils on Presbyopic Reading Performance. Invest Ophthalmol Vis Sci. 2016 Oct 1;57(13):5656-5664. doi: 10.1167/iovs.16-20008.

    PubMed 27784070

  • Eyeson-Annan ML, Hirst LW, Battistutta D, Green A. Comparative pupil dilation using phenylephrine alone or in combination with tropicamide. Ophthalmology. 1998 Apr;105(4):726-32. doi: 10.1016/S0161-6420(98)94030-1.

    PubMed 9544648

  • Compan V, Oliveira C, Aguilella-Arzo M, Molla S, Peixoto-de-Matos SC, Gonzalez-Meijome JM. Oxygen diffusion and edema with modern scleral rigid gas permeable contact lenses. Invest Ophthalmol Vis Sci. 2014 Sep 4;55(10):6421-9. doi: 10.1167/iovs.14-14038.

    PubMed 25190661

  • Holden BA, Mertz GW. Critical oxygen levels to avoid corneal edema for daily and extended wear contact lenses. Invest Ophthalmol Vis Sci. 1984 Oct;25(10):1161-7.

    PubMed 6592160

Questions about this trial

What is this clinical trial studying?

A study testing Scleral contact lens without a passive artificial iris, Scleral contact lens with a passive artificial iris with low contrast (<1:5) and Scleral contact lens with a passive artificial iris with high contrast (>1:5) in people with Low Vision, run by University Ghent at 1 site in Belgium.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 1 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: stopped early, as of the sponsor's last update on 27 Apr 2022. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Belgium. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study was stopped early (reason given: Several reasons: Financing ended before all study assessments were performed, covid-19 delayed design, production and shipment of IMD, experience gained during the study made it clear that lens design should be changed). Results are not available in the source record.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

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). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04040790, which also lists 6 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 Apr 2022.

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