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

NCT04040790 | Terminated DMC

• 1 other identifier: RGPIRIS_PA
• Study Type: interventional
• Target: 10
• Locations: 1 country
• Sites: 1

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.

Conditions

Low Vision

Keywords

visual acuity; contrast sensitivity; scleral contact lens; artificial iris

Outcome Measures

Primary Outcomes (2)

• 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

  5 months from fitting session

• 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

  5 months from fitting session

Secondary Outcomes (6)

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

  5 months from fitting session

• Correct fitting

  5 months from fitting session

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

  5 months from fitting session

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

  5 months from fitting session

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

  5 months from fitting session

Study Arms (1)

Healthy volunteers

EXPERIMENTAL

15 healthy volunteers for trials with passive artificial iris

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

Interventions

Scleral contact lens without a passive artificial iris DEVICE

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

Also known as: Control lens Design A

Healthy volunteers

Scleral contact lens with a passive artificial iris with low 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

Also known as: Test lens Design B

Healthy volunteers

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

Healthy volunteers

Tropicamide and phenylephrine DRUG

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)

Also known as: Pupil dilation eye drops

Healthy volunteers

Eligibility Criteria

• Age: 18 Years - 45 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• \- Age between 18 and 45 years old

You may not qualify if:

• 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).

Sponsors & Collaborators

• University Ghent: lead

Study Sites (1)

University Hospital Ghent (UZGent)

Ghent, 9000, Belgium

Location

Related Publications (6)

• 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.

  PMID: 22424803 BACKGROUND

• 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.

  PMID: 23079328 BACKGROUND

• 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.

  PMID: 27784070 BACKGROUND

• 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.

  PMID: 9544648 BACKGROUND

• 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.

  PMID: 25190661 BACKGROUND

• 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.

  PMID: 6592160 BACKGROUND

MeSH Terms

Conditions

Vision, Low

Interventions

Tropicamide; Phenylephrine

Condition Hierarchy (Ancestors)

Vision Disorders; Sensation Disorders; Neurologic Manifestations; Nervous System Diseases; Eye Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Pyridines; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Ethanolamines; Amino Alcohols; Alcohols; Organic Chemicals; Amines

Study Officials

• Andres F Vasquez Quintero, Professor

  University Ghent

  STUDY CHAIR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: June 13, 2019
• First Posted: August 1, 2019
• Study Start: September 16, 2019
• Primary Completion: June 22, 2021
• Study Completion: June 22, 2021
• Last Updated: April 27, 2022

Record last verified: 2021-11

Data Sharing

• IPD Sharing: Will not share

Locations

BE (1)