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

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.

Study Overview

• Status: Terminated
• Conditions: Low Vision
• Intervention / Treatment: 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

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.

• Study Type: Interventional
• Enrollment (Actual): 10
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Belgium
  • Ghent, Belgium, 9000
    • University Hospital Ghent (UZGent)

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 45 years (ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

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).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: NA
• Interventional Model: SINGLE_GROUP
• Masking: NONE

Number of Arms

1

Arms and Interventions

Participant Group / 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 Names: 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 Names: 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 Names: Pupil dilation eye drops

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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 Outcome Measures

Outcome Measure	Measure Description	Time Frame
Device safety by comparing eventual adverse events with those found in scleral contact lenses	Comparing adverse event of similar devices	5 months from fitting session
Correct fitting	Taking and analyzing ocular coherence tomography (OCT) images and slit lamp observations to estimate the clearance	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	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).	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	Comparing visual acuity between Designs B and C	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	Comparing contrast sensitivity between Designs B and C	5 months from fitting session
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	5 months from fitting session

Collaborators and Investigators

• Sponsor: University Ghent
• Investigators: Study Chair: Andres F Vasquez Quintero, Professor, University Ghent

Publications and helpful links

General 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.
• 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.
• 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.
• 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.
• 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.
• 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.

Study record dates

Study Major Dates

• Study Start (ACTUAL): September 16, 2019
• Primary Completion (ACTUAL): June 22, 2021
• Study Completion (ACTUAL): June 22, 2021

Study Registration Dates

• First Submitted: June 13, 2019
• First Submitted That Met QC Criteria: July 30, 2019
• First Posted (ACTUAL): August 1, 2019

Study Record Updates

• Last Update Posted (ACTUAL): April 27, 2022
• Last Update Submitted That Met QC Criteria: April 19, 2022
• Last Verified: November 1, 2021

More Information

Terms related to this study

• Keywords: artificial iris; visual acuity; contrast sensitivity; scleral contact lens
• Additional Relevant MeSH Terms: Nervous System Diseases; Eye Diseases; Neurologic Manifestations; Sensation Disorders; Vision Disorders; Vision, Low; Physiological Effects of Drugs; Adrenergic Agents; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Autonomic Agents; Peripheral Nervous System Agents; Muscarinic Antagonists; Cholinergic Antagonists; Cholinergic Agents; Protective Agents; Adrenergic alpha-Agonists; Adrenergic Agonists; Cardiotonic Agents; Respiratory System Agents; Sympathomimetics; Vasoconstrictor Agents; Mydriatics; Nasal Decongestants; Adrenergic alpha-1 Receptor Agonists; Phenylephrine; Oxymetazoline; Tropicamide
• Other Study ID Numbers: RGPIRIS_PA

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No