Corneal Gas Permeable Lenses for Keratoconus

Not currently recruiting at 5 trial locations

Overseen By Bhavana Kolli, MHA

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: University of Illinois at Chicago

Disqualifiers: Corneal transplantation, Hybrid lenses, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Approved in 2 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 7

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores whether corneal gas permeable or scleral contact lenses work better for individuals with mild to moderate keratoconus, a condition where the cornea bulges out, causing vision problems. Researchers aim to determine which lens provides the best vision satisfaction and ease of use. Participants will try both types of lenses to identify their preference. The trial seeks individuals diagnosed with keratoconus who have not previously used similar lenses or undergone certain eye surgeries. As an unphased trial, it offers participants a unique opportunity to contribute to understanding which lenses yield the best outcomes for keratoconus.

Do I have to stop taking my current medications for the trial?

The trial protocol does not specify whether you need to stop taking your current medications.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications.

What prior data suggests that these lenses are safe for keratoconus patients?

Research shows that corneal gas permeable lenses are generally safe for people with keratoconus, a condition where the cornea becomes thin and cone-shaped. Studies have found these lenses effective and practical, with a high success rate in improving vision. Most users find them comfortable and safe when used correctly.

Initial findings suggest that scleral lenses, another option, are also safe. These lenses cover the entire cornea and rest on the white part of the eye, providing comfort and better vision for people with keratoconus.

Both types of lenses have been used for many years and are considered safe. The choice between them often depends on personal comfort and vision needs. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about corneal gas permeable lenses for keratoconus because these lenses offer a unique way to improve vision by allowing more oxygen to reach the cornea. Unlike standard soft lenses, these rigid lenses can provide sharper vision by maintaining their shape on the irregular corneal surface caused by keratoconus. Additionally, a notable feature of these lenses is their durability, which can lead to longer usage times and potentially lower costs for users. This approach provides a promising alternative to existing treatments like soft contact lenses or glasses, which may not correct vision as effectively in keratoconus patients.

What evidence suggests that this trial's treatments could be effective for keratoconus?

This trial will compare corneal gas permeable lenses and scleral lenses for individuals with keratoconus. Research has shown that both lens types can improve vision. Participants will be fitted with either corneal gas permeable lenses or scleral lenses first, based on their study ID. Studies have found that rigid gas permeable lenses can thicken and flatten the cornea, enhancing vision. Conversely, scleral lenses have greatly enhanced sharpness of vision and overall quality of life for those with keratoconus. Notably, scleral lenses often provide more comfort than corneal lenses. Both lens types offer benefits, and the choice may depend on personal comfort and satisfaction with vision. ^{2 3 6 7 8}

Who Is on the Research Team?

Ellen S Shorter, OD

Principal Investigator

University of Illinois at Chicago

Are You a Good Fit for This Trial?

This trial is for individuals with mild to moderate keratoconus, a condition where the cornea thins and bulges outward. Participants must have a specific stage of keratoconus (stage 1), no prior use of certain contact lenses, no corneal scarring, and not have had any previous corneal transplants.

Inclusion Criteria

I have been diagnosed with keratoconus.

Amsler-Krumeich keratoconus classification of stage 1

Available baseline corneal topography and pachymetry

Exclusion Criteria

I have never had corneal transplantation or INTACS.

No prior use of hybrid, corneal or scleral gas permeable lenses

I have scarring on my cornea.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

1 visit (in-person)

Initial Fitting and Training

Participants are fit with both corneal gas permeable and scleral lenses and trained in their application, removal, and care

2-4 weeks

2 visits (in-person)

Crossover Lens Evaluation

Participants wear each type of lens (corneal gas permeable and scleral) for a period to evaluate comfort and visual acuity

4-10 weeks

2 visits (in-person)

Final Lens Selection

Participants make a final selection of their preferred lens type for continued use

6-24 weeks

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after final lens selection

4 weeks

1 visit (in-person)

What Are the Treatments Tested in This Trial?

Interventions

• Corneal Gas Permeable Lens

Trial Overview The study is comparing two types of contact lenses: small diameter corneal gas permeable lenses and large diameter scleral lenses. It aims to determine which lens type offers better visual satisfaction, comfort, and ease of use for people with keratoconus.

How Is the Trial Designed?

Group I: Corneal gas permeable lens first Active Control 1 Intervention

Device: corneal gas permeable contact lenses (RoseK2 corneal Blanchard Contact Lens, Inc. Manchester, NH). Participants with an odd study ID will be fit with the corneal gas permeable lens first.

Group II: Scleral lens first Active Control 1 Intervention

Device: scleral lenses (SynergEyes VS (Synergeyes, Inc., Carlsbad CA). Participants with an even study ID will be fit with the scleral lens first.

Corneal Gas Permeable Lens is already approved in United States, European Union for the following indications:

Approved in United States as Corneal Gas Permeable Lens for:

• Keratoconus
• Irregular astigmatism

Approved in European Union as Corneal Gas Permeable Lens for:

• Keratoconus
• Irregular astigmatism

Who Is Running the Clinical Trial?

University of Illinois at Chicago

Lead Sponsor

Trials

653

Recruited

1,574,000+

Published Research Related to This Trial

Using rigid gas-permeable (RGP) contact lenses during cataract surgery in patients with severe keratoconus significantly improved visibility by reducing image distortion caused by irregular corneal astigmatism.

This technique allowed for safe intraocular manipulations without complications, leading to successful visualization of both the anterior and posterior capsules during surgery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Rigid gas-permeable contact lens-assisted cataract surgery in patients with severe keratoconus. Oie, Y., Kamei, M., Matsumura, N., et al.[2022]

In a study involving 126 patients with keratoconus, the Soper-McGuire design contact lenses outperformed Monocurve lenses, particularly in patients with advanced and central cones, showing better fitting and visual outcomes.

The survival rate for patients using Soper-McGuire lenses was higher (71.43%) compared to those using Monocurve lenses (60.32%) over a six-month follow-up, indicating greater long-term usability of the Soper-McGuire design.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Fitting Monocurve and Bicurve (Soper-McGuire design) rigid gas-permeable contact lenses in keratoconus patients: a prospective randomized comparative clinical trial]. Coral-Ghanem, C., Alves, MR.[2019]

Rigid Gas-Permeable contact lenses are a safer alternative for enhancing vision in patients with corneal ectasias like keratoconus.

These lenses work by reshaping the corneal surface, allowing many patients to achieve a visual acuity of 20/20 with the right lens fitting.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Lens prescription for rigid contact lenses in keratoconus]. Manea, G.[2013]

Gas permeable contact lenses provide superior oxygen permeability to the cornea compared to soft lenses, enhancing safety for both daily and extended wear.

These lenses improve visual quality and reduce the risk of allergic reactions to disinfecting solutions, as they do not absorb chemical preservatives.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Gas permeable lenses--a growing trend. Harrison, KW.[2004]

Non-contact excimer laser penetrating keratoplasty (PKP) significantly improves surgical outcomes for advanced keratoconus, resulting in better graft centration, reduced astigmatism, and improved visual acuity compared to traditional motor trephine methods, based on prospective clinical studies.

While femtosecond laser keratoplasty offers some advantages, it still presents challenges such as the need for suction during the procedure, which can lead to higher postoperative astigmatism, making non-contact excimer laser PKP the preferred option for keratoconus patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Penetrating Keratoplasty for Keratoconus - Excimer Versus Femtosecond Laser Trephination. Seitz, B., Langenbucher, A., Hager, T., et al.[2020]

In a study of 229 eyes from 133 patients with keratoconus, the use of rigid gas-permeable contact lenses significantly improved visual acuity compared to uncorrected vision and vision corrected with eyeglasses, with a statistically significant difference (p<0.005).

No serious complications were reported during the follow-up period, indicating that these contact lenses are safe for long-term use, and there was no need for keratoplasty in any patient.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Applications of different types of gas-permeable contact lenses in keratoconus and their visual results. Kazanci, B., Ozek, D., Anayol, A., et al.[2018]

Paraperm EW contact lenses, made from a new rigid gas-permeable material, achieved a 95% success rate in daily wear among 105 patients, including those with challenging conditions like keratoconus and high astigmatism.

The lenses demonstrated advantages over traditional options, such as higher oxygen permeability (Dk of 56), better initial comfort, and quick adaptation, with only minor and reversible complications reported during the three-month study.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Adaptation to Paraperm extended wear lenses: a clinical study in Sweden. Rengstorff, RH., Odby, A.[2004]

In a study of 89 cases (102 eyes) with secondary keratoconus, specially designed rigid gas permeable contact lenses (RGPCL) significantly improved visual acuity in 90% of patients, demonstrating their efficacy in treating this condition.

The use of RGPCL not only enhanced corrected vision but also led to a reduction in corneal astigmatism and improved corneal shape, indicating a positive impact on corneal health and stability.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Clinical study on treatment of secondary keratoconus with special designed rigid gas permeable contact lens]. Wang, D., Xie, PY., Zhou, JL.[2013]

A 30-year-old woman with keratoconus achieved 20/20 vision with rigid gas-permeable contact lenses, specifically using reverse-geometry and dual-geometry designs, demonstrating their effectiveness in managing this condition.

Over a 42-month follow-up, no significant complications were reported, indicating that these specialized contact lenses are a safe and viable option for improving vision in keratoconus patients before considering surgical interventions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Managing keratoconus with reverse-geometry and dual-geometry contact lenses: a case report. Hu, CY., Tung, HC.[2022]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC10286838/

Comparison of Hybrid Contact Lenses and Rigid Gas ... They reported a 92% success rate after a mean of 10 months of use and 72% of the patients continued to use the HCL. In their study, the mean ...

2. nature.com nature.com/articles/s41598-024-76819-7

Visual rehabilitation using rigid gas permeable contact ... This study showed MILK significantly increases corneal thickness and flattens corneal curvature, achieving good RGP-CLs corrected vision.

3. clinicaltrials.gov clinicaltrials.gov/ct2/show/NCT06921967

NCT06921967 | Effect of Corneal and Scleral RGP Lenses ... The purpose of this study is to compare subjective and objective outcomes from corneal rigid gas permeable lens (CRGPL) and scleral rigid gas permeable lens ( ...

4. sciencedirect.com sciencedirect.com/science/article/abs/pii/S1367048423002977

Novel deep learning approach to estimate rigid gas ... Our study presents a novel deep learning approach for predicting the base curve of rigid gas permeable contact lenses in keratoconus patients.

5. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC7321943/

Effect of rigid gas permeable contact lens on keratoconus ... Some studies have found that wearing RGP contact lens has adverse effects, which may promote disease progression.

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC7469902/

Update on Contact Lens Treatment of Keratoconus - PMC Today, RGPCLs remain the first-line treatment for KC because they are practical and safe lenses with high optical success when applied in consideration of the ...

7. sciencedirect.com sciencedirect.com/science/article/pii/S1888429625000135

A novel large diameter rigid gas-permeable corneal ... The novel large diameter RGP corneal CL demonstrated comparable efficacy to existing RGP CL designs, offering high levels of comfort and improved vision.

8. ophthalmologica-indonesiana.com ophthalmologica-indonesiana.com/index.php/journal/article/download/83/242/645

Efficacy and Safety Comparison among Rigid Gas ... Outcomes of this review are visual acuity, keratometry, comfort score and adverse event. Articles are presented in the table and narrated form. Naïve contact ...