Corneal Gas Permeable Lenses for Keratoconus

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

32 Participants Needed

Trial Summary

What is the purpose of this trial?

Keratoconus is a non-inflammatory, progressive disease in which corneal irregularity increases. As the condition develops, more advanced forms of optical correction are needed to improve vision for patients. Until recently, small diameter corneal gas permeable lenses were considered the primary mode of correction for patients with keratoconus. Now, however, practitioners have multiple options for reducing the optical aberrations caused by keratoconus, including scleral lenses. As of yet, no single option for optical correction has been identified as the preferred mode of correction in terms of overall patient satisfaction with vision, comfort, and ease of use. The order in which various forms of optical correction would be most logically introduced has yet to be determined. This is a study comparing small diameter corneal gas permeable and large diameter scleral lenses in individuals with keratoconus. This study will prospectively compare visual satisfaction and ease of use between corneal gas permeable and scleral lenses for patients with mild to moderate 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 data supports the idea that Corneal Gas Permeable Lenses for Keratoconus is an effective treatment?

The available research shows that Corneal Gas Permeable Lenses are effective for improving vision in people with keratoconus. One study mentions that these lenses can help patients achieve 20/20 vision by reshaping the cornea. Another study highlights a successful case where different designs of these lenses were used to manage keratoconus. Additionally, during cataract surgery for patients with severe keratoconus, these lenses improved image clarity and safety. Compared to other treatments like corneal transplantation, which is used in severe cases, these lenses are often the first choice because they provide good vision for a long time. ^{1 2 3 4 5}

What data supports the effectiveness of the treatment Corneal Gas Permeable Lenses for Keratoconus?

Research shows that rigid gas-permeable contact lenses can improve vision quality in people with keratoconus by reshaping the cornea, often allowing patients to achieve 20/20 vision. These lenses have been successfully used in various cases, including during cataract surgery, to enhance visual clarity and reduce complications. ^{1 2 3 4 5}

What safety data is available for corneal gas permeable lenses in treating keratoconus?

The safety data for corneal gas permeable lenses in treating keratoconus indicates that these lenses are generally safe and effective. They improve vision quality by reshaping the corneal surface, often achieving 20/20 visual acuity. A study on Paraperm extended wear lenses showed a 95% success rate with reversible complications like corneal staining (7%) and lens coating (9%). These lenses offer high oxygen permeability, initial comfort, quick adaptation, and minimal complications, making them safer for daily and prolonged wear compared to soft lenses. Additionally, they have been used successfully in cataract surgeries for patients with severe keratoconus without intraoperative or postoperative complications. ^{1 3 4 6 7}

Are corneal gas permeable lenses safe for humans?

Corneal gas permeable lenses are generally safe for humans, allowing more oxygen to reach the eye than soft lenses, which makes them safer for daily and extended wear. Complications like corneal staining and lens coating are rare and reversible, and these lenses have a high success rate with minimal complications. ^{1 3 4 6 7}

Is the treatment Corneal Gas Permeable Lens a promising treatment for keratoconus?

Yes, Corneal Gas Permeable Lenses are a promising treatment for keratoconus. They help improve vision by reshaping the cornea, often allowing patients to achieve clear vision, sometimes as good as 20/20. These lenses are considered a good first choice for managing keratoconus and can provide good visual results for a long time. ^{2 3 4 8 9}

How do Corneal Gas Permeable Lenses differ from other treatments for keratoconus?

Corneal Gas Permeable Lenses are unique because they reshape the corneal surface to improve vision, often achieving 20/20 vision, and are less risky compared to other treatments. They are typically the first choice for correcting vision in keratoconus, especially in the early stages, before more invasive options like corneal transplantation are considered. ^{2 3 4 8 9}

Research Team

Ellen S Shorter, OD

Principal Investigator

University of Illinois at Chicago

Eligibility Criteria

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

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)

Treatment Details

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.

Participant Groups

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+

Findings from Research

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]

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]

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]

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]

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]

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]

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]

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]

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]

References

1. United States pubmed.ncbi.nlm.nih.gov

Rigid gas-permeable contact lens-assisted cataract surgery in patients with severe keratoconus. [2022]

2. Netherlands pubmed.ncbi.nlm.nih.gov

Penetrating Keratoplasty for Keratoconus - Excimer Versus Femtosecond Laser Trephination. [2020]

3. Romania pubmed.ncbi.nlm.nih.gov

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

4. United States pubmed.ncbi.nlm.nih.gov

Managing keratoconus with reverse-geometry and dual-geometry contact lenses: a case report. [2022]

5. China pubmed.ncbi.nlm.nih.gov

[Clinical study on treatment of secondary keratoconus with special designed rigid gas permeable contact lens]. [2013]

6. United States pubmed.ncbi.nlm.nih.gov

Adaptation to Paraperm extended wear lenses: a clinical study in Sweden. [2004]

7. United States pubmed.ncbi.nlm.nih.gov

Gas permeable lenses--a growing trend. [2004]

8. Brazil 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]. [2019]

9. United States pubmed.ncbi.nlm.nih.gov

Applications of different types of gas-permeable contact lenses in keratoconus and their visual results. [2018]