Intraestromal Corneal Ring in Mild Keratoconus

Study Overview
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Brief Summary
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To determine whether the implantation of an intrastromal corneal ring is an effective treatment for a homogeneous group of mild keratoconus patients.

Detailed Description
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A group of 65 patients with mild keratoconus were implanted with a Ferrara ring in a single eye. Six months after surgery, the aberrations were measured and the visual function was determined using clinical indices. The aberrations, especially comatic aberration (coma), were measured independently.

Official Title
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Intrastromal Corneal Ring Was Effective for the Treatment of Mild Keratoconus

Conditions
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Cornea, Eye Diseases, Keratoconus, Ophthalmological Disorder

Intervention / Treatment
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* Device: Intraestromal corneal ring


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Investigators used the Amsler-Krumeich classification and included only patients classified as grade I or II. Exclusion Criteria: Investigators excluded patients with central corneal scarring, with other eye disorders, or with previous ocular surgery. We also excluded patients with a history of herpes infection, keratitis, corneal dystrophies, diagnoses of autoimmune diseases, systemic connective tissue disorders, or acute keratoconus.

Ages Eligible for Study
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Minimum Age: 17 Years
Maximum Age: 47 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Interventional Model Description: Intraestromal corneal ring
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Mild Keratoconus<br>A group of 65 patients with keratoconus who were implanted with an intrastromal corneal ring; the group was composed of 40 males (61.50%) and 25 females (38.50%), with a mean age of 27.88 ± 7.38 years (range, 17-47 years). The patients were fully informed about the study and signed a consent form previously approved by the ethics committee of our institution. We used the Amsler-Krumeich classification and included only patients classified as grade I or II. The investigators performed the intraestromal corneal ring surgery in the selected group. | Device: Intraestromal corneal ring<br>* The patients underwent surgery to implant the intrastromal corneal ring (Ferrara Ophthalmics, Belo Horizonte, Brazil) using a manual technique. The procedures were performed by a single surgeon with extensive training in corneal surgery. All patients received the same ring, and the number (1 or 2 segments), thickness, and arc size were calculated using the nomogram provided by the manufacturer.<br>* Other names: Ferrara ring;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Aberrations were measured and the visual function was determined using clinical indices. | Wave front data | 3 months after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| UCVA | Uncorrected visual acuity | 3 months after surgery | 
| BCVA | Best corrected visual acuity | 3 months after surgery |