Effect of Intracorneal Ring Segments on Posterior Corneal Tomography in Eyes With Keratoconus

Study Overview
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Brief Summary
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Our purpose is to analyze the changes induced in the posterior corneal surface in patients implanted with intracorneal ring segments for treatment of keratoconus. Patients are assessed with corneal imaging device preoperatively and at 1, 3, 6 and 12 months postoperatively.

Detailed Description
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Procedure: Femtosecond laser assisted implantation of intracorneal ring segments in keratoconus patients Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), refraction, keratometric (K) readings of the anterior and posterior surface, corneal asphericity (Q value) of the anterior and posterior surface, and anterior and posterior elevations are evaluated using a corneal imaging device preoperatively and at 1, 3, 6 and 12 months after surgery.

Official Title
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Effect of Intracorneal Ring Segments on Posterior Corneal Tomography in Eyes With Keratoconus

Conditions
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Keratoconus, Keratoconus Posterior

Intervention / Treatment
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* Procedure: Intracorneal ring segment implantation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria Patients with keratoconus grade 1, 2 or 3 according to Amsler-Krumeich classification. Best corrected visual acuity (BCVA) ≤ 6/12. Mean front keratometric (K) readings ≤ 60 diopters (D). Corneal thickness ≥ 400 µm at the location of ICRS implantation. Clear central cornea Exclusion Criteria Central corneal opacity. Previous corneal laser refractive surgery. Previous corneal collagen cross linking. Previous cataract surgery or phakic IOL implantation. History of herpetic keratitis. History of acute hydrops. Ocular comorbidities such as cataract, glaucoma or retinal disease. Systemic diseases affecting healing process such as autoimmune or connective tissue disease.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 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
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Study group<br>Intracorneal ring segments are implanted for treatment of keratoconus, and posterior corneal surface is assessed preoperatively and postoperatively. | Procedure: Intracorneal ring segment implantation<br>* Surgical procedure for keratoconus treatment. A tunnel is created in the corneal stroma with femtosecond laser and ring segments are implanted in the corneal stroma<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Posterior corneal astigmatism | It is measured by corneal imaging device preoperatively and postoperatively | Baseline to 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Visual Acuity | It is measured by Snellen Chart Acuity | Baseline to 12 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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keratoconus, intracorneal ring segments, posterior corneal surface