OCT in Diagnosis of Irregular Corneas

Study Overview
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Brief Summary
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This main goal of this study is to improve the detection, classification, monitoring, and treatment of irregular corneas due to keratoconus, warpage, dry eye, scar, stromal dystrophies, and other corneal conditions. The primary goal will be achieved by using optical coherence tomography (OCT) to: Develop an OCT-based system to classify and evaluate corneal-shape irregularities. Develop OCT metrics for more sensitive detection of keratoconus progression. Develop OCT-and-topography guided phototherapeutic keratectomy (PTK) for irregular corneas.

Official Title
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Optical Coherence Tomography-Aided Differential Diagnosis and Treatment of Irregular Corneas

Conditions
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Keratoconus, Corneal Opacity, Corneal Dystrophy

Intervention / Treatment
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* Device: Optical Coherence Tomography


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: GROUP A: Keratoconus: CDVA ≥ 20/25 in the better eye; and both of the following in the worse eye Topography characteristic of keratoconus or pellucid marginal degeneration Contact lens-related corneal warpage: Contact lens use; and Topography irregularities Dry eye: Symptoms of dry eye documented by Ocular Surface Disease Index (OSDI) questionnaire score ≥ 30; and Topography irregularities Presence of punctate epithelial erosion on exam with surface staining Aqueous deficiency or evaporative dry eye Epithelial basement membrane dystrophy (EBMD): Negative corneal fluorescein staining; and Corneal opacities; and Topography irregularities Stromal addition or subtraction: Scars; or Salzmann's degeneration; or Stromal dystrophies; or Complication (visual complaints) after LASIK or photorefractive keratectomy (PRK) Stromal distortion: Radial keratectomy (RK); or Corneal transplants. Normal controls: Healthy eyes with no previous eye procedures/surgeries. GROUP B: Participants will be selected from the keratoconus population in Group A based on topography findings. GROUP C: Participants will be selected from the stromal addition/subtraction and stromal distortion populations of Group A if they have vision primarily limited by scars, dystrophy, or high astigmatism that could benefit from PTK. Exclusion Criteria (all groups): Inability to give informed consent. Inability to maintain fixation for OCT imaging. Inability to commit to required study visits. Eyes with concurrent cataract, retinal disease, glaucoma, or other eye conditions that may limit the visual outcome after surgery. Previous corneal surgeries if considered as a keratoconus participant. Pregnancy or breastfeeding.

Ages Eligible for Study
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Minimum Age: 14 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Group A: Classification of Corneal Irregularities<br>This group will consist of participants >14 years old with various types of corneal irregularities. Their data will be compared against participants with healthy corneas. Data for this group will be gathered only once. | Device: Optical Coherence Tomography<br>* This device will be used to tightly classify corneal irregularities and determine eligibility of candidates from Group A into Groups B & C.<br>|
| Group B: Detection of Keratoconus Progression<br>Participants from Group A who are diagnosed with keratoconus will be selected for this longitudinal study to monitor keratoconus progression. They will be followed up to 4 years. | Device: Optical Coherence Tomography<br>* This device will be used to tightly classify corneal irregularities and determine eligibility of candidates from Group A into Groups B & C.<br>|
| Group C: OCT-and-Topography Guided PTK<br>Participants from Group A will be selected for this group if they have vision primarily limited by scars, dystrophy, or high astigmatism that could be treated by PTK. They will be followed up to 1 year. | Device: Optical Coherence Tomography<br>* This device will be used to tightly classify corneal irregularities and determine eligibility of candidates from Group A into Groups B & C.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Develop OCT-based system to classify and evaluate corneal-shape irregularities | Clinical classification of keratoconus, epithelial deformation, stromal addition/subtraction, stromal distortion, and healthy controls by OCT. Primary measurements will be corneal and epithelial thicknesses assessed in micron units. | 1 day | 
| Develop OCT-based system to classify and evaluate corneal-shape irregularities | Secondary measurement will be OCT corneal shape assessed in Diopter units. | 1 day | 
| Develop OCT metrics for more sensitive detection of keratoconus progression | Primary measurements will be OCT corneal and epithelial thicknesses assessed in micron units. | 4 year | 
| Develop OCT metrics for more sensitive detection of keratoconus progression | Secondary measurement will be OCT corneal shape assessed in Diopter units. | 4 year | 
| Develop OCT- and topography-guided phototherapeutic keratectomy (PTK) for irregular corneas | The primary goal is to improve the post-procedural outcome of uncorrected and best corrected visual acuity. This will be measured in feet by conventional Snellen fraction of 20/xx. | 1 year | 
| Develop OCT- and topography-guided phototherapeutic keratectomy (PTK) for irregular corneas | The secondary goal is to improve the post-procedural outcome of refractive error. This will be measured in Diopter units. | 1 year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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OCT, Keratoconus