Overview

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:

1. Develop an OCT-based system to classify and evaluate corneal-shape irregularities.
2. Develop OCT metrics for more sensitive detection of keratoconus progression.
3. Develop OCT-and-topography guided phototherapeutic keratectomy (PTK) for irregular corneas.

Eligibility

Inclusion Criteria:

GROUP A:

• Keratoconus:
  1. CDVA ≥ 20/25 in the better eye; and both of the following in the worse eye
  2. Topography characteristic of keratoconus or pellucid marginal degeneration
• Contact lens-related corneal warpage:
  1. Contact lens use; and
  2. Topography irregularities
• Dry eye:
  1. Symptoms of dry eye documented by Ocular Surface Disease Index (OSDI) questionnaire score ≥ 30; and
  2. Topography irregularities
  3. Presence of punctate epithelial erosion on exam with surface staining
  4. Aqueous deficiency or evaporative dry eye
• Epithelial basement membrane dystrophy (EBMD):
  1. Negative corneal fluorescein staining; and
  2. Corneal opacities; and
  3. Topography irregularities
• Stromal addition or subtraction:
  1. Scars; or
  2. Salzmann's degeneration; or
  3. Stromal dystrophies; or
  4. Complication (visual complaints) after LASIK or photorefractive keratectomy (PRK)
• Stromal distortion:
  1. Radial keratectomy (RK); or
  2. Corneal transplants.
• Normal controls:
  1. 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.