OCTOCT in Diagnosis of Irregular Corneas

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.