OCT 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.