Screening Aid to Identify Corneas That May Have Pathologies or Other Conditions

1. To establish reference values for SF, CIM, and TKM in subjects with normal corneas.

2. To establish reference values for SF, CIM, and TKM in subjects who underwent myopic
laser vision correction.

3. To establish reference values for SF, CIM, and TKM in subjects who underwent hyperopic
laser vision correction.

4. To establish reference values for SF, CIM, and TKM in subjects who were diagnosed to
have keratoconus.

5. To establish reference values for SF, CIM, and TKM in subjects with history of
orthokeratology.

6. To establish reference values for SF, CIM, and TKM in subjects with previously
diagnosed corneal conditions (diseases/pathologies/surgeries) affecting the corneal
surface that are not listed above.

7. To determine the repeatabiltity and reproducibility of the Atlas II corneal topographer
in normal human corneas using true elevation data and axial curvature.

8. To determine the sensitivity, specificity, and accuracy of the Pathfinder II Corneal
Analysis software in discriminating normal corneas from previously diagnosed corneal
conditions (diseases/pathologies/surgeries) affecting the corneal surface (Phase II).

Inclusion Criteria:

Normals

- Patients seeking initial laser vision correction that were screened to be good
candidates for the procedure.

- No history of refractive or other ocular surgery.

- No corneal pathologies.

- Normal corneal topography.

- Contact lens wearers should discontinue use at least 2 weeks for hard contacts, and 3
days for soft lenses prior to imaging.

Keratoconus

- An irregular cornea determined by distorted keratometry mires, distortion of the
retinoscopic, or ophthalmoscopic red reflex (or a combination of these)

- At least one of the following biomicroscopic signs: Vogt's striae, Fleischer's ring
of >2 mm arc, or corneal scarring consistent with keratoconus.

- Contact lens wearers should discontinue use preferably 1 day or at least half an hour
prior to imaging.

Myopic Laser Vision Correction

Patients who have undergone myopic:

- LASIK

- PRK

- LASEK

Hyperopic Laser Vision Correction

Patients who have undergone hyperopic:

- LASIK

- PRK

- LASEK

Orthokeratology

- Patients using specially designed rigid contact lenses to reshape the cornea to
temporarily reduce or eliminate refractive error.

- Subjects must be 18 years of age or older; able and willing to make the required
visit; and able and willing to give consent.

Exclusion Criteria:

- Patients that underwent corneal transplantation or any ocular surgery for the
following categories: normal, keratoconus, and orthokeratology)

- Any active infection or inflammation of the cornea.

- PI decides that subject is not suitable due to medical risk.