A prospective observational study on keratoconus and post-keratoplasty will be conducted. We will enroll 50 subjects in each of 3 groups: keratoconus, post-PK, and post-DSAEK. The Optovue anterior segment OCT prototype will be used to perform 3-D corneal scans. These scans will be used to measure corneal thickness (pachymetry), corneal topography (anterior and posterior) and epithelial thickness maps. The ultrahigh-speed MIT OCT prototypes will also be used when they become available. A comprehensive eye examination, Placido-ring corneal topography, ultrasound pachymetry, and Scheimpflug camera imagery, will be performed for comparison. In some post-PK and post-DSAEK cases, vision will be primarily affected by regular astigmatism, myopia, or hyperopia, rather than HOA. These cases can be corrected by standard PRK (not OCT guided) with adjunctive mitomycin C treatment to prevent haze formation.107, 108 In these cases PRK will be performed according to the standard of care and will not be a part of the study protocol. The postoperative results will be observed at the 3-4 month visit with UCVA, manifest refraction, BSCVA, OCT scanning, Placido topography, ultrasound pachymetry, and Scheimpflug camera imagery

Inclusion Criteria:

• Adults (18 & older) with keratoconus, keratoplasty, DSAEK procedures

Exclusion Criteria:

• Inability to give informed consent.
• Inability to maintain stable fixation for OCT imaging.
• Inability to commit to required visits to complete the study.

Post Operative surgical patients at Oregon Health & Science University for keratoconus, keratoplasty, DSAEK