A Study to Test the Diagnostic Potential of Brillouin Microscopy for Corneal Ectasia

This study uses a new eye imaging technology called Brillouin microscopy to measure the stiffness of the cornea (the clear front of the eye) in patients with keratoconus (a condition where the cornea bulges outward) and those who have had or are planning LASIK or PRK laser eye surgery. The goal is to see if this technique can detect early corneal disease or changes after surgery. You may be eligible if: - You are between 20 and 75 years old - You have healthy corneas (as a normal comparison) - You have been diagnosed with keratoconus - You have had LASIK surgery in the past 12 months without complications - You have been diagnosed with post-LASIK ectasia (corneal weakening after LASIK) - You are scheduled to undergo PRK or LASIK surgery - You have Fuchs' endothelial corneal dystrophy You may NOT be eligible if: - You have occludable narrow angles in your eyes (without treatment) - You have vision in only one eye - You do not understand or cannot follow imaging instructions - You have high astigmatism (greater than 2 diopters) or prior eye surgeries (for the surgery groups) Talk to your doctor to see if this trial is right for you.