This study aims to explore the mechanical properties of the cornea using a non-invasive imaging technique called Brillouin microscopy. This innovative method measures corneal elasticity by detecting small shifts in light frequency, which occur due to interactions with acoustic waves in the tissue. These measurements can provide insights into how corneal stiffness is altered in various eye diseases or after surgery.

The study includes 100 participants, divided into different groups: patients with Fuchs' Endothelial Dystrophy (FED), Map Dot Fingerprint Dystrophy (MDFD), and those who have undergone corneal surgeries such as Penetrating Keratoplasty (PKP), Descemet's Stripping Automated Endothelial Keratoplasty (DSAEK), and Descemet Membrane Endothelial Keratoplasty (DMEK). Healthy individuals will also be studied as a control group.

Participants will first receive a standard eye exam, including a slit-lamp examination. Then, Brillouin microscopy will be used to measure the cornea's mechanical stiffness. Additional tests include optical coherence tomography (OCT), corneal topography and tomography, pachymetry (measuring corneal thickness), endothelial cell count, and intraocular pressure (IOP) measurement.

The purpose of this study is to better understand how diseases and surgeries affect corneal biomechanics. The researchers will also examine how well the Brillouin measurements match with findings from other clinical imaging tests. The results may help improve diagnosis and treatment options for corneal disorders.

Inclusion Criteria:

• Written informed consent prior to surgery

• Patients aged 18 years and older

• Patients who have undergone one of the following corneal surgeries or are diagnosed with one of the following dystrophies:

  • Penetrating Keratoplasty (PKP) and no longer have sutures following PKP o Descemet's Stripping Automated Endothelial Keratoplasty (DSAEK)
  • Descemet Membrane Endothelial Keratoplasty (DMEK)
  • Fuchs' Endothelial Dystrophy (FED)
  • Map Dot Fingerprint Dystrophy (MDFD)

• Healthy Controls: healthy eyes without any history of corneal diseases or surgeries

Exclusion Criteria:

Any of the following will exclude a subject from the study:

• Patients with inadequate corneal imaging or corneal scarring that would impact results
• Patients with other corneal dystrophies or corneal diseases
• Patients with active ocular infections or inflammatory conditions
• Patients unable to undergo Brillouin imaging adequately
• Patients that suffered an eye trauma according to their medical history
• Patients with fixational problems (e.g., head tremor) or with any medical condition that could interfere with the measurements
• Pregnancy (pregnancy test will be performed in women of reproductive age)