Corneal tomographic features of postrefractive surgery ectasia

Area of Science:

• Ophthalmology
• Corneal Imaging
• Refractive Surgery

Background:

• Post-refractive surgery ectasia is a sight-threatening complication.
• Accurate tomographic assessment is crucial for diagnosis and management.
• Distinguishing between different corneal interfaces is key.

Purpose of the Study:

• To evaluate tomographic features of post-LASIK and post-SMILE ectasia using Scheimpflug imaging and OCT.
• To compare corneal interface aberrations between ectasia and normal/keratoconic eyes.
• To assess the utility of OCT in managing post-refractive surgery ectasia.

Main Methods:

• Retrospective analysis of three post-LASIK and two post-SMILE ectasia cases.
• Corneal imaging using Scheimpflug imaging (SI, Pentacam) and optical coherence tomography (OCT, RTVue).
• Derivation and comparison of curvature and wavefront aberrations at air-epithelium (A-E) and epithelium-Bowman's layer (E-B) interfaces.

Main Results:

• SI and OCT showed similar A-E interface characteristics.
• OCT revealed a steeper, more aberrated E-B interface compared to A-E.
• The difference between A-E and E-B interfaces was greater in ectasia eyes than keratoconic eyes.

Conclusions:

• OCT provides detailed insights into E-B interface changes in post-refractive surgery ectasia.
• OCT may offer superior diagnostic capabilities compared to conventional tomography for these eyes.
• OCT could aid in selecting optimal treatment strategies for post-refractive surgery ectasia.