Bilateral Differential Topography-A Novel Topographic Algorithm for Keratoconus and Ectatic Disease Screening

Area of Science:

• Ophthalmology
• Corneal Imaging
• Diagnostic Algorithms

Background:

• Keratoconus and corneal ectasia pose risks for corneal refractive surgery.
• Early detection is crucial to prevent post-operative complications.

Purpose of the Study:

• To develop a novel bilateral differential topographic algorithm.
• To evaluate its efficacy in screening for keratoconus and corneal ectasia prior to refractive surgery.

Main Methods:

• Utilized Scheimpflug imaging to obtain topographic data.
• Calculated key bilateral differential topographic parameters.
• Employed receiver operating characteristic (ROC) curves to assess diagnostic efficacy.

Main Results:

• Bilateral differential topographic parameters were significantly higher in the keratoconus/ectasia group.
• Parameters like ΔFKmean, ΔFKsd, ΔFEsd, and ΔFEmax showed high accuracy (AUC > 0.983) in discrimination.
• Achieved high sensitivity (95.0-96.9%) and specificity (94.8-97.7%) with established cut-off values.

Conclusions:

• Bilateral differential topographic parameters are effective for early detection of keratoconus and corneal ectasia.
• The algorithm can improve sensitivity and specificity in screening before corneal refractive surgery.
• This method complements existing diagnostic models for pre-surgical screening.