New corneal shapes in keratorefractive surgery

Area of Science:

• Ophthalmology
• Corneal Surgery
• Refractive Surgery

Background:

• Radial keratotomy (RK) is a surgical procedure to correct myopia.
• Understanding corneal shape changes post-RK is crucial for evaluating surgical outcomes.
• Objective measurement of corneal topography is essential for assessing refractive surgery effectiveness.

Purpose of the Study:

• To compare corneal shape changes measured by the Humphrey keratometer and corneascope after radial keratotomy.
• To correlate these topographical changes with refractive outcomes.

Main Methods:

• Fifty patients undergoing radial keratotomy were studied.
• Corneal shape was assessed using the Humphrey keratometer, which employs a curve fit algorithm.
• Corneal topography was also evaluated using corneascope photographs.

Main Results:

• Both instruments showed central corneal flattening after successful RK.
• The 'plus' shape factor typically converted to a 'negative' shape factor post-RK.
• This topographical alteration, confirmed by corneascope mapping, correlated with the magnitude of refractive change.

Conclusions:

• Radial keratotomy induces significant central corneal flattening.
• The change in corneal shape, quantified by the shape factor, is a reliable indicator of refractive outcomes after RK.
• Corneal topography analysis provides valuable insights into the biomechanical effects of radial keratotomy.