Ablation Resolution in Laser Corneal Refractive Surgery: The Dual Fluence Concept of the AMARIS Platform

[摘要] Purpose. To evaluate to which extent individual Zernike terms can be corrected. Methods. Ablation time and fidelity was analysed using different fluence levels (range 90–2000 mJ/cm2) and aspheric ablation profiles. With optimal parameters, the extent to which individual Zernike modes can be corrected was evaluated.Results. The range 188–565 mJ/cm2resulted as optimum fluence level with an optimum proportion range50%–90% for high fluence. With optimal parameters, it corresponds to2.4 s/D at 6 mm OZ, with fidelity variance of 53 μm RMS, and average ablation error of 0.5 μm for each location. Ablation simulation of coma Z[3,±1] showed 98,4% accuracy and 98% fit quality; trefoil Z[3,±3], 99,9% accuracy and 98% fit quality; spherical aberration Z[4,0], 96,6% accuracy and 97% fit quality;secondary astigmatism Z[4,±2], 97,9% accuracy and 98% fit quality. Real ablation on a flat plate of PMMA of coma Z[3,±1] showed 96,7% accuracy and 96% fit quality; trefoil Z[3,±3], 97,1% accuracy and 96% fit quality; spherical aberration Z[4,0], with 93,9% accuracy and 90% fit quality;secondary astigmatism Z[4,±2], with 96,0% accuracy and 96% fit quality.Conclusions. Ablation of aspherical and customised shapes based upon Zernike polynomials up to the the 8th order seems accurate using the dual fluence concept implemented at the AMARIS platform.

[学科分类] 光谱学