Choosing the best profile for standard LASIK
Roberto Bellucci MD
A WAVEFRONT-OPTIMISED profile should be the standard ablation technique for LASIK in corneal refractive surgery, according to Roberto Bellucci MD, Italy.
Speaking during the Refractive Surgery Course – Corneal session at the 25th ESCRS Winter Meeting Virtual 2021, Dr Belucci outlined how the original ‘Munnerlyn’s ablation protocol’ for correction succeeded in improving the quality of uncorrected visual acuity, but several inconveniences persisted, eg ‘cosine effect’.
He explained how newer protocols of ablation (wavefront optimised, wavefront guided, ray tracing, etc) defining better ablation profiles started improving on these drawbacks.
However, despite excellent technology, advanced ablation protocols consume more tissue and are exposed to factors limiting their precision and efficacy: laser/tissue interaction, micro eye movements, epithelial healing, etc, Dr Bellucci noted. “They are complex and frequently require complex and expensive devices, and confounding factors include dry eye, corneal and epithelial variation. The cornea may not be thick enough because the ablation depth increases with all advanced profiles.”
However, the original protocol gives good results only in certain situations; “so should only be used for specific eyes and conditions like thin cornea, low defects and small pupils,” he maintained.
Dr Bellucci concluded that wavefront-optimised profile should be the standard while wavefront-guided profile can be used in eyes with high-order aberrations above 0.3 microns at 7mm optical zone.