Weighing LASIK Ablation Profile Options

Leading refractive surgeons agree that when performing LASIK, excellent results can be achieved whether one chooses to use the now standard wavefront-optimised (WFO) technique or any of the customised options: wavefront-guided (WFG), topography-guided (TPG), or raytracing-guided (RTG).

Available evidence from comparative studies, however, indicates that between WFO-, WFG-, and TPG-LASIK, the WFG technique delivers the highest levels of 20/16 and 20/12.5 uncorrected distance visual acuity (UCDVA), better low contrast VA, and greater gains in corrected distance visual acuity (CDVA), said Edward E Manche MD.

Raytracing-guided LASIK represents the newest technique, with the platform used for this procedure only receiving the CE mark in 2019 and FDA approval in 2025. Results of a head-to-head study being conducted by Dr Manche will provide insight as to how its outcomes compare to those of a WFG procedure (study NCT07078799).

John Kanellopoulos MD agrees that more information is needed to determine how RTG-LASIK performs relative to WFG-LASIK. However, describing RTG-LASIK as a “WFG+” procedure, he suggested RTG-LASIK will give WFG-LASIK “a run for its money”, outperforming WFG-LASIK for improving visual outcomes beyond 20/20 because it provides a better view of the whole eye.

Conclusions grounded in scientific evidence

Dr Manche said there is an abundance of head-to-head studies comparing WFG-LASIK with WFO-LASIK. A meta-analysis including early studies evaluating the two techniques found their outcomes were comparable.¹ However, Dr Manche reviewed subsequently published investigations, including several he conducted, that showed superior results across multiple endpoints using WFG-LASIK.^2–4

Other published articles also describe studies that directly compared TPG-LASIK and WFO-LASIK, and these trials have generated conflicting results. Some studies showed the two techniques delivered similar outcomes, although a more recent randomised clinical trial reported superior outcomes with WFO-LASIK compared to TPG-LASIK.⁵ Stating that he found only three published papers comparing WFG- and TPG-LASIK,^6–8 Dr Manche said the results of these trials were more consistent in showing some advantages for WFG-LASIK.

Understanding a role for RTG-LASIK

Dr Kanellopoulos authored the first published paper on RTG-LASIK, followed by subsequent studies, including a multinational trial.^9–11 Prefacing a discussion of this technique, he reiterated that WFG-, WFO-, and TPG-LASIK all perform well in delivering 20/20 UCVA.

“While wavefront guidance was a major advance in LASIK, raytracing is the next optical model, and achieving better quality of vision is where raytracing matters,” Dr Kanellopoulos said.

“It only makes sense to consider RTG-LASIK if the goal is to improve the optics of the entire eye, not just the cornea, and to achieve better retinal image quality, not just emmetropia and spectacle independence.”

Providing an overview of RTG-LASIK, Dr Kanellopoulos said it uses a better planning engine than WFG-LASIK because it personalises the eye rather than just the wavefront. He explained that, while the WFG technique treats measured wavefront aberrations and low-order aberrations based on the Gullstrand 2D eye model, the raytracing approach builds a personalised 3D model of the whole eye and optimises treatment through that model using wavefront and corneal tomographic data. In addition, planning for RTG-LASIK incorporates data for expected biomechanical changes and epithelial remodelling, calculates multiple treatment patterns, and chooses the optimal pattern for correcting both low- and high-order aberrations.

“Furthermore, by reshaping the cornea along the visual path and improving corneal symmetry in relation to the visual path, RTG-LASIK may facilitate a more favourable optical system for future lens-based procedures, such as cataract surgery,” Dr Kanellopoulos said.

In a study presented at the 2026 ASCRS meeting, Dr Kanellopoulos compared RTG-LASIK with keratorefractive lenticule exchange (KLEx) performed using SMILE pro. He said the results showed subtle differences overall, but RTG-LASIK demonstrated its advantages when comparing the percentages of eyes with gains in CDVA and contrast sensitivity outcomes. However, Dr Kanellopoulos noted the results need to be considered in light of the study’s methods, which relied on RT measurements to determine the amount of myopia and astigmatism correction in the KLEx procedures.

“In addition, the elephant in the room is that none of the customised LASIK treatments take into account the contribution of the human lens. In younger patients, accommodation can bias lower- and higher-order aberrations, affecting accuracy of the treatments, including RTG-LASIK,” he said. “Managing this variability is an essential component of the learning curve when adopting raytracing technology. We routinely obtain measurements under cycloplegic conditions, using two drops of 0.5% tropicamide administered approximately 15 minutes apart. Measurements are done approximately 30 minutes later and used for planning without modification or nomogram intervention.”

Practical advice for practising surgeons

Dr Kanellopoulos emphasised the difficulty in debating which of the four LASIK techniques is the best, but he offered some personal recommendations. He suggested that surgeons who do not have a comprehensive understanding of the scientific principles underlying WFG-LASIK, TPG-LASIK, or RTG-LASIK can do well performing WFO-LASIK when the ablation plan is based on population averages. Surgeons who are comfortable with the more complex planning involved when performing WFG-LASIK or TPG-LASIK can expect to achieve good outcomes by choosing either of the two more customised procedures.

The bottom line for successful LASIK, however, is not how the procedure is performed, but by whom.

“I still believe that the best customisation tool for LASIK is the experienced refractive surgeon,” Dr Kanellopoulos said.

Drs Manche and Kanellopoulos debated the relative merits of LASIK planning at a session of the 2026 ASCRS annual meeting in Washington, DC.

Edward E Manche MD is Professor of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, California, US. edward.manche@stanford.edu; lasik.manche@stanford.edu

A John Kanellopoulos MD is Medical Director, Laservision Ambulatory Eye Surgery Unit, Athens, Greece, and Clinical Professor of Ophthalmology, NYU Grossman Medical School, New York, US. ajkmd@mac.com

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