LASIK with wavefront-guided and femtosecond technology superior

LASIK with wavefront-guided and femtosecond technology superior

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With wavefront-guided LASIK, the goal is to reduce all higher order aberrations
Preliminary results from a new study show that wavefront-guided ablations provide the best results for the vast majority of patients with the lowest rate of retreatment over conventional LASIK and wavefront optimized LASIK.
Reducing aberrations
Conventional LASIK induces higher order aberrations, including spherical aberration and coma, which are the most prominent. With optimized LASIK, the goal is not to change the spherical aberration target. The treatment basis is sphere and cylinder. Optimized simply means “not intended to induce spherical aberration,” and therefore does not address the patient’s spherical aberration or any other higher order aberrations. However, very few patients have zero spherical aberrations; those that do, are in their early 20s or younger. Numerous studies have shown that by the time most patients reach their 40s, they have positive spherical aberrations. With wavefront-guided LASIK, the goal is to reduce all higher order aberrations. The spherical aberration target is zero.

Study and results

The purpose of our study is to compare wavefront-optimized and wavefront-guided procedures to determine which is more effective. The retrospective chart review study of 200 IntraLASIK procedures included 100+ IntraLase (AMO) Wavelight (optimized) eyes and 100+ IntraLase VISX CustomVue (wavefront-guided) eyes. Pre-op and post-op wavefront scans were done on all eyes at a 6-mm pupil size Primary spherical aberrations, primary trefoil, and high order aberrations were measured. Thirty-nine CustomVue and 35 Wavelights were reviewed to this date (Figures 1 and 2).
These preliminary study results show that wavefront-guided ablation with femtosecond technology is optimal for the majority of patients who do not have zero spherical aberrations.
Overall, the wavefront-guided treatment induced significantly less higher order aberrations than the optimized procedure. There was significantly more variation with the optimized eyes. For best spectacle corrected low contrast letter acuity (BSCVA) at 5%, more wavefront-guided ablation patients achieved 20/20 than the optimized patients. When we looked at the contrast threshold using a 20/100 letter size for both groups, more wavefront-guided patients could read the lower contrast letters compared to the optimized group. This demonstrated that wavefront-guided ablation patients had better contrast letter acuity and lower contrast threshold.
For the study, the pre-op mean higher order aberration is 0.36 microns over a 6-mm pupil for both groups. With wavefront-guided, about 33% of patients were better, 33% were the same, and 33% were worse post-op. With wavefront–optimized, about 15% were better, 25% were the same, and 60% were worse. This shows that not trying to induce spherical aberrations doesn’t help 60% of the patients. The wavefront-guided ablations provide the best results for the majority of patients because they do not have zero spherical aberrations.
We are now evaluating the data on more than 100 eyes and we look forward to presenting the additional results from this study as they become available.