Topography-guided vs. Wavefront Optimized Corneal Refractive Surgery: A Prospective Contralateral Randomized Double-masked Study

In 2015, the FDA approved a new laser ablation profile for performing laser corneal refractive surgery. Multiple sophisticated profiles have been developed in an attempt to optimize visual outcomes and reduce post-operative lower and higher-order optical aberrations. Among these include wave-front optimized (WFO) and wave-front guided (WFG) ablation profiles. The former compensated for corneal curvature to reduce spherical aberration and the latter, a more complicated ablation profile, was designed to minimize specific aberrations in an individual eye. Topographic profiles have also been used for over 17 years. These profiles consider the shape of the anterior corneal surface. The newest such topographic ablation profile, Contoura Vision, is a topography guided (TG) profile that, based on over 22,000 curvature data points captured using the VARIO Topolyzer, individualizes the ablation pattern. For comparison, WFO uses a patient's estimated average corneal curvature alone to create an ablation pattern. The addition of the VARIO Topolyzer adds a significant increase of pre-operative patient preparation. Anecdotally, between 1-3hrs of additional technician hours are required to prepare a patient for the Contoura Vision TG ablation profile.

This will be a prospective randomized contralateral double-masked study. Patients will undergo the same standard of care preoperative evaluation and education as any other patient not enrolled in the study. The physician performing surgery will choose either LASIK or PRK, taking into account patient preference, preoperative data and overall clinical picture, ultimately choosing which is best for the patient. If a patient qualifies for both, the patient may choose either LASIK or PRK. Each patient will be randomized as to which eye undergoes a WFO treatment vs Contoura. At the time of surgery the patient will be blinded as to which eye receives which treatment, but the surgical team will not be blinded as to which procedure is performed. Post-operatively, the ophthalmic technicians and optometrists responsible for postoperative examinations (measurement of visual acuity, refractions, transcription of PRO's) will be blinded as to which eye underwent Contoura vs WFO. While treatments will vary, both have the same safety profile. Both involve sophisticated lasers to change the shape of the cornea to achieve the desired outcome. The variance comes in the type of pattern the laser uses to treat each individual. All post-operative care will be standard of care with medications being the same as if the patient were not enrolled in the study. Post-operative evaluations will take place at postoperative day 1, week 1, month 1, month 3, and month 6.

All data collected will be standard pre- and post-operative ophthalmic refractive surgery measurements. This includes a standard medical history, especially to include prior eye surgeries or diseases. Pre-operative measurements include vision assessments, contrast sensitivity, pre- and post-dilation as well as keratometry and axial length measurements. The Contoura requires a separate set of data collection via the VARIO topolyzer. Intraoperative data collected will include variables such as actual treatment outcomes and laser settings. Post-operative measurements will consist of many of the same measurements as those obtained preoperatively including uncorrected and corrected visual acuity, and refractive measurements. A symptoms-based questionnaire specific to corrective eye surgery (PROWL) will be given to patients before and after surgery during routine follow-ups. Each PROWL is specific to an individual eye, not specific to the surgery performed in each eye (i.e. the same PROWL questionnaire will be used regardless of whether the patient underwent PRK or LASIK). All PROWL data will be compared pre- and post-operatively and will be stratified based on surgery.