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.