Comparison of Contoura Vision Outcomes Programmed Using the Manifest Refraction Verses Using Phorcides Planning Software in Patients With Oblique Astigmatism

Study Overview
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Brief Summary
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The objective is to compare the percentage of monocular UDVA -0.1 logMAR (20/16) outcomes for each planning strategy (Phorcides and manifest refraction) at the 3-month post operative visit.

Detailed Description
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This study is a randomized, prospective contralateral eye study of visual outcomes in eyes planned with Phorcides compared to eyes planned using the manifest refraction after successful bilateral LASIK surgery. Subjects will be assessed pre-operatively, operatively and at 3 months postoperatively. Clinical evaluations will include measurement of visual acuity, manifest refraction, and administration of a questionnaire.

Official Title
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Comparison of Contoura Vision Outcomes Programmed Using the Manifest Refraction Verses Using Phorcides Planning Software in Patients With Oblique Astigmatism

Conditions
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Myopia, Astigmatism

Intervention / Treatment
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* Device: Contoura LASIK with Phorcides planning strategy
* Device: Contoura LASIK with manifest refraction planning strategy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18 years old and above Preoperative total corneal Pachymetry 490um or above BCVA 20/20 or better Stable refractive error <0.50D MRSE change in preceding year Good general and ocular health Preoperative exam completed within three months of surgery Soft contact lens wear discontinued 3 days prior to preoperative exam and the procedure Residual stromal bed greater than 270um Candidates who qualify for Contoura treatment OU (≤ -8.0 D SPH and ≤ -3.0 D CYL) Candidates who elect to target both eyes targeted for emmetropia ≤ -3.0 D Oblique astigmatism as defined as an axis between 30-60 degrees or between 120-150 degrees Exclusion Criteria: Subjects with usual relative and absolute contraindications for LASIK surgery (subjects with severe dry eye, subjects with recurrent corneal erosion, subjects with uncontrolled Glaucoma, subjects with collagen vascular disorders, keratoconus or signs of keratoconus, Uncontrolled Diabetes, Herpes, corneal dystrophies or degeneration; any irregular astigmatism) Pachymetry below 490 Autoimmune or immunodeficiency diseases, Pregnant or nursing women Subjects with signs of inability to understand consent for study and procedure planned Subjects with history of previous ocular surgery The principal investigator reserves the right to declare a patient ineligible or non-evaluable based on medical evidence that indicates they are unsuitable for the trial. Pregnancy has a known effect on the stability of refractions and visual acuity. As such, subjects who become pregnant during the study will not be discontinued but their data may be excluded from analyses of effectiveness.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Contoura LASIK with Phorcides planning strategy<br> | Device: Contoura LASIK with Phorcides planning strategy<br>* Bilateral treatment with topography guided LASIK<br>|
| Contoura LASIK with manifest refraction planning strategy<br> | Device: Contoura LASIK with manifest refraction planning strategy<br>* Bilateral treatment with topography guided LASIK<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of eyes with monocular UDVA of logMAR -0.10 (20/16) in each group |  | 3 months postoperatively | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of eyes with monocular UDVA of logMAR -0.20 (20/12.5) in each group |  | 3 months postoperatively |