Safety and Effectiveness of Arcuate Incisions Performed With the iFS Femtosecond Laser System

Surgeons will perform arcuate incisions in the cornea in arc segment patterns using the iFS femtosecond laser to treat subjects with corneal astigmatism.

Inclusion criteria

• Male or female, of any race, and at least 21 years of age at the time of pre-op exam
• Corneal astigmatism, as determined by topographic keratometry, of 0.75 D to 4.00 diopters (D)
• Best Spectacle Corrected Distance Visual Acuity (BSCVA)

• Group 1:

• Natural astigmatism, no cataract - BSCVA of 20/25 or better
• Pre cataract or phakic IOL surgery - no BSCVA criteria
• Group 2:

• Post IOL surgery- BSCVA of 20/25 or better
• Uncorrected Visual Acuity (UCVA) of 20/40 or worse
• Demonstration of agreement: Corneal astigmatism (as determined by topographic keratometry) must be in agreement with refractive astigmatism (as determined by manifest refractions) within </= 0.75 D in magnitude and 15 degrees axis when cylinder </= 1.5 D or 10 degrees axis when cylinder > 1.5 D.
• Preoperative central pachymetry of >/=480 um
• Keratometry between 38.0 D (flat) to 48.0 D (steep)
• Corneal power (diopters) difference at the 3mm point from topographic center shall be </= 1D at the steepest meridian
• Intraocular pressure of 12 to 21 mm Hg with no glaucomatous retinal/optic nerve changes
• Subjects who have worn a contact lens within the past 30 days must remove the soft lens at least 2 weeks prior and a rigid or toric lens at least 3 weeks prior to baseline measurements
• Willing and capable of returning for follow-up examinations for the duration of the study

Exclusion criteria

• Angle kappa of greater than 0.5 mm, absolute value
• Prior implantation of toric or multifocal intraocular lens
• Women who are pregnant, breast-feeding, or intend to become pregnant over the course of the study
• Concurrent use of topical or systemic medications that may impair corneal wound healing
• History of any ocular or medical conditions that could affect corneal wound healing
• History of active or recurrent ophthalmic disease, including corneal dystrophy or other non-refractive abnormality such as exposure keratitis or clinically significant dry eye
• Abnormal topography, including evidence of keratoconus or pellucid marginal degeneration in either eye
• Evidence of clinically significant corneal opacity/scar in the operative eye(s) within an 8 mm diameter zone of the visual axis
• Known sensitivity or inappropriate responsiveness to any of the medications used in the post-operative course
• Participation in any other conflicting clinical study