Primary Outcome Measures:
- Visual acuity
- Refraction
- Corneal topography
Secondary Outcome Measures:
- Patient satisfaction following procedure
The purpose of this evaluation is to study the effects of implanting INTACS inserts, identical to those commercially available to correct myopia, into the corneal stroma of patients with keratoconus (mild to moderate) and having a clear cornea. The principle of the procedure is to flatten the cornea deformed by keratoconus. One or two segments of the same or a different thickness will be selected to reduce the asymmetric astigmatism responsible for the patient impaired visual acuity.
The surgical technique is based on locating the INTACS inserts on the flattest axis of the refractive error, making the incision on the steepest axis, using 150 degree arc length inserts with different sizes (0.250, 0.300, 0.350, 0.400 & 0.450 mm) according to a nomogram designed for this technique using the INTACS Instrumentation (10-Step Prolate System instruments).
The corneal lamellar channel creation may be performed using the INTACS instrumentation or using the Femtosecond laser (Femtec 20/10 laser[Femtec,Heidelberg Germany])
Primary Assessment Criteria
- Evaluation of the safety of the device for the treatment of patients with keratoconus (mild to moderate)
- Maintenance of best corrected visual acuity (BCVA)
- Improvement in uncorrected visual acuity (UCVA)
- Reduction in manifest refraction spherical equivalent
- Reduction in asymmetric astigmatism
Secondary Assessment Criteria
- Evaluation of the effect of INTACS inserts placement for treatment of corneal ectasia
- Determination of patient satisfaction following the INTACS inserts procedure Patients meeting the eligibility criteria are required to sign a Patient Informed Consent Form prior to study participation.
A thorough examination is perform to evaluate the following:
- Manifest refraction results - Uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA)
- Cycloplegic refraction results - Uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA)
- Corneal topography
- Pachymetry
- Step axis location
- Location of incision placement
- Subjective feedback about quality of vision (Excellent, Good, Fair and Poor)
Post-operative Assessment(at 1 day, 1 week, 1 month and 3 months postop)
- Uncorrected visual acuity (UCVA) and best corrected visual acuity with manifest refraction(BCVA) at designated time interval
- Cycloplegic refraction results - Uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA) at designated time interval
- Corneal topography at designated time interval
- Pachymetry at designated time interval
- Subjective visual outcome ratings over time (Excellent, Good, Fair and Poor)
- Report adverse events