Clinical Performance of Habitual Hydrogel vs. Silicone Hydrogel Toric Contact Lenses

Clinical Performance of Habitual Wearers of Hydrogel Toric Lenses When Refitted With Avaira Toric Silicone Hydrogel Lenses

Evaluate the clinical performance of existing wearers of hydrogel toric lenses when refitted with Avaira toric silicone hydrogel contact lenses over 1 week of wear.

This is a 60-subject, single masked, bilateral, parallel study design comparing the fitting characteristics of enfilcon A toric lenses against the subjects habitual hydrogel toric lenses (omafilcon A, ocufilcon D or methafilcon B wearers). Subject's habitual toric lenses will be evaluated at the first visit and then re-fitted with a pair of Avaira toric lenses. After 1 week of daily wear, subjects will return for a second and final evaluation.

Inclusion Criteria:

• Is between 18 and 40 years of age (inclusive)
• Has had a self-reported visual exam in the last two years
• Is an adapted soft toric contact lens wearer
• Has a contact lens spherical prescription between +6.00 to - 8.00 (inclusive)
• Have no less than 0.75D of astigmatism and no more than 1.75 D in both eyes.
• Can achieve best corrected spectacle distance visual acuity of 20/25 (0.10 logMAR) or better in each eye.
• Can achieve a distance visual acuity of 20/30 (0.18 logMAR) or better in each eye with the study contact lenses.
• Has clear corneas and no active ocular disease
• Has read, understood and signed the information consent letter.
• Patient contact lens refraction should fit within the available parameters of the study lenses.
• Is willing to comply with the wear schedule (at least 5 days per week, > 8 hours/day assuming there are no contraindications for doing so).
• Is willing to comply with the visit schedule

Exclusion Criteria:

• Has a contact lens prescription outside the range of the available parameters of the study lenses.

• Has a spectacle cylinder less than -0.75D or more than -1.75D of cylinder in either eye.

• Has a history of not achieving comfortable contact lens wear (5 days per week; > 8 hours/day)

• Has contact lens best corrected distance vision worse than 20/25 (0.10 logMAR) in either eye.

• Presence of clinically significant (grade 2-4) anterior segment abnormalities

• Presence of ocular or systemic disease or need of medications which might interfere with contact lens wear.

• Slit lamp findings that would contraindicate contact lens wear such as:

  • Pathological dry eye or associated findings
  • Pterygium, pinguecula, or corneal scars within the visual axis
  • Neovascularization > 0.75 mm in from of the limbus
  • Giant papillary conjunctivitis (GCP) worse than grade 1
  • Anterior uveitis or iritis (past or present)
  • Seborrheic eczema, Seborrheic conjunctivitis
  • History of corneal ulcers or fungal infections
  • Poor personal hygiene

• Has a known history of corneal hypoesthesia (reduced corneal sensitivity)

• Has aphakia, keratoconus or a highly irregular cornea.

• Has Presbyopia or has dependence on spectacles for near work over the contact lenses.

• Has undergone corneal refractive surgery.

• Is participating in any other type of eye related clinical or research study.