performance of a multifocal contact lens - presbyopia study

Conditions: Presbyopia

Summary: this is a four week study to evaluate the performance of a multifocal contact lens in habitual wearers of silicone hydrogel multifocal contact lenses.


Eligibility criteria:
inclusion criteria: 1. healthy adult males or females age 40 to 70 and has full legal capacity to volunteer. 2. the subject is a current spherical silicone hydrogel multifocal (sihy) contact lens wearer (defined as a minimum of 2 days per week for at least 6 hours of daily wear contact lenses, for a minimum of one month prior to the study) and willing to wear the study lenses on a daily basis (defined as a minimum of 6 hours of wear per day) for the duration of the study. 3. the subject must own a pair of wearable spectacles to wear when they cannot wear the study lenses. 4. the subject's optimal vertexed spherical equivalent distance correction must be between +3.50 and -5.50 diopters (d) (inclusive) in both eyes. 5. subjective refraction cylinder power must be less than or equal to 0.75 d in both eyes. 6. requires a reading addition of +0.75 d to +2.50 d in each eye. 7. the subject must have distance and near visual acuity best correctable to logmar 0.1 (20/25) or better at both distance and near with subjective refraction for each eye. 8. the subject must read and sign the informed consent form. 9. the subject must appear able and willing to adhere the instructions set forth in this clinical protocol. exclusion criteria: 1. has a systemic condition that in the opinion of the investigator may affect a study outcome variable; 2. participant in unrelated research clinical trial within 30 days prior to enrollment; 3. known to have any infectious disease (e.g.hepatitis, tuberculosis) or a contagious immunosuppressive disease. 4. women who are pregnant or lactating or planning a pregnancy at the time of enrollment; 5. ocular or systemic allergies or disease which might interfere with contact lens wear; 6. have any systemic disease, autoimmune disease, or use of medication, which may interfere with contact lens wear. this may include, but not be limited to, hyperthyroidism, recurrent herpes simplex/zoster, sjogren's syndromes, xerophthalmia, acne rosacea, stevens-johnson syndromes. 7. systemic disease or use of medication which might interfere with contact lens wear; 8. any corneal distortion; 9. has any known active\* ocular disease and/or infection; 10. is using any systemic or topical medications that in the opinion of the investigator may affect a study outcome variable; and only uses rewetting drops on an occasional basis( greater than 2 times per week). 11. is a habitual monovision contact lens wearer wearing contact lenses on extended wear basis or for the past 6 months; 12. diagnosed with diabetes; 13. is aphakic; or has entropion, ectropion, chalazia, recurrent styes, glaucoma, history of recurrent corneal erosions. 14. has undergone refractive error surgery; 15. has amblyopia or strabismus; 16. has anisometropia \>2 d between both eyes; 17. has a known sensitivity to the diagnostic pharmaceuticals to be used in the study; 18. any grade 3.0 or greater slit lamp findings (e.g., edema, corneal neovascularization, corneal staining, tarsal abnormalities, conjunctival injection) on the efron classification scale, any previous history or signs of a contact lens-related corneal inflammatory event (e.g., past peripheral ulcer or round peripheral scar), or any other ocular abnormality that may contraindicate contact lens wear; 19. employee of investigational clinic (e.g., investigator, coordinator, technician)

Keywords: visual acuity