Comparing Silicone Hydrogel Contact Lens Wearers to Hydrogel Contact Lens Wearers and Non-lens Wearers

This is an interventional treatment trial for Myopia Read More

Inclusion Criteria:

1. Is between 17 and 60 years of age inclusive (age matching required between all 3 study groups), and has full legal capacity to volunteer;
2. Has had a self-reported oculo-visual examination in the last two years.
3. Has read and signed an information consent letter;
4. Is willing and able to follow instructions and maintain the appointment schedule;
5. No previous history of overnight contact lens wear or PMMA (polymethylmethacrylate) lens wear.
6. Auto-refraction vertexed spherical equivalent between +4.00 and -8.00 (prescription matching required between groups 1 & 2). This criterion is non-applicable to participants in group 3.

7. Is found to be in one of the study groups matched by age (±5 years), ethnicity (Asian vs. non-Asian) and CL Rx (±2.00 D) according using the following criteria.

   GROUP 1: For the past (minimum) 6 months has ONLY worn spherical DDSH lenses AND prior to wearing this lens they only wore SH material lenses in the past (minimum) 3 total years.

   GROUP 2: For the past (minimum) 6 months has ONLY worn spherical DDH lenses AND prior to wearing this lens they only wore H material lenses in the past (minimum) 3 total years.

8. For groups 1 & 2, currently and for at least the previous 6 months has had habitual daily disposable wear schedule of at least 8 hrs a day, 5 days a week in only one material category - either silicone hydrogel or hydrogel material. This criterion is not-applicable to participants in group 3.
9. Is willing to wear the study contact lens in the randomized eye for 3 hours of eye closure on the second study day. This criterion is not-applicable to participants in group 3.
10. Has clear and healthy corneas and anterior eye and no active* ocular disease;
11. Can achieve monocular HCVA of logMAR 0.10 or better in each eye with subjective refraction or pinhole.
12. Can achieve acceptable fit and comfort in the randomized eye with the study lens. This criterion will be confirmed at the baseline visit (V1). This criterion is not-applicable to participants in group 3.
13. Has a wearable pair of spectacles.

Exclusion Criteria:

1. Is participating in any concurrent clinical trial;
2. Is unable/unwilling to provide permission for the study site to seek CL history from their eye care practitioner
3. Has any known active* ocular disease and/or infection;
4. Has a systemic condition that in the opinion of the investigator may affect a study measure or interfere with contact lens wear; this may include, but not be limited to, diabetes, hyperthyroidism, recurrent herpes simplex/zoster, Sjogren's syndromes, xerophthalmia, acne rosacea, Stevens-Johnson syndromes, and systemic connective tissue disorders e.g. rheumatoid arthritis.
5. Is using any systemic or topical medications that in the opinion of the investigator may affect a study measure;
6. Has known sensitivity to fluorescein dye, topical anesthetic, or products to be used in the study;
7. Appears to have any active* ocular pathology, ocular anomaly or severe insufficiency of lacrimal secretion (severe dry eye) that would affect the wearing of contact lenses;
8. Appears to have any signs of corneal inflammation or previous infection or corneal opacity/scar;
9. Is pregnant, lactating or planning a pregnancy at the time of enrolment (by verbal confirmation at the screening visit), due to potential ocular physiological changes, such as changes in the corneal shape and cell types;
10. Is aphakic;
11. Has undergone refractive error surgery, or has a history of any ocular surgery or injury.
12. Is a toric or multifocal contact lens wearer.