Clinical Investigation of Buttermere (LENS 271) Soft Contact Lenses

The purpose of this study is to compare clinical performance of two soft contact lenses in a crossover study over a period of 7 days of wear.

Inclusion criteria

i. Age 8 to 18 years; at least half the population will be children or adolescents aged 8 to 15 years.

ii. Have experience with soft contact lens wear and able to insert and remove soft contact lenses.

iii. Parent/guardian and participant have read and understood the Participant Information Sheet.

iv. Parent/guardian and participant have read, signed and dated the Informed Consent and Assent (when applicable).

v. Best corrected visual acuity of at least 20/25 in each eye.

vi. Have normal eyes with the exception of the need for visual correction.

vii. Spectacle refraction:

• Age 8 to 12: -0.75D to -4.00D spherical equivalent, with cylinder ≤ -0.75D and maximum anisometropia of <1.00D
• Age 13-18: -0.75D to -7.00D spherical equivalent, with cylinder ≤ -0.75D and maximum anisometropia of <1.00D.

viii. Be willing and able to adhere to the instructions set in the clinical protocol and maintain the appointment schedule.

Exclusion criteria

i. Acute and subacute inflammation or infection of the anterior chamber of the eye.

ii. Any eye disease, injury, or abnormality that affects the cornea, conjunctiva, or eyelids.

iii. Severe insufficiency of lacrimal secretion (dry eyes).

iv. Corneal hypoesthesia (reduced corneal sensitivity), if not aphakic.

v. Any systemic disease that may affect the eye or be exaggerated by wearing contact lenses.

vi. Allergic reactions of ocular surfaces or adnexa that may be induced or exaggerated by wearing contact lenses or use of contact lens solutions.

vii. Any active corneal infection (bacterial, fungal, or viral).

viii. The patient is unable to follow lens handling and wear regimen or unable to obtain assistance to do so.

ix. Newly prescribed use of systemic or ocular medications for which contact lens wear could be contraindicated as determined by the investigator.

x. Monocular participants (only one eye with functional vision) or participants fit with only one lens.

xi. Subjects with slit lamp findings greater than grade 1 (e.g., edema, infiltrates, corneal neovascularization, corneal staining, tarsal abnormalities, conjunctival, anterior segment inflammation) as per ISO 11980:2012, any previous history or signs of a contact lens related corneal inflammatory event (past corneal ulcers), or any other ocular abnormality that may contraindicate contact lens wear at the enrolment visit.

xii. History of herpetic keratitis, ocular surgery or irregular cornea.

xiii. Enrolment of the family members of the investigator, family members of the investigator's staff, or individuals living in the households of these individuals.