Vision Stability and Preference for Soft Toric vs. Soft Spherical Contact Lenses

Study Overview
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Brief Summary
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The principal hypothesis is to be tested in this work is that vision stability (the primary outcome measure) with a spherical contact lens correction vs. a toric contact lens correction will be the same.

Detailed Description
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This will be a randomised, subject-masked, crossover, bilateral non-dispensing study, controlled by cross-comparison. Thirty subjects will use each lens type at a single visit in random sequence.

Official Title
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Vision Stability and Preference for Soft Toric vs. Soft Spherical Contact Lenses

Conditions
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Astigmatism, Myopia

Intervention / Treatment
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* Device: Test Contact lens
* Device: Control Contact lens


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: They are aged 18-35 years and have capacity to volunteer. They understand their rights as a research subject and are willing and able to sign a Statement of Informed Consent. They are willing and able to follow the protocol. They are an existing wearer of soft spherical contact lenses in both eyes. They have a spherical component of their spectacle refractive error between -0.50DS and -6.50DS in both eyes. They have a cylindrical component of their spectacle refractive error between -0.75DC and -1.25DC in both eyes. They can be fitted satisfactorily with both lens types. They own an acceptable pair of spectacles. They agree not to participate in other clinical research for the duration of the study. Exclusion Criteria: They have an ocular disorder which would normally contra-indicate contact lens wear. They have a systemic disorder which would normally contra-indicate contact lens wear. They are using any topical medication such as eye drops (including comfort drops) or ointment on a regular basis. They are aphakic. They have had corneal refractive surgery. They have any corneal distortion resulting from previous hard or rigid lens wear or have keratoconus. They are pregnant or breastfeeding. They have any ocular abnormality which would, in the opinion of the investigator, normally contraindicate contact lens wear. They have any infectious disease which would, in the opinion of the investigator, contraindicate contact lens wear or pose a risk to study personnel; or they have any immunosuppressive disease (e.g. HIV), or a history of anaphylaxis or severe allergic reaction. They have taken part in any other contact lens or care solution clinical trial or research, within two weeks prior to starting this study.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 35 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Test Contact lens<br>Subjects will be randomized to wear test lenses for 30 minutes, and then cross-over to control lenses. | Device: Test Contact lens<br>* Subjects will be randomized to wear test lenses for 30 minutes, and then cross-over to control lenses.<br>* Other names: Soft comfilcon A toric contact lenses;Device: Control Contact lens<br>* Subjects will be randomized to wear control lenses for 30 minutes, and then cross-over to test lenses.<br>* Other names: Soft comfilcon A sphere contact lenses;|
| Active Comparator: Control Contact lens<br>Subjects will be randomized to wear control lenses for 30 minutes, and then cross-over to test lenses. | Device: Test Contact lens<br>* Subjects will be randomized to wear test lenses for 30 minutes, and then cross-over to control lenses.<br>* Other names: Soft comfilcon A toric contact lenses;Device: Control Contact lens<br>* Subjects will be randomized to wear control lenses for 30 minutes, and then cross-over to test lenses.<br>* Other names: Soft comfilcon A sphere contact lenses;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Vision Stability While Doing Tasks on Mobile Phone | Vision stability was assessed by study subjects while doing tasks on mobile phone using a 0-100 visual analogue scales (0 - Unacceptable. Lens cannot be worn, 100 - Excellent. Unaware of any visual loss) | 30 minutes | 
| Vision Stability While Doing Tasks on Desktop | Vision stability was assessed by study subjects while doing tasks on desktop using a 0-100 visual analogue scales (0 - Unacceptable. Lens cannot be worn, 100 - Excellent. Unaware of any visual loss) | 30 minutes | 
| Vision Stability While Walking | Vision stability was assessed by study subjects while walking using a 0-100 visual analogue scales (0 - Unacceptable. Lens cannot be worn, 100 - Excellent. Unaware of any visual loss) | 30 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Lens Fit for Test Contact Lens | Lens fit was assessed for lens rotation after 10 minutes for toric fit. Lens mislocation from optimal position was measured in 0°, 1-5°, 6-10°, 11-15°, 16-20°, More than 20°. | 10 minutes | 
| Lens Fit | Lens fit was assessed as either 'acceptable' or 'not acceptable' for standard fit by study investigator. | 30 minutes |