Contact Lens-induced Corneal Fluorescein Staining
Conditions
Keywords
corneal staining, barrier function, contact lenses, contact lens care solutions, contact lens material and care solution bioincompatibility
Brief summary
The purpose of this study is to assess corneal staining and to measure the relative corneal epithelial barrier function (the degree to which the cornea can prevent penetration of colored sodium fluorescein dye into the eye) after 8 hours of wear with a known soft contact lens and multipurpose lens care solution combination.
Detailed description
This investigation will evaluate corneal staining and epithelial barrier function after eight hours of contact lens wear, which is past the peak staining time and more typical of daily lens wear time. A silicone hydrogel lens and multipurpose solution combination shown to induce significant corneal staining ( e.g. equivalent Grade 3 out of Grade 4 scale) will be used to evaluate potential corneal compromise. The study will be a prospective, single-center, double-masked, contralateral, daily wear investigation in adapted soft contact lens wearers. After a three day washout period (without lens wear, lenses will then be worn on one day for eight hours. Corneal staining and barrier function will be determined for a regimen and a saline control situation for each subject. Staining will be graded using the Efron Grading Scale, and permeability data will be estimated as the fluorescein penetration rate, Pdc in nm/sec for the test and control condition.
Interventions
DEVICEReNu Multiplus multipurpose disinfecting solution
A new lens (PureVision) soaked 6 hours to overnight in ReNu Multiplus
DEVICEControl
A new lens (PureVision) is soaked for two hours in non-preserved saline
Sponsors
Southern California College of Optometry at Marshall B. Ketchum University
Study design
Allocation
RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* At least 18 years of age. * Understand your rights as a research subject and give written informed consent by signing the Informed Consent Form, Subject Bill of Rights, and Patient Authorization for Use and Release of Health and Research Study Information (HIPAA form). * Be likely to finish the entire study, understand the study instructions, and be willing to follow the instructions. * Contact lens prescription between +4.00 D to -9.00 D (spherical equivalent). * Best correctable visual acuity of at least 20/40 in each eye. * Willing to de-adapt (do not wear) from habitual contact lenses for a period of at least two days prior to eligibility visit and at least two days prior to the testing day. * Possess a functional spectacle (eyeglass) prescription to allow adequate vision during the de-adaptation and barrier function determination periods. * No known allergies, which may interfere with contact lens wear. * No known systemic (pertaining to general health) disease, or need for medication that may interfere with contact lens wear (i.e. antihistamines, beta-blockers, steroids).
Exclusion criteria
* Less than one month successful, full time (defined as at least 8 hours per day, and more than 5 days per week) soft lens wear. * Clinically significant corneal swelling (greater than grade 3 or 4 on a 0-4 scale), corneal blood vessel growth (vascularization), corneal staining, bulbar redness, tarsal redness, or any other abnormality of the cornea that may cause unsafe contact lens wear. * Any active ocular infection. * Prior corneal refractive surgery (i.e., LASIK, PRK, etc). * Have used medications within 24 hours of study entry or have an ongoing need to use ocular medication. * Are taking part in any other study or have taken part in a study within the last 14 days * Have a medical condition that your study eye doctor thinks may make it not appropriate for you to participate in this study. * Are pregnant, or anticipate becoming pregnant during the course of this study.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| The Primary Outcome Measure Will be Corneal Epithelial Dye Diffusion Rate in Nanometers Per Second, for the Test and Control Eyes. | After eight hours of wear | The fluorescein dye diffusion rate in nanometers per second, is a diffusion rate into the corneal tissue. The fluorescein dye diffuses from the tears, where it is in high concentration, into the cornea, where it is in low concentration. It's diffusion is limited (or not) by the barrier properties and health of the epithelium. |
| Permeability Rate, nm/Sec | After eight hours of wear | A penetration rate, in nm/sec |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| The Secondary Outcome Measure Will be the Corneal Staining Grade, Compared Between the Test and Control Eye, as Well as Between the Baseline and Final Staining for Each Eye. | After eight hours of wear | Corneal staining represents corneal abrasion or damage. It is graded by us on a 0 - 4 scale (4 being worst) in five corneal sectors. The total score per cornea or eye is thus graded on a 0 - 20 total scale. |
Countries
United States
Participant flow
Pre-assignment details
Eyes were randomized to one of two conditions.
Participants by arm
| Arm | Count |
|---|---|
| All Participants A new lens (PureVision) is soaked in ReNu Multiplus multipurpose soaking solution
A new lens (PureVision) is soaked for 2 hours in non-preserved saline | 30 |
| Total | 30 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Some subject data unuseable | 4 | 4 |
Baseline characteristics
| Characteristic | All Participants |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 30 Participants |
| Age, Continuous | 25.2 years STANDARD_DEVIATION 2.1 |
| Permeability Rate, Pdc | 0.05749 nanometers per second STANDARD_DEVIATION 0.038 |
| Region of Enrollment United States | 30 participants |
| Sex: Female, Male Female | 19 Participants |
| Sex: Female, Male Male | 11 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 30 | 0 / 30 |
| serious Total, serious adverse events | 0 / 30 | 0 / 30 |
Outcome results
Primary
Permeability Rate, nm/Sec
A penetration rate, in nm/sec
Time frame: After eight hours of wear
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| PHMB-containing Disinfectant | Permeability Rate, nm/Sec | 0.057 nm/sec | Standard Deviation 0.04 |
| Non-preserved Saline | Permeability Rate, nm/Sec | 0.058 nm/sec | Standard Deviation 0.04 |
Primary
The Primary Outcome Measure Will be Corneal Epithelial Dye Diffusion Rate in Nanometers Per Second, for the Test and Control Eyes.
The fluorescein dye diffusion rate in nanometers per second, is a diffusion rate into the corneal tissue. The fluorescein dye diffuses from the tears, where it is in high concentration, into the cornea, where it is in low concentration. It's diffusion is limited (or not) by the barrier properties and health of the epithelium.
Time frame: After eight hours of wear
Population: Analysis was per protocol.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| PHMB-containing Disinfectant | The Primary Outcome Measure Will be Corneal Epithelial Dye Diffusion Rate in Nanometers Per Second, for the Test and Control Eyes. | 0.0567 nanometers per second | Standard Deviation 0.039 |
| Non-preserved Saline | The Primary Outcome Measure Will be Corneal Epithelial Dye Diffusion Rate in Nanometers Per Second, for the Test and Control Eyes. | 0.0583 nanometers per second | Standard Deviation 0.038 |
Secondary
The Secondary Outcome Measure Will be the Corneal Staining Grade, Compared Between the Test and Control Eye, as Well as Between the Baseline and Final Staining for Each Eye.
Corneal staining represents corneal abrasion or damage. It is graded by us on a 0 - 4 scale (4 being worst) in five corneal sectors. The total score per cornea or eye is thus graded on a 0 - 20 total scale.
Time frame: After eight hours of wear
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| PHMB-containing Disinfectant | The Secondary Outcome Measure Will be the Corneal Staining Grade, Compared Between the Test and Control Eye, as Well as Between the Baseline and Final Staining for Each Eye. | 4.95 score on a scale | Standard Deviation 2.4 |
| Non-preserved Saline | The Secondary Outcome Measure Will be the Corneal Staining Grade, Compared Between the Test and Control Eye, as Well as Between the Baseline and Final Staining for Each Eye. | 4.52 score on a scale | Standard Deviation 2.2 |