Myopia, Safety Issues
Conditions
Keywords
Myopia, Orthokeratology
Brief summary
In Hong Kong, approximately 80% of children are myopic by the end of childhood. There is intense interest currently in the potential role of peripheral defocus as a clinical treatment to slow myopia progression. One of the most successful treatments for myopia is orthokeratology. Currently, Breath-O correct lenses are new designed ready-made orthokeratology lenses. This study is to evaluate the safety of wearing this new orthokeratology lens and the effectiveness of clinical performance in young adult.
Detailed description
Short-sightedness (myopia) is the most common refractive error in the world. In Hong Kong, approximately 80% of children are myopic by the end of childhood. Current treatment strategies to control (i.e. slow) myopia progression in children are primarily designed to harness the natural emmetropization process, in which visual feedback from retinal image clarity regulates the rate of eye growth. There is intense interest currently in the potential role of peripheral defocus as a clinical treatment to slow myopia progression, not least since this approach permits clear central vision. One of the most successful treatments for myopia is orthokeratology, which is a therapy of using custom-made rigid gas permeable contact lens. The special design of this contact lens can reshape the corneal profile to minimize the central refractive error while producing beneficial peripheral defocus. Currently, Breath-O correct lenses are new designed ready-made orthokeratology lenses which are made of new material with more elasticity as compared traditional lens material. This study is to evaluate the safety of wearing this new orthokeratology lens and the effectiveness of clinical performance in young adult.
Interventions
OTHERBreath-O-Correct Lens
Breath-O correct lenses are new designed ready-made orthokeratology lenses which are made of new material with more elasticity as compared traditional lens material
Sponsors
SEED Co. Ltd.
The Hong Kong Polytechnic University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
Randomized control trial
Eligibility
Sex/Gender
ALL
Age
18 Years to 30 Years
Healthy volunteers
Yes
Inclusion criteria
1. Refractive error: Spherical: normally -1.00D to -4.00D (maximum up to -5.00D); Cylindrical: normally half of Sph (against-the-rule Astigmatism.: lower than -0.75D) (maximum up to -1.50D) 2. Best corrected Visual acuity: monocular ETDRS 0.0 or better 3. Ocular health: No ocular abnormality, no contra-indications for overnight orthokeratology lens wear, no refractive surgery 4. General health: No systemic diseases 5. Requirement: No history of orthokeratology lens wearing. Agree to participate in this study and willing to wear the orthokeratology lenses overnight in accordance with the instructions given and to come back for follow up within the study period
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Corneal Endothelial Health in Terms of Endothelial Cell Density | Baseline, 1st Month, 3rd Month | measured by specular microscope |
| Anterior Ocular Health in Terms of Limbal and Bulbar Redness | Baseline, 1st Month, 3rd Month | measured by OCULUS Keratograph® 5M and graded by JENVIS redness grading system It is a scale of 0 to 4, the higher the score, the more redness the ocular surface manifests |
| Anterior Ocular Surface Evaluation in Terms of Non-invasive Keratography Break-up Time (NIKBUT) | Baseline, 1st Month, 3rd Month | measured by OCULUS Keratograph® 5M |
| Corneal Biomechanics in Terms of Corneal Hysteresis and Resistance Factor | Baseline, 1st Month, 3rd Month | measured by ocular response analyser |
| Corneal Endothelial Health in Terms of Percentage of Variation in Cell Size | Baseline, 1st Month, 3rd Month | measured by specular microscope |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Reduction of the Refractive Power After Wearing the Breath-O-correct Lens | Baseline, 1st Week, 1st Month, 3rd Month | Refractive errors were determined by subjective refraction for treatment group (Breath-O correct lens wearer), the outcome was represented as mean spherical equivalent refraction with unit in diopter (SER, = 1/2 Cylindrical power + spherical power) |
| Best Corrected Visual Acuity in Terms of High and Low Contrast | Baseline, 1st Month and the 3rd Month | The best corrected visual acuity was measured in LogMAR (Snellen 20/20 vision = 0.00 in LogMAR ; each readable letter add -0.02 to the score, the smaller the number i.e. more negative, the better visual acuity) |
Countries
Hong Kong
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Treatment Wearing the orthokeratology lenses for 3 months
Breath-O-Correct Lens: Breath-O correct lenses are new designed ready-made orthokeratology lenses which are made of new material with more elasticity as compared traditional lens material | 15 |
| Control Not wearing any contact lenses | 15 |
| Total | 30 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Withdrawal by Subject | 1 | 0 |
Baseline characteristics
| Characteristic | Treatment | Control | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 15 Participants | 15 Participants | 30 Participants |
| Age, Continuous | 19.8 years STANDARD_DEVIATION 0.7 | 22.2 years STANDARD_DEVIATION 2.4 | 21.1 years STANDARD_DEVIATION 2.1 |
| Race and Ethnicity Not Collected | — | — | 0 Participants |
| Refractive errors | -3.47 Diopters STANDARD_DEVIATION 1.01 | -3.71 Diopters STANDARD_DEVIATION 1.76 | -3.61 Diopters STANDARD_DEVIATION 1.4 |
| Region of Enrollment Hong Kong | 15 participants | 15 participants | 30 participants |
| Sex: Female, Male Female | 11 Participants | 9 Participants | 20 Participants |
| Sex: Female, Male Male | 4 Participants | 6 Participants | 10 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 16 | 0 / 15 |
| other Total, other adverse events | 1 / 16 | 0 / 15 |
| serious Total, serious adverse events | 0 / 16 | 0 / 15 |
Outcome results
Primary
Anterior Ocular Health in Terms of Limbal and Bulbar Redness
measured by OCULUS Keratograph® 5M and graded by JENVIS redness grading system It is a scale of 0 to 4, the higher the score, the more redness the ocular surface manifests
Time frame: Baseline, 1st Month, 3rd Month
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Treatment | Anterior Ocular Health in Terms of Limbal and Bulbar Redness | Bulbar redness_Baseline | 0.57 units on a scale | Standard Deviation 0.18 |
| Treatment | Anterior Ocular Health in Terms of Limbal and Bulbar Redness | Bulbar redness_1st Month | 0.47 units on a scale | Standard Deviation 0.19 |
| Treatment | Anterior Ocular Health in Terms of Limbal and Bulbar Redness | Bulbar redness_3rd Month | 0.54 units on a scale | Standard Deviation 0.31 |
| Treatment | Anterior Ocular Health in Terms of Limbal and Bulbar Redness | Limbal redness_Baseline | 0.26 units on a scale | Standard Deviation 0.19 |
| Treatment | Anterior Ocular Health in Terms of Limbal and Bulbar Redness | Limbal redness_1st Month | 0.23 units on a scale | Standard Deviation 0.15 |
| Treatment | Anterior Ocular Health in Terms of Limbal and Bulbar Redness | Limbal redness_3rd Month | 0.27 units on a scale | Standard Deviation 0.21 |
| Control | Anterior Ocular Health in Terms of Limbal and Bulbar Redness | Limbal redness_1st Month | 0.31 units on a scale | Standard Deviation 0.21 |
| Control | Anterior Ocular Health in Terms of Limbal and Bulbar Redness | Bulbar redness_Baseline | 0.58 units on a scale | Standard Deviation 0.28 |
| Control | Anterior Ocular Health in Terms of Limbal and Bulbar Redness | Limbal redness_Baseline | 0.29 units on a scale | Standard Deviation 0.26 |
| Control | Anterior Ocular Health in Terms of Limbal and Bulbar Redness | Bulbar redness_1st Month | 0.52 units on a scale | Standard Deviation 0.21 |
| Control | Anterior Ocular Health in Terms of Limbal and Bulbar Redness | Limbal redness_3rd Month | 0.38 units on a scale | Standard Deviation 0.28 |
| Control | Anterior Ocular Health in Terms of Limbal and Bulbar Redness | Bulbar redness_3rd Month | 0.61 units on a scale | Standard Deviation 0.27 |
Primary
Anterior Ocular Surface Evaluation in Terms of Non-invasive Keratography Break-up Time (NIKBUT)
measured by OCULUS Keratograph® 5M
Time frame: Baseline, 1st Month, 3rd Month
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Treatment | Anterior Ocular Surface Evaluation in Terms of Non-invasive Keratography Break-up Time (NIKBUT) | NIKBUT_1st break_Baseline | 6.72 Second | Standard Deviation 3.96 |
| Treatment | Anterior Ocular Surface Evaluation in Terms of Non-invasive Keratography Break-up Time (NIKBUT) | NIKBUT_1st break_1st Month | 9.13 Second | Standard Deviation 5.45 |
| Treatment | Anterior Ocular Surface Evaluation in Terms of Non-invasive Keratography Break-up Time (NIKBUT) | NIKBUT_1st break_3rd Month | 9.83 Second | Standard Deviation 6.37 |
| Treatment | Anterior Ocular Surface Evaluation in Terms of Non-invasive Keratography Break-up Time (NIKBUT) | NIKBUT_average_Baseline | 10.94 Second | Standard Deviation 4.15 |
| Treatment | Anterior Ocular Surface Evaluation in Terms of Non-invasive Keratography Break-up Time (NIKBUT) | NIKBUT_average_1st Month | 12.42 Second | Standard Deviation 5.73 |
| Treatment | Anterior Ocular Surface Evaluation in Terms of Non-invasive Keratography Break-up Time (NIKBUT) | NIKBUT_average_3rd Month | 12.07 Second | Standard Deviation 6.76 |
| Control | Anterior Ocular Surface Evaluation in Terms of Non-invasive Keratography Break-up Time (NIKBUT) | NIKBUT_average_1st Month | 11.86 Second | Standard Deviation 5.99 |
| Control | Anterior Ocular Surface Evaluation in Terms of Non-invasive Keratography Break-up Time (NIKBUT) | NIKBUT_1st break_Baseline | 9.92 Second | Standard Deviation 6.76 |
| Control | Anterior Ocular Surface Evaluation in Terms of Non-invasive Keratography Break-up Time (NIKBUT) | NIKBUT_average_Baseline | 13.24 Second | Standard Deviation 6.56 |
| Control | Anterior Ocular Surface Evaluation in Terms of Non-invasive Keratography Break-up Time (NIKBUT) | NIKBUT_1st break_1st Month | 9.17 Second | Standard Deviation 5.63 |
| Control | Anterior Ocular Surface Evaluation in Terms of Non-invasive Keratography Break-up Time (NIKBUT) | NIKBUT_average_3rd Month | 9.57 Second | Standard Deviation 5.02 |
| Control | Anterior Ocular Surface Evaluation in Terms of Non-invasive Keratography Break-up Time (NIKBUT) | NIKBUT_1st break_3rd Month | 7.64 Second | Standard Deviation 4.97 |
Primary
Corneal Biomechanics in Terms of Corneal Hysteresis and Resistance Factor
measured by ocular response analyser
Time frame: Baseline, 1st Month, 3rd Month
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Treatment | Corneal Biomechanics in Terms of Corneal Hysteresis and Resistance Factor | Corneal Hysteresis_Baseline | 11.12 mmHg | Standard Deviation 1.12 |
| Treatment | Corneal Biomechanics in Terms of Corneal Hysteresis and Resistance Factor | Corneal Hysteresis_1st Month | 10.37 mmHg | Standard Deviation 1.36 |
| Treatment | Corneal Biomechanics in Terms of Corneal Hysteresis and Resistance Factor | Corneal Hysteresis_3rd Month | 10.14 mmHg | Standard Deviation 0.89 |
| Treatment | Corneal Biomechanics in Terms of Corneal Hysteresis and Resistance Factor | Corneal Resistance Factor_Baseline | 11.07 mmHg | Standard Deviation 1.32 |
| Treatment | Corneal Biomechanics in Terms of Corneal Hysteresis and Resistance Factor | Corneal Resistance Factor_1st Month | 9.87 mmHg | Standard Deviation 1.45 |
| Treatment | Corneal Biomechanics in Terms of Corneal Hysteresis and Resistance Factor | Corneal Resistance Factor_3rd Month | 9.99 mmHg | Standard Deviation 1.37 |
| Control | Corneal Biomechanics in Terms of Corneal Hysteresis and Resistance Factor | Corneal Resistance Factor_1st Month | 10.92 mmHg | Standard Deviation 2.45 |
| Control | Corneal Biomechanics in Terms of Corneal Hysteresis and Resistance Factor | Corneal Hysteresis_Baseline | 11.10 mmHg | Standard Deviation 1.36 |
| Control | Corneal Biomechanics in Terms of Corneal Hysteresis and Resistance Factor | Corneal Resistance Factor_Baseline | 11.14 mmHg | Standard Deviation 2.23 |
| Control | Corneal Biomechanics in Terms of Corneal Hysteresis and Resistance Factor | Corneal Hysteresis_1st Month | 11.20 mmHg | Standard Deviation 1.89 |
| Control | Corneal Biomechanics in Terms of Corneal Hysteresis and Resistance Factor | Corneal Resistance Factor_3rd Month | 10.79 mmHg | Standard Deviation 2.17 |
| Control | Corneal Biomechanics in Terms of Corneal Hysteresis and Resistance Factor | Corneal Hysteresis_3rd Month | 11.19 mmHg | Standard Deviation 1.66 |
Primary
Corneal Endothelial Health in Terms of Endothelial Cell Density
measured by specular microscope
Time frame: Baseline, 1st Month, 3rd Month
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Treatment | Corneal Endothelial Health in Terms of Endothelial Cell Density | Corneal Endothelial Cell Density_Baseline | 2909 cell/mm^2 | Standard Deviation 145.1 |
| Treatment | Corneal Endothelial Health in Terms of Endothelial Cell Density | Corneal Endothelial Cell Density_1st month | 2923 cell/mm^2 | Standard Deviation 123.01 |
| Treatment | Corneal Endothelial Health in Terms of Endothelial Cell Density | Corneal Endothelial Cell Density_3rd month | 2917 cell/mm^2 | Standard Deviation 157.34 |
| Control | Corneal Endothelial Health in Terms of Endothelial Cell Density | Corneal Endothelial Cell Density_Baseline | 2861 cell/mm^2 | Standard Deviation 181.05 |
| Control | Corneal Endothelial Health in Terms of Endothelial Cell Density | Corneal Endothelial Cell Density_1st month | 2818 cell/mm^2 | Standard Deviation 182.65 |
| Control | Corneal Endothelial Health in Terms of Endothelial Cell Density | Corneal Endothelial Cell Density_3rd month | 2825 cell/mm^2 | Standard Deviation 177.8 |
Primary
Corneal Endothelial Health in Terms of Percentage of Variation in Cell Size
measured by specular microscope
Time frame: Baseline, 1st Month, 3rd Month
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Treatment | Corneal Endothelial Health in Terms of Percentage of Variation in Cell Size | Corneal Endothelial Cell Variance_Baseline | 28.68 percentage | Standard Deviation 3.78 |
| Treatment | Corneal Endothelial Health in Terms of Percentage of Variation in Cell Size | Corneal Endothelial Cell Variance_1st month | 28.47 percentage | Standard Deviation 3.51 |
| Treatment | Corneal Endothelial Health in Terms of Percentage of Variation in Cell Size | Corneal Endothelial Cell Variance_3rd month | 29.00 percentage | Standard Deviation 6.53 |
| Control | Corneal Endothelial Health in Terms of Percentage of Variation in Cell Size | Corneal Endothelial Cell Variance_Baseline | 29.35 percentage | Standard Deviation 3.66 |
| Control | Corneal Endothelial Health in Terms of Percentage of Variation in Cell Size | Corneal Endothelial Cell Variance_1st month | 29.00 percentage | Standard Deviation 3.58 |
| Control | Corneal Endothelial Health in Terms of Percentage of Variation in Cell Size | Corneal Endothelial Cell Variance_3rd month | 30.01 percentage | Standard Deviation 3.32 |
Secondary
Best Corrected Visual Acuity in Terms of High and Low Contrast
The best corrected visual acuity was measured in LogMAR (Snellen 20/20 vision = 0.00 in LogMAR ; each readable letter add -0.02 to the score, the smaller the number i.e. more negative, the better visual acuity)
Time frame: Baseline, 1st Month and the 3rd Month
Population: It is a comparison of visual performance before-and-after treatment and therefore only the best corrected visual acuity in treatment group in different time points were compared.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Treatment | Best Corrected Visual Acuity in Terms of High and Low Contrast | High contrast VA_Baseline | -0.10 LogMAR | Standard Deviation 0.06 |
| Treatment | Best Corrected Visual Acuity in Terms of High and Low Contrast | High contrast VA_1st Month | -0.07 LogMAR | Standard Deviation 0.08 |
| Treatment | Best Corrected Visual Acuity in Terms of High and Low Contrast | High contrast VA_3rd Month | -0.08 LogMAR | Standard Deviation 0.08 |
| Treatment | Best Corrected Visual Acuity in Terms of High and Low Contrast | Low contrast VA_Basline | 0.08 LogMAR | Standard Deviation 0.08 |
| Treatment | Best Corrected Visual Acuity in Terms of High and Low Contrast | Low contrast VA_1st Month | 0.22 LogMAR | Standard Deviation 0.14 |
| Treatment | Best Corrected Visual Acuity in Terms of High and Low Contrast | Low contrast VA_3rd Month | 0.17 LogMAR | Standard Deviation 0.13 |
Secondary
Reduction of the Refractive Power After Wearing the Breath-O-correct Lens
Refractive errors were determined by subjective refraction for treatment group (Breath-O correct lens wearer), the outcome was represented as mean spherical equivalent refraction with unit in diopter (SER, = 1/2 Cylindrical power + spherical power)
Time frame: Baseline, 1st Week, 1st Month, 3rd Month
Population: It is a comparison of refractive errors before-and-after treatment and therefore only the refractive errors in treatment group in different time points were compared.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Treatment | Reduction of the Refractive Power After Wearing the Breath-O-correct Lens | Refractive errors_Baseline | -3.52 Diopter | Standard Deviation 1.02 |
| Treatment | Reduction of the Refractive Power After Wearing the Breath-O-correct Lens | Refractive errors_1st Week | -0.17 Diopter | Standard Deviation 0.99 |
| Treatment | Reduction of the Refractive Power After Wearing the Breath-O-correct Lens | Refractive errors_1st Month | -0.11 Diopter | Standard Deviation 0.92 |
| Treatment | Reduction of the Refractive Power After Wearing the Breath-O-correct Lens | Refractive errors_3rd Month | -0.03 Diopter | Standard Deviation 0.82 |