TransPRKCXL: Simultaneous TransPRK and Corneal Collagen Cross-Linking
Study Details
Study Description
Brief Summary
Young patients with keratoconus face two problems: disease progression and corneal shape irregularity leading to poor vision even in spectacles.
Corneal collagen cross-linking (CXL) is a new treatment designed to halt disease progression in keratoconus. The aim is to stiffen the cornea thereby preventing further shape deterioration.
Topography or wavefront guided transepithelial photorefractive keratectomy (transPRK) uses the excimer laser (the laser used to correct sight in 'laser eye surgery') to reduce corneal shape irregularity in early stage keratoconus, reducing dependence on contact lenses.
In transPRK, the corneal skin layer is removed in a well controlled, no touch procedure, preparing the cornea for CXL. Performing both treatments simultaneously (combining both procedures in one operation) may offer several advantages over performing CXL first then waiting for corneal shape to stabilise before performing transPRK. In particular, visual rehabilitation may be faster. This study aims to evaluate visual recovery after simultaneous CXL and transPRK in progressive early stage keratoconus. Visual recovery in these patients will be compared with results for a similar group of patients with early stage keratoconus who have already been treated with CXL alone.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
N/A |
Detailed Description
Features which distinguish this trial from previous trials of combined photorefractive keratectomy (PRK) and corneal collagen cross-linking (CXL) are: a rapid, pulsed light, CXL protocol; and a treatment programming algorithm for PRK designed to target higher order aberrations only with no compensatory additional laser corneal tissue removal.
Excimer laser treatment will be performed with the Schwind Amaris 750S laser (www.eye-tech-solutions.com). Unique features of this system utilised here include:
-
Pre-programmed transepithelial ablation - laser removal of the minimum area of corneal epithelium required for PRK promoting more rapid recovery than conventional methods (20% alcohol application and manual epithelial removal). An 8mm diameter ablation zone will be applied throughout.
-
Enhanced algorithms for minimal laser tissue removal - in this trial, the investigators are targeting higher order aberrations only (coma in particular) with the aim of improving spectacle corrected visual acuity without regard to the predicted spherocylindrical outcome. Unlike other current excimer laser platforms, Schwind Amaris treatment programming software allows treatment for irregular astigmatism without additional compensatory laser tissue removal to correct the spherocylindrical change induced by treatment of higher order aberrations. Higher order aberrations can also be treated selectively. The investigators will use an algorithm step that targets only aberrations (up to 6th order Zernike polynomials) with a value greater than 2 standard deviations from the population mean in normative data. These treatment planning steps allow the laser to create a large diameter treatment with minimal treatment depth.
Laser epithelial removal alone (transPTK at depth 55µm) removes a maximum 65µm of tissue in the corneal periphery. For patients with 390µm at the thinnest point, transPTK will therefore leave above 325µm residual stromal thickness prior to CXL. This is in line with recommendations for minimum stromal thickness after epithelial removal in the CXL protocol used here. Limited stromal reshaping is achieved in this simple embodiment of transPRK for keratoconus by taking advantage of the masking effect of the corneal epithelium, which tends to be thinnest over the cone apex. Where the thinnest point is greater than 390µm, further reductions in corneal shape irregularity can be produced by adding either wavefront or topography guided additional stromal ablation using custom programming on the Schwind Amaris laser. Ocular wavefront (aberrometry) guided smoothing will be used for patients with a 5.5mm or larger pupil at scanning and a consistent scan sequence (3 scans within 0.5 dioptre (D) spherical equivalent refraction). Corneal wavefront (topography) guided smoothing will be used for patients with ocular wavefront scans which do not meet these criteria. In all cases, a minimum corneal stromal thickness prior to CXL of 325µm will be preserved.
Immediately after PRK, corneal collagen cross-linking will be performed using the following protocol
Riboflavin soak: 10 minutes total soak time; application of 0.1% riboflavin preparation (VibeX Rapid - www.avedro.com) each 2 minutes with gentle balanced salt solution irrigation to remove excess riboflavin prior to UV light exposure.
UV light exposure: Total treatment time 8 minutes (370nm wavelength; 30mW/cm2 irradiance; 4 minutes total UV exposure time, pulsed 1.5 seconds on 1.5 seconds off; Avedro KXL I light source)
Mitomycin C will not be used. A bandage contact lens will be applied at the end of treatment and a standard post photorefractive keratectomy topical and systemic drug treatment regimen will be used in every case with initial clinical review 1 week after surgery.
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: TransPRKCXL Simultaneous combined transepithelial photorefractive keratectomy (TransPRK) and corneal collagen cross-linking (CXL) |
Procedure: Transepithelial Photorefractive Keratectomy (TransPRK)
Aberrometry or topography guided transepithelial photorefractive keratectomy (TransPRK) using the Schwind Amaris 750s excimer laser (www.eye-tech-solutions.com), an 8mm treatment diameter, and a tissue saving algorithm targeting selected higher order aberrations only. TransPRK will be followed immediately by corneal collagen cross-linking (CXL).
Other Names:
Procedure: Corneal Collagen Cross-Linking (CXL)
Riboflavin soak: 10 minutes total soak time; application of 0.1% riboflavin preparation (VibeX Rapid - www.avedro.com) each 2 minutes with gentle balanced salt solution irrigation to remove excess riboflavin prior to UV light exposure.
UV light exposure: Total treatment time 8 minutes (370nm wavelength; 30mW/cm2 irradiance; 4 minutes total UV exposure time, pulsed 1.5 seconds on 1.5 seconds off; Avedro KXL I light source)
Other Names:
|
| Active Comparator: CXL only Corneal collagen cross-linking (CXL) using the same protocol without transepithelial photorefractive keratectomy |
Procedure: Corneal Collagen Cross-Linking (CXL)
Riboflavin soak: 10 minutes total soak time; application of 0.1% riboflavin preparation (VibeX Rapid - www.avedro.com) each 2 minutes with gentle balanced salt solution irrigation to remove excess riboflavin prior to UV light exposure.
UV light exposure: Total treatment time 8 minutes (370nm wavelength; 30mW/cm2 irradiance; 4 minutes total UV exposure time, pulsed 1.5 seconds on 1.5 seconds off; Avedro KXL I light source)
Other Names:
|
Outcome Measures
Primary Outcome Measures
- Change in LogMAR Corrected Distance Visual Acuity (CDVA) [Preoperative vs 24 months]
Change in spectacle corrected logarithm minimum angle of resolution (LogMAR) distance visual acuity recorded in a 4m testing lane in photopic lighting conditions between baseline measurement and final review at 24 months (note that negative change = better vision; 0.1 logMAR units = 1 line on the test chart)
Secondary Outcome Measures
- Clinically Significant Visual Gain [Preoperative vs 24 months postoperative]
Number of participants with gain of ≥2 lines (≥0.20 logMAR units) corrected distance visual acuity (CDVA) on a standard 5 letter per line EDTRS visual acuity testing chart
- Clinically Significant Visual Loss [preoperative vs 24 months postoperative]
Number of participants with loss of ≥2 lines (≥0.20 LogMAR units) corrected distance visual acuity (CDVA)
- Change in Kmax - Maximum Local Anterior Corneal Surface Curvature on Tomography Map [Preoperative vs 24 months postoperative]
Pentacam (www.oculus.de) measure: Maximum local curvature (Kmax). Reduction in dioptric value = corneal flattening
- Progression Rate [6 months postoperative - 24 months postoperative]
The number of participants with possible keratoconus disease progression after treatment defined by a ≥1.5D increase in Kmax, anterior and posterior K2 (maximum local corneal curvature, maximum anterior and posterior meridional corneal curvature) measured using a Pentacam HD corneal tomographer (www.oculus.de).
Eligibility Criteria
Criteria
Inclusion Criteria:
-
Patients with progressive stage II or III keratoconus
-
CDVA < 0.00 logMAR or subjective problems with spectacle corrected visual quality (ghost images or light scatter symptoms)
Exclusion Criteria:
-
Active ocular surface disease
-
Minimum corneal thickness <390µm (leaving 325µm residual stromal thickness after transPTK - in line with minimum thickness recommendations for the study CXL protocol)
-
Vulnerable groups (patients whose capacity for giving informed consent to participate in the trial may be impaired)
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Moorfields Eye Hospital NHS Foundation Trust, 162 City Road | London | United Kingdom | EC1V 2PD |
Sponsors and Collaborators
- Bruce Allan
- Moorfields Eye Hospital NHS Foundation Trust
Investigators
- Principal Investigator: Bruce D Allan, MD FRCOphth, Moorfields Eye Hospital NHS Foundation Trust
- Principal Investigator: Dan M Gore, FRCOphth, Moorfields Eye Hospital NHS Foundation Trust
Study Documents (Full-Text)
None provided.More Information
Publications
- Gore DM, Shortt AJ, Allan BD. New clinical pathways for keratoconus. Eye (Lond). 2013 Mar;27(3):329-39. doi: 10.1038/eye.2012.257. Epub 2012 Dec 21. Review.
- Kanellopoulos AJ, Asimellis G. Keratoconus management: long-term stability of topography-guided normalization combined with high-fluence CXL stabilization (the Athens Protocol). J Refract Surg. 2014 Feb;30(2):88-93. doi: 10.3928/1081597X-20140120-03.
- ALLB1018
Study Results
Participant Flow
| Recruitment Details | Patients with Stage I-III keratoconus and corrected vision <20/20 were recruited. Recruitment period: August 2014-July2015. Location: dedicated keratoconus clinic at Moorfields Eye Hospital, London. |
|---|---|
| Pre-assignment Detail | 63 eligible patients were screened; 11 declined to participate after discussing consent information; 5 patients were found to be ineligible because of insufficient residual corneal stromal depth following PRK programming, leaving 47 patients who were treated with TransPRK/CXL |
| Arm/Group Title | TransPRKCXL | CXL Only |
|---|---|---|
| Arm/Group Description | Simultaneous combined transepithelial photorefractive keratectomy (TransPRK) and corneal collagen cross-linking (CXL) Transepithelial Photorefractive Keratectomy (TransPRK): Aberrometry or topography guided transepithelial photorefractive keratectomy (TransPRK) using the Schwind Amaris 750s excimer laser (www.eye-tech-solutions.com), an 8mm treatment diameter, and a tissue saving algorithm targeting selected higher order aberrations only. TransPRK will be followed immediately by corneal collagen cross-linking (CXL). Corneal Collagen Cross-Linking (CXL): Riboflavin soak: 10 minutes total soak time; application of 0.1% riboflavin preparation (VibeX Rapid - www.avedro.com) each 2 minutes with gentle balanced salt solution irrigation to remove excess riboflavin prior to UV light exposure. UV light exposure: Total treatment time 8 minutes (370nm wavelength; 30mW/cm2 irradiance; 4 minutes total UV exposure time, pulsed 1.5 seconds on 1.5 seconds off; Avedro KXL I light source) | Patients treated with standard accelerated corneal collagen cross-linking (historical controls) |
| Period Title: Overall Study | ||
| STARTED | 47 | 47 |
| COMPLETED | 40 | 47 |
| NOT COMPLETED | 7 | 0 |
Baseline Characteristics
| Arm/Group Title | TransPRKCXL | CXL Only | Total |
|---|---|---|---|
| Arm/Group Description | Simultaneous combined transepithelial photorefractive keratectomy (TransPRK) and corneal collagen cross-linking (CXL) Transepithelial Photorefractive Keratectomy (TransPRK): Aberrometry or topography guided transepithelial photorefractive keratectomy (TransPRK) using the Schwind Amaris 750s excimer laser (www.eye-tech-solutions.com), an 8mm treatment diameter, and a tissue saving algorithm targeting selected higher order aberrations only. TransPRK will be followed immediately by corneal collagen cross-linking (CXL). Corneal Collagen Cross-Linking (CXL): Riboflavin soak: 10 minutes total soak time; application of 0.1% riboflavin preparation (VibeX Rapid - www.avedro.com) each 2 minutes with gentle balanced salt solution irrigation to remove excess riboflavin prior to UV light exposure. UV light exposure: Total treatment time 8 minutes (370nm wavelength; 30mW/cm2 irradiance; 4 minutes total UV exposure time, pulsed 1.5 seconds on 1.5 seconds off; Avedro KXL I light source) | Corneal collagen cross-linking (CXL), manual corneal epithelial removal, no excimer laser treatment CXL protocol was identical in both study arms. After corneal epithelial removal, a 10 minute soak with Vibex rapid (www.avedro.com) was followed by 8 minutes pulsed UV light using a uniform beam source (KXL - www.avedro.com) and a 1.5 second on/off cycle (7.2mJ/cm2 total energy @ 30mW/cm2 irradiance). | Total of all reporting groups |
| Overall Participants | 47 | 47 | 94 |
| Age (years) [Mean (Standard Deviation) ] | |||
| Mean (Standard Deviation) [years] |
24.6
(3.8)
|
24.3
(4.3)
|
24.5
(4.1)
|
| Sex: Female, Male (Count of Participants) | |||
| Female |
14
29.8%
|
16
34%
|
30
31.9%
|
| Male |
33
70.2%
|
31
66%
|
64
68.1%
|
| Region of Enrollment (participants) [Number] | |||
| United Kingdom |
47
100%
|
47
100%
|
94
100%
|
Outcome Measures
| Title | Change in LogMAR Corrected Distance Visual Acuity (CDVA) |
|---|---|
| Description | Change in spectacle corrected logarithm minimum angle of resolution (LogMAR) distance visual acuity recorded in a 4m testing lane in photopic lighting conditions between baseline measurement and final review at 24 months (note that negative change = better vision; 0.1 logMAR units = 1 line on the test chart) |
| Time Frame | Preoperative vs 24 months |
Outcome Measure Data
| Analysis Population Description |
|---|
| [Not Specified] |
| Arm/Group Title | TransPRKCXL | CXL Only |
|---|---|---|
| Arm/Group Description | Simultaneous combined transepithelial photorefractive keratectomy (TransPRK) and corneal collagen cross-linking (CXL) Transepithelial Photorefractive Keratectomy (TransPRK): Aberrometry or topography guided transepithelial photorefractive keratectomy (TransPRK) using the Schwind Amaris 750s excimer laser (www.eye-tech-solutions.com), an 8mm treatment diameter, and a tissue saving algorithm targeting selected higher order aberrations only. TransPRK will be followed immediately by corneal collagen cross-linking (CXL). Corneal Collagen Cross-Linking (CXL): Riboflavin soak: 10 minutes total soak time; application of 0.1% riboflavin preparation (VibeX Rapid - www.avedro.com) each 2 minutes with gentle balanced salt solution irrigation to remove excess riboflavin prior to UV light exposure. UV light exposure: Total treatment time 8 minutes (370nm wavelength; 30mW/cm2 irradiance; 4 minutes total UV exposure time, pulsed 1.5 seconds on 1.5 seconds off; Avedro KXL I light source) | CXL only (no PRK) using manual corneal epithelial removal and the same accelerated pulsed protocol as used in the TransPRK group |
| Measure Participants | 40 | 47 |
| Mean (Standard Deviation) [LogMAR CDVA] |
-0.13
(0.2)
|
-0.05
(0.13)
|
Statistical Analysis 1
| Statistical Analysis Overview | Comparison Group Selection | TransPRKCXL, CXL Only |
|---|---|---|
| Comments | Null hypothesis = TransPRK produced no gains in vision over and above those produced by CXL only | |
| Type of Statistical Test | Superiority | |
| Comments | ||
| Statistical Test of Hypothesis | p-Value | 0.03 |
| Comments | ||
| Method | t-test, 2 sided | |
| Comments | ||
| Title | Clinically Significant Visual Gain |
|---|---|
| Description | Number of participants with gain of ≥2 lines (≥0.20 logMAR units) corrected distance visual acuity (CDVA) on a standard 5 letter per line EDTRS visual acuity testing chart |
| Time Frame | Preoperative vs 24 months postoperative |
Outcome Measure Data
| Analysis Population Description |
|---|
| [Not Specified] |
| Arm/Group Title | TransPRKCXL | CXL Only |
|---|---|---|
| Arm/Group Description | Simultaneous combined transepithelial photorefractive keratectomy (TransPRK) and corneal collagen cross-linking (CXL) Transepithelial Photorefractive Keratectomy (TransPRK): Aberrometry or topography guided transepithelial photorefractive keratectomy (TransPRK) using the Schwind Amaris 750s excimer laser (www.eye-tech-solutions.com), an 8mm treatment diameter, and a tissue saving algorithm targeting selected higher order aberrations only. TransPRK will be followed immediately by corneal collagen cross-linking (CXL). Corneal Collagen Cross-Linking (CXL): Riboflavin soak: 10 minutes total soak time; application of 0.1% riboflavin preparation (VibeX Rapid - www.avedro.com) each 2 minutes with gentle balanced salt solution irrigation to remove excess riboflavin prior to UV light exposure. UV light exposure: Total treatment time 8 minutes (370nm wavelength; 30mW/cm2 irradiance; 4 minutes total UV exposure time, pulsed 1.5 seconds on 1.5 seconds off; Avedro KXL I light source) | Corneal collagen cross-linking (CXL), manual corneal epithelial removal, no excimer laser treatment CXL protocol was identical in both study arms. After corneal epithelial removal, a 10 minute soak with Vibex rapid (www.avedro.com) was followed by 8 minutes pulsed UV light using a uniform beam source (KXL - www.avedro.com) and a 1.5 second on/off cycle (7.2mJ/cm2 total energy @ 30mW/cm2 irradiance). |
| Measure Participants | 40 | 47 |
| Count of Participants [Participants] |
12
25.5%
|
3
6.4%
|
Statistical Analysis 1
| Statistical Analysis Overview | Comparison Group Selection | TransPRKCXL, CXL Only |
|---|---|---|
| Comments | Null hypothesis = an equal proportion of patients in both study arms have clinically significant visual gains | |
| Type of Statistical Test | Superiority | |
| Comments | ||
| Statistical Test of Hypothesis | p-Value | 0.005 |
| Comments | ||
| Method | Chi-squared | |
| Comments | ||
| Title | Clinically Significant Visual Loss |
|---|---|
| Description | Number of participants with loss of ≥2 lines (≥0.20 LogMAR units) corrected distance visual acuity (CDVA) |
| Time Frame | preoperative vs 24 months postoperative |
Outcome Measure Data
| Analysis Population Description |
|---|
| [Not Specified] |
| Arm/Group Title | TransPRKCXL | CXL Only |
|---|---|---|
| Arm/Group Description | Simultaneous combined transepithelial photorefractive keratectomy (TransPRK) and corneal collagen cross-linking (CXL) Transepithelial Photorefractive Keratectomy (TransPRK): Aberrometry or topography guided transepithelial photorefractive keratectomy (TransPRK) using the Schwind Amaris 750s excimer laser (www.eye-tech-solutions.com), an 8mm treatment diameter, and a tissue saving algorithm targeting selected higher order aberrations only. TransPRK will be followed immediately by corneal collagen cross-linking (CXL). Corneal Collagen Cross-Linking (CXL): Riboflavin soak: 10 minutes total soak time; application of 0.1% riboflavin preparation (VibeX Rapid - www.avedro.com) each 2 minutes with gentle balanced salt solution irrigation to remove excess riboflavin prior to UV light exposure. UV light exposure: Total treatment time 8 minutes (370nm wavelength; 30mW/cm2 irradiance; 4 minutes total UV exposure time, pulsed 1.5 seconds on 1.5 seconds off; Avedro KXL I light source) | Corneal collagen cross-linking (CXL), manual corneal epithelial removal, no excimer laser treatment CXL protocol was identical in both study arms. After corneal epithelial removal, a 10 minute soak with Vibex rapid (www.avedro.com) was followed by 8 minutes pulsed UV light using a uniform beam source (KXL - www.avedro.com) and a 1.5 second on/off cycle (7.2mJ/cm2 total energy @ 30mW/cm2 irradiance). |
| Measure Participants | 40 | 47 |
| Count of Participants [Participants] |
1
2.1%
|
2
4.3%
|
Statistical Analysis 1
| Statistical Analysis Overview | Comparison Group Selection | TransPRKCXL, CXL Only |
|---|---|---|
| Comments | null hypothesis = rates of clinically significant visual loss are equal for TransPRKCXL and CXL only | |
| Type of Statistical Test | Non-Inferiority | |
| Comments | Non-inferiority = no significant difference between rates of clinically significant visual loss between groups at the p≤0.05 level | |
| Statistical Test of Hypothesis | p-Value | 0.13 |
| Comments | ||
| Method | Chi-squared | |
| Comments | ||
| Title | Change in Kmax - Maximum Local Anterior Corneal Surface Curvature on Tomography Map |
|---|---|
| Description | Pentacam (www.oculus.de) measure: Maximum local curvature (Kmax). Reduction in dioptric value = corneal flattening |
| Time Frame | Preoperative vs 24 months postoperative |
Outcome Measure Data
| Analysis Population Description |
|---|
| [Not Specified] |
| Arm/Group Title | TransPRKCXL | CXL Only |
|---|---|---|
| Arm/Group Description | Simultaneous combined transepithelial photorefractive keratectomy (TransPRK) and corneal collagen cross-linking (CXL) Transepithelial Photorefractive Keratectomy (TransPRK): Aberrometry or topography guided transepithelial photorefractive keratectomy (TransPRK) using the Schwind Amaris 750s excimer laser (www.eye-tech-solutions.com), an 8mm treatment diameter, and a tissue saving algorithm targeting selected higher order aberrations only. TransPRK will be followed immediately by corneal collagen cross-linking (CXL). Corneal Collagen Cross-Linking (CXL): Riboflavin soak: 10 minutes total soak time; application of 0.1% riboflavin preparation (VibeX Rapid - www.avedro.com) each 2 minutes with gentle balanced salt solution irrigation to remove excess riboflavin prior to UV light exposure. UV light exposure: Total treatment time 8 minutes (370nm wavelength; 30mW/cm2 irradiance; 4 minutes total UV exposure time, pulsed 1.5 seconds on 1.5 seconds off; Avedro KXL I light source) | Corneal collagen cross-linking (CXL), manual corneal epithelial removal, no excimer laser treatment CXL protocol was identical in both study arms. After corneal epithelial removal, a 10 minute soak with Vibex rapid (www.avedro.com) was followed by 8 minutes pulsed UV light using a uniform beam source (KXL - www.avedro.com) and a 1.5 second on/off cycle (7.2mJ/cm2 total energy @ 30mW/cm2 irradiance). |
| Measure Participants | 40 | 47 |
| Mean (Standard Deviation) [Dioptres] |
-5.5
(2.6)
|
-0.54
(1.6)
|
| Title | Progression Rate |
|---|---|
| Description | The number of participants with possible keratoconus disease progression after treatment defined by a ≥1.5D increase in Kmax, anterior and posterior K2 (maximum local corneal curvature, maximum anterior and posterior meridional corneal curvature) measured using a Pentacam HD corneal tomographer (www.oculus.de). |
| Time Frame | 6 months postoperative - 24 months postoperative |
Outcome Measure Data
| Analysis Population Description |
|---|
| [Not Specified] |
| Arm/Group Title | TransPRKCXL | CXL Only |
|---|---|---|
| Arm/Group Description | Simultaneous combined transepithelial photorefractive keratectomy (TransPRK) and corneal collagen cross-linking (CXL) Transepithelial Photorefractive Keratectomy (TransPRK): Aberrometry or topography guided transepithelial photorefractive keratectomy (TransPRK) using the Schwind Amaris 750s excimer laser (www.eye-tech-solutions.com), an 8mm treatment diameter, and a tissue saving algorithm targeting selected higher order aberrations only. TransPRK will be followed immediately by corneal collagen cross-linking (CXL). Corneal Collagen Cross-Linking (CXL): Riboflavin soak: 10 minutes total soak time; application of 0.1% riboflavin preparation (VibeX Rapid - www.avedro.com) each 2 minutes with gentle balanced salt solution irrigation to remove excess riboflavin prior to UV light exposure. UV light exposure: Total treatment time 8 minutes (370nm wavelength; 30mW/cm2 irradiance; 4 minutes total UV exposure time, pulsed 1.5 seconds on 1.5 seconds off; Avedro KXL I light source) | Corneal collagen cross-linking (CXL), manual corneal epithelial removal, no excimer laser treatment CXL protocol was identical in both study arms. After corneal epithelial removal, a 10 minute soak with Vibex rapid (www.avedro.com) was followed by 8 minutes pulsed UV light using a uniform beam source (KXL - www.avedro.com) and a 1.5 second on/off cycle (7.2mJ/cm2 total energy @ 30mW/cm2 irradiance). |
| Measure Participants | 39 | 37 |
| Count of Participants [Participants] |
3
6.4%
|
3
6.4%
|
Adverse Events
| Time Frame | 2 years following the intervention | |||
|---|---|---|---|---|
| Adverse Event Reporting Description | ||||
| Arm/Group Title | TransPRKCXL | CXL Only | ||
| Arm/Group Description | Simultaneous combined transepithelial photorefractive keratectomy (TransPRK) and corneal collagen cross-linking (CXL) Transepithelial Photorefractive Keratectomy (TransPRK): Aberrometry or topography guided transepithelial photorefractive keratectomy (TransPRK) using the Schwind Amaris 750s excimer laser (www.eye-tech-solutions.com), an 8mm treatment diameter, and a tissue saving algorithm targeting selected higher order aberrations only. TransPRK will be followed immediately by corneal collagen cross-linking (CXL). Corneal Collagen Cross-Linking (CXL): Riboflavin soak: 10 minutes total soak time; application of 0.1% riboflavin preparation (VibeX Rapid - www.avedro.com) each 2 minutes with gentle balanced salt solution irrigation to remove excess riboflavin prior to UV light exposure. UV light exposure: Total treatment time 8 minutes (370nm wavelength; 30mW/cm2 irradiance; 4 minutes total UV exposure time, pulsed 1.5 seconds on 1.5 seconds off; Avedro KXL I light source) | Standard accelerated corneal collagen cross-linking (historical controls) Corneal Collagen Cross-Linking (CXL): Riboflavin soak: 10 minutes total soak time; application of 0.1% riboflavin preparation (VibeX Rapid - www.avedro.com) each 2 minutes with gentle balanced salt solution irrigation to remove excess riboflavin prior to UV light exposure. UV light exposure: Total treatment time 8 minutes (370nm wavelength; 30mW/cm2 irradiance; 4 minutes total UV exposure time, pulsed 1.5 seconds on 1.5 seconds off; Avedro KXL I light source) | ||
All Cause Mortality |
||||
| TransPRKCXL | CXL Only | |||
| Affected / at Risk (%) | # Events | Affected / at Risk (%) | # Events | |
| Total | 0/47 (0%) | 0/47 (0%) | ||
Serious Adverse Events |
||||
| TransPRKCXL | CXL Only | |||
| Affected / at Risk (%) | # Events | Affected / at Risk (%) | # Events | |
| Total | 0/47 (0%) | 0/47 (0%) | ||
Other (Not Including Serious) Adverse Events |
||||
| TransPRKCXL | CXL Only | |||
| Affected / at Risk (%) | # Events | Affected / at Risk (%) | # Events | |
| Total | 1/47 (2.1%) | 0/47 (0%) | ||
| Eye disorders | ||||
| Corneal Infection | 1/47 (2.1%) | 1 | 0/47 (0%) | 0 |
Limitations/Caveats
More Information
Certain Agreements
All Principal Investigators ARE employed by the organization sponsoring the study.
There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.
Results Point of Contact
| Name/Title | Mr Bruce Allan |
|---|---|
| Organization | Moorfields Eye Hospital NHS Foundation Trust |
| Phone | 02075662320 |
| bruce.allan@ucl.ac.uk |
- ALLB1018