Trial Outcomes & Findings for Simultaneous TransPRK and Corneal Collagen Cross-Linking (NCT NCT02208089)
NCT ID: NCT02208089
Last Updated: 2019-02-08
Results Overview
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)
Recruitment status
COMPLETED
Study phase
NA
Target enrollment
55 participants
Primary outcome timeframe
Preoperative vs 24 months
Results posted on
2019-02-08
Participant Flow
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.
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
Participant milestones
| Measure |
TransPRKCXL
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
Patients treated with standard accelerated corneal collagen cross-linking (historical controls)
|
|---|---|---|
|
Overall Study
STARTED
|
47
|
47
|
|
Overall Study
COMPLETED
|
40
|
47
|
|
Overall Study
NOT COMPLETED
|
7
|
0
|
Reasons for withdrawal
| Measure |
TransPRKCXL
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
Patients treated with standard accelerated corneal collagen cross-linking (historical controls)
|
|---|---|---|
|
Overall Study
Withdrawal by Subject
|
1
|
0
|
|
Overall Study
Lost to Follow-up
|
6
|
0
|
Baseline Characteristics
Simultaneous TransPRK and Corneal Collagen Cross-Linking
Baseline characteristics by cohort
| Measure |
TransPRKCXL
n=47 Participants
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
n=47 Participants
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
n=94 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Continuous
|
24.6 years
STANDARD_DEVIATION 3.8 • n=5 Participants
|
24.3 years
STANDARD_DEVIATION 4.3 • n=7 Participants
|
24.5 years
STANDARD_DEVIATION 4.1 • n=5 Participants
|
|
Sex: Female, Male
Female
|
14 Participants
n=5 Participants
|
16 Participants
n=7 Participants
|
30 Participants
n=5 Participants
|
|
Sex: Female, Male
Male
|
33 Participants
n=5 Participants
|
31 Participants
n=7 Participants
|
64 Participants
n=5 Participants
|
|
Region of Enrollment
United Kingdom
|
47 participants
n=5 Participants
|
47 participants
n=7 Participants
|
94 participants
n=5 Participants
|
PRIMARY outcome
Timeframe: Preoperative vs 24 monthsChange 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)
Outcome measures
| Measure |
TransPRKCXL
n=40 Participants
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
n=47 Participants
CXL only (no PRK) using manual corneal epithelial removal and the same accelerated pulsed protocol as used in the TransPRK group
|
|---|---|---|
|
Change in LogMAR Corrected Distance Visual Acuity (CDVA)
|
-0.13 LogMAR CDVA
Standard Deviation 0.2
|
-0.05 LogMAR CDVA
Standard Deviation 0.13
|
SECONDARY outcome
Timeframe: Preoperative vs 24 months postoperativeNumber 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
Outcome measures
| Measure |
TransPRKCXL
n=40 Participants
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
n=47 Participants
CXL only (no PRK) using manual corneal epithelial removal and the same accelerated pulsed protocol as used in the TransPRK group
|
|---|---|---|
|
Clinically Significant Visual Gain
|
12 Participants
|
3 Participants
|
SECONDARY outcome
Timeframe: preoperative vs 24 months postoperativeNumber of participants with loss of ≥2 lines (≥0.20 LogMAR units) corrected distance visual acuity (CDVA)
Outcome measures
| Measure |
TransPRKCXL
n=40 Participants
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
n=47 Participants
CXL only (no PRK) using manual corneal epithelial removal and the same accelerated pulsed protocol as used in the TransPRK group
|
|---|---|---|
|
Clinically Significant Visual Loss
|
1 Participants
|
2 Participants
|
SECONDARY outcome
Timeframe: Preoperative vs 24 months postoperativePentacam (www.oculus.de) measure: Maximum local curvature (Kmax). Reduction in dioptric value = corneal flattening
Outcome measures
| Measure |
TransPRKCXL
n=40 Participants
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
n=47 Participants
CXL only (no PRK) using manual corneal epithelial removal and the same accelerated pulsed protocol as used in the TransPRK group
|
|---|---|---|
|
Change in Kmax - Maximum Local Anterior Corneal Surface Curvature on Tomography Map
|
-5.5 Dioptres
Standard Deviation 2.6
|
-0.54 Dioptres
Standard Deviation 1.6
|
SECONDARY outcome
Timeframe: 6 months postoperative - 24 months postoperativeThe 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).
Outcome measures
| Measure |
TransPRKCXL
n=39 Participants
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
n=37 Participants
CXL only (no PRK) using manual corneal epithelial removal and the same accelerated pulsed protocol as used in the TransPRK group
|
|---|---|---|
|
Progression Rate
|
3 Participants
|
3 Participants
|
Adverse Events
TransPRKCXL
Serious events: 0 serious events
Other events: 1 other events
Deaths: 0 deaths
CXL Only
Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths
Serious adverse events
Adverse event data not reported
Other adverse events
| Measure |
TransPRKCXL
n=47 participants at risk
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
n=47 participants at risk
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)
|
|---|---|---|
|
Eye disorders
Corneal Infection
|
2.1%
1/47 • Number of events 1 • 2 years following the intervention
|
0.00%
0/47 • 2 years following the intervention
|
Additional Information
Mr Bruce Allan
Moorfields Eye Hospital NHS Foundation Trust
Phone: 02075662320
Email: [email protected]
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place