Clinical trial NCT01143389
Conditions: Keratoconus Post-Refractive Ectasia
Keywords: Keratoconus Ectasia cross linking collagen cross linking
Sponsor: Price Vision Group
Start date: 2010-05-01; Completion date: 2017-08-30
Enrollment: 510 participants; Allocation: RANDOMIZED; Intervention model: PARALLEL

Brief summary:
The purpose of this study is to evaluate the effectiveness of using riboflavin and UV light to treat progressive keratoconus or post-refractive corneal ectasia.

Detailed description:
The primary objective of this study is to evaluate two riboflavin-dosing regimens for corneal collagen cross-linking to slow the progressive changes in corneal curvature in eyes with progressive keratoconus or post-refractive ectasia.

Arms: arm 1: The eye will be irradiated for 30 minutes with UVX light, during which time instillation of riboflavin will continue (1 drop every 5 minutes for this arm). arm 2: The eye will be irradiated for 30 minutes with UVX light, during which time instillation of riboflavin will continue (1 drop every 2 minutes for this arm).
Interventions: intervention 1: Riboflavin intervention 2: UVX light
Intervention descriptions: intervention 1: Riboflavin 0.1% eye drops are applied before and during irradiation of the cornea. intervention 2: UVX 365 nm wavelength light source is applied with continued application of riboflavin.

Protocol documents:
SAP_002.pdf: 
Version 2 
 
9/12/17 
Statistical Analysis Plan 
 
Study Title: Evaluation of two Riboflavin Dosing Regimens for Corneal Collagen 
Cross-Linking in Eyes with Progressive Keratoconus or Ectasia 
Study Number: 2010-0243 
NCT01143389  
Version 2, Sept 12, 2017 


Version 2 
 
9/12/17 
Main Outcome Measure 
The main efficacy outcome is the change in maximum keratometry (assessed by corneal tomography) 
from baseline to the 6-month post-treatment examination. This will be assessed for the per-protocol 
population as well as the intent-to-treat (randomized) population.  The last-observation-carried-forward 
method will be used to impute missing data for participants lost to follow-up in the intent-to-treat 
analysis.   
Null and Research Hypotheses 
The null hypothesis is that the 2 riboflavin dosing frequencies do not produce equivalent results and the 
research hypothesis is that they do produce equivalent results. Equivalence will be assessed with a 2 
one-sided test at the 0.05 significance level.  A clinically relevant margin of equivalence is considered to 
be ± 0.75 D. Enrollment of 510 patients will provide 80% power to determine whether the 2 treatment 
arms are equivalent within this margin of equivalence, assuming a mean change in maximum 
keratometry of -1.0 D in each group, a standard deviation of 2.7, and 10% loss to follow up during the 6-
month follow up period.  
Secondary Efficacy Outcomes 
The secondary efficacy outcome measures are the changes from baseline to 6 months after treatment in 
corrected distance visual acuity, uncorrected distance visual acuity, and minimum corneal thickness 
assessed by corneal tomography. The visual acuities will be measured with Snellen charts and converted 
to the logarithm of the minimum angle of resolution (logMAR) for statistical analysis. A 2-sided, 2-
sample t test will be run for the per-protocol population at a 0.05 significance level. 
Safety Analysis 
The safety analysis will tabulate adverse events for all treated eyes (both study eyes and fellow eyes).  
Exploratory Analysis 
The protocol specifies randomization of one eye per subject to 2- or 5-minute riboflavin dosing. Study 
subjects may elect to have the fellow eye treated with 5-minute riboflavin dosing. An exploratory 
analysis will be run to examine the variability and confidence intervals for the mean paired difference 
between fellow eyes treated with the same or differing riboflavin dosing intervals (paired t test) with 
regard to the main outcome. 
 

Prot_000.pdf: 
CONFIDENTIAL 
 
 
 
 
Evaluation of two Riboflavin Dosing Regimens for Corneal 
Collagen Cross-Linking in Eyes with Progressive Keratoconus 
or Ectasia 
 
Protocol 2010-0243, Version: 15  
                          Protocol Date:  September 16, 2016 
 
 
 
 
PHYSICIAN SPONSOR: 
Francis W. Price, Jr. MD  
 
 
 
 
 
 
 
 
 
 
 
 
 


 
2 
 
 
Background 
 
This clinical protocol is designed to evaluate two riboflavin-dosing regimens for 
treatment of patients with progressive keratoconus or corneal ectasia using investigational 
technology that increases the cross linking of the corneal stroma using the photochemical 
interaction of UVA light with the chromophore riboflavin.  
 
In this treatment, the corneal stroma is saturated with riboflavin by irrigating the surface 
after removal of the corneal epithelium.  The riboflavin-saturated cornea is then exposed 
to a uniform field of UVA light with a narrow bandwidth centered at 365 nm.  The light 
is generated by an IROC UV-X irradiation system that creates a uniform 11 mm circle of 
UVA light. The device has a timer that allows a precise 30-minute exposure of the 
corneal tissues.  The irradiation field of the UVX system produces UVA light with a 
uniform irradiance of 3 mj/cm2 at the corneal surface.       
 
The FDA has classified this technology as a combination product with two components.  
First is the UV-X light source, which has an LED source and is calibrated and rendered 
uniform by the use of an optical homogenizer.  The second component is a riboflavin 
ophthalmic solution.  This solution is used to saturate the corneal stroma prior to its 
photochemical activation.  
 
 This combination product has been studied in a FDA-approved, randomized, placebo-
controlled, multi-center trial that has enrolled patients.  Financial problems led to 
suspension of this trial (IND 77882).  In addition, the system has been the subject of a 
prospective double blind study in Australia and the preliminary report on the first 66 
randomized eyes indicated stabilization of the cornea after the treatment.1 
 
Additional published literature has reported on extended clinical follow up of up to 6 
years on 241 eyes.2 These reports supply compelling evidence that this technology 
stabilizes the corneal structure, prevents further degradation of the corneal topography 
and improved visual function in some percentage of patients. 
 
The clinical conditions to be treated in this protocol are characterized by a bulging or 
ectasia of the anterior corneal surface.  The most common of these progressive conditions 
are keratoconus, post-LASIK ectasia, and pellucid marginal degeneration.  Keratoconus 
and pellucid marginal degenerations are genetically based ocular conditions and post-
surgical ectasia is an iatrogenic condition.  All three of these syndromes are characterized 
by a weakening of the corneal stroma that produces progressive thinning and steepening 
of the central and inferior cornea.  This distortion of the essential anterior optical element 
of the eye results in increasing steepening and unevenness of the optical surface.  This 
produces a progressive myopia and progressive irregular astigmatism.  The irregular 
astigmatism produces an attendant loss of vision when using spectacles.  The next step in 
the management of these patients when spectacles are no longer effective is to use rigid 
contact lenses to create an artificial anterior corneal surface, a step that improves visual 
acuity in many patients.  Eventually, contact lenses fail because they cannot be tolerated, 


 
3 
 
or the surface irregularity has become so severe that the contact lenses are rejected and 
fall off the eye.  At this stage there is usually thinning and opacification within the 
cornea. The only treatment that has been shown to stabilize the cornea has been 
augmentation of the corneal strength by photochemically inducing cross linking. This 
technique has been studied over a ten-year period and is widely used throughout the 
world.   
 
Together, keratoconus and post-refractive corneal ectasia are the second most frequent 
indication for corneal transplantation and accounted for 21% of the transplanted corneas 
supplied by the Eye Bank Association of America in 2008 (2008 Eye Banking Statistical 
Report, available at www.restoresight.org).  Corneal transplantation has inherent risks 
that could result in permanent loss of vision and significantly impact the patient’s quality 
of life during the surgical recovery phase, with lost work time, and often permanent 
changes in lifestyle.  Moreover, corneal transplantation permanently weakens the eye 
leading to a lifetime of increased risk of perforation from minor trauma and loss of the 
eye.3 Some patients also require prolonged, even lifetime use of topical corticosteroids to 
prevent immunologic graft rejections. Long term topical corticosteroids can lead to 
increased intra-ocular pressure in at least a third of eyes and can lead to the need of 
glaucoma surgery to control intra-ocular pressure.4 Filtration surgery, and to a lesser 
degree, the use of topical glaucoma medications appear to increase the risk of graft 
failure and immunologic graft reactions. African-Americans in particular, may be at 
increased risk of immunologic graft reactions based on the rejection rate encountered in a 
variation of corneal transplantation, Descemet’s stripping and endothelial keratoplasty 
where just the endothelium and posterior stromal tissue are transplanted.5 Clearly, any 
modality that can delay or prevent corneal transplantation in these patients is of great 
benefit.  The evidence seems compelling that photochemically increased cross linking is 
the sole and unique treatment for these conditions.   
 
Because this treatment is unique, many of our patients have been so desperate to mitigate 
their disease that a significant number of patients with progressive keratoconus and post-
refractive ectasia have traveled to Europe or Canada to have this corneal collagen cross-
linking procedure performed.  They are subjectively aware that the disease has 
progressed and seek the treatment in an effort to avoid or delay corneal transplantation.  
This international treatment is not an entirely satisfactory solution to their problem.  In 
addition there is a great expense involving travel, professional fees, increased risk, and 
the necessity to arrange follow by a local ophthalmologist. 
 
Based on the available data, corneal collagen cross-linking offers the only alternative to 
the relentless progression of optical degradation that leads to vision loss and surgical 
corneal transplantation.  The practice of having treatment overseas is not ideal.  While the 
patient’s immediate needs are met, their follow up is uneven and there is no attempt to 
capture the clinical data associated with their case.   
We are experienced in the use of this technology, as we have been a part of the multi-
center placebo-controlled trial.  Furthermore, we are conducting an independent 
investigator-sponsored investigational plan for this technology that is being used to study 
the effect of this photochemical interaction on corneal infections (IND 104,456).  Our 


 
4 
 
center is unique in that we perform approximately 1% of all corneal transplants in the 
United States, and many keratoconus patients are referred to our busy tertiary referral 
center for treatment. 
Rationale 
Previous studies of corneal collagen cross-linking have employed riboflavin dosing 
regimens of 2 to 5 minutes. However, none have investigated whether the specific dosing 
regimen affects the efficacy or safety of the treatment.  With each application, the  
riboflavin ophthalmic solution coats the corneal surface with a thick layer that absorbs 
much of the incident UVA light. With increasing length of time between subsequent 
doses, this layer thins from evaporation. This may affect the effective depth of the 
treatment. This study is a prospective randomized study to evaluate potential dosing 
effects. 
Clinical Experience 
 
UVA/riboflavin corneal collagen cross-linking was first used clinically in 1998.6  (Unless 
specified otherwise, the treatments referenced below all used UVA light (365-370 nm, 3 
mw/cm2, 30 minutes) with photosensitizing riboflavin 0.1% (10 mg in 10 ml dextran-T-
500 20% solution) applied after a central corneal abrasion, beginning at least 5 minutes 
before irradiation and continuing every 2-5 minutes during irradiation.) 
 
Wollensak et al. treated 23 eyes of 22 patients to evaluate the effect of cross-linking on 
patients with moderate or advanced keratoconus. The mean preoperative maximum K-
value (Kmax) was 50.93 D, and the mean preoperative progression of Kmax was 1.42 D 
(±1.18 D) in the before cross-linking.  After cross-linking, there was a mean decrease in 
Kmax of 2.01 D (p=0.001) with follow-up of 3 to 47 months (mean 23.2 ±12.9 months).  
In five of the untreated contralateral eye controls, the mean Kmax progressed an average 
of 1.48 D in the first year after cross-linking was performed in the contralateral eyes.  
Best spectacle corrected visual acuity (BSCVA) improved by an average of 1.26 lines 
(p=0.026) and manifest refraction spherical equivalent (MRSE) improved by an average 
of 1.14 D (p=0.03) in the treated eyes.  No adverse events occurred.  The postoperative 
healing process was unremarkable except for slight transient stromal edema during the 
first 3 postoperative days.  Corneal and lens transparency, intraocular pressure (IOP), and 
endothelial cell density (p=0.45) were unchanged after treatment compared to baseline.  
 
Similarly, Caporossi et al. reported a 3.6 line increase in uncorrected visual acuity 
(UCVA), a 1.66 line improvement in BSCVA, a mean reduction in Kmax of 2.1 D 
(±0.13), and a 2.5 D reduction in MRSE at 3 months after cross-linking in a series of 10 
eyes in 10 patients with progressive keratoconus.7  There were no changes in endothelial 
cell density or IOP. 
 
Patients treated in an ongoing clinical study at the University of Dresden (Dresden, 
Germany), have experienced outcomes similar to those reported by Wollensak.  A 
preliminary analysis of the Dresden keratometry data shows a 1.25 D reduction in 


 
5 
 
maximum corneal curvature (K-max) in those eyes that have reached the 6-month 
evaluation timepoint.  Progressively increasing corneal curvature is a hallmark of 
keratoconus and corneal ectasia.  Based on the preliminary analysis of the Dresden data, 
corneal curvature progression is halted in this series of patients.  The effect is significant 
through 5 years after the CCCL treatment and the trend continues to be observed as long 
as 7 years after cross-linking. 
 
Table:  Change in Maximum Corneal Curvature (K-Max) in Eyes treated with CCCL 
Time 
N 
Baseline 
Mean K-Max 
(diopters) 
Post-CCCL 
Mean K-Max 
(diopters) 
Difference in 
K-Max 
(diopters) 
K- Max Percent 
Difference 
(%) 
K-Max 
Difference 
(p<0.05) 
K-Max 
% 
Difference 
(p<0.05) 
Baseline 365 
53.6044 
 
 
 
. 
. 
6 
Months 
196 
53.9003 
52.6523 
-1.24801 
-1.83121 
0.001013 
0.002256 
1 Year 136 
53.7790 
52.3346 
-1.44449 
-2.35446 
0.000025 
0.000039 
2 Years 
60 
54.0197 
52.4340 
-1.58567 
-2.52731 
0.001214 
0.001250 
4 Years 
30 
53.4627 
50.7030 
-2.75967 
-4.58245 
0.000396 
0.000342 
5 Years 
13 
52.2777 
50.0723 
-2.20538 
-3.78418 
0.020667 
0.019656 
6 Years 
5 
50.6400 
48.1740 
-2.46600 
-4.81223 
0.064549 
0.067719 
7 Years 
4 
52.3825 
49.4500 
-2.93250 
-5.48322 
0.057697 
0.056259 
8 Years 
1 
47.3400 
47.1400 
-0.20000 
-0.42248 
. 
. 
Kohlhaas presented results for 127 of these eyes at the 2005 Congress of the German-
Language Society for Intrakularlinsen Implantation and Refraktive Surgery with a 
follow-up of up to 60 months.  Progression of keratoconus was stopped in all the eyes, 
and 81.7% of them showed a mean decrease of 2.87 D in Kmax.  No opacification of the 
lens or change in endothelial cell density was seen in any patient.  Long term follow-up 
results in a subset of 60 eyes in the Dresden Clinical Study that underwent cross-linking 
3-5 years ago confirm the lasting effects of cross-linking in that there has been no 
progression of keratoconus in any of the eyes and 51.2% (31/60) of the eyes have a slight 
reversal and flattening of the Kmax. Kohlhaas et al. also reported a patient who 
developed bilateral keratectasia at 4 weeks after LASIK and underwent UVA/riboflavin 
cross-linking 6 months later. In this case, corneal topography remained stable for 18 
months after cross-linking. 
 
Sixty-six eyes in 49 patients have been enrolled in an Australian randomized study of 
observation-only control versus cross-linking in eyes with progressive keratoconus.1  
Maximum K-readings taken before and at 6 and 12 months after cross-linking showed a 
mean decrease of –0.92 diopters and -1.45 diopters in the treatment group (P=0.002).1  In 
contrast, the untreated control eyes show a statistically significant increase of 0.60 D and 
1.28 D in K-readings at 6 and 12 months after randomization.1  The treatment group also 
showed an improvement in BSCVA, while BSCVA in the control group worsened.  


 
6 
 
Similar to the Dresden experience, these data lead to the conclusion that corneal cross-
linking halts, and even reverses, the progression of keratoconus. 
 
The only adverse event reported after epithelial healing was complete has been corneal 
edema in an eye with a pretreatment corneal thickness of approximately 300 microns, 
presumably caused by UV damage to the corneal endothelium. Subsequent experiments 
led to the conservative recommendation that corneas not be treated with UVA/riboflavin 
unless they are thicker than 375 microns after epithelial debridement.  It has also been 
recommended that complete or partial epithelial removal be created prior to instillation of 
the riboflavin drops to promote penetration of the cornea by riboflavin and assure 
maximal absorption of UVA light in the anterior corneal stroma. The recommended 
epithelial debridement heals rapidly and is not affected by the cross-linking procedure.   
 
To date, there have been no known reports of cataract formation as a result of 
UVA/riboflavin treatment.  Most of the UVA light is absorbed within the first 300 
microns of the cornea. By requiring 375-micron minimum corneal thickness, we stay well 
below the cytotoxic threshold for the corneal endothelium. A study by Jacob et al has 
shown that a riboflavin-soaked non-UV-blocking soft contact lens (approximately 100 
microns thick) can be applied to the cornea when necessary to increase the minimum 
thickness.9  Any UVA not absorbed in the cornea is absorbed as soon as it enters the 
anterior chamber, which is saturated with riboflavin, which has an absorption peak at the 
exact wavelength of UVA used. Therefore we do not anticipate any significant level of 
UVA light reaching the crystalline lens. 
 
Using confocal microscopy, Mazotta et al. evaluated 10 patients treated with 
UVA/riboflavin for progressive keratoconus and found normal epithelial morphology and 
an absence of subepithelial stromal nerve fibers in the central irradiated area at 5 days 
after cross-linking.  Nerve regeneration was observed at 1 month and nerve fiber 
recolonization was complete at 6 months with restoration of corneal sensitivity.  No 
changes were observed in the peripheral untreated area at any time.  Recently, Seiler et al. 
described a thin corneal stromal demarcation line that was detectable by slit lamp 
microscopy at a depth of approximately 300 microns 2 weeks after cross-linking in 14 of 
16 eyes evaluated. This demarcation line is believed to be due to a difference in the 
refractive index or reflection properties of untreated and cross-linked corneal stroma.  
When epithelial thickness (approximately 50 microns) is taken into account, the 300 
micron demarcation line observed by Seiler et al. is consistent with the studies and 
theoretical principles that the selected parameters for UVA/riboflavin treatment produce 
maximal cross-linking to a depth of about 200 microns and that 94% of the UVA light is 
absorbed in the anterior 300 microns of corneal stroma without injury to the endothelium. 
 
The above data showing a flattening of the steepest corneal meridian is identical to the 
findings reported from the FDA approved American multi center trial as summarized in 
data shown at professional meetings. 
 


 
7 
 
Risks 
 
Riboflavin, also known as Vitamin B2, is a naturally occurring photosensitizer.  It is the 
precursor of flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), two 
coenzymes that are crucial for the metabolism of carbohydrates, fats and proteins into 
energy.  Riboflavin is an essential constituent of all living cells.  It is water-soluble and 
only a trace amount is found in the human body.  Riboflavin is non-toxic and it is used as 
a coloring agent in food and pharmaceuticals.  The intake of riboflavin from food and diet 
supplements ranges from 4 to 10 mg a day.  No adverse effects have been associated with 
high intakes of riboflavin from food or supplements.   
 
Pharmacokinetic studies have shown that the maximal amount of riboflavin that is 
absorbed after a single oral dose is 27 mg, regardless of the amount in excess of this that 
is ingested. Excess riboflavin is excreted in urine and, since it is not a fat-soluble vitamin, 
is not stored in fat or other body tissues. No upper limit for riboflavin uptake has been 
established by the Food and Nutrition Board of the Institute of Medicine of the National 
Academy of Sciences due to insufficient human and animal data. A risk assessment 
performed by the UK government has determined that a total intake of 43 mg is not 
expected to result in any adverse effects. 
 
The standard concentration of riboflavin used in the riboflavin/UVA treatment is 0.1%.  
The maximum amount of riboflavin to which a patient is exposed during treatment is 
estimated to be  1.6 mg based on the volume of one drop being 0.05 ml and 1 drop 
being instilled every 2 minutes during the 30-minute pre-treatment, and every 2 or 5 
minutes for 30 minutes during the UVA light irradiation. This amount is below the 43 mg 
“safe” limit by an order of magnitude. 
 
The potential cytotoxicity of UVA light and the UVA/riboflavin exposure on keratocytes 
and endothelial cell function have been characterized in a series of in vitro experiments. 
In each of these experiments, UVA exposure (370 nm, 30 minutes) and riboflavin 
(0.025% solution; equivalent to the corneal concentration after diffusion of a 0.1% 
solution) were administered to mimic conditions of clinical usage. Irradiance levels were 
varied to determine the irradiance threshold for cytotoxic effects. Keratocyte toxicity was 
evaluated in porcine keratocyte cell cultures after exposure to riboflavin alone, UVA light 
alone (irradiance range 2 to 9 mw/cm2), and UVA light plus riboflavin (irradiance range 
0.4 to 1 mw/cm2). Riboflavin alone had no cytotoxic effect on keratocytes.  The cytotoxic 
threshold for inducing cellular necrosis or apoptosis was 5 mw/cm2 for UVA light alone 
and 0.5 mw/cm2 for the UVA/riboflavin treatment.  Using the Lambert-Beer equation, in 
human corneas the cytotoxic keratocyte UVA irradiance of 0.5 mw/cm2 is reached at a 
stromal depth of 300 microns.  The potential for endothelial cell toxicity was evaluated 
on endothelial cell cultures obtained from porcine cornea that were exposed to riboflavin 
alone and to various UVA irradiances (range 0.1 to 1.6 mw/cm2) with and without 
riboflavin. An abrupt cytotoxic threshold was observed at an irradiance of 4 mw/cm2 for 
UVA light alone and was ten-fold lower with an irradiance threshold of 0.35 mw/cm2 for 
the UVA/riboflavin treatment.  No endothelial cell damage was observed in the cells 
treated with riboflavin alone.  Endothelial cell damage in the UVA groups is believed to 


 
8 
 
be due to oxidative damage caused by the oxygen reactive free radicals (singlet oxygen, 
superoxide anion, hydrogen peroxide) that are generated by the UV light. 
 
The lower cytotoxic thresholds observed for the UVA/riboflavin combination in the 
keratocyte and endothelial cell toxicity studies are consistent with the increase in UVA 
absorption in the presence of riboflavin. For example, 94% of incident UVA light is 
absorbed in the anterior 400 microns of the corneal stroma in the presence of riboflavin, 
as depicted in the graph at the right, whereas only 32% is absorbed within that depth in 
the absence of riboflavin.  
 
UV-X™ Illumination System 
 
The UV-X™ Illumination System is a portable electronic medical device. The device’s 
light emitting diode (LED) is used to deliver a metered dose of UV-A light to a targeted 
treatment area for illuminating the cornea during corneal collagen cross-linking.  
Components of the UV-X™ System include the LED light source, UV light detector, UV 
detector sensor probe and adapter, wall power supply with DC cord, transportation case, 
safety goggles (to be worn by user), mechanical stand (C-clamp, cross clamp, rods), and 
an instruction manual. System specifications are as follows: 
 
Light Source 
High Power UV-grade LED; LED Laser class 3R (EN 60825-1) 
(Mfg. Nichia Co. LTD; Tokyo, Japan)  
Wavelength 
365 nm (± 10 nm) 
Optical Power 
Maximum 10 mw 
Beam Diameter 
7.5 mm to 11.5 mm 
Light Emission 
Continuous wave 
Intensity Setting 
3.0 mw/cm2 (±0.3 mw/cm2) 
Safety Class 
Class II Equipment (EN 60601-1) 
Medical Device Class Class Imia according to MDD 93/42/EEC 
EMI.EMC Class 
Class B (EN 60601-1) 
Power Supply 
SELV (Safety Extra Low Voltage)   9V;   max. 1.7A 
 
The Light Source houses the UVA irradiation mechanism.  The LED is preset by the 
manufacturer to emit UVA radiation at a wavelength of 365 nm at an intensity of 
3 mw/cm2 (±0.3 mw/cm2). UVA light emission is controlled by an internal 
microprocessor, which controls the electrical current used to drive the UV-LED.  No UV 
light will be emitted in case of processor or LED failure. The diameter of the Light 
Source beam aperture is 25 mm and the treatment plane is 50 mm from the beam 
aperture. An aperture wheel mounted in the UVA irradiation beam path is used to 
produce a circular area of irradiation at the treatment plane with an approximate diameter 
of 7.5 mm, 9.5 mm or 11.5 mm, which is controlled by selecting the corresponding 
aperture wheel setting on the device. An intensity of 3 mw/cm2 and irradiance time of 30 
minutes results in a standard surface dose of 5.4 J/cm2 surface exposure. The Light 
Source has an integrated timer that automatically shuts off the light emission after 30 
minutes of exposure. A Power Supply plugged into a main electrical wall outlet and into 
the Light Source via the DC cord powers the Light Source.  The On/Off switch (On = 


 
9 
 
ready mode) powers the device; the Start/Stop button controls UVA emission; and, status 
display lights (Red- Internal error, yellow-UV emission, Green-Device is powered, but no 
UV emission) indicate the status of the UV-X™ device. A battery operated UV Light 
detector, with a built-in low battery warning, is used to check the UV light irradiation in 
the treatment plane before patient treatment.  The UV Light detector consists of a Sensor 
Probe and an indicator. The Sensor Probe Adapter with a Sensor Probe is permanently 
mounted to the UV-light illumination system to shield the beam aperture and should only 
be removed for treatment. 
Riboflavin Ophthalmic Solution  
  
The riboflavin ophthalmic solution is covered under IND (redacted).  
 
 
Objectives 
 
The primary objective of this study is to evaluate two riboflavin-dosing regimens for 
corneal collagen cross-linking to slow the progressive changes in corneal curvature in 
eyes with progressive keratoconus or post refractive ectasia.  
 
Efficacy and Safety 
 
The primary efficacy outcome measure is change in corneal curvature, as measured by 
maximum keratometry (Kmax). Secondary efficacy measurements will include: 
pachymetry, corrected distance acuity (CDA), and manifest refraction. Safety 
assessments will mean reporting any adverse events. All subjects will be evaluated at 
baseline, Day 1, Week 1 and 3 and 6 months after treatment with vision and intraocular 
pressure assessed at each visit.  
 
Ophthalmic medical records after subjects exit the study will be retrospectively reviewed 
to assess visual changes and incidence of any subsequent ocular interventions. 
 
Patient Population 
 
Six hundred patients will be enrolled in the study. 
Inclusion Criteria: 
Subjects who have one or both eyes that meet all of the following criteria will be 
considered candidates for this treatment: 
1. 10 years of age or older  
2. Having documented ectasia on topography or tomography after previous 
refractive surgery OR documented keratoconus on topography or tomography. 
Subjects > 32  years old who have not had prior refractive surgery must have a 
diagnosis of progressive keratoconus defined as one or more of the following 
changes over a period of 36 months or less before randomization: 


 
10 
 
a. An increase of ≥ 1.00 D in the steepest keratometry value (or sim K) 
b. An increase of  ≥ 1.00 D in regular astigmatism evaluated by subjective 
manifest refraction 
c. A myopic shift (decrease in the spherical equivalent) of ≥ 0.50 D on 
subjective manifest refraction 
d. Documented decrease in visual acuity associated with irregular 
astigmatism and topographic features of ectasia. 
3. Subjects with keratoconus diagnosis only:  
a. Axial topography consistent with keratoconus  
b. Presence of central or inferior steepening on the Pentacam map. 
c. Presence of one or more slit lamp findings associated with keratoconus, 
such as: 
i. Fleischer ring 
ii. Vogt striae 
iii. Corneal thinning 
iv. Corneal scarring  
4. Contact Lens Wearers Only:  Removal of contact lenses for the required period of 
time prior to the screening refraction: 
Contact Lens Type 
Minimum Discontinuation Time 
Soft 
3 Days 
Soft Extended Wear 
1 Week 
Soft Toric 
2 Weeks 
Rigid gas permeable 
2 Weeks 
 
5. Signed written informed consent 
Exclusion Criteria: 
All subjects meeting any of the following criteria will be excluded from this treatment: 
1. Any keratoconus patient over the age of 32 years without evidence of progression 
of the corneal deformity within the past 36 months. 
2. Patients with excessively thin corneas based off of Pentacam map and Optical 
coherence tomography images. 
3. Previous ocular condition in the eyes to be treated that may predispose the eye for 
future complications, for example: 
a. History of corneal disease (e.g., herpes simplex, herpes zoster keratitis, 
recurrent erosion syndrome, corneal melt, corneal dystrophy, etc.) 
b. Clinically significant corneal scarring in the proposed treatment zone 
4. A history of chemical injury or delayed epithelial healing in the eye(s) to be 
treated. 
5. A known sensitivity to treatment medications. 
6. Patients with a current condition that, in the treating physician’s opinion, would 
interfere with or prolong epithelial healing. 
7.   Pregnancy (including plan to become pregnant) or lactation during the course of 
the study 
 
Vulnerable Populations:  


 
11 
 
Non-English Speaking 
This study plans to exclude any person who does not speak English as this is an 
unfunded study and there are no available funds to provide for a translator at each 
study visit or to translate the consent form in the patient’s native language.  
 
Minors:  
If a person not of age of legal consent (18), but who is at least 10 years of age meets 
all inclusion/exclusion criteria for the study, parents will be given a copy of the 
consent form and will be given time to read it, ask any questions of the investigator 
and staff, and explain it to the underage subject. The parent will then determine 
whether the subject voluntarily decides to participate in the research.  The minor will 
sign the consent with the parent providing assent.   
 
Decisionally Impaired:  
All subjects will be evaluated for capacity to consent through the use of the Cornea 
Research Foundation of America Evaluation to Sign a Consent Form.  Any subjects 
who answer all questions satisfactorily will be permitted to provide informed consent.  
If the enrolling physician or designated staff member determines that a potential 
subject is not competent to provide a research informed consent, it will be determined 
whether or not the subject has a Legally Authorized Representative (LAR).  If the 
subject does not have a LAR, they will not be permitted to enter the study.  If the 
potential subject has a LAR, both the subject and LAR will be given a copy of the 
consent form and will be given time to read it and ask any questions of the 
investigator and staff.  The LAR will then be given time to explain it to the subject. 
The subject will sign the consent with the LAR providing assent.   
    
Pregnant Women: 
Pregnant women will not be enrolled into this study because hormonal changes 
during pregnancy can sometimes temporarily alter the shape of the cornea. 
Examination Schedule: 
The patients will be followed to 6 months.  The following examination schedule will be 
followed:  
 Preoperative (-60 to day 0; any routine exam procedures that we performed within 
60 days of study enrollment do not have to be repeated at the screening visit) 
 Operative (Day 0) 
 Day 1 (1-3 days) 
 Week 1 or duration to healing of epithelium 
 Month 3 (7 to 16 weeks) 
 Month 6 (16 to 40 weeks) 
Screening Eye Examination: 
Potential candidates will undergo a complete eye examination to determine their 
eligibility for treatment.  A complete ocular history, medical history and medication 
history will be obtained.  The complete eye examination and ocular history will include: 
 History of contact lens wear 


 
12 
 
 Family history of keratoconus 
 History of eye rubbing 
 History of refractive surgery 
 UCVA (distance) 
 BSCVA (distance) 
 Manifest refraction 
 Pentacam analysis 
 Optical coherence tomography (OCT) 
 Corneal topography 
 Intraocular pressure (by Goldmann applanation tonometry) 
 Slit lamp examination of the cornea, anterior chamber and lens 
 Dilated fundus examination 
 
Randomization 
 
Subjects will be classified as having keratoconus, post-refractive ectasia, or pellucid 
marginal degeneration. In addition those with keratoconus will be classified as mild (flat 
keratometry reading < 51.00D), moderate (flat keratometry reading of 51.25 to 56D or 
astigmatism  8D), or severe (flat keratometry reading >56D). Block randomization will 
be employed to ensure representation of each classification in both treatment groups.  If a 
subject has both eyes affected by the condition, the first eye treated will be randomized 
and the fellow eye will not.  Fellow eyes will not be included in the efficacy analysis and 
will be dosed at 5 minute intervals during irradiation. 
 
Subjects who elect to be treated will undergo the following procedure: 
Treatment: 
Subjects will be prepared for treatment in accordance with the instructions for use in the 
UV-X™ Illumination System Operator’s Manual, including the administration of the 
riboflavin and preoperative medications (e.g. topical anesthetics). 
 
Prior to the treatment, the presence of an informed consent for it will be confirmed.  
Patients will receive a therapeutic contact lens after the treatment is complete. An 
operative report or chart note will be placed in the subject’s medical records documenting 
the procedures used for each patient. Selected treatment information, including the 
riboflavin administration, irradiance settings, and duration of irradiation exposure will be 
documented. 
 
The subject will lie on a surgical table or chair with the head supported in a headrest. The 
bed will be adjusted so the subject can lie flat or recline comfortably for the duration of 
the procedure without moving.  The skin around the eye and the conjunctival surfaces 
will receive a surgical cleansing.  Topical anesthesia will be applied and a lid speculum 
will be placed between the lids of the eye to be treated.  The surgeon will remove the 
epithelium from a circular area approximately 6 mm in diameter centered on the 
maximum of the posterior float on the corneal tomography assessment performed at the 
screening visit.   Additional local anesthetics will be applied as needed. 


 
13 
 
 
After the epithelium has been removed, Riboflavin ophthalmic solution will be instilled 
topically to the stromal surface every 2 minutes for 30 minutes. The corneal thickness 
will be measured and if the minimum thickness is at least 375 microns the irradiation will 
be started. If the minimum thickness is between 275 and 375 microns, balanced salt 
solution may be applied to swell the cornea or a riboflavin-soaked non-UV-blocking soft 
contact lens (approximately 100 microns in thickness) may be applied to increase the 
minimum thickness to at least 375 microns before starting the irradiation.  
 
During irradiation, instillation of riboflavin will be continued every 2 minutes or every 5 
minutes, depending on the group to which the patient was randomized.    
 
Prior to use, the UV-X™ illumination system will be assembled and tested according to 
the manufacturer’s instructions.  The UV irradiance dose is the product of the irradiance 
intensity and the exposure time.  The intensity is a fixed parameter of the device. It is 
checked during the light test and cannot be changed by the user. 
 
The eye will be aligned under the UV-X™ light with the treatment plane at a working 
distance that is 50 mm from the UV-X™ beam aperture.  The correct aperture setting will 
be selected for the size of the eye (7.5, 9.5, or 11 mm), and the eye will be irradiated for 
30 minutes, during which time instillation of riboflavin will continue (1 drop every 2 
minutes or every 5 minutes, depending upon the randomization).  At the end of 30 
minutes, the UV light source will automatically switch to the off position.  The operator 
will keep track of irradiation time independently to confirm the actual treatment time. 
 
The eye will be examined at a slit lamp, a drop of antibiotic and a bandage contact lens 
will be placed.  The lens will be removed after the epithelial defect has closed. 
Postoperative Care 
Prescriptions for postoperative medications and written postoperative instructions will be 
given to each subject and reviewed prior to discharge. The following postoperative eye 
drops will be prescribed: 
1. 
antibiotic drops gtt 1 qid until; 24 hours after epithelialization is complete.   
2. 
Prednisolone 1% ophthalmic suspension (PredForte® or generic 
equivalent) 1 drop qid X 2 weeks 
3. 
Preservative-free artificial tears for dryness 
All postoperative eye drop usage will be recorded in the subject's chart.  Other 
prescription or nonprescription medications may be taken as needed throughout the 
treatment.  
Follow-Up Visits (1 Day, 1 Week, 3 and 6 months) 
A treatment flow chart summarizing the follow-up examination schedule and required 
procedures to be performed at each treatment visit is provided in Appendix A. All 
subjects will be seen at 1 day, 1 week, 3, and 6 months.  If a study participant is unable to 
return to the study site for the 1-week exam, they may see a local doctor and efforts will 
be made to obtain copies of this exam.   


 
14 
 
 
The following will be performed at each visit unless noted otherwise. 
 UCVA distance 
 BSCVA distance (omit on Day 1 and Week 1) 
 Manifest refraction (omit on Day 1 and Week 1) 
 Pentacam measurements (omit on Day 1 and Week 1) , including 
o Pachymetry 
o Scheimpflug photography 
 Corneal topography (omit on Day 1 and Week 1) 
 Intraocular pressure (by Goldmann applanation tonometry (omit on Day 1) 
 Slit lamp examination of the cornea, anterior chamber and lens 
 Optical coherence tomography (OCT, omit on Day 1) 
 
Reasonable effort will be made by telephone and mail to contact subjects who miss a 
scheduled follow-up visit. 
Retreatment  
Any subject who is at least 1-year post- cross-linking treatment and who shows signs of 
progression at two visits will be considered for retreatment.  Retreated eyes will not be 
included in the efficacy analysis and will be dosed at 5 minute intervals during 
irradiation. 
 
Fellow Eyes 
Patients who, at the discretion of the investigator, could benefit from the study treatment 
in both eyes may have both eyes treated; however, only the first treated eye per patient 
will be considered for the efficacy analysis. All treated eyes will be included in the safety 
analysis.  Fellow eyes can be treated on the same or a different day as the randomized 
eye; this decision will be made by the patient and the principal investigator.   
Safety Monitoring 
During the CXL treatment procedure, subjects will be observed closely to detect the 
occurrence of any adverse events or complications.  On the day of treatment and at each 
follow-up visit, the subjects will be questioned to determine whether any adverse events 
might have occurred since the last examination.  The presence or absence of adverse 
events or complications will be documented. 
 
Ophthalmic safety will be evaluated by slit lamp examination of the operated eye, 
measurements of refraction, and measurement of visual acuity.  In the case of an adverse 
event or complication, the frequency of the examinations will be increased until the 
problem is resolved.  Any complications or visual adverse events will be recorded in the 
medical record and reported to the FDA. 
UV-X and Riboflavin Accountability 
All use of the UV-X™ Illumination System and Riboflavin  Ophthalmic Solution will be 
under the direct supervision of the designated study coordinator.  The use of the 
Riboflavin solution will be maintained in a clinical treatment program log. 


 
15 
 
 
Data Analysis 
 
Statistical analyses will be performed using SAS software.  All enrolled subjects will be 
included in the safety analysis. Testing will be 2-sided and P-values < 0.05 will be 
considered significant. To preclude confounding effects between fellow eyes, only the 
first treated eye per subject will be included in the efficacy analysis.  
 
Ethical and Regulatory Considerations 
 
This treatment will be conducted in accordance with FDA’s Good Clinical Practice 
regulations.  
Informed Consent 
In accordance with the provision of 21 CFR Part 50, each subject will provide written 
informed consent for participation in this treatment prior to the use of the investigational 
device.  The treatment will be explained to the patients, or guardian, by the surgeon.  The 
alternatives to this treatment will be discussed together with the potential hazards of the 
proposed treatment. The potential patients will be informed that they are free to not treat 
their condition or to obtain treatment outside the United States.  We will emphasize the 
fact that this treatment has not been approved by the FDA, and just because their disease 
has progressed in the past does not mean that it will continue to progress. 
Institutional Review Board 
This proposal and the informed consent form will be approved initially and reviewed 
annually by the Institutional Review Board.   
Adverse Events 
For all adverse events, a description of the event, date first observed, action taken, and its 
resolution will be reported.  
Non-serious or Anticipated Drug or Device Adverse Events 
Non-serious or anticipated drug or device adverse events and complications will be 
documented on the case report forms and tabulated for reporting in the annual reports to 
FDA. 
Serious and Unanticipated Adverse Device Effects 
Any adverse experience associated with the use of the drug that is both serious and 
unexpected shall be reported to the FDA and IRB. An unanticipated adverse device effect 
is defined as “any serious adverse effect on health or safety or any life-threatening 
problem or death caused by, or associated with, a drug or device if that effect, problem, 
or death was not previously identified in nature, severity, or degree of incidence in the 
investigational plan, or any other unanticipated serious problem associated with a drug or 
device that relates to the rights, safety or welfare of subjects.” Since CDER has primary 
jurisdiction for the regulation of this combination product, serious and unanticipated 


 
16 
 
adverse device effects will be reported to FDA and the IRB in accordance with the 
reporting requirements described above.  
 
References 
 
1. Wittig-Silva C, Whiting M, Lamoure E, et al. A randomized controlled trial of corneal 
collagen cross-linking in progressive keratoconus: preliminary results. J Refract Surg 
2008;24:S720-5. 
2.  Raiskup-Wolf F, Hoyer A, Spoerl E, Pillunat LE. Collagen crosslinking with 
riboflavin and ultraviolet-A light in keratoconus: long-term results. J Cataract Refract 
Surg 2008;34:796-801. 
3.  Elder MJ, Stack RR. Globe rupture following penetrating keratoplasty: how often, 
why, and what can we do to prevent it? Cornea 2004;23(8):776-80. 
4.  Vajaranant TS, Price MO, Price FW, Gao W, Wilensky JT, Edward DP. Vision and 
Intraocular Pressure After Descemet-Stripping Endothelial Keratoplasty in Patients With 
and Without Pre-existing Glaucoma, Ophthalmology 2009;116:1644-50. 
5.  Price MO, Jordan CS, Moore G, Price FW. Graft Rejection Episodes after Descemet’s 
Stripping with Endothelial Keratoplasty: Part Two: the Statistical Analysis of Probability 
and Risk Factors. Br J Ophthalmology 2009;93:391-5. 
6.  Wollensak G, Spoerl E, Seiler T. Riboflavin/ultraviolet-A-induced collagen 
crosslinking for the treatment of keratoconus. Am J Ophthalmol 2003;135:620-7. 
7. Caporossi A, Baiocchi S, Mazzotta C, Traversi C, Caporossi T. Parasurgical therapy 
for keratoconus by riboflavin-ultraviolet type A rays induced cross-linking of corneal 
collagen: preliminary refractive results in an Italian study. J Cataract Refract Surg 
2007;33:1143-4 
8.  Mazzotta C, Traversi C, Baiocchi S, Sergio P, Caporossi T, Caporossi A. 
Conservative treatment of keratoconus by riboflavin-uva-induced cross-linking of corneal 
collagen: qualitative investigation. Eur J Ophthalmol 2006;16:530-5. 
9. Jacob S, Kumar DA, Agarwal A, Basu S, Sinha P, Agarwal A. Contact lens-assisted 
collagen cross-linking (CACXL): a new technique for cross-linking thin corneas. J 
Refract Surg 2014;30:366-72. 


 
17 
 
Table 1.  Procedure schedule 
 
 
Screening Treatment Day 1 
Week 1 Month 3 Month 6 
Informed Consent 
x 
 
 
 
 
 
Inclusion/Exclusion 
x 
 
 
 
 
 
Medical & Ophthalmic History 
x 
 
 
 
 
 
Urine pregnancy testing (females 
of child-bearing age) 
x 
 
 
 
 
x 
Adverse Events  
x 
x 
x 
x 
x 
x 
Uncorrected distance acuity 
x 
 
x 
x 
x 
x 
Manifest refraction 
x 
 
 
 
x 
x 
Corrected distance acuity 
x 
 
 
 
x 
x 
Corneal tomography (Pentacam) 
x 
 
 
 
x 
x 
Corneal topography 
x 
 
 
 
x 
x 
Intraocular pressure 
x 
 
 
x 
x 
x 
Slit lamp examination of cornea, 
anterior chamber and lens 
x 
 
x 
x 
x 
x 
 
 
 
 
 
 
 
Dilated fundus exam 
x 
 
 
 
 
x