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Clinical Trial Results - Presbyopia - U.S.A., Europe and Latin America
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In March of
2000, the Refocus Group initiated Phase I of a U.S. Food and Drug
Administration (FDA) monitored clinical study, authorized under an
investigational device exemption (IDE) granted by the FDA in 1999.
Phase I of this presbyopia clinical trial was designed to assess the
safety of the procedure and was launched at six sites in the United
States. Published results of this study (See “References” below)
confirmed the safety of the PresVIEW™ Scleral Implant
in 29 eyes of 29 patients with no loss of any distance parameters
throughout the two year post-op course in any patient. Despite the
technical limitations of these early surgeries, an average gain of
almost two diopters of accommodation was found in the operated eyes.
Prior to
the commencement of Phase II of the FDA monitored IDE clinical trials,
Refocus Group embarked on a major re-vamping of the surgical technique
with the introduction of an automated Scleratome designed to reduce the
inter-surgeon variability that was found with the prior manual
technique of surgery. Upon completion of this project in January 2004
our Phase II clinical trial was began. This phase of the FDA monitored
study was designed to show efficacy of the implant in patients and was
designed as a prospective, randomized control study. Results of Phase
II clinical surgeries were reported at the European Society of Cataract
and Refractive Surgery annual meeting in Lisbon in Sept. 2005 for the
first 44 eyes at six months from patients undergoing Refocus Group’s PresVIEW™ Scleral Spacing Procedure (SSP) for Presbyopia.
These
patients, along with 23 randomized, non-surgical control patients at
six months, were monitored for reading and near acuity vision using
standard near vision reading charts pre-operatively and at three and
six-month intervals. SSP patients experienced a median of three lines
of improvement at six months, though several patients showed
improvement of five to seven lines in unaided near vision. As
expected, control patients not undergoing the SSP procedure showed no
improvement in their close-up reading vision. About 90 percent of the
surgical patients reported that their close-up vision was either better
or significantly better. These results, along with the continued safety
of the SSP surgery (as evidenced by no change in uncorrected distance
acuity or contrast sensitivity), demonstrated that this cohort of
patients compared favorably to other methods of presbyopia correction
presented at the time. We believe these successful cases, along with
ongoing improvements in the surgical technique and results received by
recent patients, demonstrate the significant potential for our surgical
treatment.
In June
2009, Refocus Group received FDA approval to start Phase III clinical
trials, allowing us to expand the number of investigators and sites
engaged in the FDA study. We also received permission to treat both
eyes of patients in the United States (binocular vs. monocular
surgery), as we had been doing internationally for years. Phase III
continues to enroll patients and monitor them for two years after
implantation. We continue to see our excellent safety profile with no
loss of any distance metrics such as acuity or contrast sensitivity.
In the European Union where we have received our CE mark, and in Latin America, we are currently setting up centers of excellence and training. In our German sites we continue to monitor the results of surgeries carefully, reporting them to a centralized European monitoring group. We expect to open new clinical sites in Spain and Italy in 2010. Our Latin American results are monitored through our United States engineering and surgical group.
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Clinical Trial Results – Glaucoma – Canada
Clinical trials of the PresVIEW™ Scleral Implant and PresVIEW™ Scleral Spacing Procedure
for the treatment of ocular hypertension and/or primary open-angle
glaucoma were conducted by Aaron Rifkind, M.D., associate clinical
professor of ophthalmology at McMaster University in Hamilton, Canada.
The study indication was “the reduction of intraocular pressure in
patients with ocular hypertension and primary open-angle glaucoma.” The
summary two-year results were presented at the April 2003 meeting of
the American Society of Cataract and Refractive Surgery in San
Francisco. Each of the 24 patients enrolled had already been
receiving at least one, and in some cases two or three glaucoma
medications prior to entering into the study and at the time the
pre-surgery intraocular pressure was measured. This study required
that each patient then complete a three-week wash-out period where they
discontinued all of their glaucoma medications to establish an
unmedicated baseline intraocular pressure for the study.
The PresVIEW™ Scleral Spacing Procedure was then performed on the dominant eye of these 27 patients. At six months post-operative, 16 subjects elected to have the PresVIEW™ Scleral Spacing Procedure performed on their non-dominant eye as permitted by the protocol. After the PresVIEW™ Scleral Spacing Procedure,
if the intraocular pressure was greater than 25 mm Hg, or if there
appeared to be any glaucomatous progression in the optic nerve, the eye
was treated with glaucoma medication.
In the
two-year follow-up exam, data was available for 23 dominant eyes. In
these eyes a mean intraocular pressure decrease of 7.1 mm Hg was
found. Of significant interest was that the mean pressure of these
eyes was even lower than the pre-surgery mean IOP value by 0.7mmHg. Additionally, at the two-year point, and also at the four-year point, over half of the study patients were receiving no glaucoma medication, nor had they received any other secondary treatment. Moreover, in the balance of patients who were still receiving some continued medication for treatment, either for the non-operated eye or for both eyes, a large majority were receiving substantially less medication than prior to the study. Although not a specific entry criteria as in
the United States presbyopia study, near vision was also evaluated in
those patients and it was found that there was an overall improvement
in the patients’ near visual acuity at 20 centimeters. There were no
significant surgical complications.
The company
may apply to Health Canada to initiate additional clinical trials
related to ocular hypertension and glaucoma to eventually receive
approval for commercial sales in Canada and elsewhere. The company
has also received approval to commence glaucoma trials in at least one
European country and may seek approval to commence glaucoma trials in
Latin America as well.
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References:
Qazi, M.,
Pepose, J., Shuster, J., et al. Implantation of Scleral Expansion Band
Segments for the Treatment of Presbyopia. American Journal of
Ophthalmology, 134(6) 808-15, December 2002
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