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Positive
results seen at 12 months for laser presbyopia reversal Most
achieved J3 near vision or better, greater than 1 D increased
amplitude of accommodation
By Cheryl
Guttman
Reviewed by Sandra C. Belmont, MD
New York—Laser presbyopia reversal (LAPR) is showing
significant promise and patient
satisfaction based on 12-month follow-up results from a U.S.
phase II clinical trial, said Sandra C. Belmont,MD.
The procedure involves the use of an infrared erbium:YAG laser
(OptiVision, SurgiLight) fitted with a conical tip fiber to
create eight radial incisions in the sclera via tissue ablation.
It is designed to improve accommodation by expanding the scleral
tissue in order to enhance the efficiency of the ciliary muscle
and zonules.
Dr. Belmont, director of the corneal service, and associate
professor of clinical ophthalmology, Weill Medical College
of Cornell University,New York, spoke during the refractive
surgery subspecialty day before the American Academy of Ophthalmology
annual meeting.
The phase II study was conducted at two centers and enrolled
60 eyes of 30 patients with a mean age of 53 years (range
50 to 58). The eligibility criteria required patients to have
distance uncorrected visual acuity (UCVA) of 20/25 or better
in each eye, accommodation 2.5 D, stable manifest refraction
between –0.5 and +0.75 D with < 0.5 D difference
between the manifest and cycloplegic SE values, normal IOP,
=0.75 D astigmatism, and no prior ophthalmic surgery.
First-eye and second-eye surgery were performed 1 day apart.
Patients were able to read immediately after surgery, and
at 12 months, the group demonstrated a statistically significant
increase in near uncorrected visual acuity (UCVA), with 90%
achieving J3 or better.
In addition, 100% of eyes had >1 D increased amplitude
of accommodation with a mean increase after 12 months of about
2.4 D when measured by push-up and blur and a maximum increase
of 3.25 D. One patient with a poor 12-month near vision outcome
had resumed spectacle wear. Safety was favorable with no changes
in IOP, axial length, or corneal topography, and patients
have been very happy with the results. “Expanded U.S.
trials are needed, with longer follow-up.However, these early
data mirror the results from international studies that involve
several hundreds of patients and show minimal regression during
follow-
up extending to 4 years,” she said.
Dr. Belmont is a clinical investigator in the study. Jon Siems,MD,
is the second investigator and has treated patients in his
private practice in Las Vegas. The laser used for the surgery
is set at an output energy of 20 mJ, operates at a frequency
of 20 Hz, and has a spot size of 600
µm produced by a conical contact tip. LAPR is performed
under topical anesthesia using 2% lidocaine gel applied preoperatively
and topical 1% proparacaine delivered via a pledget to the
sclera for 3 to 5 minutes during the procedure. The eye is
marked at 6 and 12 o’clock with the patient in the sitting
position, and four fornix-based triangular peritomies are
made at 1:30, 4:30, 7:30 and 10:30.Wet field cautery is applied
as needed. The eight radially oriented ablations are made
in the scleral tissue 0.5 mm posterior to the limbus. They
measure 4.5 mm in length and are placed two per quadrant and
spaced 2.5 mm apart. The depth of the ablation is about 80%
of scleral thickness, and the appearance of the dark blue
hue of the choroid marks the treatment endpoint.
The peritomy sites are closed with a Expanding scleral tissue
Laser presbyopia reversal (LAPR) is an investigational procedure
in which an erbium:YAG laser (OptiVision,
SurgiLight) is used to create radial incisions in the sclera.
bipolar forceps and topical treatment with a nonsteroidal
anti-inflammatory agent and antibiotic is administered.
“The procedure takes about 15-45 minutes per eye, but
it is easy to learn,”Dr. Belmont said.
A postoperative evaluation performed at 1 hour after the surgery
includes examination at the slit-lamp to verify complete conjunctival
closure, IOP measurement, and a check of UCVA at 14 inches.
In addition, patients are instructed to use the eyes for reading
on an hourly basis and to continue their nonsteroidal anti-inflammatory
drug and antibiotic treatment for 1 week after surgery.
“Over
the longer term, it is important to make sure that patients
use their eyes to read at a new focal length and do not return
to wearing their glasses or they will lose the effect,”
Dr. Belmont said. In a preclinical study performed in rabbit
eyes to study the safety of the procedure, there were no signs
of inflammatory changes or collateral damage to tissue beneath
the laser ablations. During follow-up in the human trial,
there were no problems
noted with regard to development of inflammation, changes
in corneal clarity, or iris atrophy.Minimal conjunctival vascular
injection developed after surgery, but resolved completely
within 2 weeks. At Dr. Siems’ site, two eyes developed
blebs, and internationally, there have been seven microperforations
in more than 1,500 procedures. Observations from the preclinical
and clinical studies support the hypothesis that LAPR works
to improve accommodation by increasing the space between the
crystalline lens and the sclera to afford the ciliary muscles
more room to work and zonular tension to increase. In the
rabbit study,
the LAPR incision sites were found to be filled by flexible
scar tissue. Consistent with that finding, an increase in
circumferential diameter of the globe of about 10 mm was noted
in the clinical trial.
However, the surgery has also been found to result in decreased
axial length.Measurements
obtained in the phase II study showed axial length shortening
occurred in 70% of eyes with an average change of 0.012 mm,
and use of high-frequency ultrasonography (Artemis-2) showed
a statistically significant decrease in anterior chamber depth.
“Those
findings suggest that as an alternative mechanism of action,
the procedure might result in forward movement of the crystalline
lens,”Dr. Belmont said. The FDA trial is expected to
be expanded in 2005. The procedure has been cleared by regulatory
agencies in many Pacific Rim countries and has just received
CE approval in Europe following a medical panel review similar
to that conducted by the FDA, LAPR is also being investigated
in several other countries.
SurgiLight, Inc. (OTCBB: SRGL)
12001 Science Drive, Suite 140, Orlando, FL 32826 •
Tel. (407) 482-4555 • Fax (407) 482-0505 • Website
www.surgilight.com • Email surgilightsales@aol.com
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