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CLINICAL
OUTCOMES AND THEORY OF OPTIVISION™ LASER PRESBYOPIA
REVERSAL
(LAPR)
V. Kadambi, M.D.
Sai Krupa Clinical of Laser Vision
Bangalor, India
INTRODUCTION
Presbyopia is a condition that effects the vast majority of
middle-aged individuals. Conventionally, it is treated by
the use of additional convex lens spectacles for near work
and reading. In the last decade many attempts have been made
to surgically reverse this condition. Two of the most common
techniques, although neither are FDA cleared, are the Schachar
technique, which involves the insertion of implants to expand
the sclera, and the Thorton technique, which uses surgical
incisions to expand the sclera.
Laser
Presbyopia Reversal (LAPR) is being tested by clinical evaluators.
The technique is still being evolved, but it may be described
in brief as multiple four-quadrant ablative excisions over
the sclera overlying the ciliary muscle. A prospective study
to assess the safety, efficacy and stability of LAPR is underway
at the Sai Krupa Clinic of Laser Vision, Bangalore, India.
MATERIALS AND METHODS
Six patients each had both eyes treated with the
OptiVision™ Er:YAG Laser System
and fiber-optic delivery system manufactured by SurgiLight
Inc., USA. In our study, the
patients were divided into two groups based on age. Group
I was between 40-50 years while Group II was between 51-60
years. Subjects were selected with pre-operative refractive
distance vision between +1.0 to +1.5 Diopters. The eyes were
thoroughly screened to rule out pre-existing pathology. Pre-operative
and follow-up examinations included refraction,
slit lamp
examination, fundoscopy, IOP measurements, keratometry, corneal
topography and visual
field evaluation. Currently, the followup periods range from
2 weeks to 3 months.
The
procedure was done under infiltration anesthesia using 2%
Lidocaine with adrenaline.
Topical anesthesia was instilled just prior to infiltration.
After making four fornix-based conjunctival flaps in the intermuscular
region and achieving hemostasis with bipolar cautery, four
pairs of radial ablative scleral excisions were made –
one pair in each quadrant. The ength of each incision was
approximately 4.5 mm starting 0.5 mm from the limbus. The
separation between the paired incisions was approximately
2.5 mm. The depth of the grooves was about 75% of scleral
thickness using the blue hue of choroid as the endpoint indicator.
The peritomy sites were closed with bipolar forceps. The patient
was prescribed topical antibiotics and teroids along with
analgesic tablets. The patients’ eye was not patched
and they were instructed to use their eyes normally for near
and far vision within 24 hours postoperatively.
RESULTS
The mean pre-operative near add in Group I was 1.56
Diopters while in Group II was 2.25
Diopters. The near vision (tested at 35 cm reading distance)
in Group I with full distance
correction was J2 to J4 and in Group II between J5 to J6.
One week post-LAPR all subjects
read J1 without near addition. All patients reported mild
discomfort for 24 to 48 hours post-operatively, including
dry eyes. Conjunctival hyperemia lasted 2-4 weeks. The general
observation was that subjective near visionimprovement was
noticed within 2 days following the procedure. It continued
to improve over 2-4 weeks, showing dramatic improvement after
the fellow eye was treated. The time interval for treating
the fellow eye varied from 0-4 weeks. No myopic shift and
no regression were noted during the follow-up period (maximum
3 months). No significant change in refraction for distance
was noticed. There was no induced astigmatism. There were
some differences in the manner and speed of conjunctival healing.
Specifically, the scleral scars were visible and quite noticeable
in some cases, but there was tendency for this to decrease
with time. No significant complications were encountered.
DISCUSSION
It is believed that accommodation results from the
contraction of the ciliary muscle. As age dvances, there is
a relative decrease in functional range of the ciliary muscle.
Factors such as hardening of the lens, atrophy of the muscle,
as well as “crowding of the muscle” have been
attributed as causes for decreased accommodation. Thornton
proposed reversal of presbyopia by anterior ciliary sclerotomy.
He recognized that some of his RK patients, in whom the ncisions
extended through the limbus in the sclera, had not developed
presbyopia at the same time or in the same amount as his untreated
patients. He hypothesized that the scleral incisions were
responsible for this decrease in loss of accommodation. He
organized several surgeons worldwide to study the results
of the scleral incisions. Fukasaku carried out anterior iliary
sclerotomy with the implantation of silicone expansion plug.
Schachar achieved scleral expansion by insertion of implants.
SurgiLight’s LAPR technique proposed by Dr. J.T. Lin
involves four pairs of symmetrical partial thickness radial
incisions in the sclera over the ciliary body. This ablation
of the scleral and resulting ingrowth of fibrous tissue, appears
to improve the ciliary muscle function. Another hypothesis,
the “Lin-Kadambi” theory, attributes the increased
ciliary muscle functional range to increased elasticity of
the scleral ring resulting
from the ablation. The absence of significant regression is
due to a “fill-in” of the grooves by fibrin-like
tissue. As a procedure, LAPR was found to be non skill-intensive
with a short learning curve. Initially, the average surgical
time was around 45 minutes. This has been
reduced to around 20 minutes per eye, while lasing time is
a few seconds per incision. The OptiVision is an extremely
reliable laser, since it employs solidstate technology. The
energy output is very stable provided the surgeon ensures
that proper contact tip technique is utilized. All cases demonstrated
a significant subjective increase in accommodation.
Although the amount of presbyopic reversal is more or less
the same in both age-groups, it is my belief that the net
effect is more demonstrable in the younger age group. It is
my feeling that patients above the age of fifty may not show
uniform results due to the additional factor of lens hardening
or scleral rigidity.
SUMMARY
Our initial clinical study demonstrates that LAPR
procedure using the OptiVision Erbium:YAG Laser is an effective
and safe method to surgically reverse presbyopia. Visual recovery
is quick. Our patients are satisfied with the results. Long-term
follow-up is necessary to evaluate stability of effect. Reference:
Lin, JT, Kadambi, V, Mallo, O, Hwang, MY, Book Chapters in:
Presbyopia: the Last Frontier, ed. by S. Agarwal et al. (2001),
New York, SLAK..
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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