|
Indications
for use of the Schanzlin Ocular Laser Shields
Part Numbers: 34-600 / 34-605 / 34-610 / 34-615
/ 34-620
David J. Schanzlin, M.D.
La Jolla, CA
Surgical
Technique:
The
Schanzlin Ocular (Laser) Shield(s) was designed
to protect the anterior surface of the eye during
laser refractive surgery. The instrument when
used properly provides protection to the corneal
epithelium beyond the flap and to the flap hinge
in LARK cases. The instrument is especially useful
in cases with small diameter flaps where large
diameter treatment zones are necessary, such as
with the treatment of consecutive hyperopia after
a LARK for myopia.
The
instruments consist of large diameter stainless
steel domes that have been formed to match the
shape of the anterior surface of the eye. The
surface of the shield that comes in contact with
the eye has been coated and polished to a mirror
surface to avoid any abrasion to the cornea or
conjunctiva. The interiors of the shields are
cut out with diameters of 8.0, 8.5, 9.0, 9.5,
and 10.0 mm and along one edge there is a flattened
area to protect the flap. There is a small nub
at the opposite end to provide a surface for grasping
the shield with a forceps. As with all new stainless
steel surgical instruments, the Schanzlin Ocular
(Laser) Shield(s) should be thoroughly cleaned
and sterilized prior to use.
In
cases of LARK enhancement or hyperopic LASIK the
flap is reflected back and the diameter of the
corneal flap is measured with a caliper. A shield
is selected with an inner diameter to match the
flap diameter. The shield is positioned over the
reflected flap and aligned to match the outer
flap diameter. If the shield is positioned in
this manner, then the corneal epithelial surface
outside the area of the flap and the flap hinge
will be shielded from any laser energy that goes
beyond the flap diameter.
I
have used these shields in cases where I needed
to do a hyperopic pattern to treat a consecutive
hyperopia after myopic LASIK. In these cases the
hyperopic pattern had an outer diameter of 9.0
mm and the previous flap diameter was 8.5 mm.
By using the corneal shield in the manner described
above I was able to deliver the hyperopic pattern
without causing any epithelial erosion along the
edge of the flap. Similarly, the hinge of the
flap was protected.
I
have also routinely use the shield during cases
of hyperopic LASIK to protect the hinge of the
flap. In these cases generally a larger corneal
shield is utilized. Again the shield size is chosen
based on the measured diameter of the flap.
The
corneal shield is easy to use and to date I have
not had any problems with movement of the shield
during the delivery of the laser pattern. Care
should be exercised, however, to insure that the
shield is not contacting the upper or lower lid
since movement of the eye could cause the shield
to make contact resulting in dislodging of the
shield.
|