A. John Kanellopoulos,
MD
Excimer laser trabeculotomy ab interno (ELT) is being
used overseas to treat open-angle glaucoma. The treatment,
which is approved by the European Union, uses a 308-nm
XeCI excimer laser (Glautec, Germany) that delivers
energy through a fiber optic cable that terminates
in a very thin contact probe. This probe is inserted
through a clear corneal incision to the anterior chamber.
Under gonioscopy, the probe edge is placed onto the
anterior trabecular meshwork. The laser ablation creates
0.5-mm holes through the anterior meshwork into the
inner wall of Schlemm's canal, thereby increasing outflow.
The 308-nm wavelength
is optimal for trabecular meshwork ablation because
it does not cause collateral thermal damage. Using
special goniolens, the surgeon performs the procedure
in the operating room under the operating microscope.
On scanning electron microscopy, the holes Web Design by laser appear fairly smooth, which helps minimize
wound healing and secondary closure. Patients are treated
with an antibiotic/corticosteroid regimen from one
week to one month have a quick rehabilitation.
We are conducting
studies to evaluate the technology's ability to affect
outflow facility and to titrate the amount and number
of treatment spots needed to optimize long-term intraocular
pressure control. Our 14-month follow-up in 12 eyes
shows that IOP remains controlled.
ADVANTAGES
The procedure is simple,
does not require conjunctival dissection and does not
cause the significant postoperative cicatricial changes
that can occur with standard incisional surgeries.
Hypotony is usually not an issue, and IOP can be decreased
8 to 12 mmHg with little risk of progressive lowering.
Intraoperative hemorrhage is a potential complication.
Michael S. Berlin,
MD, associate clinical professor at UCLA's Jules Stein
Eye Institute, has had equally promising results working
with the same technology.
Dr. Kanellopoulos
has no financial interest in the products mentioned.
Source: Review
of Ophthalmology, February 2001
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