| Clinical Tips by:
David Gosiengfiao, MD, Makati Medical Center, Philippines
|
| Pre-op medications: Exposure is everything. Give pilocarpine to patients with convex irises. A drop of brimonidine or apraclonidine an hour before SLT will help blunt post-operative IOP spikes. |
| Anesthetize well: Often, the discomfort that patients feel during the procedure can be blunted by
adequate anesthesia. Loading the patient pre-operatively with topical anesthetics will minimize squeezing, and
make the entire experience more pleasant for the patient. |
| Start at 12 o’clock for each 180 degrees of treatment: Trabecular meshwork (TM) pigmentation is
often lightest superiorly and darkest at the opposite pole. Because the endpoint in SLT is invisible, maintaining
the appropriate energy levels throughout the treatment session can be diffi cult. Starting at 12 o’clock ensures
that you begin at the maximum energy requirement, and as the threshold is crossed because of increasing
pigmentation, you are able to titrate down. |
| Follow a routine: If you choose to treat only 180 degrees, treat the same 180 degrees fi rst routinely,
whether it is temporal or nasal, 12 to 6 o’clock or 6 to 12 o’clock. Should the patient’s records be misplaced,
knowing how many treatments he or she has undergone will be enough to know which half to treat next. |
Stay in the center of the mirror: The Latina SLT lens is a special gonio lens with unity gain, and provides
a non-astigmatic view. Lasing through the center of the gonio lens mirror induces the least beam distortion and
ensures reproducible energy delivery. Turning the gonio lens frequently also makes following landmarks easier. |
| Focus on target tissue at all times: Maintain slit lamp focus of the TM when performing treatment and do not use the aiming spot to focus. |
| Watch where the bubbles are coming from: Sometimes, the laser beam glances off the iris when
the lens is poorly positioned, causing bubbles to form. The beam may also overlap onto the iris root, causing
bubbles to form. In both cases, you should not titrate the power down, but should instead reposition the lens
and adjust your aim to avoid those structures. |
| Understand the role of the bubbles: The bubbles are formed because of the photoacoustic effect of the
laser – microcavitation. Too much of this can cause damage to the trabecular beams. In some cases, this
actually results in improved drainage, almost like the old YAG goniopuncture. However, the goal is NOT to
damage the beams but to induce cellular repair and repopulation. |
| When in doubt, give post-operative steroids: The risk of post-operative spikes increases with highly
pigmented meshworks, 360-degree treatments, and high baseline IOP. Giving post-operative steroids for a
few days can help avoid this complication. |
| Do not taper meds too quickly: There is often an immediate decrease in IOP following treatment, followed
by a return to near baseline levels within a few days, and then a more gradual reduction in IOP. Some patients
do not show a response until four weeks after treatment. In general, wait six weeks before making any
decisions about changes in therapy. |
