| Clinical Tips by:
Prin RojanaPongpun, MD
|
| 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. |
SLT is considerably easier than ALT. With limited exposure and visualization of the angle though an open
but narrow inlet, focusing a large SLT spot size of 400 microns is considerably easier than the 50 micron spot
size of ALT. This is most obvious with our trainees, who are not experienced in gonioscopy. |
SLT is quick and comfortable. It normally takes one or two minutes to perform 180º treatment. Based on
our study, this is certainly preferable to both physician and patient. The broad beam of SLT can easily cover the
target treatment area and shorten the procedure time. We do not leave any free space between spots. |
| High magnification goniolens help. Using either Magna View goniolens (Ocular Instruments) or CGA-1
goniolens (Contact Glass Anterior, Lasag) provides a superb magnifi ed and panoramic view of the treating
angle. Most treatments can be performed with low slit-lamp magnifi cation, which allows a wider view of the
angle. As a result, less frequent rotation of the gonio-mirror is required. |
Look toward the mirror. Asking the patient to look toward the mirror is extremely helpful, especially when
treating an eye with a relatively narrow angle inlet. After each goniolens rotation, the patient is instructed to
change his or her gaze. An extreme gaze is not necessary. |
| Start at a six o’clock position. Begin treating the inferior angle by viewing it through the superior mirror. In
most cases, this is usually the easiest shot, because the angle opening is generally wider when compared to
the superior angle. Also, patients tend to get slightly anxious and move their eyes upward, which enhances
the visualization of the inferior angle. We usually rotate the goniolens counter-clockwise to complete the 180-
degree nasal half of the angle. |
| Look for small champagne bubbles. With SLT, we do not see blanching of the pigmented trabecular
meshwork. A visible small champagne bubble is a good endpoint. This is usually seen with 0.6-0.8 mJ in most
Asian eyes. Once this is evidenced, we rarely need to adjust the power. |
| Do not touch the PAS. With angle-closure patients, treat only the visible area of the trabecular meshwork. Avoid
the area with PAS (peripheral anterior synechiae). Unlike ALT, we usually do not see new PAS formation with SLT. |
| No more post-laser steroids. Currently, we do not prescribe topical steroid drops after SLT, but a few days
of topical NSAID instead. It is hypothesized that topical steroids may compromise the effect of SLT. However,
this requires more evidence and study. |
| Continue anti-glaucoma medication. The maximum effect of SLT might be seen a couple of weeks postlaser,
so all pre-laser anti-glaucoma medications should be continued until a certain IOP reduction level is
documented. We normally judge our results at the end of six weeks. |
