| Clinical Tips by:
Ivan Goldberg, MB,BS (Syd); FRANZCO, FRACS
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| Patients to be considered for SLT are those with visible trabecular meshwork on gonioscopy, whose intraocular pressure (IOP) needs to be lowered, and/or for whom medications are ineffective, intolerable, contraindicated or inappropriate. |
| To minimize potential alarm and anxiety, patients should understand what is being done, how and why, and should know what reactions may follow. |
| Consider pre-treatment with pilocarpine (to tauten the trabecular meshwork), alpha-2 agonists and/or topical carbonic anhydrase inhibitors to facilitate treatment and to protect against a post-SLT IOP spike. For the same reason, consider applying SLT to an eye in two sessions, each with 180 degrees of meshwork treated, separated by one to two weeks. |
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Consider avoiding topical steroids and other anti-inflammatory agents so as not to inhibit cytokine release, the mechanism by which trabecular endothelial cells are thought to reduce IOP. |
Apply the laser energy as evenly as possible over the entire meshwork, with each application abutting the previous one. |
| Aim for a minimal but definite champagne bubble reaction with each laser application. This requires titrating laser energy levels with meshwork pigmentation. While a mildly pigmented meshwork usually requires an energy setting of about 0.8mJ, one that is more heavily pigmented may need only 0.3 - 0.4mJ, and one that has no pigment and an amorphous appearance may need up to 1.6mJ. |
| Titrating laser energy levels to achieve a minimal but definite champagne bubble response with each application means not only varying laser energy settings between eyes, but from one part of an eye's meshwork to another, depending on variations in pigmentation and reaction to previous treatments. |
| Advise patients that a treated eye may become somewhat red and uncomfortable - even with a little photophobia - for a few days after each laser session. If the reaction is severe or troublesome, the patient should contact the ophthalmologist. |
| If the clinical situation will allow, wait at least four weeks after completing the 360-degree meshwork treatment before assessing the IOP response to SLT. |
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If there is a satisfactory IOP response that subsequently fails, consider repeating SLT. There would seem to be little value in repeating SLT if the first treatment provides no improvement whatsoever. |
