SLT: effective in the long-term?

The IOP-lowering effect of selective laser trabeculoplasty (SLT) does weaken with time but, unlike argon laser trabeculoplasty (ALT), it is a repeatable procedure and offers a better risk/benefit ratio than other glaucoma treatments, according to Madhu Nagar from the Clayton Eye Centre, UK.

In a retrospective analysis of the case notes of patients treated with SLT between January 2000 and December 2005, Dr Nagar examined the long-term effectiveness of SLT, compared its effectiveness as a primary and secondary treatment and evaluated the effect of SLT re-treatment.

A total of 274 eyes received SLT as a primary treatment and 231 received it as an adjunctive/replacement treatment. In the primary group, intraocular pressure (IOP) fell from 27.8±3.9 mmHg at baseline to 19.0±4.7 mmHg (mean follow-up: 39 months), representing an average 32% drop in IOP. In the secondary group, IOP dropped from 26.0±-3.9 mmHg to 17.2±2.8 mmHg (mean follow-up: 45 months), representing an average 33% reduction in IOP.

In a separate study group (275 eyes), patients already receiving glaucoma medications were examined to see whether retreatment with SLT would reduce the number of medications required. Preoperatively, patients were taking an average of 1.8 medications, however, postoperatively, this reduced to an average of 0.86 (mean follow-up: 24.6 months).

In terms of the long-term efficacy of SLT, it was discovered that its effectiveness did gradually decrease over a five-year period. However, since it is a repeatable procedure, unlike ALT, this does not represent a major problem for SLT patients.

In conclusion, Dr Nagar believes that SLT offers the best risk/benefit ratio over any other glaucoma treatment; it can improve compliance since it lowers the numbers of medications required and it can help improve a patient's quality of life.