Name

Éléments anatomiques de bonne réponse à la Trabéculoplastie Sélective : le rôle de l’examen de l’angle iridocorneen

The purpose of this study was to assess demographic and anatomical iridocorneal angle factors that may predict the success of Selective Laser Trabeculoplasty (SLT).

In this prospective randomized institutional study, patients who were candidates to SLT had a careful anterior angle examination and were randomly assigned 1 of 2 regimens: the (2x180°) group (11 eyes) had two 180° SLTs two weeks apart and the (1x270°) group (17 eyes) had one 270° SLT session. Success was defined as a 20% reduction of intra-ocular pressure (IOP) at latest follow-up. Demographic and anatomical factors (irido-corneal angle opening grade, trabecular meshwork pigmentation, peripheral iris configuration (PIC) and peripheral anterior synechiae) were studied to assess for potential predictors of success.

Mean follow-up duration was 8.04 ± 5.45 months [range, 3 – 18 months]. At latest follow-up visit, IOP dropped significantly in both groups. 6 eyes (54.55%) from the (2x180°) group and 8 eyes (47.06%) from the (1x270°) group were successful at reaching target IOP (p=0.70). The 2 techniques were comparably safe in terms of adverse effects. A multiple regression analysis of the different variables thought to have an effect on the success rate showed a significant correlation between PIC and peripheral anterior synechiae (PAS) with failure of SLT (p<0.05 and p<0.05, respectively). A baseline IOP equal to or greater than 21 mmHg was also associated with a higher SLT success rate (p=0.02).

Our results, not described elsewhere in the literature, showed the importance of the anatomical iridocorneal angle as a potential factor that may predict the SLT’s success rate. In fact, steep-PIC and PAS were associated with a higher failure rate, whereas queer-PIC was associated with a higher success rate.

Both (2x180°) and (1x270°) regimens seem to yield comparable results in safety and IOP reduction, and have their hypotensive effect optimized with a higher baseline IOP. A careful and thorough examination of the anterior chamber angle by gonioscopy is crucial prior to SLT and may predict the procedure’s success rate.