IOP fluctuation in primary open angle glaucoma (POAG) receiving canaloplasty (CP) and microcatheter-assisted trabeculotomy (MAT).

Abstract

Purpose : To evaluate the influence of CP and MAT on IOP and its fluctuation.

Methods : Retrospective observational study. Twenty-nine POAG eyes initially scheduled for MAT and 19 eyes for CP between February 1^st 2016 and December 31^st 2016 were recruited in this study. After one-year fellow-up, fourteen subjects with good IOP control in MAT and 10 in CP further received 24-hour IOP monitoring and IOP variation measurement induced by the postural change. All statistical analyses were performed with SPSS 18.0. ANOVA was performed for IOP and glaucoma medication at all postoperative time points and compared with the baseline values. Independent t test was used to compare the IOP between groups. The cumulative probability of success rate was estimated by Kaplan–Meier plots. The endpoint was failure of surgery. A p<0.05 was considered statistically significant.

Results : Postoperatively, the mean IOP and the number of medications used decreased dramatically at all the follow-up time point in both groups comparing with those before surgery. The mean IOP in postoperative 3-mon and 6-mon in MAT is much lower than that in CP (p=0.039 & 0.003). The cumulative success rate was 86.2% for MAT and 84.2% for CP, similar between groups (p=0.866). For 24-hour IOP monitoring, the IOP presented stable in MAT group, the IOP_max= 15.88 ± 2.82 mmHg and dIOP= 4.10 ± 1.20 mmHg. In contrast, in CP group, the IOP at 2:00 am showed a peak with the IOP_max= 17.84 ± 2.1 mmHg and dIOP= 5.08 ± 1.74 mmHg. When subjects laying down, IOP increased significantly in both groups (p<0.001). The difference of the IOP induced by the posture is much higher in CP than that in MAT (p=0.043). With topical 2% pilocarpine, the IOP did not change dramatically either in MAT or in CP (p=0.192 and p=0.118). Pulsatile aqueous could not be seen in both groups.

Conclusions : Both MAT and CP are good options for POAG as an initial surgery. The MAT presented more stable IOP.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.