Effect of trabeculectomy and canaloplasty on intraocular pressure modifications after postural changes in primary open-angle glaucoma

Abstract

 

Purpose

 

The present study investigated the effect of trabeculectomy (TE) and canaloplasty (CP) upon the posture-induced intraocular pressure (IOP) changes in patients with primary open-angle glaucoma (POAG).

 

Methods

 

This observational study was conducted on patients with bilateral POAG who had undergone successful TE with Mitomycin C, or CP in one eye for at least 1 year. The IOP was measured first in a sitting position and thereafter in supine position. Absolute change of sitting IOP before and after surgery was calculated and compared for each surgical group, and between groups. The pressure change from sitting to supine position was evaluated and compared between groups.

 

Results

 

Twenty-six POAG patients were enrolled in each surgical group. Mean post-operative sitting IOP was 10.2 mm Hg (SD 2.3) and 14.9 mm Hg (SD 2.7) in the TE and CP groups respectively (p<0.0001). The relative increase in supine IOP was greater in the CP group (28.4%, SD 13.7) with an absolute difference of 4.3 mm Hg (SD 1.9), compared with the TE group (18.1%, SD 11.4) with an absolute difference of 1.7 mm Hg (SD 0.9); (p=0.005). (Table 1, Figure 1)

 

Conclusions

 

The current study shows that TE is more effective than CP in reducing IOP variations between sitting and supine position. It is important to consider postural changes in IOP while managing glaucoma patients, especially those requiring a greater IOP reduction or at a greater risk of glaucoma progression.

 

 

Table 1

 

 

Figure 1: Postural changes of IOP after canaloplasty and trabeculectomy

 

Keywords: 568 intraocular pressure • 458 circadian rhythms