Abstract
Purpose :
To evaluate and quantify the filtering bleb after the Baerveldt glaucoma implantation using magnetic resonance imaging (MRI).
Methods :
This cross-sectional case series study included 62 patients who underwent Baerveldt glaucoma implants. High resolution orbital images were obtained using 3-Tesla MRI with phased-array head coil in six months or later after surgery. Three dimensional images were constructed, and the filtering bleb volume was measured. The relationship between bleb images and postoperative intraocular pressure (IOP) were compared.
Results :
In total, 52 quantifiable MR images were obtained in this study. The mean periods which obtained MRI after surgery was 15.2 months. This study found that bleb structures in eyes with Baerveldt glaucoma implants were classified into the single bleb-layer (n=28) and the double bleb-layer (n=24). Each bleb had 4 holes, which correspond to the pillars of subconjunctival tissue through the holes in the endplate. The postoperative IOP was significantly lower in double bleb-layer eyes than single bleb-layer eyes (12.3 mmHg vs 14.7 mmHg, P = 0.033). The mean bleb volume was 0.23 cm3 (n=52). Although there was no significant correlation between the bleb volume and the postoperative IOP (r = -0.080, P = 0.57), the bleb volume was significantly larger in double bleb-layer eyes than single bleb-layer eyes (0.28 cm3 vs 0.19 cm3, P = 0.024).
Conclusions :
The MR images in this study revealed that bleb structures in eyes with Baerveldt glaucoma implants were classified into the single bleb-layer and the double bleb-layer. Our data indicate that the formation of the double bleb-layer contributes to lower IOP levels rather than the bleb volume.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.