Factors Affecting Bleb Morphology and Postoperative Intraocular Pressure in Inferotemporal PreserFlo MicroShunt...

To investigate factors associated with bleb morphology and postoperative intraocular pressure (IOP) in eyes with inferotemporal PreserFlo MicroShunt implantation.

We analyzed 94 eyes that underwent PreserFlo in the inferotemporal quadrant. Slit-lamp photographs of the bleb approximately 6 months after surgery were used for bleb morphology analysis. Bleb vascularity was assessed via two classification criteria. Multivariate analysis was performed to identify factors associated with bleb morphology and 6-month postoperative IOP.

The mean age of the patients was 71.6 ± 12.0 years, and 46 patients (64%) were male. Primary open-angle glaucoma was observed in 69 eyes (73%), the mean axial length was 25.4 ± 2.2 mm, and 54 eyes (57%) underwent standalone surgery. The IOP significantly decreased from 24.9 ± 6.8 mm Hg preoperatively to 14.4 ± 2.8 mm Hg at the time of photography (P < 0.001). Avascular blebs were observed in seven eyes (7%) according to both classification systems. There was no significant difference in IOP between avascular and vascularized blebs (13.5 ± 0.9 mm Hg vs. 14.4 ± 2.9 mm Hg; P = 0.08). No preoperative factors predict bleb morphology. Age was the only factor significantly associated with 6-month postoperative IOP (P < 0.001), with a 0.157 mm Hg decrease in IOP for each 1-year increase in age.

Although inferotemporal PreserFlo may result in avascular blebs in a small proportion of patients, postoperative IOP is associated primarily with age rather than with bleb morphology.

We provide valuable surgical information for inferotemporal PreserFlo implantation.