Purpose: To analyze the surgical outcomes and complication rates in a group of patients with refractory glaucoma who underwent simultaneous pars plana vitrectomy (PPV) and PC7 or PC8 Ahmed glaucoma valve (AGV) implantation.
Methods: Retrospective case series study of 10 eyes in 9 patients with secondary glaucoma, refractory to other treatment, who underwent 23G-PPV and implantation of PC7 or PC8 AGV between 2012 and 2014. Study variables were postoperative BCVA, IOP and the number of glaucoma medications, which were evaluated preoperatively and at 1 day, 1 week and 1, 3, 6, and 12 months after the surgical intervention. Absolute success was defined as IOP less than 21 mmHg in the absence of any medication and qualified success if medication was needed to control IOP under 21 mmHg.
Results: The average follow-up was 10.2 ± 2.89 months. Postoperative IOP levels decreased in all cases in comparison with preoperative values (p < 0.05). Absolute success rate was 60%, reaching 100% in terms of qualified success. Kaplan-Meier survival analysis showed 60% absolute success at 12 months. Changes in postoperative BCVA were not statistically significant in comparison with preoperative data. Early postoperative complications were athalamia, hyphema, and retinal detachment; late complications were pars plana clip extrusion and cystic bleb.
Conclusions: PC7 and PC8 Ahmed valve implantation via pars plana is a safe and useful option in patients with secondary refractory glaucoma who are either candidates for PPV or have been previously vitrectomized.
Keywords: Ahmed valve; PC7; Pars plana clip; Pars plana vitrectomy; Refractory glaucoma.