The effect of the hypertensive phase on the long-term outcomes of Ahmed glaucoma valve (AGV) implantation

BackgroundTo investigate the long-term effect of hypertensive phase(HP) on the clinical outcomes of Ahmed Glaucoma Valve (AGV) implantation.MethodThe records of patients with different etiologies of glaucoma who underwent AGV implantation were retrospectively reviewed. HP was defined as the IOP> 21 mm Hg during the first three months after surgery. The main outcome measure was cumulative success defined as 5 < IOP< 21 mmHg and 20 % reduction from the baseline with or without IOP lowering medications. The secondary outcome measures were intraocular pressure (IOP) and the number of glaucoma medications. ResultsA total of 120 patients (28 patients of HP, 92 patients without HP) with an average age (±SD) of 48.9 ± 19.6 years and a mean follow-up of 4.5 ± 1.4 years were enrolled. The mean duration of survival was 5.3 ± 0.5 years in HP which was significantly shorter than 6.4 ± 0.2 years in non-HP. (log Rank= 4.2, P= 0.04) Mean IOP and number of IOP lowering agents were higher in postoperative visits at 1,2, 3, and 4 years in HP patients compared with non-HP. (All Ps < 0.01) Higher Baseline IOP was significantly associated with higher rates of surgical failure. Neovascular glaucoma was the only factor associated with the occurrence of HP in a logistic regression model. (Odds ratio: 3.14 CI: 1.2-8.1). Conclusion In the long-term follow up the duration of survival was significantly longer in the non-HP group. In the non-HP group, the success rate was significantly higher than the HP group

Ologen augmentation of Ahmed glaucoma drainage devices in pediatric glaucomas

Background Limited data exists on the effectiveness of the collagen matrix, Ologen, on increasing Ahmed glaucoma valve (AGV) success in childhood glaucomas. Methods Ocular examination and surgical details of pediatric patients who underwent AGV placement ± Ologen augmentation between 2012 and 2020. Complete success was defined as intraocular pressure (IOP) between 5 and 20 mmHg without glaucoma medications and additional IOP-lowering surgeries. Qualified success was defined as above, except IOP control maintained with or without glaucoma medications. Results Twenty-two eyes of 16 patients underwent AGV placement of which 6 eyes had Ologen-augmentation (OAGV) and 16 eyes had conventional surgery (CAGV). Average age was 6.4 ± 5.1 years with 4.2 ± 2.5 follow-up years. There was no difference in age, number of previous surgeries, and preoperative IOP and glaucoma medications. At final follow-up, success rate was 100% (5 eyes complete, 6 eyes qualified) in the OAGV group compared to 31% (0 eyes complete, 5 eyes qualified) in the CAGV group. One and two-year survival rates were 100% for OAGV compared to 62 and 38% for CAGV. Postoperative IOP was significantly lower at 1-month and final follow-up (p = 0.02) as was the number of glaucoma medications at 3, 6, 12-months and final follow-up (p < 0.05) in the OAGV group. Conclusions Ologen-augmentation increased the success and survival rates of AGVs in childhood glaucomas. Further, Ologen mitigated the hypertensive phase and decreased medication dependency. Longer follow-up with a greater number of eyes is required to fully evaluate the effectiveness of OAGV.

Clinical outcomes of Ahmed glaucoma valve implantation without fixation of a plate: The free plate technique

Objective This study compared surgical outcomes between free plate Ahmed glaucoma valve (FPAGV) implantation without plate fixation and conventional Ahmed glaucoma valve (CAGV) implantation with plate fixation. Methods A retrospective, comparative case series study. Patients with refractory glaucoma who underwent FPAGV or CAGV implantation and were followed >1 year were enrolled consecutively. We reviewed medical records, including data on postoperative intraocular pressure (IOP) and postoperative complications. The success rate and early postoperative hypertensive phase were compared between groups. Results A total of 74 patients with CAGV implantations and 36 patients with FPAGV implantations were studied. The average follow-up periods were 23.3 ± 2.6 months (CAGV) and 22.8 ± 2.8 months (FPAGV; p = 0.424). The surgery time was significantly shorter in the FPAGV group than in the CAGV group (42.6 ± 4.1 vs. 47.3 ± 5.4 min; p < 0.001). Postoperative IOP at 1 week and 1 month were significantly lower in the FPAGV group than in the CAGV group (11.8 ± 3.6 and 14.0 ± 5.3 mmHg vs. 18.7 ± 5.5 and 22.2 ± 5.2 mmHg; p = 0.012 and p = 0.002, respectively). An early postoperative hypertensive phase occurred in 62 eyes, and the frequency was greater in the CAGV group (50 eyes) than the FPAGV group (12 eyes; p = 0.001). There was no significant difference in postoperative complications between the two groups (p = 0.735). The success rate was 84.2% in the FPAGV group and 80.6% in the CAGV group 24 months after surgery (p = 0.367). Conclusion FPAGV implantation was associated with a shorter surgery time, without any change in the extent of IOP reduction or complication rate. This procedure may be considered a good alternative for CAGV implantation in patients with refractory glaucoma.

Bleb Morphology Using Anterior-Segment Optical Coherence Tomography after Ahmed Glaucoma Valve Surgery with Tenon Capsule Resection

Objectives. To evaluate the internal morphology of blebs using anterior-segment optical coherence tomography (AS-OCT) and the surgical outcomes of Ahmed glaucoma valve (AGV) surgery with Tenon capsule resection compared to conventional AGV surgery in patients with refractory glaucoma. Patients and Methods. This randomised prospective study included 30 eyes from 30 patients (age range: 42–55 y) with refractory glaucoma from March 2018 to February 2020. The study included two groups: AGV with the Tenon capsule resection group (n = 15) and the conventional AGV surgery group (n = 15). Follow-up continued until 6 months after surgery. The primary outcome was intraocular pressure (IOP) and its association with the number of postoperative glaucoma medications, best corrected visual acuity, visual field, and postoperative complications. The internal morphology of the blebs in both groups was evaluated at 1-day, 1-week, 1-month, 3-month, and 6-month follow-up using AS-OCT in terms of the consequent changes in bleb wall thickness, bleb wall reflectivity, and bleb cavity morphology throughout the 6-month follow-up period. Results. A significant reduction in IOP was found in both groups, with a greater reduction in group I, where the mean IOP decreased from 32.73 ± 2.12 mmHg in the preoperative period to 13.33 ± 1.59 mmHg after 6 months, whereas in group II, the mean IOP decreased from 33.2 ± 2.21 mmHg in the preoperative period to 14.27 ± 1.44 mmHg after 6 months ( p value <0.05). The difference between the 2 groups in terms of the decrease in IOP was insignificant except at 1 and 3 months, where there was a significant difference ( p value = 0.016 and 0.01 at 1 and 3 months, respectively). The bleb analysis revealed a significant reduction in the wall thickness in both groups at 1 and 3 months, which was mostly associated with the hypertensive phase. In group I, the bleb wall thickness decreased from 754.67 ± 53.93 μm in the first postoperative day to 684 ± 81.66 μm and 671.6 ± 69.48 μm at 1 and 3 months, respectively, while in group II, the bleb wall thickness decreased from 707.13 ± 31.7 μm in the first postoperative day to 499.53 ± 99.1 μm and 506 ± 76.91 μm at 1 and 3 months, respectively. There was a significant reduction in AS‐OCT, and bleb reflectivity was insignificant throughout the follow-up period ( p value >0.05). Regarding postoperative complications, the hypertensive phase occurred more frequently in group II (6 eyes, 40%) than in group I (2 eyes, 13.3%). Other complications were also reported more frequently in group II such as hypotony, shallow anterior chamber (AC), and tube exposure. Conclusion. AS-OCT was beneficial in the analysis of bleb morphology after AGV surgery where there were more diffuse functioning multicystic blebs and less thinning in the bleb wall thickness during the hypertensive phase after resection of the Tenon capsule, which might be related to the less incidence of fibrosis around the surgical site.

Initial Glaucoma Medication in the Hypertensive Phase Following Ahmed Valve Implantation: A Comparison of Results Achieved Using Aqueous Suppressants and Prostaglandin Analogs

Background: To compare the effects of aqueous suppressants (AS) and prostaglandin (PG) analogs during the hypertensive phase on intraocular pressure (IOP) and surgical outcomes. Methods: In this retrospective, observational study, 66 eyes (66 patients) with Ahmed glaucoma valve (AGV) implantation were included. As evaluation items, IOP changes, number of postoperative medications, the surgical success rate, and postoperative complications were examined. Complete success was defined as IOP between 6 and 21 mmHg without medications, while qualified success was with a maximum of four medications. Results: The short-term IOP reduction following initial medication was 9.3 mmHg for AS and 4.4 mmHg for PG analogs (p = 0.016). More postoperative medications were used in PG than in AS from postoperative 3 months to 3 years (all p < 0.05). The qualified success rate with the initial medication was higher in AS than in PG (67.5% vs. 42.3% at 1 year, 80.6% vs. 37.5% at 2 years, 80.0% vs. 35.0% at 3 years, all p < 0.05). Conclusions: Association between AS used as the first medications during the hypertensive phase and better IOP control and a higher success rate was observed. The type of the initial glaucoma medication after AGV implantation could affect short- and long-term surgical outcomes.