Underwent Ahmed Glaucoma Valve Implantation Research Articles

Evaluation of pericardium patch graft thickness in patients with Ahmed glaucoma valve implantation: an anterior segment OCT study

PurposeTo evaluate the changes in thickness of tissues, specifically the pericardium patch graft (PPG) covering the silicone tube in Ahmed Glaucoma Valve (AGV) surgery.Study designProspective observational study.MethodsThis study included cases with refractory glaucoma that underwent AGV implantation with PPG coverage. Conjunctival epithelium, stroma and PPG thickness covering the tube were measured using anterior segment optical coherence tomography (AS-OCT) at 1, 6 and 12 months. Additionally, the same measurements were taken 1500 µm away from the tube as a control for the central measurements.ResultsTwenty-seven eyes of 27 patients were evaluated in the study. Although PPG thickness decreased significantly in both regions, the amount of reduction was more pronounced centrally. Centrally, the reduction rate was 21.2% and 34.8% during the 1-6 months period and 6-12 months period, while peripherally it was 3.5% and 5.1%, respectively. No change was observed in the thickness of the epithelium during the follow-up period. There was a significant thinning of the stroma in the central and peripheral regions during the 1-6 months period (30.5% and 17%, respectively). No cases of exposure were observed during the follow-up period.ConclusionAlthough the most evident thinning of the layers covering the tube was observed in the early postoperative period, PPG showed a stable decrease even in the late period. The progressive reduction in the PPG thickness observed also in the peripheral region indicates that factors beyond mechanical forces contribute to this degenerative process. AS-OCT could be a valuable non-invasive tool in clarifying this process.

Full Thickness Prophylactic Scleral Windows Decrease the Rate of Choroidal Effusion and Drainage Surgery after Ahmed Glaucoma Valve Implantation.

To evaluate the effect of creating a full-thickness prophylactic scleral window (PSW) during Ahmed glaucoma valve (AGV) surgery on the rate of postoperative choroidal effusion and choroidal drainage surgery. In this retrospective matched case-control study, after insertion of AGV tube a PSW was created in one group. The control-matched group had AGV without a PSW. Primary outcome measures were the rate of choroidal effusion formation and choroidal drainage surgery. In total, 544 patients (604 eyes) had undergone AGV implantation from 2013 to 2017. The PSW group consisted of 111 eyes of 111 patients and the control group had 111 eyes of 98 matched patients. There were no differences for systemic diseases, number of anti-glaucoma drugs, aspirin use, smoking, laterality of the operated eye, axial length, and central corneal thickness between the groups. Out of 12 eyes with choroidal effusion, only one belonged to the PSW group (P=0.02). Six eyes in the control group needed choroidal drainage surgery, but none of the eyes in the PSW group required this procedure (P=0.02). No intra- and postoperative issues were observed at the site of the scleral window in the PSW group. PSW creation during AGV surgery is a safe method to decrease the rate of choroidal effusion and choroidal drainage surgery.

New approach to AGV implantation with scleral tunnel method by prolene suture: Şimşek Technique.

To present the short-term outcomes of our novel technique, the suture-assisted method, in long scleral tunnel Ahmed Glaucoma Valve (AGV) implantation. This retrospective study included glaucoma patients who underwent AGV implantation using the suture-assisted long scleral tunnel method and were fellowed for at least 6 months between January 2022 and November 2022. Preoperative and postoperative assessments included best-corrected visual acuity (BCVA), intraocular pressure (IOP), anterior and posterior segment examinations, anti-glaucomatous medications, and intraoperative and postoperative complications were also evaluated. Eight eyes of seven patients were included in the study. The mean age was 52.25 ± 29.38 years (r:8-76 years), and there were 5 female and 2 male patients. The mean follow-up duration period was 8.62 ± 2.50 months (r:6-12 months). The mean IOP was 27.12 ± 3.48 mmHg preoperatively and 11.62 ± 3.48 mmHg on postoperative on 1st day, 11.62 ± 3.20 mmHg at 1st week, 18.75 ± 8.94 mmHg at 1st month, 16.62 ± 2.72 mmHg at 3rd month, 16.12 ± 3.75 mmHg at 6th month. Postoperative hyphema was observed in one eye, and tenon cyst excision was performed in two eyes. No tube exposure was observed in any eye during the follow-up period. No hypotony-related complications were observed during follow-up. We believe that suture-asissted application of the long scleral tunnel method not only prevents tube exposure but also facilitates the passage of the AGV silicone tube through the scleral tunnel, reducing the surgical time contributing to a decreased the risk of infection.

Comparison of Tenon duplication with dura mater covering technique for Ahmed glaucoma valve implantation.

To compare the efficacy and complications of Tenon duplication with dura mater covering technique for Ahmed glaucoma valve (AGV) implantation. This retrospective study included 44 refractory glaucoma patients (44 eyes) who underwent AGV implantation from 2017 to 2020 in the Ophthalmology Clinic of Eskişehir Osmangazi University Hospital and attended regular postoperative follow-ups. The patients were divided based on whether they underwent Tenon duplication technique (group 1: n = 20) or dura mater covering technique (group 2: n = 24) during surgery. The patients' age, gender, systemic diseases, glaucoma type, pre-op intraocular pressure (IOP), and ocular surgeries were recorded. The groups were compared for IOP level control, early and late complications, postoperative antiglaucomatous medication requirements, glaucoma surgery requirements, presence of postoperative hypertensive phase (HP), and surgical success which was defined as an IOP ≥5 and ≤21 mmHg, with or without antiglaucoma medication. By the end of the mean follow-up (22.6 ± 10.6 months), the success rates were 95% (group 1) and 96% (group 2). The groups showed no differences in postoperative complications, postoperative antiglaucomatous drugs' onset time, additional glaucoma surgery, need for needling, presence of HP at 6 months postoperatively, and relationship between the glaucoma type and success rates ( P values: 0.86, 0.9, 0.48, 0.12, 0.36, and 0.8, respectively). The IO P values at the last follow-up were 15.2 ± 4.1 in group 1 and 14.7 ± 4.8 in group 2. The IOP reduction rates showed no significant differences. Since success and complications are similar in both Tenon duplication and dura mater covering technique, unique grafting materials may not be needed in AGV implantation surgery, except in special cases.

Clinical outcomes of Ahmed glaucoma valve implantation in primary open-angle glaucoma and pseudoexfoliative glaucoma.

To investigate the clinical outcomes of Ahmed glaucoma valve (AGV) implantation in primary open-angle glaucoma (POAG) and pseudoexfoliative glaucoma (PEXG). The patients who underwent AGV implantation for POAG and PEXG between January 2015 and December 2021 in a single tertiary center eye clinic were reviewed retrospectively. Thirty-one eyes with the diagnosis of POAG constituted Group 1 and 40 eyes with the diagnosis of PEXG constituted Group 2. The primary outcome measures were intraocular pressure (IOP) changes after AGV implantation and surgical success at the last visit. We evaluated complete and qualified surgical success using the following three criteria: (1) IOP ≤ 21mmH g, (2) IOP ≤ 18mmHg, and (3) IOP ≤ 15mmHg, as well as the absence of any serious complications, such as light perception loss and phthisis bulbi, and additional de novo glaucoma surgery. The mean follow-up times were 25.2 (± 21.4) months and 27.6 (± 19.8) months for Groups 1 and 2, respectively (p > 0.05). In Groups 1 and 2, the mean preoperative IOPs were 31.9 ± 9.4mmHg and 32.3 ± 8.4mmHg, respectively, which significantly reduced to 14.5 ± 0.7mmHg and 11.6 ± 0.6mmHg, respectively at the last postoperative visit (p < 0.001 for both). The mean IOP value at the last visit was statistically significantly lower in Group 2 (p = 0.006). At the last visit, the number of eyes with qualified success according to criteria 1, 2, and 3 was 26 (83.9%), 25 (80.6%), and 18 (58.1%), respectively, in Group 1 and 39 (97.5%), 39 (97.5%), and 32 (80%), respectively, in Group 2. The comparison of the qualified success rates showed statistically significantly higher rates in Group 2 for criterion 2 (p = 0.038). AGV implantation had high success rates in both POAG and PEXG, but at the final visit, lower IOP levels were reached in the latter.

Effect of a Pericardium Graft Inserted Adjacent to the Endplate in the Ahmed Glaucoma Valve Implantation.

The surface area of encapsulation around the Ahmed glaucoma valve (AGV) endplate is a critical factor in the surgical outcome as it is associated with the degree of IOP reduction. We investigated the surgical outcome of AGV implantation with an additional pericardium graft inserted adjacent to the endplate, with the intent of expanding the surface area of encapsulation. We enrolled 92 patients (92 eyes) who underwent AGV implantation. Of them, 50 patients underwent conventional surgery (termed the without-expansion group), and 42 received an additional an 8 × 6 mm pericardium graft inserted adjacent to the AGV endplate at the sub-Tenon's space (with-expansion). The hypertensive phase was classified as mild (>21 mmHg), moderate (>25 mmHg), and severe (>30 mmHg). Six months post-surgery, the with-expansion group exhibited a lower IOP (14.90 ± 4.27 mmHg) and lower peak IOP (22.29 ± 4.95 mmHg) than the without-expansion group (17.56 ± 4.88 mmHg and 25.06 ± 6.18 mmHg, p = 0.008 and p = 0.021, respectively). The with-expansion group exhibited a relatively low rate of moderate (16.7%) and severe (4.8%) hypertensive phases compared to the without-expansion group (40.0% and 20.0%, with p = 0.014 and p = 0.031, respectively). The additional pericardium graft was associated with a reduced occurrence of moderate hypertensive phase in both univariate and multivariate analysis logistic regression analyses (p = 0.017 and p = 0.038, respectively). Endplate surface area expansion using an additional pericardium graft reduced the occurrence of moderate and severe hypertensive phases, and lower postoperative 6-month IOP could be achieved.

Evaluation of the Hypertensive Phase after Ahmed Glaucoma Valve Implantation in Neovascular Glaucoma.

To compare Ahmed glaucoma valve (AGV) outcomes in neovascular glaucoma (NVG) eyes with and without a postoperative (PO) hypertensive (HTN) phase. Retrospective study at a single tertiary care center of patients who underwent AGV implantation for NVG treatment with ≥6-month follow-up. Main outcome measures included intraocular pressure (IOP), number of glaucoma medications (GM), and failure at month 6 or at the most recent visit. Failure was defined as decline to no light perception (NLP) vision, IOP >21 mm Hg, or need for glaucoma reoperations (all with GM). A total of 76 eyes of 74 patients (37 without HTN phase and 39 with HTN phase) with a mean follow-up duration of 28.9 ± 25.7 months (p = 0.602) were included. Both groups had similar demographics, visual acuity (VA), number of GM, etiology of NVG, and retina treatment perioperatively. Baseline IOP was significantly higher in the HTN phase group (p = 0.001). Compared to eyes without an HTN phase, HTN phase eyes more commonly met failure criteria at month 6 (33.3 vs 9.1%; p = 0.01), but both groups had a comparable cumulative failure for the entire follow-up period (p = 0.180). At the most recent visit, the number of GM was higher in the HTN phase group (p = 0.019), but IOP was similar in both groups. PO complications were comparable and uncommon in both groups. Hypertensive (HTN) phase following AGV implantation for NVG is associated with higher preoperative IOP and greater failure by PO month (POM) 6. However, eyes with and without the HTN phase had similar needs for GM and failure rates over the long term. Ramesh S, Shalaby WS, Myers JS, et al. Evaluation of the Hypertensive Phase after Ahmed Glaucoma Valve Implantation in Neovascular Glaucoma. J Curr Glaucoma Pract 2023;17(2):91-97.

Effect of Intraoperative Mitomycin C on the Surgical Outcomes of Ahmed Glaucoma Valve Implantation with Ciliary Sulcus Tube Placement.

To evaluate the effect of intraoperative mitomycin C (MMC) on the surgical outcomes of ciliary sulcus (CS) Ahmed glaucoma valve (AGV) tube placement. A retrospective review of medical records of 54 consecutive patients who underwent AGV implantation with tube placed in CS was performed. Consecutive cases operated without the use of intraoperative MMC from 2017 to 2019 were compared with consecutive cases operated with MMC from 2019 to 2021. Surgical failure was defined as intraocular pressure (IOP) exceeding 21 mmHg in two consecutive visits after postoperative 3 months or ≤30% IOP reduction, IOP ≤5 mmHg in two consecutive visits, or loss of light perception. Kaplan-Meier survival analysis and log-rank test were performed to compare the surgical failure rates. A total of 54 eyes of 54 patients were investigated. Mean follow-up period after AGV implantation was 1.4 ± 0.8 years. The MMC group showed significantly lower IOP during the 1st postoperative month (20.5 ± 8.6 mmHg vs. 15.8 ± 6.4 mmHg, p = 0.027), but the difference did not persist 6 months after the surgery (p = 0.805). The mean number of postoperative antiglaucoma medications was significantly lower in the MMC group in the 1st postoperative month (p = 0.047) but no difference was found at 6 months. No statistical difference was noted in the rates of postoperative complications. Kaplan-Meier survival analysis showed comparable survival rates between MMC group and no MMC group (p = 0.356). The intraoperative use of MMC significantly lowered IOP in the 1st postoperative month but did not increase 6 months success rates in patients receiving AGV tube placement in CS.

Comparison of Short and Long-Tunnel Needle Track for Ahmed Glaucoma Valve Implantation in a Private Eye Center in the Philippines: A Retrospective Study.

This study aimed to compare the success and complication rates among patients implanted with Ahmed Glaucoma Valve (AGV) using the short and long tunnel technique through retrospective chart review. We reviewed 54 charts of adult patients who underwent AGV implantation using a Short-Needle Track (SNT) or Long-Needle Track (LNT) technique. Intraocular pressures (IOP), Best Corrected Visual Acuity (BCVA) and number of medications were recorded pre-operatively, and at Day 1, 3, 7, Month 1, 3, 6 post-operatively. Treatment success, occurrence of Hypertensive Phase (HP), complication and procedures done after AGV implantation were compared between the two groups using one-tailed Z-test of proportions. A total of 20 (LNT) and 21 (SNT) charts were included in the study. There was no significant difference between the median postoperative IOP, BCVA, and number of anti-glaucoma medications between the two groups at each time interval. The comparison between the occurrence of HP (P = 0.435) and success rates (P = 0.476) between the two groups yielded no significant difference. Flat/shallow anterior chamber (AC) was seen exclusively in three eyes (14%) in the SNT group (P = 0.039). There was one occurrence of plate exposure in the LNT group (P = 0.149). The LNT technique of AGV Implantation may be used as an alternative to the traditional SNT (with autologous graft). The long needle track offers the advantage reducing the risk of complications arising from shallow anterior chamber post-operatively.

Long-Term Outcomes of Ahmed Glaucoma Valve Surgery in a Scottish Cohort of Patients With Refractory Glaucoma.

Purpose The purpose of this study was to evaluate the long-term efficacy and safety profile of the Ahmed glaucoma valve (AGV) implantation in cases of refractory glaucoma. Methods We conducted a retrospective audit of patients that underwent AGV implantation between 2006 and 2017 by two glaucoma surgeons in a tertiary glaucoma centre (Glasgow, UK). Primary outcome measures included the post-operative intraocular pressure (IOP), number of glaucoma medications, best-corrected visual acuity, complications, re-operation rates, and failure (defined as IOP > 21 mmHg or not reduced by 20% from baseline, IOP ≤ 5 mmHg, reoperation for glaucoma, removal of implant, or loss of light perception) at pre-defined time points (years 1 to 8). Results A total of 111 eyes of 94 patients were identified with a mean follow-up of 48.5 months (SD: 31.5); 60.3% of eyes had undergone at least one previous glaucoma surgery. Mean presenting IOP was 31.7 mmHg (SD: 11.4), and it reduced to 13.9 mmHg (SD: 4.2) in year 5 and 16.3 mmHg in year 8 (p<0.05). The number of glaucoma medications reduced from 3.8 (SD: 1.4) to 2.4 (SD: 1.4) and 2.6 (SD: 1.4) in the above time points (p<0.05 except year 8). The five-year success rate was 65.2%, and the five-year reoperation rate was 37% excluding cataract surgery. The most common early complications were hyphaema (12.6%) and transient hypotony (8.1%), whereas the most common late complication was an encapsulated bleb (15.1%). Conclusions AGV implantation is an effective procedure for controlling IOP in the long term in cases of refractory glaucoma.

Effect of guided Ahmed glaucoma valve implantation on corneal endothelial cells: A 2-year comparative study.

To compare the effects of guided and non-guided Ahmed glaucoma valve (AGV) implantation on the corneal endothelium. Medical records of patients who underwent AGV implantation in the anterior chamber (AC) were reviewed retrospectively. The eyes were divided into two groups depending on the use of a guidance technique with spatula and a 4-0 nylon intraluminal stent. Specular microscopy was performed to measure corneal endothelial cell density (ECD) loss after surgery, and the rate of ECD change was calculated. Tube parameters were measured using anterior segment optical coherence tomography (AS-OCT). The ECD loss during 2 years of follow-up was significantly lower in the guided AGV implantation (gAGV) group than in the non-guided implantation (ngAGV) group, and the rate of ECD change was -0.62 ± 1.23 and -1.42 ± 1.57%/month in the gAGV and ngAGV groups, respectively (p = 0.003). The mean tube-cornea distance (TCD) and mean tube-cornea angle (TCA) were significantly greater in the gAGV group than in the ngAGV group. The frequency of tube repositioning within 2 years after surgery was 0% in the gAGV group and 12.66% in the ngAGV group (p = 0.005). The use of a guidance technique can reduce corneal endothelial loss during the first 2 years after AGV implantation in the AC. The tube was positioned at a more distant and wider angle from the cornea in the eyes of the gAGV group, which may have contributed to the reduced need for tube repositioning to prevent corneal decompensation.

Comparison of conjunctiva-related complications between scleral and corneal patch grafts in Ahmed glaucoma valve implantation.

Comparison of the conjunctiva related complication rates and success rates among eyes with Ahmed glaucoma valve (AGV) implantation in which eye bank derived scleral and corneal patch grafts had been used to cover the tube. Retrospective comparative study. Patients who underwent AGV implantation between January 2000 to December 2016 were included. Demographic, clinical data, intra and post operative data was obtained from electronic medical records. Conjunctiva related complications were divided into two groups: with and without implant exposure. Conjunctiva related complication rates, success rate, risk factors among eyes with corneal and scleral patch graft were compared. Three hundred and twenty three eyes of 316 patients underwent AGV implantation. Scleral patch graft was used in 214 eyes of 210 patients (65.9%) and corneal patch graft was used in 109 eyes of 107 patients (34%). Median follow up was 14 months. There was no significant difference in the conjunctiva related complication rate (7.3 % in corneal patch graft versus 7.0% in scleral patch graft;p=0.5) and conjunctival dehiscence rate (3.7% versus 4.6%, P = 0.7) among the two groups. Success rate was significantly higher in the corneal patch graft group versus the scleral patch graft group (98% versus 72%; p=0.001). Eyes with corneal patch graft had a higher survival rate (P = 0.01). There was no significant difference in the rate of conjunctiva related complications following corneal and scleral patch grafts used to cover the AGV tube. Eyes with corneal patch graft had a higher success rate and survival rate.

Cytokines Associated With Onset of a Hypertensive Phase and Surgical Failure After Ahmed Glaucoma Valve Implantation

To investigate the relationship between cytokines of the aqueous humor or Tenon capsule, the onset of a hypertensive phase, and surgical failure in patients undergoing Ahmed Glaucoma Valve (AGV) implantation DESIGN: Prospective clinical cohort study. A total of 36 patients who underwent AGV implantation were included. Samples of aqueous humor and Tenon tissue were collected at the time of surgery. Multiple cytokines were evaluated in the samples using a bead-based multiplex cytokine assay. As for surgical outcomes, a hypertensive phase was defined as an intraocular pressure (IOP) of greater than 21 mm Hg within 3 months after surgery, whereas surgical failure was defined as an IOP greater than 21 mm Hg with maximum tolerable glaucoma medications during 2 consecutive visits. Patients who entered a hypertensive phase showed higher transforming growth factor-β2 (TGF-β2) levels in the aqueous humor (P=.012). A longer axial length and higher TGF-β2 concentration of the aqueous humor were associated with higher maximum IOP values during 3 months after surgery per multiple regression analysis (P=.028 and P=.034). In the multiple logistic regression analysis, higher monocyte chemoattractant protein-1 (MCP-1) concentrations in the aqueous humor and higher interleukin-4 concentrations in Tenon tissue were related to surgical failure (P=.022 and P=.040). Greater concentrations of TGF-β2 and MCP-1 were related to surgical outcome after glaucoma drainage device implantation. Further studies are needed to confirm that down-regulation of these cytokines could be helpful in improving surgical outcomes.

Tube-Iris Distance and Corneal Endothelial Cell Damage Following Ahmed Glaucoma Valve Implantation.

The most significant factor for endothelial cell loss should be readily identified, since prevention is the most crucial treatment. Here, we investigate risk factors for corneal endothelial cell density (ECD) decline following Ahmed glaucoma valve (AGV) implantation and determine the optimal cut-off values. This study included 103 eyes (95 patients) with glaucoma that underwent AGV implantation between January 2006 and January 2021 at a single medical center (Severance Hospital). We conducted consecutive t-tests between two groups separated by the ECD change rate to determine the survival state of the enrolled patients. Associations were evaluated using univariable and multivariable linear regressions. Optimal cut-off values for identified risk factors were analyzed using a Cox proportional hazards model and a receiver operating characteristic (ROC) curve based on logistic regression. Mean follow-up duration was 4.09 ± 2.20 years. After implementing consecutive t-tests, only patients with an ECD change rate greater than −6.1%/year were considered to have survived. Tube–iris distance (TID) was the only statistically significant factor identified in both the univariable and multivariable linear regressions. The cut-off value determined from the consecutive Cox regression method was 0.33 mm (smallest p-value of 0.0087), and the cut-off value determined from the ROC method was 0.371 mm (area under the receiver operating characteristic curve [AUC], 0.662). Patients with short TIDs showed a better ECD prognosis following AGV surgery; we suggest optimal TID cut-off values of 0.33 mm and 0.371 mm based on the implemented Cox regression and ROC methodology, respectively.

Long-term surgical outcomes of Ahmed valve implantation in refractory glaucoma according to the type of glaucoma

BackgroundWe evaluated the long-term efficacy and surgical outcomes of Ahmed glaucoma valve (AGV) implantation in patients with refractory glaucoma by glaucoma type.MethodsIn total, 135 eyes of 135 patients diagnosed with refractory glaucoma and underwent AGV implantation between 2002 and 2018 were reviewed retrospectively. The best-corrected visual acuity (BCVA), intraocular pressure (IOP), and number of antiglaucoma medications were investigated at baseline and follow-up. The cumulative probability of qualified success according to the glaucoma type was evaluated at 12, 24, 36, and 60 months postoperatively.ResultsThe mean IOP of all patients was 35.7 ± 11.7 mmHg, which was significantly reduced 12.7 ± 7.0 mmHg at 1 week, 16.2 ± 7.5 mmHg at 2 weeks, 17.6 ± 6.8 mmHg at 1 month, 17.5 ± 6.4 mmHg at 3 months, 16.1 ± 6.0 mmHg at 6 months, 16.7 ± 8.0 mmHg at 12 months, 16.4 ± 6.6 mmHg at 24 months, 15.6 ± 5.0 mmHg at 36 months, and 15.6 ± 5.6 mmHg at 60 months after surgery (p < 0.001, respectively). The mean number of antiglaucoma medications was 3.7 ± 1.3, which significantly decreased to 0.4 ± 0.9 at 1 week, 0.3 ± 0.8 at 2 weeks, 0.7 ± 0.9 at 1 month, 1.1 ± 1.1 at 3 months, 1.4 ± 1.0 at 6 months, 1.5 ± 1.1 at 12 months, 1.6 ± 1.2 at 24 months, 1.7 ± 1.2 at 36 months, and 1.8 ± 1.3 at 60 months after surgery (p < 0.001, respectively). The mean BCVA significantly improved from postoperative 2 weeks. Although 71 (52.6%) eyes had postoperative complications, the cumulative probability of surgical success was 72.6% at 12 months, 66.7% at 24 months, and 63.7% at 36 and 60 months. According to the glaucoma type, the success rate of AGV implantation was more than 50% even after 60 months follow-up, except subgroup of neovascular glaucoma (NVG) due to retinal vein occlusion (RVO).ConclusionsAGV implantation in patients with refractory glaucoma was, after long-term follow-up, successful overall. Therefore, AGV implantation can be an effective surgical option to reduce the IOP and number of antiglaucoma medications and to improve visual acuity for various glaucoma types.

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

To investigate the long-term effect of hypertensive phase (HP) on the clinical outcomes of Ahmed glaucoma valve (AGV) implantation. The records of patients with different etiologies of glaucoma who underwent AGV implantation with at least 3years of follow-up were retrospectively reviewed. HP was defined as the IOP > 21mm Hg during the first three months after surgery. The main outcome measure was cumulative success defined as 5 < IOP ≤ 21mmHg and 20% reduction from the baseline with or without IOP lowering medications. Results that do not achieve cumulative success or undergo glaucoma reoperation during the follow-up period are considered failures. The secondary outcome measures were intraocular pressure (IOP) and the number of glaucoma medications. A total of 120 patients (28 patients of HP, 92 patients without HP) with an average age (± SD) of 48.9 ± 19.6years and a mean follow-up of 4.5 ± 1.4years were enrolled. The mean duration of survival was 5.3 ± 0.5years in HP which was significantly shorter than 6.4 ± 0.2years 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 4years in HP patients compared with non-HP (all Ps < 0.01). Higher baseline IOP was significantly associated with higher rates of surgical failure. In the long-term follow-up, the duration of survival was significantly longer in the non-HP group. In the non-HP group, the failure rate was significantly lower than the HP group.

Surgical Outcomes of Ahmed Glaucoma Valve Implantation with Postoperative Use of Prednisolone Acetate versus Difluprednate

To evaluate the effect of postoperative topical prednisolone acetate and difluprednate on surgical outcomes of Ahmed glaucoma valve (AGV) implantation. Retrospective, comparative case series. The study population consisted of 102 eyes of 90 patients, including 52 eyes that received 1% prednisolone acetate (Pred Forte [PF]; Allergan Inc) and 50 eyes that received 0.05% difluprednate (Durezol [DZ]; Novartis Inc). The medical records of consecutive patients who underwent AGV implantation at the University of California, San Francisco, were retrospectively reviewed. Patients in the PF group received 1% prednisolone acetate 6 to 8 times per day tapered over 5 to 6 months postoperatively, and patients in the DZ group received 0.05% difluprednate 4 times daily tapered over 4 months postoperatively. Intraocular pressure (IOP), number of glaucoma medications, visual acuity (VA), postoperative complications, and the rate of treatment success. At 1 year, the IOPs (mean ± standard deviation) were 12.4 ± 3.7 mmHg in the DZ group and 13.0 ± 4.0 mmHg in the PF group (P= 0.49). The numbers of glaucoma medications were 0.72 ± 0.71 in the DZ group and 1.09 ± 0.91 in the PF group (P= 0.04), with reductions from baseline of 2.5 ± 1.0 glaucoma medications in the DZ group and 1.8 ± 1.6 glaucoma medications in the PF group (P= 0.01). The logarithm of the minimum angle of resolution VAs (mean ± standard deviation) were 0.55 ± 0.80 in the DZ group and 0.59 ± 0.65 in the PF group after 1 year of follow-up (P= 0.81). The cumulative probabilities of success were 95.8% in the DZ group and 93.5% in the PF group at 1 year (P= 0.61). Postoperative complications occurred in 4 eyes (7.7%) in the DZ group and 6 eyes (12%) in the PF group (P= 0.52). After 1 year, postoperative treatment with 0.05% difluprednate after AGV implantation resulted in a similar IOP, with the use of fewer glaucoma medications, compared with postoperative treatment with 1% prednisolone acetate. The rates of treatment success and surgical complications were comparable between the 2 groups during the first year of follow-up.

Outcomes of Ahmed glaucoma valve implantation and risk factors for graft failure in eyes with Descemet's stripping endothelial keratoplasty.

The aim of this study was to assess the efficacy of Ahmed glaucoma valve (AGV) in eyes with Descemet's stripping endothelial keratoplasty (DSEK) and glaucoma and evaluate the risk factors for failure. Retrospective interventional study included 27 eyes (27 subjects) that underwent AGV implantation following DSEK. The main outcome measure was AGV success, defined as IOP between 6 and 21mmHg with or without topical antiglaucoma medications (AGMs). Secondary outcome measure was graft survival. Graft failure was defined as corneal edema for ≥ 1month or irreversible graft opacity requiring intervention. Eighteen eyes (66.7%) had anterior chamber tube and 9 eyes (33.3%) had sulcus tube placement. Median follow-up was 1.2years (interquartile range, IQR, 0.5-2.5years). Following AGV implantation, the median IOP decreased significantly (p < 0.0001), median number of AGMs reduced significantly (p < 0.001) and median visual acuity was maintained (p = 0.76). Cumulative success probability of AGV was 75.8 ± 10.6% at 1year, and 75.8 ± 10.6% at 2years. For 24 clear grafts before AGV, estimates of success post-AGV were 100% at 1year, 77.8 ± 10% at 2years and 51.9 ± 16.4% at 3years. Postoperative tube intervention was a borderline significant risk factor for graft failure (p = 0.05) with hazards ratio of 7.2; however, tube location was not associated with failure. AGV can be considered an effective surgical option for IOP control in eyes with DSEK and glaucoma. However, high risk of long-term graft failure in these eyes needs to be considered specially those eyes needing tube intervention.

Effect of immediate shallow anterior chamber after Ahmed glaucoma valve implantation on intermediate-term intraocular pressure control.

To evaluate the incidence of shallow anterior chamber in the early postoperative period following Ahmed glaucoma valve (AGV) implantation and its effect on the hypertensive phase (HP), intermediate-term intraocular pressure (IOP) control, and success rate. A retrospective analysis of 369 eyes of 360 patients who underwent AGV implantation between January 2005 and January 2020 with a minimum follow-up of 2 months was performed. Twenty-six patients developed shallow anterior chamber (AC) within 8 weeks following surgery (cases). They were compared with 39 randomly selected controls (no shallow AC post AGV). HP (IOP spike >21 mmHg), use of ocular hypotensive medications, and other associations were compared. Incidence of shallow AC post AGV was 7% (95% confidence interval [CI] 4, 9). The onset of shallow AC was 3 ± 2.1 days and resolved within 6 ± 4.7 days. Hypotony (12 [47%] vs. 1 [2.5%], P 0.0001) and choroidal detachment (CD; 7 [27%] vs. 3 [8%], P 0.03) were more common in cases compared to controls. The HP occurred in 11 (43%) cases versus 13 (34%) controls (P 0.4). Cases required more ocular hypotensive medications than controls at the end of 8 weeks (1.1 ± 1 vs. 0.5 ± 0.5, P 0.01). There was no significant difference in the qualified success between the groups at 1 year. The development of postoperative shallow AC post AGV implantation was not detrimental to IOP control at 1 year. However, there is a need to monitor the occurrence of HP in these eyes.

Long-term vision outcomes and breed differences of Ahmed Glaucoma Valve implantation in 132 eyes of 122 dogs.

To evaluate the long-term vision outcomes of Ahmed glaucoma valve (AGV) implantation in dogs. The medical records of dogs that underwent AGV implantation from January 2010 to December 2019 were reviewed to assess the duration of post-surgical vision preservation (PVP). The relationship between PVP and the underlying cause of glaucoma, implant placement, and preoperative intraocular pressure was evaluated. One hundred and thirty-two eyes of 122 dogs (mean age, 8.3±2.6years) were included. The mean±standard error of PVP for all eyes was 57.5±3.9months. PVP in the dogs with primary acute glaucoma and prior history of cataract surgery was 56.4±4.7 and 59.3±5.9months, respectively (p=.712). The PVP of the Shiba Inu, American Cocker Spaniel, and other breeds was 63.1±5.5, 33.7±5.3, and 59.1±6.3months, respectively (p<.05). The PVP in dogs with medial implantation was 61.9±4.7months, and in those with lateral implantation was 45.4±6.4months (p=.034). Among the 132 eyes investigated, 48 (36.4%) lost vision by the last follow-up, and 18 eyes retained vision for more than 5years. Two of the total number of eyes retained their vision for more than 8years. The vision outcomes regarding the use of AGV for the management of canine glaucoma were favorable in dogs.