Ahmed Valve Implantation Research Articles

Surgical results of trabeculectomy and Ahmed valve implantation following a previous failed trabeculectomy in primary congenital glaucoma patients.

PurposeTo compare the surgical results of trabeculectomy and Ahmed glaucoma valve implantation after a previous failed trabeculectomy.MethodsA retrospective comparative case series review was performed on 31 eye surgeries in 20 patients with primary congenital glaucoma who underwent trabeculectomy or Ahmed glaucoma valve implantation after a previous failed trabeculectomy with mitomycin C.ResultsThe preoperative mean intraocular pressure was 25.5 mmHg in the trabeculectomy group and 26.9 mmHg in the Ahmed glaucoma valve implantation group (p = 0.73). The 48-month postoperative mean intraocular pressure was 19.6 mmHg in the trabeculectomy group and 20.2 mmHg in the Ahmed glaucoma valve implantation group (p = 0.95). The 12-month trabeculectomy success rate was 69%, compared with 64% for Ahmed glaucoma valve implantation, and the 48-month success rates were 42% and 36% for trabeculectomy and valve implantation, respectively. The success rates following the entire follow-up period were not significantly different between the two groups (p > 0.05 by log rank test). Postoperative complications occurred in 25% of the trabeculectomy-operated eyes and 9% of the Ahmed-implanted eyes (p = 0.38).ConclusionsThere was no significant difference in surgical outcome between the trabeculectomy and Ahmed glaucoma valve implantation groups, neither of which had favorable results. However, the trabeculectomy group demonstrated a higher prevalence of adverse complications such as post-operative endophthalmitis.

A Case of Malignant Glaucoma in a Vitrectomized Eye

Purpose: To report a case of malignant glaucoma in an eye vitrectomized 5 years previously due to endophthalmitis. Case summary: A 55-year-old male visited clinic due to a painful right eye 2 days in duration. Five years ago, he suffered endophthalmitis in his right eye and underwent pars plana vitrectomy. On slit-lamp examination, shallow anterior chamber depth of 2 central corneal thickness and corneal edema were observed along with remnant cortical lens material behind the intraocular lens. Intraocular pressure was 68 mm Hg measured using applanation tonometry. Maximal medical treatment failed to lower the intraocular pressure on the first day of visit. The very next day, anterior chamber became shallower less than 0.5 central corneal thickness and intraocular pressure was 70 mm Hg. Posterior capsular syndrome was suspected on anterior optical coherence tomography and neodymium:yttrium-aluminum-garnet laser posterior capsulotomy was performed, however, normal anterior chamber could not be restored. Despite continuous medical therapy for 3 weeks, the patient’s symptoms worsened and intraocular pressure increased over 99 mm Hg and therefore, the Ahmed glaucoma valve was implanted. One day after the operation, intraocular pressure decreased to 10 mm Hg and anterior chamber depth became deeper with the depth of over 5 central corneal thickness. At the final visit 4 months postoperatively, intraocular pressure and normal anatomy of the anterior segment were well maintained. Conclusions: Malignant glaucoma syndrome can occur even in vitrectomized eyes and capsular block syndrome can initiate this. Malignant glaucoma syndrome in a vitrectomized eye resistant to maximal medical treatment can be treated with Ahmed valve implantation. J Korean Ophthalmol Soc 2015;56(4):638-642

A Case of Cyclodialysis Cleft with Hypotony during Ahmed Valve Implantation Surgery

Purpose: To report a case of cyclodialysis cleft with hypotony during Ahmed valve implantation. Case summary: A 47-year-old male was referred for uncontrolled intraocular pressure (IOP) in the right eye. The patient had a history of ocular trauma and traumatic hyphema. He underwent pars plana vitrectomy, phacoemulsification and intraocular lens implantation 1 month prior due to rhegmatogenous retinal detachment. At the end of the Ahmed valve implantation surgery, the eye was hypotonic despite a deep anterior chamber. The hypotony continued and choroidal effusion developed. Anterior segment optical coherence tomography and gonioscopic examinations revealed small cyclodialysis clefts. After medical treatment with cycloplegics and steroids, choroidal effusion disappeared and IOP was normalized. Conclusions: Patients with previous ocular trauma or surgery could be prone to developing cyclodialysis cleft with hypotony. Inadvertent cyclodialysis cleft with hypotony can be treated with cycloplegics and steroids. J Korean Ophthalmol Soc 2015;56(2):300-303

Value of fibrin glue use with Ahmed valve implantation in refractory glaucoma

Purpose This study aimed to evaluate the efficacy and safety of the fibrin glue use with Ahmed glaucoma valve (AGV) implantation in refractory glaucoma. Patients and methods Twenty-two eyes of 22 patients diagnosed with refractory glaucoma were scheduled to receive an AGV and were grouped into two groups: group I included 12 eyes in which fibrin glue was used to secure the scleral flap and conjunctiva over the valve tube. Group II included 10 eyes in which sutures were used as the standard technique for valve implantation. Results The mean age of the patients was 29.5 ± 13.4 and 27.1 ± 10.3 years in groups I and II, respectively, and there was no statistically significant difference between the two groups (P > 0.5). Congenital glaucoma was the most common preoperative diagnosis in each group. The surgical outcome of both groups showed a statistically significant reduction in the mean operation time in group I (37 ± 6 min) than in group II (43 ± 5 min) (P 0.05). There was no statistically significant difference in the mean final intraocular pressure between the two groups (18.1 ± 2.2 and 17.4 ± 3.5 mmHg) in groups I and II, respectively (P > 0.05). The operative complications were hyphema, which occurred in one case in group I (8%) and in two cases in group II (20%). Suprachoroidal hemorrhage occurred in one case in group II. Shallow anterior chamber occurred in two cases (17%) in group I and in two cases (20%) in group II. One case in group I developed choroidal detachment. Tube exposure occurred in three cases, two cases in group I (17%), and one case (10%) in group II. Encysted valve occurred in three cases, two of which belonged to group I (17%) and one case belonged to group II (10%). Conclusion The use of fibrin glue with AGV implantation in refractory glaucoma makes its implantation easier, with a shorter operation time and less postoperative pain and inflammation, but its added cost usually limits its use. However, larger multicenter studies with longer-term follow-up are needed before the widespread use of this surgical technique.

Comparison of the changes in corneal endothelial cells after pars plana and anterior chamber ahmed valve implant.

Purpose. To compare the changes in corneal endothelial cells after pars plana Ahmed glaucoma valve (AGV) implantation with those after the anterior chamber AGV implantation for refractory glaucoma. Methods. The medical records of 18 eyes with pars plana implantation of AGV (ppAGV) were reviewed retrospectively and were compared with 18 eyes with the anterior chamber AGV (acAGV) implant. The preoperative and postoperative endothelial cells, intraocular pressure (IOP), and postoperative complications during the follow-up in both groups were compared. Results. The average follow-up was 18 months. The postoperative endothelial cells in the ppAGV and acAGV groups were 2044 ± 303 and 1904 ± 324, respectively (P = 0.25). The average percentage decrease in the endothelial cells in the ppAGV and acAGV groups at 18 months was 12.5% and 18.4%, respectively, and showed significant difference between the 2 groups (P = 0.01). No difference in IOP control and the number of postoperative glaucoma medications was observed between the 2 groups. Conclusions. Endothelial cell damage in the ppAGV group for refractory glaucoma appeared to be lower than that in the acAGV group. Therefore, pars plana implantation of AGV may be preferred as it may have lower level of endothelial cell damage while maintaining similar level of IOP control.

Ahmed valve implantation: intraoperative and early postoperative complications

Purpose. To analyze the causes of intraoperative and early postoperative complications and to develop a plan to improve the surgical technique. Methods. An Ahmed valve implantation by a standard method with obligatory posterior sclerectomy was performed in 238 patients aged from 18 to 88 years. Results. There were 7 cases of corneal perforation during the preparatory stage in excessively deep bridle suture; 3 cases of conjunctival and scleral perforation; 4 cases of inadvertent orifice enlargement in needle perforation of limbal scar tissue with consequent excessive filtration; in 37 patients, there was a hemorrhage from new vessels situated in the anterior chamber angle and the iris; 59 cases of serous cilio-choroidal effusion; 12 cases of hemorrhagic detachment. Conclusions. It is mandatory to follow the main principles of surgical technique and to take into consideration associated diseases.

Risk Factors for Decompression Retinopathy After Glaucoma Surgery

To evaluate the risk factors for decompression retinopathy after glaucoma surgery. We reviewed the medical records of patients who underwent a trabeculectomy or Ahmed valve implantation and divided them into 2 groups by the development of decompression retinopathy. Various factors were compared between the 2 groups, including age, sex, glaucoma type, previous intraocular surgery, preoperative and postoperative intraocular pressure (IOP), refractive error, axial length, anesthesia, and systemic risk factors such as history of diabetes, hypertension, medication, and a laboratory examination including hemoglobin, hematocrit, platelet, prothrombin time (PT), and activated partial thromboplastin time (aPTT). The proportion of eyes with decompression retinopathy was 3.05% (21 of 688 eyes), and 50 control eyes were selected randomly. No significant differences were observed between the 2 groups in age, systemic disease, glaucoma type, anesthesia, or the incidence rate of postoperative hypotony. Preoperative maximum IOP and the change of IOP was higher (P=0.016, 0.019), PT and aPTT was prolonged (P=0.001, 0.006), and hemoglobin and hematocrit level was lower in patients with decompression retinopathy (P=0.005, 0.002). Preoperative maximum IOP and hemoglobin showed a significant association with the development of decompression retinopathy in a multivariate analysis (P=0.031, 0.040). No significant difference was observed between the 2 groups for IOP and visual acuity 6 months postoperatively. Patients with high preoperative IOP and hematologic abnormalities have a higher risk for developing decompression retinopathy. Surgeons should carefully assess the potential risks and pay close attention to sufficiently decrease IOP preoperatively.

Surgical Outcome of Ahmed Valve Implantation in Mexican Patients with Neovascular Glaucoma.

ABSTRACTPurpose: To describe clinical results of Ahmed glaucoma valve implantation in Mexican patients with neovascular glaucoma (NVG).Materials and methods: We reviewed records of 60 eyes of 60 patients with NVG who underwent Ahmed valve implantation, with a follow-up period of 1 year. We identified successful and failed cases and compared baseline and follow-up characteristics to identify possible differences between both groups.Results: We classified 36 eyes (60%) as successful and 24 (40%) as failed cases. We found a significant difference in success rate in patients who had a hypertensive phase at any time during the follow-up period (OR = 5.15, CI = 1.49-20.15, p = 0.004). Patients in the success group showed a statistically significant decrease in the number of glaucoma medications 1 year after surgery (p <0.0001). We found a statistically significant difference in success rate in patients who had preoperative best corrected visual acuity (BCVA) better than logmar 0.70 (odds ratio 4.31, CI = 1.1-19.3, p = 0.03086).Conclusion: A hypertensive postoperative phase and a preoperative BCVA worse or equal to 20/100 seem to be risk factors for Ahmed valve surgical failure in patients with NVG.How to cite this article: Hernandez-Oteyza A, Lazcano-Gomez G, Jimenez-Roman J, Hernandez-Garciadiego C. Surgical Outcome of Ahmed Valve Implantation in Mexican Patients with Neovascular Glaucoma. J Curr Glaucoma Pract 2014;8(3):86-90.

Combined Ahmed glaucoma valve implantation and 23-gauge vitrectomy for neovascular glaucoma with vitreous hemorrhage

Objective To evaluate the clinical efficacy of Ahmed glaucoma valve (AGV) implantation combined with transconjunctival sutureless 23-gauge vitrectomy(23G-TSV) for treatment of neovascular glaucoma (NVG) with vitreous hemorrhage.Methods 25 eyes of 25 patients with neovascular glaucoma and vitreous hemorrhage were treated with combined AGV implantation and 23G-TSV.The intraocular pressure(IOP),best corrected visual acuity,success rate and postoperative complications were followed up for 6-12 months.The avevage follow up time was (9.96 ± 1.93) months.Results The IOP was(15.94±6.05),(14.76±2.39),(17.12±6.06),(17.44±2.75) and (18.96 ± 3.56) mmHg (1 mm Hg =0.133 kPa) at 1 day,1 week,1 month,3 months and the last follow-up postoperatively.Compared with pre-operative IOP of (48.12 ± 7.29) mmHg,the IOP was significantly(t =16.733,P ＜ 0.05 ; t =21.961,P＜0.05;t =16.917,P＜0.05 ;t =17.609,P＜0.05 ;t =18.091,P＜0.05)decreased after surgery; The total success rate was 84.0％ at final follow-up; The visual acuity was improved in all patients.Conclusion AGV implantation combined with 23G-TSV is effective for treating NVG with vitreous hemorrhage. Key words: Implants, drainage, glaucoma, Ahmed; Vitrectomy, 23G; Hemorrhage, Vitreous; Glaucoma, neovascular

Efficacy and safety of intravitreal bevacizumab in eyes with neovascular glaucoma undergoing Ahmed glaucoma valve implantation: 2-year follow-up.

To evaluate the efficacy and safety of intravitreal bevacizumab (IVB) in eyes with neovascular glaucoma (NVG) undergoing Ahmed glaucoma valve (AGV) implantation. This was a multicentre, prospective, randomized clinical trial that enrolled 40 patients with uncontrolled neovascular glaucoma that had undergone panretinal photocoagulation and required glaucoma drainage device implantation. Patients were randomized to receive IVB (1.25 mg) or not during Ahmed valve implant surgery. Injections were administered intra-operatively, and 4 and 8 weeks after surgery. After a mean follow-up of 2.25 ± 0.67 years (range 1.5-3 years), both groups showed a significant decrease in IOP (p < 0.05). There was no difference in IOP between groups except at the 18-month interval, when IOP in IVB group was significantly lower (14.57 ± 1.72 mmHg vs. 18.37 ± 1.06 mmHg - p = 0.0002). There was no difference in survival success rates between groups. At 24 months, there was a trend to patients treated with IVB using less antiglaucoma medications than the control group (p = 0.0648). Complete regression of rubeosis iridis was significantly more frequent in the IVB group (80%) than in the control group (25%) (p = 0.0015). Intravitreal bevacizumab may lead to regression of new vessels both in the iris and in the anterior chamber angle in patients with neovascular glaucoma undergoing Ahmed glaucoma valve implantation. There is a trend to slightly lower IOPs and number of medications with IVB use during AGV implantation for neovascular glaucoma.

Ahmed valve encapsulation as a main cause of its implantation failures

Objective. To study the relationship of post-operative ocular hypertension with the encapsulation of Ahmed valve’s plate. Methods. The standard Ahmed valve implantation was performed in 238 patients aged 18-86 with multiple glaucoma surgeries (39 %), secondary neovascular (36 %), pseudophakic (23 %), juvenile (8 %), uveal (5 %) and post-traumatic (2 %) glaucomas. A routine ophthalmic examination was performed in 1 week, 1, 3, 6, 9, 12 and 36 months after surgery. Results. Excision of the fibrous capsule as the only way to cope with post Ahmed valve ocular hypertension was performed on 16 patients 3-36 months after surgery. Macro- and microscopic analysis of the excised capsules was done. In all cases, preparations of 1.2-2.2 mm thickness were obtained. We found a bilaminar structure of the capsule, the inner surface consisting of densely-packed collagen fibers, whereas the outer layer is represented by a loose fi-brovascular layer. Suspension of encapsulation is possible at initial stages of scarring, by applying ocular massage, needling, revision of the surgical area, and injection of antimetabolites.

Artificial iris devices: Benefits, limitations, and management of complications

To discuss limitations and benefits of a custom-made foldable artificial iris (Artificialiris) in the management of acquired iris defects. Hochkreuzklinik Eye Hospital, Bonn, and the Department of Ophthalmology, University of Cologne, Germany. Case series. We reviewed the clinical course and surgical management in eyes with sight-compromising complications after phakic anterior chamber implantation of synthetic iris devices between November 2011 and January 2012. Three eyes of 2 patients were reviewed. One patient developed cataract and corneal decompensation after anterior chamber artificial iris implantation in the left eye to treat post-uveitic mydriasis. Further treatment included artificial iris removal, cataract surgery, iridoplasty, and Descemet membrane endothelial keratoplasty (DMEK). By the 6-month follow-up, visual acuity had increased from 20/50 to 20/25. The second patient presented with bilateral secondary glaucoma, cataract, corneal edema, and iris atrophy after implantation of Newiris devices for cosmetic reasons. He consecutively had binocular explantation of the cosmetic devices, cataract surgery, artificial iris implantation, and DMEK in both eyes and Ahmed valve implantation in the right eye. During the 6-month follow-up, the intraocular pressure remained sufficiently adjusted in both eyes. Photophobia was eliminated, and visual acuity improved to 20/32 in the right eye and 20/20 in the left eye. In patients with major iris defects ineligible for pupilloplasties, the artificial iris allows functionally and esthetically satisfactory anterior segment reconstruction. To prevent secondary complications, the artificial iris should only be implanted in aphakic or pseudophakic eyes and placed in the posterior chamber.

Reasons for Early Ocular Hypertension after Uneventful Cataract Surgery

To discuss the reasons for and measurements of early ocular hypertension after uneventful phacoemulsification and intraocular lens (IOL) implantation. This was a retrospective review of patients who had early ocular hypertension after cataract surgery from a single-surgeon practice that medications failed to control or required additional surgery from September 2011 to January 2013. Of the 1270 eyes that had cataract surgery by one surgeon in our department in 16 months, 12 (9.4‰) eyes of 12 patients met the inclusion criteria. The mean postoperative intraocular pressure (IOP) peak was 41 (range 32-62) mm Hg. The median time of initial onset after cataract surgery was 3.5 days (range 1-60 days). Six eyes had antiglaucoma surgery history. Ahmed valve implantation with mitomycin C (MMC) was applied to 4 eyes. Two eyes underwent 5-fluorouracil needling revision with MMC. The IOP dropped in 3 eyes only in the case that the conventional topical corticosteroid agent was stopped, diagnosed as steroid responders. One eye of a patient with diabetes mellitus (DM) developed pseudophakic pupillary block angle-closure glaucoma due to the plasma glucose fluctuations. The IOP was controlled after Nd:YAG laser iridotomies. Residual cortex caused ocular hypertension in 2 eyes and surgical aspirations were performed. Following monitoring of IOP for 6 to 24 months, all eyes were within the normal range. Patients with history of glaucoma surgery; high myopia, especially in young age; and DM merit particular observation and treatment for possible IOP elevation following cataract surgery.

Marfan Syndrome in ophthalmology

Authors report the case of a 59-year old woman with bilateral posterior lens luxation in vitreous, medically controlled glaucoma and corneal adherent leucoma with vascularization in whom Marfan syndrome was diagnosed. The patient underwent complete clinical eye and systemic examinations and blood samples were drawn for mutational screening of fibrillin1 gene (FBN1). The patient was diagnosed with Marfan syndrome on clinical basis do to genetic testing revealed a new heterozygous mutation in the FBN1 gene and described with ocular signs. The patient required pars plane vitrectomy with lensectomy, or Ahmed valve implantation in vitreous to control glaucoma secondary, but the finally treatment was without surgical modules from recommendation of referent expert team. In our patient glaucoma secondary was under therapy control.

Efficacy of Intravitreal Bevacizumab With Panretinal Photocoagulation Followed by Ahmed Valve Implantation in Neovascular Glaucoma

To establish the efficacy and safety of intravitreal bevacizumab (Avastin) with panretinal photocoagulation (PRP) followed by Ahmed valve implantation in the treatment of neovascular glaucoma (NVG). This prospective randomized study included 40 eyes of 40 patients with refractory NVG. Twenty eyes underwent Ahmed valve implantation with intravitreal bevacizumab (Avastin) (1.25 mg in 0.5 mL) and PRP and 20 eyes were managed by Ahmed valve and PRP (control group). The follow-up period was 18 months. Complete success was defined as an intraocular pressure ≤ 21 mm Hg. Qualified success was considered when the above criteria were fulfilled but with additions of antiglaucoma topical medical treatment. The results revealed 95% total success (75% complete success and 20% qualified success) in the first group in which Avastin-augmented Ahmed valve was performed compared with 50% total success in the control group in which Ahmed valve implantation was performed alone (25% complete success and 25% qualified success). Intravitreal bevacizumab (Avastin) with PRP followed by Ahmed valve implantation appears to be effective in the management of NVG.

Ahmed Valve, Suture-less Implantation

Tissue adhesives have been used in ophthalmology instead of sutures to minimize the operating time. This case series investigated the effectiveness and safety of use of cyanoacrylate in Ahmed valve implantation through pars plana for refractory glaucoma. Seventeen eyes of 17 patients with refractory glaucoma underwent Ahmed valve scleral suture-less implantation through pars plana with a cyanoacrylate suture of the plate. Refractory glaucoma was defined as intraocular pressure (IOP) ≥ 21 mm Hg with antiglaucoma eye drops, good adherence to treatment, and no previous glaucoma surgery. IOP control and development of complications were evaluated during the follow-up (mean follow-up, 13.23 mo, 6 to 28 mo). IOP control, defined as IOP ≤ 21 mm Hg with or without antiglaucoma eye drops, was achieved in 82.2% of patients, and 58.8% were able to eliminate antiglaucoma eye drops. Mean surgical time was 9.76 ± 2.60 and 6 ± 0.81 minutes in patients with previous vitrectomy (4 cases). Postoperative complications included transiently increased IOP, transient hyphema, early postoperative hypotony (4 cases), and tube block by the vitreous (2 cases): 1 resolved by Nd:YAG and the other by second vitrectomy. No cases of tube or plate extrusion, plate migration, choroidal or retinal detachment, or vitreous hemorrhage were observed. These results are promising and demonstrate a safe and effective alternative to the traditional scleral suture. Our data suggest that Ahmed valve implantation through pars plana with cyanoacrylate is a safe and effective method for refractory glaucoma. Further studies are needed to confirm our observation.

The effect of intravitreal bevacizumab injection before Ahmed valve implantation in patients with neovascular glaucoma

To evaluate the effect of intravitreal bevacizumab (IVB) before Ahmed valve implantation for treatment of neovascular glaucoma (NVG). This study is a retrospective, comparative, consecutive case series. The study group consisted of 27 eyes of 26 patients with NVG who underwent an Ahmed valve implantation. Thirteen eyes were treated with Ahmed valve implantation alone (control group), and 14 eyes were treated with a combination of preoperative IVB injection and Ahmed valve implantation (IVB group). Visual acuity, intraocular pressure (IOP), number of anti-glaucoma medications, surgical complications, and success rate were compared between the two groups. There were no significant differences in preoperative characteristics between the two groups. Visual acuity at 1, 2 weeks, and 1 month after surgery were significantly better in the IVB group (p = 0.038, 0.034, and 0.032, respectively). Hyphema associated with Ahmed valve implantation occurred significantly less in the IVB group (p = 0.016). On the other hand, the mean IOP and number of anti-glaucoma medications at all follow-up periods were similar between the two groups. Kaplan-Meier survival analysis showed the probability of success 6 months after surgery as 71.4 % in the IVB group and 84.6 % in the control group. No significant difference in success rate was found between the groups (p = 0.422). IVB before Ahmed valve implantation for treatment of NVG reduced the incidence of hyphema. In this retrospective study, IVB provided better visual outcome in the early postoperative periods but did not significantly improve mean IOP, number of anti-glaucoma medications, or success rate.

The surgical management of massive intraoperative and postoperative suprachoroidal hemorrhage: anatomic and functional outcomes

To describe the clinical characteristics, management and treatment outcomes of patients with post-surgical suprachoroidal hemorrhage (SCH). A retrospective cross-sectional study was conducted, in which the medical records of 9 consecutive patients with SCH admitted to the Goldschleger Eye Institute were reviewed. The mean age was 74 years (range 61-84) and the mean follow-up time was 38.3 ± 0.1 months (range 4-87 months). Four cases were associated with glaucoma surgeries (2 trabeculectomies and 2 Ahmed valve implantations), 3 cases with cataract surgery and 2 cases with pars plana vitrectomy. The diagnosis of SCH was ranging from intra-operative to 8 days following the primary procedure. Most patients underwent posterior sclerotomies and drainage alone or combined with pars plana vitrectomy in a mean timing of intervention of 11 ± 4 days. At one month of follow-up the visual acuity improved in 7 eyes and remained stable in 2, compared to the VA prior to the drainage operation. The mean VA improved from 2.03 to 1.285 logMAR units at 1 month following the drainage procedure (p=0.003). SCH still remains a challenging complication of many ophthalmological procedures. The current surgical management may improve visual acuity though the general prognosis is still poor.

Epithelial Downgrowth After Ahmed Implantation Presenting as a Peritubular Fibrovascular Membrane

This is a case report of a 54-year-old woman with chronic uveitis who developed epithelial downgrowth after an Ahmed valve implantation. The epithelial downgrowth presented in an unusual fashion, as a peritubular fibrovascular membrane. Our case suggests that in patients who have undergone glaucoma drainage implantation with clinical features such as persistent hypotony and atypical inflammatory cells, high clinical suspicion for epithelial downgrowth and careful search for potential fistulas are necessary, even without an obvious wound leak.

Ahmed valve implantation for neovascular glaucoma after 23-gauge vitrectomy in eyes with proliferative diabetic retinopathy.

To report on the outcome of Ahmed glaucoma valve (AGV) implantation for the management of neovascular glaucoma (NVG) after 23-gauge vitrectomy for proliferative diabetic retinopathy (PDR). Twelve medically uncontrolled NVG with earlier 23-gauge vitrectomy for PDR underwent AGV implantation. The control of intraocular pressure (IOP), preoperative and postoperative best-corrected visual acuity, the development of intraoperative and postoperative complications were evaluated during the follow-up. The mean follow-up was 15.4±4.3 months (9-23 months). Mean preoperative IOP was 49.4±5.1mmHg and mean postoperative IOP at the last visit was 17.5±1.6mmHg. The control of IOP was achieved at the final follow-up visits in all patients, however, 8 of 12 patients still needed anti-glaucoma medication (mean number of medications, 0.8±0.7). The visual acuity improved in nine eyes, and the visual acuity unchanged in three eyes at the final follow-up visits. The complications that occurred were minor hyphema in three eyes, choroid detachment in two eyes, and the minor hyphema and choroid detachments were reabsorbed without any surgical intervention. AGV implantation is a safe and effective procedure that enables successful IOP control and vision preservation in the NVG patients with the history of earlier 23-gauge vitrectomy for PDR.