Extender-tube for Ahmed glaucoma valve implant

CASE REPORT: We describe the case of a 16 year-old woman, with inflammatory glaucoma secondary to juvenile rheumatic arthritis, successfully treated by Ahmed glaucoma valve implant. Two years later, a severe increase of intraocular pressure related to anterior tube migration occurred. The Ahmed valve tube extender was successfully used to lengthen the tube. DISCUSSION: If the tube length is too short to reintroduce it into the eye, there are three surgical options: to use a tube extender, to insert the tube via the pars plana or to insert a new drainage implant. A piece of an angiocatheter or a silastic tube have been used for lengthening the tube of the valve implant; however the Ahmed valve tube extender design makes surgery easier and allows keeping the valve in the original place, minimizing the risk of postoperative migration.     

Intraoperative management of nonfunctioning Ahmed glaucoma valve implant.

A 62-year-old woman with neovascular glaucoma underwent filtering surgery with the Ahmed glaucoma valve (New World Medical, Inc., Rancho Cucamonga, CA). Intraoperative hypotony secondary to a defective valve was noted and managed by excising the valve mechanism. The implant was then treated as if it was non-valved by placement of an obturator suture. The postoperative course was unremarkable for a non-valved implant. This case demonstrates how intraoperative hypotony secondary to overfiltration of an Ahmed glaucoma valve implant can be successfully managed by converting to a non-valved implant.     

Acquired Pseudo-Brown's syndrome immediately following Ahmed valve glaucoma implant.

A 76-year-old woman noted vertical and horizontal diplopia one day following placement of an Ahmed valve in the superonasal quadrant of her left eye. She was unable to elevate her left eye, especially in adduction. She refused implant removal and strabismus surgery alone failed to satisfactorily resolve her problem. On forced duction testing, the implant became wedged between the globe and orbit superonasally. Subsequent repositioning of the valve resulted in resolution of her motility problem. Implant-orbital disproportion can produce a pseudo-Brown's syndrome. Surgeons are encouraged to perform forced duction testing at the time of glaucoma implant placement to detect and prevent this complication.     

Ahmed valve drainage implant surgery in the management of paediatric aphakic glaucoma

BACKGROUND: Paediatric aphakic glaucoma presents months or years after cataract surgery in children and is a major long term complication. The results of surgical treatment are poor and many children require multiple and repeat procedures with poor visual outcomes. METHODS: 13 children (19 eyes) had Ahmed valve implantation surgery, nine of the children had previous procedures such as cycloablation or trabeculectomy. Mitomycin was used at surgery in some patients and valve needling with Healon GV and 5-fluorouracil in some blebs after surgery. SF(6) gas was also used at the time of surgery in most children to reform the anterior chamber. RESULTS: 12 of the children (18 eyes) achieved intraocular pressure control of 15 mm Hg or less with a valve alone or with additional medical therapy. CONCLUSION: Ahmed valve implantation surgery alone or in combination with medical therapy is successful and safe in the management of paediatric aphakic glaucoma.     

Endophthalmitis associated with the Ahmed glaucoma valve implant

AIM: To investigate the rate, risk factors, clinical course, and treatment outcomes of endophthalmitis following glaucoma drainage implant (GDI) surgery. METHODS: A computerised relational database search was conducted to identify all patients who were implanted with Ahmed glaucoma valve (AGV) and developed endophthalmitis following surgery at the King Khaled Eye Specialist Hospital in Riyadh, Saudi Arabia, between 1 January 1994 and 30 November 2003. Only medical records of the patients who developed endophthalmitis were retrospectively reviewed. RESULTS: 542 eyes of 505 patients who were on active follow up were included in the study. Endophthalmitis developed in nine (1.7%) eyes; the rate was five times higher in children than in adults. Delayed endophthalmitis (developed 6 weeks after surgery) occurred in eight of nine eyes. Conjunctival erosion overlying the AGV tube was present in six of nine eyes. Common organisms isolated in the vitreous included Haemophilus influenzae and Streptococcus species. Multiple regression analysis revealed that younger age and conjunctival erosion over the tube were significant risk factors associated with endophthalmitis. CONCLUSION: Endophthalmitis is a rare complication of GDI surgery that appears to be more common in children. Conjunctival dehiscence over the GDI tube seems to represent a major risk factor for endophthalmitis. Prompt surgical revision of an exposed GDI tube is highly recommended.     

Two-staged Baerveldt glaucoma implant for childhood glaucoma associated with Sturge-Weber syndrome

PURPOSE: To report the outcome and complications of 10 eyes of 9 children with Sturge-Weber syndrome (SWS) who underwent two-stage insertion of a Baerveldt glaucoma implant (BGI) for glaucoma. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: The authors reviewed the medical records of children under the age of 14 years with SWS who underwent two-stage BGI for glaucoma at two tertiary care referral centers. MAIN OUTCOME MEASURES: Intraoperative and postoperative complications, intraocular pressure (IOP), number of glaucoma medications, visual acuity, and further surgical intervention. RESULTS: Ten eyes of nine patients were included in the study. Ages of the nine patients at time of first stage BGI ranged between 6 weeks and 13 years. With average follow-up of 35 months (range, 10-50), all eyes had adequate IOP control (< or = 21 mmHg) without the need for additional glaucoma surgery. Intraocular pressure was reduced from a mean (+/- standard deviation) of 24.8 +/- 6.2 mmHg preoperatively to 16.9 +/- 2.3 mmHg at last follow-up visit (P = 0.001). The number of medications used for control of glaucoma was reduced from a mean (+/- standard deviation) of 1.8 +/- 1.0 preoperatively to 1.1 +/- 1.4 at last follow-up visit (P = 0.2). One eye had serous choroidal effusions with overlying serous retinal detachment that resolved spontaneously after 7 days with no permanent visual loss, and one eye had low choroidal effusion that lasted 4 days. There were no intraoperative or postoperative suprachoroidal hemorrhages. At last follow-up, visual acuity had improved by one or more lines in all patients in whom vision was measurable. CONCLUSIONS: Two-stage BGI surgery appears to be a safe and effective treatment for refractory glaucoma in children with SWS.     

Long-term results of Ahmed glaucoma valve and Molteno implant in neovascular glaucoma

AIMS: To evaluate the surgical success results of Ahmed glaucoma valve (AGV) and Molteno single-plate implant (MSPI) in cases of neovascular glaucoma (NVG). METHODS: Between May 1997 and May 2002, 38 of 38 NVG patients that underwent implantation of AGV and 27 eyes of 27 NVG patients that underwent MSPI (a total 65 eyes of 65 patients) included to the study. RESULTS: The cumulative probabilities of success were 63.2% at 1 year, 56.2% at 2 years, 43.2% at 3 years, 37.8% at 4 years, and 25.2% at 5 years in AGV group whereas the cumulative probabilities of success were 37.0% at 1 year, 29.6% at 2 years, 29.6% at 3 years, 29.6% at 4 years, and 29.6% at 5 years in MSPI group (P=0.141). Preoperative visual acuity <2/200 (P=0.003), diagnosis of diabetes mellitius (P=0.050), and preoperative IOP>or=35 mmHg (P=0.038) were found to be poor prognostic factors for surgical success. CONCLUSIONS: Both AGV and single plate MSPI were successful for early and intermediate-term of IOP control but in long term both implants were failed to achieve control of IOP in patients with NVG.     

A clinical study of the Ahmed glaucoma valve implant in refractory glaucoma

OBJECTIVE: To assess clinical outcomes of the Ahmed glaucoma valve implant in patients with refractory glaucoma. PARTICIPANTS: 15 patients (16 eyes), including 7 women and 8 men; patients with glaucoma: phakic- 10 eyes, pseudophakic - 4 eyes, and aphakic - 2 eyes, average age: 47.2 (18-72 years old), average IOP before the intervention: 47 mmHg (32-71 mmHg), average number of medications taken before the intervention: 3.0. MAIN OUTCOME MEASURES: Success was defined as IOP less than or equal to 21 mmHg and no need to perform another surgical intervention. Average period of observation was 23.2 months (6-42 months). RESULTS: Intervention was successful in 12 out of 16 eyes. Average number of medicaments taken after the intervention decreased to 1.2. 4 out of 16 patients had a hypertensive phase. Cumulative probabilities of success at 1 and 2 years were 88% and 72% respectively. Complications: hyphema - 4 eyes (25%), tube exposure - 1 eye (6.25%), corneal graft failure - 4 eyes (25%), hypertensive phase - 4 eyes (25%) anterior chamber shallowing - 2 eyes (12.5%) CONCLUSIONS: The Ahmed glaucoma valve implant is an effective way of treating the patients with refractory glaucoma.     

Pars plana Ahmed valve implant and vitrectomy in the management of neovascular glaucoma.

BACKGROUND AND OBJECTIVE: To evaluate the efficacy and safety of the pars plana Ahmed glaucoma valve (New World Medical, Inc., Rancho Cucamonga, CA) implant combined with pars plana vitrectomy and panretinal photocoagulation for the management of neovascular glaucoma in patients with vitreous hemorrhage. PATIENTS AND METHODS: The records of 18 eyes of 17 consecutive patients with neovascular glaucoma who had undergone pars plana vitrectomy and pars plana Ahmed valve implant were evaluated. The patients were observed for a mean time of 14.2 months (range, 6 to 28 months). RESULTS: Mean preoperative intraocular pressure with oral and two or three topical antiglaucoma medications was 53.3 +/- 10 mm Hg, and mean postoperative intraocular pressure without oral antiglaucoma medications was 16.3 +/- 7.1 mm Hg (P < .0001) at the final visit. Overall success rate was 72.2%, defined as an intraocular pressure of 5 to 21 mm Hg with or without antiglaucoma medication. A postoperative hypertensive phase occurred in 7 patients (38.8%), of which all but one responded to medical therapy. Visual acuity was stabilized or improved in 77.7% of the eyes. There was one case of each of the following adverse events: mild vitreous cavity hemorrhage, hypotony, choroidal effusion, epiretinal membrane, corneal edema, and corneal ulcer. Two cases developed phthisis bulbi and lost light perception. CONCLUSIONS: Pars plana vitrectomy and Ahmed valve implantation seems to be a viable surgical modality in the management of neovascular glaucoma and coexisting posterior segment pathology with a relatively low rate of serious permanent postoperative complications.     

Malignant glaucoma following combined Ahmed valve implant and phacoemulsification surgery for chronic angle-closure glaucoma

CASE REPORT: Simultaneous Ahmed valve implant, combined with phacoemulsification cataract surgery, is a useful therapeutic option for patients with chronic angle-closure glaucoma, when conventional filtering surgery fails. This combined approach permits both control of intraocular pressure and early recovery of visual function. We report the results in five patients successfully treated with this combined procedure, two of whom developed early postoperative malignant glaucoma. DISCUSSION: Predisposing anatomic features in patients with chronic angle-closure glaucoma, associated with sudden anterior chamber decompression and increased postoperative inflammation, may facilitate the development of malignant glaucoma following combined glaucoma implant and phacoemulsification surgery.     

Ahmed引流阀植入术治疗难治性青光眼

目的探讨Ahmed引流阀治疗难治性青光眼的效果及其并发症的防治。方法对21例难治性青光眼行Ahmed引流阀植入术，术后随访6～24月。结果眼压控制的有效率达到85．71％，术后并发症主要是早期的短暂性浅前房和高眼压，以及晚期的纤维化。结论Ahmed引流阀植入术对于难治性青光眼是一种有效的治疗方法。     

青光眼阀植入治疗难治性青光眼

目的 探讨研究Ahmed青光眼阀(AGV)植入术对难治性青光眼的治疗效果.方法 抗青光眼手术失败等类型的难治性青光眼21例(23眼).施以AGV植入术,随访6～24个月,观察术后视力、眼压,以及并发症等,以评价AGV植入手术的效果.结果 术后平均随访(20.1±7.2)月,手术前后视力比较差异无统计学意义(Z=-0.365,P＞0.05);眼压术前(45.70±11.44) mmHg、术后(26.28±12.02) mm Hg.随访1年,2年治疗的完全成功率分别为40.00％、16.67％,治疗有效率分别为70.00％、50.00％.在23眼中,术后1周内有13眼(56.52％)出现了并发症,中晚期(6～24个月间)共有6眼(26.09％)出现并发症,并发症的总体发生率为82.61％.结论 房水引流管植入术可以提高难治性青光眼滤过手术的成功率,但其诸多并发症应当引起高度的重视.     

Ahmed青光眼阀植入术治疗新生血管性青光眼

目的:探讨Ahmed青光眼引流阀植入术治疗新生血管性青光眼的疗效及其并发症的防治。方法:回顾性分析18例18眼新生血管性青光眼行Ahmed青光眼阀植入术的疗效,主要观察指标为手术前后视力、眼压、并发症及手术成功率等,术后随访6~18mo。结果:术后最佳矫正视力不变11眼,提高5眼,下降2眼。术后眼压控制的有效率达到89%,术后并发症主要是早期的短暂性浅前房和高眼压、前房积血以及晚期的滤过道瘢痕纤维化。结论:Ahmed引流阀植入术是治疗新生血管性青光眼的一种比较有效的方法。     

Ahmed青光眼阀植入术治疗难治性青光眼

目的评价Ahmed青光眼阀（AGV）植入术治疗难治性青光眼的早期和中远期临床疗效,探讨术后早期和中远期并发症的防治。方法对35例（35只眼）难治性青光眼患者施行Ahmed青光眼阀植入术,术后随访3～66个月,对术前术后眼压采用配对比较。结果术前平均眼压为（43.17&#177;11.54）mmHg,术后早期（术后第7～10天）平均眼压为（13.11&#177;5.52）mmHg（P〈0.01）,成功率为91.43%;中远期平均眼压为（19.03&#177;9.17）mmHg（P〈0.01）,成功率为80%。术后早期常见的并发症有前房出血12只眼（34.29%）、前房形成迟缓及低眼压9只眼（25.71%）及一过性高眼压5只眼（11.43%）等;中远期常见并发症有盘周纤维包裹6只眼（17.14%）,引流管外露1只眼（2.86%）,角膜失代偿1只眼（2.86%）。结论尽管Ahmed青光眼阀植入术存在一些不容忽视的并发症,但仍不失为治疗难治性青光眼的一种有效方法。     

Long-term follow-up of primary glaucoma surgery with Ahmed glaucoma valve implant versus trabeculectomy

PURPOSE: To compare the long-term results of trabeculectomy and Ahmed glaucoma valve implant in the initial surgical management of primary open- and closed-angle glaucoma. DESIGN: Randomized controlled clinical trial. METHODS: One eye each of consecutive patients with primary glaucoma and without prior intraocular surgery was randomized to receive either trabeculectomy or the Ahmed implant.Large university-affiliated eye hospital in Columbo, Sri Lanka. RESULTS: Of 123 patients, 64 were randomized to trabeculectomy and 59 to the Ahmed implant. With a mean follow-up of 31 months, the trabeculectomy group had statistically lower intraocular pressures (IOP) during the first postoperative year. After the first year, the IOPs were comparable. No statistically significant differences between groups were noted for postoperative visual acuity, visual field, anterior chamber depth, and short-term or long-term complications. Adjunctive medication requirement was comparable for both groups. The cumulative probabilities of success (IOP <21 mm Hg and at least 15% reduction in IOP from preoperative levels) at the final follow-up period (months, 41-52) were 68.1% for trabeculectomy and 69.8% for Ahmed implant (P =.86). CONCLUSIONS: Lower IOPs were noted for the trabeculectomy group during the first year. With longer follow-up, the IOPs and the cumulative probabilities of success were comparable between the two groups.     

Ahmed青光眼阀植入及其联合手术治疗难治性青光眼的临床观察

目的:观察Ahmed青光眼阀植入及其联合手术治疗难治性青光眼的临床疗效.方法:回顾在我院行Ahmed青光眼阀植入及其联合手术的难治性青光眼病例45例,对他们手术前后的视力,眼压,术后并发症及其防治措施等进行总结分析.结果:难治性青光眼45例(45眼)实行了Ahmed青光眼阀植入术或联合晶状体摘除、玻璃体切割、人工晶状体植入术等;术后平均观察(3～18)9.7mo;患者术前的平均眼压36.8±12.3mmHg,术后平均眼压18.0±4.5mmHg;手术成功率87%;术后最佳矫正视力提高16眼(35%),视力无变化21眼(47%),视力降低8眼(18%);术后早期最常见的并发症是一过性浅前房及低眼压,发生率为20%,晚期最常见的并发症是滤过泡包裹,发生率是13%.结论:Ahmed青光眼阀植入及其联合术治疗难治性青光眼是相对安全和有效的.     

Ahmed青光眼阀植入联合手术治疗外伤性晶状体半脱位继发青光眼

目的:回顾性评价Ahmed青光眼阀植入、晶状体玻璃体切除联合手术治疗外伤性晶状体半脱位继发青光眼的临床疗效。方法:对9眼外伤性晶状体半脱位继发青光眼患者行Ahmed青光眼阀植入、晶状体及前部玻璃体切除、人工晶状体睫状沟固定联合手术。结果:术后视力提高8眼;眼压由术前的44.11±8.85mmHg降至14.78±5.52mmHg;并发症主要有一过性低眼压、引流管内口阻塞和引流盘周纤维包裹等,经过处理均得到良好的恢复。结论:Ahmed青光眼阀植入、晶状体及前部玻璃体切除联合人工晶状体睫状沟固定手术是治疗外伤性晶状体半脱位继发青光眼安全有效的手术方法。     

Clinical study of the pars plana Ahmed glaucoma valve implant in refractory glaucoma patients

PURPOSE: To evaluate the effect of pars plana implantation of the Ahmed glaucoma valve on refractory glaucoma. METHOD: Five patients (5 eyes) (3 men, 2 women) were fitted with the Ahmed glaucoma valve. Mean age was 51.8 21.3 years, and mean follow-up was 9.4 +/- 2.6 months. Among the 5 eyes studied, 4 eyes were in neovascular glaucoma patients. Of these 4 eyes, 2 eyes were in diabetic retinopathy patients and 2 eyes were in a patient with central retinal vein occlusion. The remaining eye was in a developmental glaucoma patient. As a surgical procedure after pars plana vitrectomy, the inlet tube of the Ahmed glaucoma valve was placed in the posterior chamber. RESULT: The mean preoperative IOP of 46.8 +/- 15.7 mmHg (30-64 mmHg) under maximum tolerable medication was reduced to 16.0 +/- 2.0 mmHg (14-19 mmHg) after surgery. Postoperative visual acuity improved in 3 eyes, and the mean visual acuity in these eyes improved from 0.05 +/- 0.09 (sl.-0.07) to 0.17 +/- 0.3(0-0.7). A reduction in visual acuity was observed in 2 eyes; in one, due to retinal detachment, and in the other, due to transient high IOP and vitreous hemorrhage. The visual acuity improved in 60% of patients and the IOP controlled in 80% of patients. CONCLUSION: The implantation of the Ahmed glaucoma valve for refractory glaucoma was effective in our study.