Treatment outcomes in the tube versus trabeculectomy study after one year of follow-up

A comparative study of trabeculectomy and the new clear-cornea filtering procedure, intrastromal diathermal keratostomy (IDK)

PURPOSE

For the first time to compare the 1-year success rates of trabeculectomy and the new clear-cornea filtering procedure, intrastromal diathermal keratostomy (IDK).

METHODS

Prospective clinical observational study including 99 consecutively operated eyes (69 patients) with well-established primary open-angle glaucoma referred for filtering operation. We compared the change in intraocular pressure (IOP), number of anti-glaucomatous medication, complications and reoperations after 1 year. Seventy-four eyes were operated with trabeculectomy, and 25 with IDK. Complete success was defined as IOP ≤ 18 mmHg, IOP lowered ≥ 30%, no medication and no reoperation. Qualified success was defined as IOP ≤ 18 mmHg, and IOP lowered ≥ 30% with or without medication or reoperation.

RESULTS

Intraocular pressure pre- and postoperatively in the trabeculectomy group was 25.3 and 14.1 mmHg versus 23.8 and 15.8 mmHg in the IDK group. The number of medications pre- and postoperatively in the trabeculectomy group was 3.1 and 0.5 versus 3.2 and 1.3 in the IDK group. Forty-four (59%) of the eyes in the trabeculectomy group met the complete success criteria compared with 5 (20%) in the IDK group (p < 0.01). Sixty-eight (92%) in the trabeculectomy group and 16 (64%) in the IDK fulfilled the qualified success criteria (p < 0.01).

CONCLUSION

Both the complete and qualified 1-year success rates of IDK are significantly lower compared with the success rates of trabeculectomy. The IDK does not reduce the IOP as much as the procedure of trabeculectomy, and it carries a higher frequency of reoperations and more medication postoperatively. Thus, our prospective data do not support the procedure of IDK as 'the gold standard' for filtering surgery in patients with open-angle glaucoma.

Current status of epibulbar anti-glaucoma drainage devices in glaucoma surgery

BACKGROUND

The term "glaucoma" covers a heterogeneous group of progressive optic neuropathies that are accompanied by characteristic visual-field defects. Primary open-angle glaucoma, the most common type, progresses insidiously and causes blindness if untreated. All current forms of treatment aim at lowering the intraocular pressure (IOP) in patients whose IOP is elevated. The implantation of anti-glaucoma drainage systems is one of the available options for surgical treatment.

METHODS

This review is based on pertinent literature retrieved by a selective search, including glaucoma treatment guidelines from Germany and abroad.

RESULTS

A paradigm shift is currently underway regarding the indications for the implantation of anti-glaucoma drainage systems. Trabeculectomy (a "fistulating" operation in which the aqueous humor is led out of the eye under the conjunctiva) is still considered the surgical gold standard, but drainage systems have been implanted with increasing frequency in recent years. Studies have shown that these systems are more likely to be beneficial the earlier they are implanted in the course of the patient's disease. Five-year follow-up data from the randomized, multicenter Tube Versus Trabeculectomy (TVT) study have now revealed that anti-glaucoma drainage systems are equivalent to trabeculectomy with respect to long-term IOP reduction, complication rates, and absolute and relative clinical success rates.

CONCLUSION

Glaucoma is a major clinical and socio-economic problem whose surgical treatment increasingly involves the implantation of anti-glaucoma drainage systems.

Silicone Ahmed glaucoma valve with and without intravitreal triamcinolone acetonide for neovascular glaucoma: randomized clinical trial

PURPOSE

To compare the effect on intraocular pressure (IOP) of the silicone Ahmed glaucoma valve with and without an intravitreal injection of triamcinolone acetonide.

PATIENTS AND METHODS

Forty-nine patients with clinically uncontrolled neovascular glaucoma were included in the study; 22 were randomly assigned to the study group (silicone Ahmed glaucoma valve implant with intravitreal triamcinolone acetonide) and 27 to the control group (silicone Ahmed glaucoma valve). IOP was the primary outcome measure in this study. The secondary outcome measure was success, defined by IOP lower than 22 mm Hg and higher than 5 mm Hg, and no serious complications. Success rates in both the groups were compared using Kaplan-Meier survival curves and the log-rank test. IOP levels were compared using mixed linear model analysis to correct for repeated measures correlation.

RESULTS

Forty-three patients, 18 in the study group and 25 in the control group, completed the study (follow-up of 12 mo). The mean IOP was significantly lower after 1 year in both the groups (P<0.001). The mean IOP in the first month of follow-up was lower in the study group (control; 20.4±9.7, study; 13.6±6.5, P<0.01). The success rate at 1 year was 78% for the study group and 76% for the control group (P=0.82). Complication rates were not different between the groups.

CONCLUSIONS

Intravitreal injection of triamcinolone acetonide in neovascular glaucoma did not affect the intermediate-term success of the silicone Ahmed valve nor reduce the incidence of complications. The mean IOP spike in the first month was lower in the triamcinolone group.

Treatment outcomes in the Tube Versus Trabeculectomy (TVT) study after five years of follow-up

PURPOSE

To report 5-year treatment outcomes in the Tube Versus Trabeculectomy (TVT) Study.

DESIGN

Multicenter randomized clinical trial.

METHODS

SETTINGS

Seventeen clinical centers.

STUDY POPULATION

Patients 18 to 85 years of age who had previous trabeculectomy and/or cataract extraction with intraocular lens implantation and uncontrolled glaucoma with intraocular pressure (IOP) ≥18 mm Hg and ≤40 mm Hg on maximum tolerated medical therapy.

INTERVENTIONS

Tube shunt (350-mm(2) Baerveldt glaucoma implant) or trabeculectomy with mitomycin C ([MMC]; 0.4 mg/mL for 4 minutes).

MAIN OUTCOME MEASURES

IOP, visual acuity, use of supplemental medical therapy, and failure (IOP >21 mm Hg or not reduced by 20%, IOP ≤5 mm Hg, reoperation for glaucoma, or loss of light perception vision).

RESULTS

A total of 212 eyes of 212 patients were enrolled, including 107 in the tube group and 105 in the trabeculectomy group. At 5 years, IOP (mean ± SD) was 14.4 ± 6.9 mm Hg in the tube group and 12.6 ± 5.9 mm Hg in the trabeculectomy group (P = .12). The number of glaucoma medications (mean ± SD) was 1.4 ± 1.3 in the tube group and 1.2 ± 1.5 in the trabeculectomy group (P = .23). The cumulative probability of failure during 5 years of follow-up was 29.8% in the tube group and 46.9% in the trabeculectomy group (P = .002; hazard ratio = 2.15; 95% confidence interval = 1.30 to 3.56). The rate of reoperation for glaucoma was 9% in the tube group and 29% in the trabeculectomy group (P = .025).

CONCLUSIONS

Tube shunt surgery had a higher success rate compared to trabeculectomy with MMC during 5 years of follow-up in the TVT Study. Both procedures were associated with similar IOP reduction and use of supplemental medical therapy at 5 years. Additional glaucoma surgery was needed more frequently after trabeculectomy with MMC than tube shunt placement.

Practice preferences for glaucoma drainage device implantation and cyclodestruction in Australia and New Zealand

PURPOSE

To evaluate the practice patterns in the use of glaucoma drainage devices (GDD) and cyclodestruction among consultant ophthalmologists in Australia and New Zealand.

MATERIALS AND METHODS

A 22-part questionnaire regarding GDD implantation and cyclodestruction practices was sent to all ophthalmologists registered with the Royal Australian and New Zealand College of Ophthalmologists in 2008 by post or e-mail.

RESULTS

Sixty-six percent of 872 questionnaires were returned, of these, 14% were from glaucoma subspecialists. Ten percent of all respondents performed GDD implantations. Molteno drains were the most popular device (69%). The most commonly recognized indications for GDD implantation were a history of 2 failed trabeculectomies (85%), neovascular glaucoma (71%), iridocorneal endothelial syndrome (55%), and uveitic glaucoma (52%). Only a minority of surgeons used intraoperative mitomycin C (38%) or 5-fluorouracil (26%) when implanting GDD. Cyclodestruction had been performed by 20% of all respondents. External diode cyclophotocoagulation was the most preferred treatment mode (73%). Sixty-seven percent treated 180 degrees of the ciliary body during initial treatment. Fifty-five percent treated only the earlier untreated area during retreatment. Only 11% of surgeons who performed cyclodestruction agreed that the indications for cyclodestruction are expanding.

CONCLUSIONS

A wide range of practice patterns for GDD implantation and cyclodestruction exist among Australian and New Zealand ophthalmologists. This likely reflects a paucity of good evidence to guide practice. The Australasian indications for GDD implantation were moderately different from the reported practice in America. Well-designed clinical trials are needed to better define the indications and best practice for these 2 important glaucoma treatment modalities.

Endoscopic cyclophotocoagulation (ECP) in the management of uncontrolled glaucoma with prior aqueous tube shunt

PURPOSE

To evaluate the efficacy and safety of endoscopic cyclophotocoagulation (ECP) in the treatment of uncontrolled glaucoma with a prior aqueous tube shunt.

METHODS

A prospective, nonrandomized, interventional clinical trial with up to 2 years of follow up included 25 eyes of 25 consecutive glaucoma patients with a previous tube shunt and uncontrolled intraocular pressure (IOP) despite medical therapy. Patients had IOP greater than 21 mm Hg on maximal medications or IOP ≤21 mm Hg but intolerant to medications or using an oral carbonic anhydrase inhibitor. Application of ECP over 360 degrees was performed and subjects were followed for 6 months minimum. Main outcome measures were mean reduction in IOP and medications at 12 months. Success was defined as reduction in IOP of 3 mm Hg and discontinuation of nontolerated glaucoma medications. A failure was defined as continued uncontrolled IOP, vision loss to no light perception, or additional medications or glaucoma surgery required.

RESULTS

At 12 months, the mean IOP dropped from 24.02 to 15.36 mm Hg. The mean of the differences was -7.77 mm Hg (-30.8%). The mean number of medications was 3.2 before laser and 1.5 at 12 months (P<0.001). The success rate at 12 months (n=18) was 88% and remained at that level until the end of the follow-up period of 2 years (n=11, P<0.00005). There were no serious complications.

CONCLUSIONS

ECP seems to be a safe and effective treatment in patients with uncontrolled IOP with a prior aqueous tube shunt, and is a reasonable option in this group of refractory glaucoma patients.

Comparison of trabeculectomy and Ex-PRESS implantation in fellow eyes of the same patient: a prospective, randomised study

PURPOSE

To compare intraocular pressure (IOP) over time after standard trabeculectomy vs Ex-PRESS implantation in patients with bilateral primary open-angle glaucoma (POAG).

DESIGN

Prospective, randomised study.

PATIENTS AND METHODS

This study included adult patients with bilateral POAG necessitating surgery. Each patient underwent trabeculectomy in one eye and Ex-PRESS implantation under a scleral flap in the other eye according to randomised contralateral allocations. Efficacy was assessed by IOP values and success rates (IOP threshold and/or need for topical glaucoma medication) during 30 months. Statistical analysis included Generalised Estimate Equation and Cox Survival models, and paired t-tests.

RESULTS

Thirty eyes of 15 patients were studied for a mean of 23.6 months (SD, ± 6.9). At the last follow-up visit, mean pre-operative IOP decreased from 31.1 (± 14.2) to 16.2 (± 1.5) mm Hg after trabeculectomy, and from 28.1 (± 9.0) to 15.7 (± 1.8) mm Hg after Ex-PRESS implantation (P=0.001). The mean number of anti-glaucoma medicines prescribed at the last follow-up decreased from 3.7 pre-operatively (both groups) to 0.9 after trabeculectomy vs 0.3 after Ex-PRESS implantation (P=0.001). Complete success rates (5<IOP<18 mm Hg without medications) were higher with Ex-PRESS compared with trabeculectomy (P=0.0024). Postoperative complications were more frequent after trabeculectomy (33%) compared with Ex-PRESS (20%), with four trabeculectomy eyes (27%) needing postoperative interventions, compared with none with Ex-PRESS.

CONCLUSIONS

Trabeculectomy and Ex-PRESS implantation provided similar IOP control, but the Ex-PRESS group had a lower rate of complications, fewer postoperative interventions, and needed less glaucoma medications.

Intermediate term safety and efficacy of transscleral cyclophotocoagulation after tube shunt failure

PURPOSE

To determine the efficacy and safety of diode transscleral cyclophotocoagulation (TSCPC) after tube shunt failure.

PATIENTS AND METHODS

The patient population consisted of 32 eyes of 31 patients with uncontrolled glaucoma. Each eye had a previously implanted aqueous tube shunt and was currently on maximally tolerated medication. Each eye also underwent TSCPC treatment using the Iridex (Mountain View, CA) diode laser with a maximum of 360 degrees of treatment. All 31 charts were reviewed for data pertaining to demographics, treatment, ocular history, and follow-up clinical examinations. Safety was evaluated by complication data. Efficacy was evaluated in terms of TSCPC treatment parameters (number of laser applications, laser power, application duration, and degrees of ciliary body treated), intraocular pressure, number of hypotensive medications, and any further treatment required.

RESULTS

With a mean (SD) follow-up of 17.1 (16.3) (median=11.7) months from the last treatment, the mean intraocular pressure decreased from 28.6 (10.2) mm Hg to 16.8 (7.5) mm Hg (35% reduction) at 3 months (n=30, P<0.0001) and to 14.7 (7.9) mm Hg (43% reduction) at 1 year (n=13, P<0.0001). Complications included hypotony (n=4), hyphema (n=2), failed corneal transplant (n=1), and loss of light perception (n=5).

CONCLUSIONS

TSCPC has a significant ocular hypotensive effect on glaucoma refractory to both tube shunt and medical therapy. The safety of this intervention remains unclear in this high risk patient population and warrants further study.

The value of tests in the diagnosis and management of glaucoma

PURPOSE

To assess the noneconomic value of tests used in the diagnosis and management of glaucoma, and explore the contexts and factors that determine such value.

DESIGN

Perspective.

METHODS

Selected articles from primary and secondary sources were reviewed and interpreted in the context of the authors' clinical and research experience, influenced by our perspectives on the tasks of reducing the global problem of irreversible blindness caused by glaucoma. The value of any test used in glaucoma is addressed by 3 questions regarding: its contexts, its kind of value, and its implicit or explicit benefits.

RESULTS

Tonometry, slit-lamp gonioscopy, and optic disc evaluation remain the foundation of clinic-based case finding, whether in areas of more or less abundant resources. In resource-poor areas, there is urgency in identifying patients at risk for severe functional loss of vision; screening strategies have proven ineffective, and efforts are hindered by the inadequate allocation of support. In resource-abundant areas, the wider spectrum of glaucoma is addressed, with emphasis on early detection of structural changes of little functional consequence; these are increasingly the focus of new and expensive technologies whose clinical value has not been established in longitudinal and population-based studies. These contrasting realities in part reflect differences among the value ascribed, often implicitly, to the tests used in glaucoma.

CONCLUSIONS

The value of any test is determined by 3 aspects: its context of usage; its comparative worth and to whom its benefit accrues; and how we define historically what we are testing. These multiple factors should be considered in the elaboration of priorities for the development and application of tests in glaucoma.

Deep sclerectomy with mitomycin C in eyes with failed glaucoma surgery and pseudophakia

PURPOSE

To report outcomes of deep sclerectomy (DS) with intraoperative mitomycin C (MMC) application in eyes with previous failed glaucoma surgery (GS) and/or cataract extraction (CE).

PATIENTS AND METHODS

Single-surgeon case series of 82 eyes of 82 patients undergoing DS with MMC. The patients had previous CE with IOL and/or conjunctival GS and treated intraocular pressure (IOP) >18 mm Hg. MMC (0.2 mg/ml) was applied for 2-3 min before scleral flap dissection. Complete success was defined as IOP between 6 and 21 mm Hg or a reduction of 20% from baseline without medications. Reoperation for glaucoma or related complications, or loss of light perception vision was considered as failure.

RESULTS

Mean follow-up was 57.7 ± 22.4 months with 78% of patients completing the 3-year follow-up. Mean IOP decreased from 24.0 mm Hg (22.3-25.6, 95% confidence intervals) to 13.4 mm Hg (12.0-14.2) at 3 years after surgery (P<0.001). There was a significant decrease in the number of glaucoma medications from 2.0 ± 1 preoperatively, to 0.3 ± 0.7, 3 years after surgery. Kaplan-Meier cumulative success rates were 85.6% at 1 year, 80.0% at 2 years, and 76% at 3 years. At 3 years, IOP was maintained <19 and 15 mm Hg in 83 and 70% of eyes, respectively. Fourteen eyes (17.1%) had complications. Delayed hypotony (IOP <6 mm Hg) was the commonest complication in five eyes (6.1%).

CONCLUSION

DS with MMC appears to be a safe and effective surgical procedure for eyes with previous intraocular surgery.

Use of amniotic membrane graft in glaucoma shunt surgery

BACKGROUND AND OBJECTIVE

To determine the safety and efficacy of amniotic membrane graft in glaucoma drainage device surgery.

PATIENTS AND METHODS

Institutional retrospective case series of 44 patients undergoing glaucoma drainage device implantation with use of 300-μm thick amniotic membrane as a patch graft. Endpoints assessed were tube exposure, graft thinning, graft clarity, graft-related infection, and inflammation.

RESULTS

A total of 41 (93%) eyes had an uneventful course over a mean follow-up of 22 ± 3 months (range: 17 to 28 months). Tube exposure and hypotony each occurred in one eye and were successfully treated with a tube revision using double pericardial and amniotic membrane patch graft. The translucency of amniotic membrane graft enabled good visualization of the occluding suture when performing laser suture lysis in 16 eyes. Sequential anterior segment optical coherence tomography showed stable amniotic membrane graft thickness with a change from low to moderate reflectivity in the subconjunctival-graft bilayer.

CONCLUSION

Amniotic membrane graft offers good tectonic support and allows direct visualization of the underlying tube.

Prospective study of surgical outcomes and bleb morphology using indocyanine green as a surgical dye in trabeculectomy with mitomycin C

BACKGROUND

To investigate the effect of adding indocyanine green to mitomycin C in augmented trabeculectomy.

DESIGN

A prospective, non-comparative interventional case series.

PARTICIPANTS

A total of 37 eyes of 37 patients followed up for 1 year.

METHODS

A solution containing 12.5 mg/mL of indocyanine green was added to mitomycin C, resulting in an mitomycin C concentration of 0.2-0.4 mg/mL, which was applied to bare sclera and Tenon's capsule for 3 min during trabeculectomy.

MAIN OUTCOME MEASURES

Visual acuity, intraocular pressure, bleb morphology, Moorfields Bleb Grading System scores and complications.

RESULTS

Indocyanine green could be visualized on clinical examination for all eyes on the first postoperative day. Mean intraocular pressure decreased from 22.9 ± 6.2 mmHg to 12.1 ± 4.4 mmHg postoperatively (P < 0.001) at 1 year. Thirty-four eyes (91.9%) achieved an intraocular pressure of less than 21 mmHg at final visit without additional topical intraocular pressure-lowering medications. Three eyes (8.1%) developed bleb failure and required Baerveldt device implantation. There were no cases of blebitis or late bleb leak. No adverse effects attributable to indocyanine green could be identified postoperatively.

CONCLUSION

The addition of indocyanine green during trabeculectomy improves the visibility of antimetabolites intraoperatively and allows for the estimation of antimetabolite treatment area intraoperatively and postoperatively. It appears to have no adverse effect on surgical outcomes and complication rates, while improving safety of antimetabolite use.

Outcome of repeat trabeculectomies

BACKGROUND

To determine the success of repeat trabeculectomy augmented with mitomycin C in a cohort of patients who had undergone previously failed trabeculectomy surgery.

DESIGN

A consecutive cohort series of patients.

PARTICIPANTS

Fifty patients undergoing augmented trabeculectomy surgery following a previously failed trabeculectomy and at least 12 months' follow up.

METHODS

All patients had demographic and clinical data collected at the time of surgery and at all subsequent follow-up visits.

MAIN OUTCOME MEASURES

Visual field progression, loss of visual acuity, intraocular pressure (IOP) control.

RESULTS

The mean follow up was 36.7 months. Forty-one patients (82%) achieved an IOP ≤21 mmHg (with ≥20% reduction of preoperative IOP) and ≥6 mmHg on no additional glaucoma treatment at 12 months' follow up. Forty-four patients (88%) achieved a qualified success with the same criteria at 1 year. The median logMAR acuity preoperative was unchanged after surgery; however, 11 patients (22%) lost ≥2 Snellen lines during follow up. There was no significant change in mean deviation during the follow-up period.

CONCLUSIONS

  Repeating trabeculectomy augmented with mitomycin C is an effective method of controlling IOP and preventing further visual deterioration in the majority of patients treated. However, visual loss was seen in a significant proportion of patients.

Update on aqueous shunts

Medicare claims data and surveys of the American Glaucoma Society membership show that aqueous shunts are being increasingly utilized in the surgical management of glaucoma. New clinical trials data have identified differences in the efficacy and safety of shunts in common use. Recent studies have reported comparable results with trabeculectomy and aqueous shunts in similar patient groups. Intraoperative and postoperative complications may develop with aqueous shunt surgery related to the implantation of a foreign material. Several modifications in surgical technique have been directed toward improving surgical success, reducing complications, and optimizing efficiency and cost.

The Ahmed Baerveldt Comparison Study methodology, baseline patient characteristics, and intraoperative complications

PURPOSE

The Ahmed Baerveldt Comparison (ABC) Study compares the long-term outcomes and complications of the Ahmed glaucoma valve (AGV; model FP7; New World Medical, Los Ranchos, CA) and the Baerveldt glaucoma implant (BGI; model 101-350; Abbott Medical Optics, Abbott Park, IL).

DESIGN

Multicenter, randomized, controlled clinical trial.

PARTICIPANTS

Two hundred seventy-six glaucoma patients at 16 clinical centers worldwide who were 18 to 85 years of age with inadequately controlled intraocular pressure (IOP; ≥18 mmHg) in whom placement of an aqueous shunt was planned.

METHODS

Study patients were randomized to undergo implantation of an AGV or a BGI.

MAIN OUTCOME MEASURES

Failure, defined as IOP >21 mmHg or not reduced by 20% less than baseline or IOP ≤5 mmHg (2 consecutive visits after 3 months), additional glaucoma surgery, removal of the implant, or loss of light perception vision.

RESULTS

A total of 276 patients were enrolled between October 2006 and April 2008, including 143 in the AGV group and 133 in the BGI group. The mean age±standard deviation (SD) of patients enrolled was 63±14 years, and 52% were male. The mean baseline IOP±SD was 31.5±11.8 mmHg. Except for a 13% higher prevalence of hypertension in the AGV group, no significant differences in baseline demographic or ocular characteristics were observed between the study groups. Intraoperative complications occurred in 11 (8%) patients in the AGV group and in 16 (12%) patients in the BGI group (P = 0.31).

CONCLUSIONS

The ABC Study should yield valuable prospective data comparing 2 commonly used aqueous shunts in clinical practice.

Treatment outcomes in the Ahmed Baerveldt Comparison Study after 1 year of follow-up

PURPOSE

To determine the relative efficacy and complications of the Ahmed glaucoma valve (AGV) model FP7 (New World Medical, Ranchos Cucamonga, CA) and the Baerveldt glaucoma implant (BGI) model 101-350 (Abbott Medical Optics, Abbott Park, IL) in refractory glaucoma.

DESIGN

Multicenter, randomized, controlled clinical trial.

PARTICIPANTS

Two hundred seventy-six patients, including 143 in the AGV group and 133 in the BGI group.

METHODS

Patients 18 to 85 years of age with refractory glaucoma having intraocular pressure (IOP) of 18 mmHg or more in whom an aqueous shunt was planned were randomized to undergo implantation of either an AGV or a BGI.

MAIN OUTCOME MEASURES

The primary outcome was failure, defined as IOP >21 mmHg or not reduced by 20% from baseline, IOP ≤5 mmHg, reoperation for glaucoma or removal of implant, or loss of light perception vision. Secondary outcomes included mean IOP, visual acuity, use of supplemental medical therapy, and complications.

RESULTS

Preoperative IOP (mean±standard deviation [SD]) was 31.2±11.2 mmHg in the AGV group and 31.8±12.5 mmHg in the BGI group (P = 0.71). At 1 year, mean±SD IOP was 15.4±5.5 mmHg in the AGV group and 13.2±6.8 mmHg in the BGI group (P = 0.007). The mean±SD number of glaucoma medications was 1.8±1.3 in the AGV group and 1.5±1.4 in the BGI group (P = 0.071). The cumulative probability of failure was 16.4% (standard error [SE], 3.1%) in the AGV group and 14.0% (SE, 3.1%) in the BGI group at 1 year (P = 0.52). More patients experienced early postoperative complications in the BGI group (n = 77; 58%) compared with the AGV group (n = 61; 43%; P = 0.016). Serious postoperative complications associated with reoperation, vision loss of ≥2 Snellen lines, or both occurred in 29 patients (20%) in the AGV group and in 45 patients (34%) in the BGI group (P = 0.014).

CONCLUSIONS

Although the average IOP after 1 year was slightly higher in patients who received an AGV, there were fewer early and serious postoperative complications associated with the use of the AGV than the BGI.

New surgical technique for correcting tube-iris touch following glaucoma drainage implant surgery

Glaucoma drainage implant surgery may be associated with a number of potential complications including tube malpositioning. This malpositioning may have serious sequelae such as corneal endothelial damage, chronic iritis, cataract formation or tube occlusion. Traditional management of tube malpositioning involves major surgical re-dissection and reinsertion of the tube. Alternatively, shortening of the tube within the anterior chamber can, in some circumstances, relieve tube contact with the endothelium or iris. However, these procedures are associated with important risks. We describe a new minimally invasive surgical technique for correcting posterior tube malpositioning that avoids the need to shorten the tube or re-dissect the conjunctiva. This technique is straightforward to perform and has successfully maintained proper drainage device tube position during more than 1 year of follow up.

What is new after 40 years of glaucoma implants

Forty years ago, Molteno introduced the prototype of the present day long tube implant. Since then, modifications in size and shape and introduction of valve system have taken place. Aqueous has been shown to contain proinflammatory substances that have been shown to influence the thickness of the bleb wall, and the hypertensive phase has been seen with the implants. The effect of the aqueous may be modified by the use of systemic antiinflammatory medication or by surgical modification, namely supra-Tenon insertion of the implant. Recent studies have shown that tube implantation is as efficacious as trabeculectomy in patients who were either pseudophakic or earlier had failed filters. Newer nontube implants, such as the Express shunt, have been introduced along with others, such as the gold micro shunt implant and the iStent, presently in clinical trials.

Evaluation of Ahmed glaucoma valve implantation through a needle-generated scleral tunnel in Mexican children with glaucoma

Purpose:

To evaluate the results and extrusion rates of the Ahmed glaucoma valve (AGV) implantation through a needle-generated scleral tunnel, without a tube-covering patch, in children.

Materials and Methods:

A retrospective review of the charts of 106 Mexican children implanted with 128 AGVs operated between 1994 and 2002, with the needle track technique, at our institution, with at least six months follow up was done. Main outcome measures were intraocular pressure (IOP) control, tube extrusions or exposure and other complications.

Results:

Kaplan-Meier analysis demonstrated a 96.9% survival rate at six months, 82.4% at one year, 78.7% at two years, 70% at three years and 41.6% at four years. Total success at the last follow-up (IOP between 6 and 21 mm Hg without medications) was achieved in 30 eyes (23.5%), 58 eyes (45.3%) had qualified success (only topical hypotensive drugs) and 40 eyes (31.3%) were failures. The mean pre- and post-operative IOP at the last follow up was 28.4 mmHg (SD 9.3) and 14.5 mmHg (SD 6.3), respectively. No tube extrusions or exposures were observed. Tube-related complications included five retractions, a lens touch and a transitory endothelial touch. The risk of failure increased if the eye had any complication or previous glaucoma surgeries.

Conclusion:

Medium-term IOP control in Mexican children with glaucoma can be achieved with AGV implantation using a needle-generated tunnel, without constructing a scleral flap or using a patch to cover the tube. There were no tube extrusions, nor any tube exposures with this technique.

Trainee glaucoma surgery: experience with trabeculectomy and glaucoma drainage devices

BACKGROUND AND OBJECTIVE

To examine outcomes of trabeculectomy with mitomycin C and glaucoma drainage device placement for uncontrolled glaucoma when performed by resident surgeons.

PATIENTS AND METHODS

This study included any patient who underwent a trabeculectomy with mitomycin C (n = 93) or a glaucoma drainage device (n = 60) by a resident surgeon between 2001 and 2006. Outcome measures at 3, 6, and 12 months included failure of treatment, number of follow-up appointments, complications, number of medications, and need for further surgery.

RESULTS

One year postoperatively, intraocular pressure averaged 12.1 ± 5.1 mm Hg in the trabeculectomy group and 13.0 ± 5.1 mm Hg in the glaucoma drainage device group (P = .31). Complications occurred in 30% of eyes with trabeculectomy and 10% of eyes with a glaucoma drainage device.

CONCLUSION

During the first postoperative year, glaucoma drainage device surgery may have fewer complications and less morbidity than a trabeculectomy with mitomycin C when these surgeries are performed by resident surgeons. Final intraocular pressures were similar between the two groups.

Resident-performed Ahmed glaucoma valve surgery

BACKGROUND AND OBJECTIVE

To evaluate the safety and efficacy of residents performing glaucoma valve surgery at a metropolitan county hospital.

PATIENTS AND METHODS

A retrospective analysis was performed of consecutive resident-performed Ahmed valve (New World Medical, Inc., Rancho Cucamonga, CA) glaucoma surgeries from 1993 to 2005. Data of 50 eyes of 48 patients were evaluated for intraocular pressure (IOP) and best-corrected visual acuity.

RESULTS

The mean follow-up period was 34.7 +/- 30.5 months, with an IOP decrease from 30.8 +/- 11.3 mm Hg preoperatively to 15.3 +/- 11.6 mm Hg at last visit. Success, defined by a postoperative IOP of greater than 5 mm Hg and at most 21 mm Hg or less or a decreased postoperative IOP of at least 25% if the preoperative IOP was already 21 mm Hg or less, occurred in 78% of eyes. Best-corrected visual acuity decreased in 58% of eyes. Four eyes (8%) required subsequent penetrating glaucoma procedures.

CONCLUSION

This retrospective study suggests that placement of an Ahmed valve can be a safe and effective procedure in the hands of residents under appropriate attending physician supervision.

Review of results from the Tube Versus Trabeculectomy Study

PURPOSE OF REVIEW

The Tube Versus Trabeculectomy (TVT) Study is a multicenter randomized clinical trial comparing the safety and efficacy of tube-shunt surgery to trabeculectomy with mitomycin (MMC) in eyes with previous cataract and/or unsuccessful glaucoma surgery. This article reviews published results from the TVT Study.

RECENT FINDINGS

Tube-shunt surgery had a higher success rate than trabeculectomy with MMC during the first 3 years of follow-up. Trabeculectomy with MMC produced greater intraocular pressure (IOP) reduction in the early postoperative period compared with tube-shunt placement, but similar IOPs were observed after 3 months. Tube-shunt surgery was associated with greater use of adjunctive-medical therapy than trabeculectomy with MMC during the first 2 years of the study, but no difference in medication use was seen at 3 years. The incidence of postoperative complications was higher after trabeculectomy with MMC compared with tube-shunt surgery, but serious complications associated with vision loss and/or reoperation developed with similar frequency after both surgical procedures. No difference in the rate of vision loss was present following trabeculectomy with MMC and tube-shunt surgery after 3 years of follow-up. Cataract progression was common, but occurred with similar frequency with both procedures.

SUMMARY

Intermediate-term results of the TVT Study support the expanded use of tube shunts beyond refractory glaucomas. Tube-shunt surgery is an appropriate surgical option in patients who have undergone prior cataract and/or unsuccessful filtering surgery.

Recurrent vitreous occlusion of glaucoma drainage device tube in a patient with glaucoma in aphakia: a case report

Patients with spontaneous lens dislocation and glaucoma can be challenging to manage. We present a forty-six year old Caucasian lady who was referred with bilateral high intraocular pressure, and was subsequently diagnosed with glaucoma in association with lens dislocation and Marfan syndrome. Baerveldt glaucoma drainage device tubes were inserted in both eyes due to poor response to medical therapy. However, this was complicated by recurrent vitreous occlusion of both glaucoma drainage tubes requiring further multiple surgical interventions. There have not been any further recurrences of vitreous incarceration or posterior segment complications since, but the patient remains under close follow-up.

Results from the tube versus trabeculectomy study

The Tube Versus Trabeculectomy (TVT) Study is a multicenter randomized clinical trial comparing the safety and efficacy of tube shunt surgery to trabeculectomy with mitomycin (MMC) in eyes with previous cataract and/or failed glaucoma surgery. Tube shunt surgery was more likely to maintain intraocular pressure (IOP) control and avoid persistent hypotony, reoperation for glaucoma, or loss of light perception vision than trabeculectomy with MMC during the first year of follow-up. Both surgical procedures had similar IOP reduction at 1 year, but less supplemental medical therapy was used following trabeculectomy. The incidence of postoperative complications was higher after trabeculectomy with MMC relative to tube shunt surgery, but serious complications associated with vision loss and/or reoperation developed with similar frequency after both of the procedures. There was no significant difference in the rate of vision loss following trabeculectomy with MMC and tube shunt surgery after 1 year of follow-up. Cataract progression was common, but occurred with similar frequency with both of the surgical procedures.

Sequential glaucoma implants in refractory glaucoma

PURPOSE

To evaluate the efficacy of a second glaucoma implant in eyes with prior glaucoma implant surgery and inadequate intraocular pressure (IOP) control.

DESIGN

Retrospective observational cohort study.

METHODS

Patients undergoing a second glaucoma implant surgery from 1996 to 2008 were included. Outcome measures included visual acuity, IOP, glaucoma medication use, and complications. Success was defined as IOP < 21 mm Hg (criterion 1) and IOP < 17 mm Hg (criterion 2), with at least 25% reduction in IOP and no prolonged hypotony.

RESULTS

Forty-three eyes (43 patients) had a mean follow-up of 32.6 +/- 21.6 months. Life-table analysis demonstrated success rates of 93%, 89%, and 83% using criterion 1 and 83%, 75%, and 75% using criterion 2 at 1, 2, and 3 years, respectively. At last follow-up, mean IOP (13.6 +/- 4.6 vs 24.7 +/- 7.5 mm Hg; P < .001) and mean number of medications (1.4 +/- 1.2 vs 3.9 +/- 1.2; P < .001) were lower following the second implant. There was no difference in preoperative and most recent logarithm of the minimal angle of resolution (logMAR) visual acuities (0.86 +/- 0.13 vs 1.1 +/- 0.13; P = .07). The most frequently used second implants were similar in percentage IOP reduction (Baerveldt implant, 45 +/- 19%; Ahmed valve, 40 +/- 18%; P = .4).

CONCLUSIONS

A second glaucoma implant may effectively lower IOP in eyes with refractory glaucoma.

Expanded polytetrafluoroethylene membrane alters tissue response to implanted Ahmed glaucoma valve

PURPOSE

Long-term intraocular pressure control by glaucoma drainage implants is compromised by the formation of an avascular fibrous capsule that surrounds the glaucoma implant and increases aqueous outflow resistance. It is possible to alter this fibrotic tissue reaction and produce a more vascularized and potentially more permeable capsule around implanted devices by enclosing them in a porous membrane.

METHODS

Ahmed glaucoma implants modified with an outer 5-microm pore size membrane (termed porous retrofitted implant with modified enclosure or PRIME-Ahmed) and unmodified glaucoma implants were implanted into paired rabbit eyes. After 6 weeks, the devices were explanted and subject to histological analysis.

RESULTS

A tissue response containing minimal vascularization, negligible immune response, and a thick fibrous capsule surrounded the unmodified Ahmed glaucoma implant. In comparison, the tissue response around the PRIME-Ahmed demonstrated a thinner fibrous capsule (46.4 +/- 10.8 microm for PRIME-Ahmed versus 94.9 +/- 21.2 microm for control, p < 0.001) and was highly vascularized near the tissue-material interface. A prominent chronic inflammatory response was noted as well.

CONCLUSIONS

Encapsulating the aqueous outflow pathway with a porous membrane produces a more vascular tissue response and thinner fibrous capsule compared with a standard glaucoma implant plate. Enhanced vascularity and a thinner fibrous capsule may reduce aqueous outflow resistance and improve long-term glaucoma implant performance.

Outcome of Ahmed valve implantation when preoperative IOP less than 21 mm Hg

PURPOSE

To examine the results of Ahmed glaucoma drainage device (GDD) implantation in patients with a preoperative intraocular pressure (IOP) of 20 mm Hg or less.

METHODS

Noncomparative retrospective case series.

RESULTS

Sixty-six surgeries in 63 patients were analyzed. Mean follow-up was 51 months. The mean drop in IOP was 3.8 mm Hg (23.3%, P<0.0001) at 12 months and 3.9 mm Hg (24.0%, P<0.0001) at final follow-up. The number of glaucoma medications used postoperatively was significantly less than preoperatively. Although the mean visual acuity was poorer postoperatively this did not reach statistical significance. Surgical success was defined as IOP > or =5 mm Hg and 20% lower than preoperatively with or without hypotensive therapy, visual acuity perception of light or better and no further glaucoma surgery. About 57.6% and 53.0% of patients were considered a success at 12 months and final follow-up, respectively. Fourteen patients (21.2%) underwent additional glaucoma surgery, 8 of which had a second Ahmed GDD inserted whereas 6 had cyclodestruction. All failures were due to inadequate IOP control or further glaucoma surgery, with no cases considered failures due to vision loss or hypotony. Perioperative complications developed in 6 cases (9.1%) whereas long-term problems related to surgery occurred in 8 cases (12.1%).

CONCLUSIONS

In patients with IOPs of 20 mm Hg or less who require IOPs in the low teens and below Ahmed GDD surgery does seem to be an effective option. The success rates of surgery, however, must be balanced against the risk of complications. In addition, the relative merits of Ahmed GDD implantation versus mitomycin trabeculectomy and/or nonvalved GDDs requires further investigation.

Moving the goal posts definitions of success after glaucoma surgery and their effect on reported outcome

PURPOSE

To determine (1) the extent to which the definition of success of glaucoma surgery varies in the literature and (2) the degree to which the reported outcome after trabeculectomy is affected by the criteria used to define success.

DESIGN

A systematic review of the literature and application of definitions to a retrospective cohort.

PARTICIPANTS

A cohort of 100 patients who previously underwent trabeculectomy.

METHODS

A literature search was performed of PubMed using the search term trabeculectomy for a 5-year period. Studies presenting original data relating to longitudinal intraocular pressure (IOP) control after glaucoma surgery were included. The definitions of success and failure used were documented for each publication. Each IOP-related definition of success was applied to a cohort of patients who previously underwent trabeculectomy. Success rates were derived for each published definition up to 36 months after surgery.

MAIN OUTCOME MEASURES

Intraocular pressure measured by Goldmann applanation tonometry.

RESULTS

From 100 publications meeting the inclusion criteria, 92 distinct IOP-related definitions of success were identified. Using these definitions, success rates for this series of 100 trabeculectomies varied between 36.0% and 98.0% after 3 years of follow-up.

CONCLUSIONS

Over a recent 5-year period, there were nearly as many different definitions of success after glaucoma surgery as publications on the subject. The definition used markedly affects the quoted success rate after trabeculectomy, making interpretation of and comparison between published results extremely difficult. Standardization of published outcome parameters after glaucoma surgery is essential to allow meaningful comparisons between different study reports.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Three-year follow-up of the tube versus trabeculectomy study

PURPOSE

To report 3-year results of the Tube Versus Trabeculectomy (TVT) Study.

DESIGN

Multicenter randomized clinical trial.

METHODS

SETTING

Seventeen clinical centers.

STUDY POPULATION

Patients 18 to 85 years of age who had previous trabeculectomy, cataract extraction with intraocular lens implantation, or both and uncontrolled glaucoma with intraocular pressure (IOP) > or =18 mm Hg and < or =40 mm Hg on maximum tolerated medical therapy.

INTERVENTIONS

A 350-mm(2) Baerveldt glaucoma implant or trabeculectomy with mitomycin C (MMC 0.4 mg/ml for 4 minutes).

MAIN OUTCOME MEASURES

IOP, visual acuity, use of supplemental medical therapy, surgical complications, and failure (IOP >21 mm Hg or not reduced by 20%, IOP < or =5 mm Hg, reoperation for glaucoma, or loss of light perception vision).

RESULTS

A total of 212 eyes of 212 patients were enrolled, including 107 in the tube group and 105 in the trabeculectomy group. At 3 years, IOP (mean +/- standard deviation [SD]) was 13.0 +/- 4.9 mm Hg in the tube group and 13.3 +/- 6.8 mm Hg in the trabeculectomy group (P = .78). The number of glaucoma medications (mean +/- SD) was 1.3 +/- 1.3 in the tube group and 1.0 +/- 1.5 in the trabeculectomy group (P = .30). The cumulative probability of failure during the first 3 years of follow-up was 15.1% in the tube group and 30.7% in the trabeculectomy group (P = .010; hazards ratio, 2.2; 95% confidence interval, 1.2 to 4.1). Postoperative complications developed in 42 patients (39%) in the tube group and 63 patients (60%) in the trabeculectomy group (P = .004). Surgical complications were associated with reoperation and/or loss of > or =2 Snellen lines in 24 patients (22%) in the tube group and 28 patients (27%) in the trabeculectomy group (P = .58).

CONCLUSIONS

Tube shunt surgery had a higher success rate compared to trabeculectomy with MMC during the first 3 years of follow-up in the TVT Study. Both procedures were associated with similar IOP reduction and use of supplemental medical therapy at 3 years. While the incidence of postoperative complications was higher following trabeculectomy with MMC relative to tube shunt surgery, most complications were transient and self-limited.