Glaucoma Valve Research Articles

Pars Plana Baerveldt Implantation for Refractory Childhood Glaucomas

To evaluate the effectiveness and associated complications of Baerveldt glaucoma implant (BGI) surgery with pars plana tube insertion in aphakic and pseudophakic children. The medical records of 30 patients (30 eyes) younger than 18 years old with uncontrolled glaucoma associated with aphakia or pseudophakia who underwent pars plana BGI surgery were retrospectively reviewed. Clinical outcome assessment included the measurement of intraocular pressure (IOP) and visual acuity and the identification of complications. Success was defined as 5 mm Hg<final postoperative IOP < or =21 mm Hg with or without glaucoma medications and without visually devastating complications or further glaucoma surgery. Outcomes were evaluated using Kaplan-Meier life-table analysis. Mean follow-up after BGI surgery was 29.8+/-26.4 months. Twelve, 24, and 36-month life-table rates for successful IOP control were 85%, 81%, and 72%, respectively. Six of 30 patients were considered failures. Complications included hypotony (5 patients, with 1 developing hemorrhagic choroidals which required surgical intervention and a second progressing to phthisis), retinal detachment (4 patients), tube obstruction (2 patients), pupillary membrane (1 patient), worsening esotropia (1 patient), focal scleral ectasia (1 patient), and loss of light perception (1 patient). Visually devastating complications were observed in 3 patients (hemorrhagic choroidals 1 patient, phthisis 1 patient, loss of light perception 1 patient). BGI surgery with pars plana tube insertion is a reasonable option for managing aphakic and pseudophakic children with uncontrolled glaucoma. Complications of BGI surgery related to anterior chamber tube placement, such as tube-cornea touch, are minimized with this approach. The incidence of posterior segment complications, although possibly higher compared with limbal tube insertion, was not excessive.

Combined Phacoemulsification and Ahmed Valve Glaucoma Drainage Implant: A Retrospective Case Series

To report on the efficacy and safety of combined phacoemulsification and an Ahmed valve glaucoma drainage implant with respect to visual acuity improvement, intraocular pressure (IOP) control, and requirement for antiglaucoma medication. A retrospective chart review was conducted of 41 eyes (31 patients) with coexisting visually significant cataracts and uncontrolled glaucoma who had combined phacoemulsification and Ahmed valve implantation. The outcome measures were: visual acuity, IOP, antiglaucoma medication requirements, and intra- and post-operative complications. Success was categorized as absolute (IOP<21 mmHg without the need for antiglaucoma medication) and relative (IOP<21 mmHg with one or more antiglaucoma medications). Failure was considered to be an IOP<6 mmHg or IOP>21 mmHg on maximally tolerated medications or any devastating complication. The mean patient age was 67.3+/-5.9 years old. The mean visual acuity improved from 0.73+/-0.5 to 0.16+/-0.16 (p=0.000). The mean IOP decreased from 28.2+/-3.1 to 16.8+/-2.1 (p=0.000, 40.4%), while the number of antiglaucoma medication decreased from 2.6+/-0.66 to 1.2+/-1.4 (p=0.000). The absolute and relative success rates were 56.1% and 31.7%, respectively; 5 eyes (12.2%) were considered failures. There were no intraoperative complications; postoperative complications occurred in 8 eyes (19.5%). A hypertensive phase was detected in 12 (29.3%) eyes. Combined phacoemulsification and Ahmed valve glaucoma drainage implantation is a safe and effective alternative to phacotrabeculectomy in patients with coexisting cataract and refractory glaucoma.

Late-onset proptosis with Baerveldt glaucoma implants

Surgeons use glaucoma implants in patients with uncontrolled intraocular pressure (IOP) and poor surgical prognosis with trabeculectomy. We report two cases of late-onset proptosis subsequent to a Baerveldt glaucoma implant...

Outcomes of Inferonasal Baerveldt Glaucoma Drainage Implant Surgery

To determine the outcomes of inferonasal Baerveldt glaucoma implant (BGI) surgery. A retrospective, non-comparative case series of 182 eyes of 182 patients who underwent inferonasal placement of a Baerveldt glaucoma implant. The main outcome measures included intraocular pressure, number of glaucoma medications, best corrected visual acuity, and complications. Patients were followed for an average (+/- SD) of 19 +/- 15 months. Median Snellen visual acuity was unchanged at last follow-up. Intraocular pressure was reduced from a mean (+/- SD) of 28.6 +/- 11.5 mm Hg preoperatively to 13.4 +/- 5.7 mm Hg at most recent follow-up (P < 0.001). The number of antiglaucoma medications was reduced from a mean (+/- SD) of 2.7 +/- 1.3 preoperatively to 1.1 +/- 1.1 at most recent follow-up. Nineteen eyes met our criteria for failure, yielding a cumulative percent survival of 92% at 12 months, 88% at 24 months, and 77% at 44 months. The most common complications were hyphema (14 eyes, 8%), choroidal effusion (12 eyes, 7%), and corneal decompensation (19 eyes, 10%). Endophthalmitis and diplopia occurred rarely (1 eye, <1%; 3 eyes, 2%, respectively). Inferonasal Baerveldt glaucoma implant placement appears to be a safe and effective surgical option that may be helpful in certain clinical situations.

Modeling and Characterization of a Valved Glaucoma Drainage Device With Implications for Enhanced Therapeutic Efficacy

We report on modeling and bench test results targeted at better understanding of valved glaucoma drainage devices (GDDs), a common current surgical treatment for glaucoma. A simple equivalent circuit is described to model fluid mechanical behavior of the aqueous humor in an eye with glaucoma, both before and after implantation of a valved GDD. Finite element method simulations (FEM), based on the lubrication-von Kármán model, are then performed to analyze the valve's mechanical and fluidic performance. Using nanoporous membranes to mimic the in vivo fibrous capsule, we have developed a microfluidic bench test to simulate the aqueous humor flow and the post-implantation fibrous tissue encapsulation around the GDD back plate. Our numerical and bench test results show that, contrary to the prevailing belief, the valve significantly contributes to the total pressure drop even after fibrous capsule formation. Furthermore, we show that bypassing the valve through a simple polyimide tube insertion will dramatically lower the intraocular pressure (IOP) after fibrous capsule formation. This may offer a new treatment option in some patients with advanced glaucoma.

Experience With the Baerveldt Glaucoma Implant in the Management of Pediatric Glaucoma

To report the clinical outcome in 48 eyes of 48 children who received a Baerveldt glaucoma implant (BGI) for the management of pediatric glaucoma. Retrospective, noncomparative case series. The medical records of all patients with pediatric glaucoma who underwent a BGI at two tertiary care referral centers in Los Angeles between 1990 and 1999 were reviewed. Intraocular pressure (IOP), intraoperative and postoperative complications, number of glaucoma medications, visual acuity, and pre- and postoperative corneal diameter and axial length were collected from patient records. Criteria for success were IOP between 6 and 21 mm Hg with or without glaucoma medications, no need for further glaucoma surgery, the absence of visually threatening complications, and some residual vision (minimum visual acuity of light perception). The study included 48 eyes from 48 patients aged 16 years and younger (mean age 4.1 years). Mean preoperative IOP was 31.2 +/- 25.7 mm Hg, and mean postoperative IOP was 16.4 +/- 4.9 mm Hg. Cumulative probability of success (based on the Kaplan-Meier survival curve) was 95% at 6 months, 90% at 1 year, 84% at 2 years, 74% at 36 months, and 58% at 48 months. On average, the BGIs were successful for a mean period of 5.6 years (67.7 months). Overall, 11 eyes failed, with the causes being uncontrolled IOP (eight eyes), retinal detachment (two eyes), and no light perception (one eye). Baerveldt glaucoma implants can be a safe and effective treatment modality for the management of pediatric glaucoma refractive to medical therapy.

The effect of adjunctive mitomycin C in Ahmed glaucoma valve implantation.

To evaluate the effectiveness and safety of adjunctive mitomycin C (MMC) in Ahmed glaucoma valve (AGV) implantation for refractory glaucoma. Twenty-two eyes of 22 patients who underwent AGV implantation with adjunctive MMC (0.5 mg/ml) for 3 minutes (Group A) were compared to a control group of 26 eyes of 26 patients (Group B) who received AGV implantation without MMC. Nine patients were female and 13 patients were male in Group A and 11 patients were female and 15 patients were male in Group B. The mean age was 56 years ranging from 13 to 77 in Group A and 58 ranging from 14 to 71 years in Group B. Success was defined as an intraocular pressure (IOP) between 4 and 21 mmHg with or without glaucoma medication and with no additional glaucoma surgery, phthisis, or loss of light perception. The probability of success at 1 year was 86.36% and 80.76% in Group A and Group B, respectively. The number of glaucoma medications decreased from 2.82 to 0.56 in Group A and from 2.65 to 0.73 in Group B. Postoperative hypotony as an early complication was higher in Group A (31.81% in Group A and 15.38% in Group B). As a late postoperative complication, tube exposure developed in 3 patients (13.63%) in Group A and no such complication was seen in Group B. There was no statistically significant difference in success and complication rates between the two groups (p>0.05). Although adjunctive MMC in AGV implantation is safe and effective, it may not offer a better chance of surgical success compared with AGV implantation without MMC. (Eur J Ophthalmol 2005; 15: #-31).

Experience with the use of Baerveldt and Ahmed glaucoma drainage implants in an Asian population

Purpose To evaluate the efficacy and safety of Baerveldt and Ahmed glaucoma drainage implants in Asian patients with refractory glaucoma. Design Retrospective nonrandomized study. Participants Forty-one patients. Methods The authors reviewed the insertion of 18 Ahmed glaucoma valved (AGV-S2) implants and 24 350 mm 2 Baerveldt glaucoma implants performed by a single surgeon at the Department of Ophthalmology, National University Hospital, Singapore, from January 1, 2000, to December 31, 2000. A total of 42 glaucoma drainage implants was inserted into the eyes of 41 patients. All patients had at least 6 months of follow-up. Main outcome measures Intraocular pressure (IOP), visual acuity, and complications. Results Both drainage implants achieved remarkable reductions in IOP; from pretreatment IOP of 40.1±13.8 mmHg and 43.7±9.3 mmHg to postoperative IOP of 17.4±6.2 and 14.9±5.5 mmHg in the Baerveldt and Ahmed groups, respectively. A decrease in IOP of 56.6% and 65.9% had been achieved. Success rates were 20 (83.3%) for Baerveldt and 12 (66.7%) for Ahmed implants, whereas qualified success occurred in 1 (4.2%) Baerveldt and 3 (16.7%) Ahmed implants. Conversely, failure to control IOP occurred in 3 (12.5%) Baerveldt implants and 3 (16.7%) Ahmed implants. More than 80% of the patients had maintained or improved visual function, whereas only 4 (16.0%) of the patients with Baerveldt implants and 2 (16.7%) patients with Ahmed implants had loss of more than 1 Snellen line. Conclusions Both Baerveldt and Ahmed glaucoma drainage implants performed well in terms of IOP control, preservation of visual function, and having low complication rates.

Intermediate-term outcome of Baerveldt glaucoma implants in Asian eyes

Purpose To determine the intermediate-term efficacy and safety of Baerveldt glaucoma implants in Asian eyes with complicated glaucoma. Design Retrospective, nonrandomized, comparative trial. Participants One hundred twenty-four Asian patients (124 eyes) with complicated glaucoma. Intervention Implantation of 54 250-mm 2 and 70 350-mm 2 Baerveldt glaucoma drainage implants at Singapore National Eye Center from 1994 through 1999. Main outcome measures Intraocular pressure, number of glaucoma medications, and complications. Results The mean follow-up period was 33.4 ± 14.4 months (mean ± SD; range, 12–72 months). Intraocular pressure (IOP) was reduced from a mean preoperative IOP of 36.5 ± 10.7 mmHg (range, 21–80 mmHg) to 15.3 ± 6.0 mmHg (range, 1–34 mmHg), and the number of glaucoma medications decreased from 2.6 ± 0.6 (range, 1–5) before the time of surgery to 0.5 ± 0.9 (range, 0–4) medications at last follow-up. Overall, there were 67 eyes (54%) that were classified as complete successes, 27 eyes (22%) that were qualified successes, and 30 eyes that failed (24%). Postoperative complications occurred in 43 eyes (34.7%), and 21 eyes (17%) required further surgical intervention and revision. There was no statistically significant difference between the 250-mm 2 and 350-mm 2 type of implants in terms of success rates, final IOP, number of medications, and rates of complications. After adjusting for gender, preoperative IOP, and length of follow-up, increasing age (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.01–1.09; P = 0.02) and the number of previous operations performed before implant surgery (OR, 1.57; 95% CI, 1.07–2.31; P = 0.01) were found to be correlated positively with failure. Conclusions In Asian eyes with complicated glaucoma, Baerveldt glaucoma implants achieve stable and satisfactory IOP reduction with low incidence of complications in the intermediate term after surgery.

Combined Baerveldt glaucoma drainage implant and trabeculectomy with mitomycin C for refractory glaucoma.

To describe the surgical technique and clinical outcomes of a procedure for refractory glaucoma, concurrent Baerveldt glaucoma implant (BGI) and trabeculectomy with mitomycin C. Medical records of all patients who underwent combined Prolene-ligated BGI and trabeculectomy with mitomycin C were retrospectively reviewed. Main outcome measures were intraocular pressure (IOP), number of glaucoma medications, visual acuity, and complications. Kaplan-Meier survival analysis was used to determine success, defined as IOP < 22 mm Hg, no reoperation for glaucoma, and no loss of light perception vision. The mean +/- SD follow-up period for 38 eyes of 36 patients was 34 +/- 36 months (range, 3-121 months), during which 18 of 38 eyes (47%) required laser suture lysis of the Prolene suture. Intraocular pressure was reduced from a mean (+/- SD) preoperative value of 35.7 +/- 12.8 to 12.7 +/- 4.7 mm Hg at 1-year follow-up and 11.9 +/- 5.5 mm Hg at the last follow-up visit ( < 0.001). Number of medicines used for glaucoma was reduced from a mean +/- SD preoperative value of 2.5 +/- 0.9 to 0.5 +/- 0.6 at 1-year follow-up and 0.6 +/- 0.8 at the last follow-up visit ( < 0.001). LogMar visual acuity remained stable at mean of 1.15 +/- 0.85 preoperatively, compared with 1.14 +/- 1.05 at 1-year follow-up, but declined to 1.61 +/- 1.01 at the last follow-up visit, a loss of an average of four lines of vision ( = 0.004). Cumulative success was 91% at year 1, 86% at year 2, and 81% at year 3. Three eyes (8%) had suprachoroidal hemorrhages, one eye (3%) needed reoperation for an extruded implant, one (3%) eye had poor vision due to chronic hypotony, three eyes (8%) required additional glaucoma surgery during the postoperative period, and one eye (3%) needed revision of the implant for pressure control. Combined BGI and mitomycin C trabeculectomy provides excellent postoperative IOP control in patients with refractory glaucoma.

Intermediate-term outcomes of 350-mm(2) Baerveldt glaucoma implants.

To determine the intermediate-term outcome of 350-mm(2) Baerveldt glaucoma implants. Retrospective, noncomparative case series. Sixty-five patients (65 eyes). Implantation of 350-mm(2) Baerveldt glaucoma drainage device. Intraocular pressure, number of glaucoma medications, best-corrected Snellen visual acuity, length of follow-up, risk factors for failure, and complications. Mean intraocular pressure was reduced from a preoperative value of 32 mmHg to a 2-year postoperative value of 14 mmHg (56% reduction, P < 0.001). Success rates at 2-year follow-up were 71%, 81%, 78%, 60%, and 47% for the overall group, primary open-angle glaucoma group, neovascular group, uveitic group, and other group, respectively. After accounting for the effect of diagnosis group, significant risk factors in the overall group for failure at 2 years included younger age, high preoperative intraocular pressure, and more prior incisional surgeries. Glaucoma medication use in our overall study population was reduced from 2.5 mean preoperative medications to 0.8 postoperative medications (68%). Median change in Snellen visual acuity between preoperative and 2-year postoperative visits was not significant in the overall group. Postoperative complications included choroidal effusion in 15 patients (23%), tube obstruction by blood or vitreous in five patients (8%), phthisis in four patients (6%), aqueous misdirection in two patients (3%), strabismus in two patients (3%), tube-cornea touch in two patients (3%), endophthalmitis in two patients (3%), and retinal detachment in two patients (3%). No patients had suprachoroidal hemorrhage. The 350-mm(2) Baerveldt glaucoma implants are a safe and effective treatment for intermediate-term intraocular pressure control in patients with refractory glaucoma.

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 (≤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.

Initial experience with pneumatically stented baerveldt implant modified for pars plana insertion for complicated glaucoma

ObjectiveTo assess the efficacy of pneumatically stented drainage tube implants specially modified for pars plana insertion in the treatment of complicated glaucoma. DesignRetrospective, non-comparative case series. Participants50 consecutive patients with refractory complicated glaucoma nonresponsive to medical treatment. InterventionBaerveldt glaucoma implants modified by Hofmann for pars plana insertion were placed following pars plana vitrectomy and gas–fluid exchange (pneumatically stented implant, or PSI procedure). Main outcome measureReduction of intraocular pressure (IOP) to 21 mmHg or less. Results31 neovascular and 19 complicated non-neovascular glaucoma eyes in 48 patients referred to a vitreoretinal subspecialty practice, average age 69 years (range 29–91), were followed an average of 18 months (range 3–41). The average preoperative IOP was 44 mmHg (14–78) on an average 3.2 glaucoma medications (range 2–6). The average final postoperative IOP was 14 mmHg (range 5–31) on an average 0.6 glaucoma medications (range 0–3, median 0). The final intraocular pressure was 21 mmHg or less in 47 of 50 (94%) operated eyes. Serious complications related to the procedure occurred in five eyes (10%). ConclusionsPneumatically stented Baerveldt glaucoma implants modified with the Hofmann elbow to facilitate pars plana insertion are effective in the treatment of complicated glaucoma.

Randomized clinical trial of the 350-mm 2 versus the 500-mm 2 Baerveldt implant: longer term results : Is bigger better?

Objective To report the longer term results of a randomized, clinical trial comparing the 350-mm 2 and the 500-mm 2 Baerveldt glaucoma implants. Design Extended follow-up on a randomized, controlled trial. Participants Between March 1991 and April 1993, 107 patients with uncontrolled intraocular pressure (IOP) due to non-neovascular glaucoma associated with aphakia, pseudophakia, or failed filters were randomly assigned for surgical placement of either the 350-mm 2 or the 500-mm 2 Baerveldt implant at the Doheny Eye Institute. Methods A random-numbers table was used to assign each patient to one of the two groups. Preoperative IOPs and visual acuities were recorded. Clinical records were reviewed to ascertain postoperative IOPs, visual acuities, number of medications used, and implant-related complications that occurred throughout the follow-up period. Main outcome measures Success was defined as IOP of 6 mmHg or greater and of 21 mmHg or less in two or more consecutive follow-up visits without further glaucoma surgery or loss of light perception attributable to glaucoma. Results The overall success rates were 87% for the 350-mm 2 group and 70% for the 500-mm 2 group ( P = 0.05). Average follow-up was 37 months (range, 1–76 months) for the 350-mm 2 group and 34 months (range, 5–77 months) for the 500-mm 2 group. The life-table success rates declined over time for both implant groups, from a high of 98% for the 350-mm 2 group and 92% for the 500-mm 2 group at 1 year to a cumulative success rate of 79% for the 350-mm 2 group and 66% for the 500-mm 2 group at 5 years. Visual acuities were better or remained the same in 50% of the patients in the 350-mm 2 group and 46% of those in the 500-mm 2 group. Complications during the 5-year follow-up were also statistically similar. Conclusions The longer term results show that the 350-mm 2 Baerveldt implant is more successful than the 500-mm 2 implant for overall IOP control. Interval comparisons indicate a higher rate of success for the 350-mm 2 implant in the first, second, third, fourth, and fifth years of implantation. Visual acuities, implant-related complications, and average IOPs were statistically indistinguishable between the two groups.

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.

Penetrating Keratoplasty With a Valved Glaucoma Drainage Implant for Congenital Glaucoma and Corneal Scarring Secondary to Hydrops

The simultaneous management of glaucoma and corneal opacification is sometimes required in infants with severe congenital glaucoma if timely visual rehabilitation is to be achieved. A 1-month-old female infant presented with an enlarged, protuberant, opaque cornea in each eye and elevated intraocular pressure. An intrastromal, fluid-filled cleft was noted in both corneas. It resolved over 3 weeks as corneal scarring progressed. Peripheral corneal clearing allowed a view of an essentially normal anterior chamber. Penetrating keratoplasty and Ahmed (New World Medical Inc., Rancho Cucamonga, CA) valve implant surgery with mitomycin-C were performed simultaneously in the two eyes 1 months apart. At 15 months of age, the patient's grafts were clear and the intraocular pressure was well controlled in both eyes. One eye required multiple procedures for eventual glaucoma control. No postoperative overfiltration occurred. The authors conclude that the use of a valved implant should be considered in patients who require urgent simultaneous corneal and glaucoma surgery for severe congenital glaucoma. This combination may improve early postoperative control of aqueous outflow and positively affect long-term graft survival in these difficult cases.

Effects of Intraoperative Mitomycin-C on the Function of Baerveldt Glaucoma Drainage Implants in Rabbits

The purpose of this study was to assess the effects of intraoperative mitomycin-C (MMC) on the function of Baerveldt glaucoma implants in rabbits. Bilateral implantations of 200 mm2 Baerveldt drainage devices were performed in 30 normal albino rabbits. One eye, randomly selected, received intraoperative application of MMC at the site of the implant plate for 5 min, via a 6 x 4 x 2 mm cellulose sponge saturated with 0.5 mg/ml of MMC. The opposite eye served as a control. MMC-treated and control eyes (five animals each group) were compared for intraocular pressure (IOP), resistance to flow, flow rates through the implant and histopathological findings at 2, 4, 6, 12, and 24 weeks postoperatively. Resistance to flow and flow rates through the implants were studied after opening the cornea and connecting the drain tube to a micromanometric system. Preoperative IOP did not differ between groups. MMC-treated eyes had lower levels of IOP than did controls at all postoperative times. The differences in IOP were statistically significant up to 8 weeks postoperatively. Resistance to flow was lower in MMC-treated eyes at all times studied, but the differences were statistically significant only at the time points of 2, 4, and 6 weeks. Flow rates through the implant bleb were always higher in MMC-treated eyes, and statistically significant differences were seen at 2, 4, 6, and 24 weeks. Histopathologically, MMC-treated eyes had thinner implant capsules with delayed maturation and less inflammatory infiltrate. MMC causes lower IOP and higher perfusion rates through the implant capsule at 2, 4, and 6 weeks postoperatively. Wound dehiscence, bleb leaks, and extraocular muscle injury were observed only in MMC-treated eyes.

Experience with the Baerveldt Glaucoma Implant in Treating Neovascular Glaucoma

The authors present a retrospective study designed to assess the effectiveness of the Baerveldt glaucoma implant in controlling intraocular pressure (IOP) and maintaining visual function in eyes with neovascular glaucoma. The medical records of all 36 patients (36 eyes) who underwent Baerveldt glaucoma implantation for medically uncontrolled neovascular glaucoma between February 1991 and December 1992 were reviewed. Eighteen patients received Model 350 implants, 16 received Model 500 implants, and 2 received Model 200 implants. The 12- and 18-month life-table success rates (success defined as 6 mmHg < or = final IOP < or = 21 mmHg without additional glaucoma surgery or devastating complication) were 79% and 56%, respectively. Visual acuity remained stable or improved in 10 (31%) patients. Postoperative complications included flat anterior chamber, serous choroidal detachment, and obstruction of the proximal tube tip with fibrovascular tissue, each of which occurred in four (11%) patients. Eleven (31%) patients lost light perception. There were no significant differences between the groups receiving the Model 350 and Model 500 implants with respect to life-table success rates, percentage of postoperative IOP reduction, or complication rates. Patients in the Model 500 implant group required significantly fewer antiglaucoma medications post-operatively, but also demonstrated a significantly greater mean visual acuity reduction. Better preoperative visual acuity and increased patient age were positively correlated with a successful outcome. Baerveldt implantation is effective in controlling IOP elevation associated with neovascular glaucoma. Postoperative visual loss, despite adequate IOP control, is common. Young patient age and poorer preoperative visual acuity are significant predictors of surgical failure.

Intracameral Tissue Plasminogen Activator to Treat Blocked Glaucoma Implants

ABSTRACT I report the use of tissue plasminogen activator to open blocked silicone tubes of Baerveldt glaucoma implants in two cases. A dose of 25 µg was used in both cases; lysis of fibrin clots occurrsd within 15 to 45 minutes.