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Biomedical subjects

G Baerveldt

Publications and source records attributed to G Baerveldt.

At least 19 recordsLinked to original sources
PubMed2000

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

OBJECTIVE: To assess the efficacy of pneumatically stented drainage tube implants specially modified for pars plana insertion in the treatment of complicated glaucoma. DESIGN: Retrospective, non-comparative case series. PARTICIPANTS: 50 consecutive patients with refractory complicated glaucoma nonresponsive to medical treatment. INTERVENTION: Baerveldt 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 MEASURE: Reduction of intraocular pressure (IOP) to 21 mmHg or less. RESULTS: 31 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%). CONCLUSIONS: Pneumatically stented Baerveldt glaucoma implants modified with the Hofmann elbow to facilitate pars plana insertion are effective in the treatment of complicated glaucoma.

Adult↗
PubMed2000

Management of glaucoma implants occluded by vitreous incarceration.

PURPOSE: To review the authors' experience in the management of aphakic or pseudophakic patients without an intact posterior capsule who had undergone glaucoma implant surgery complicated by vitreous incarceration in the tube, resulting in increased intraocular pressure or combined rhegmatogenous and tractional retinal detachment. METHODS: Retrospective review of the clinical features, treatment, and outcomes of eight patients who had vitreous incarceration in a glaucoma implant drainage tube. In each patient, a model 425 (7 patients) or model 350 (1 patient) Baerveldt glaucoma implant was used. RESULTS: Vitreous incarceration in the tube was first diagnosed 1 day to 49 weeks after surgery (mean, 7.5 weeks; median, 1 week). The interval between glaucoma implant surgery and pars plana vitrectomy ranged from 22 to 365 days (mean, 125 days). Before management with pars plana vitrectomy or neodymium:yttrium-aluminum-garnet laser vitreolysis, intraocular pressure ranged from 25 to 62 mm Hg (mean, 40 mm Hg). Four patients were initially treated with neodymium:yttrium-aluminum-garnet laser vitreolysis, which was successful in only one patient. Six patients were successfully treated with pars plana vitrectomy, and one patient declined surgery. Follow-up after treatment of the incarceration ranged from 5 weeks to 15 months (mean, 8.3 months). After pars plana vitrectomy, intraocular pressure ranged from 9 to 24 mm Hg (average, 14 mm Hg). Postoperative visual acuity remained within one line of the preoperative visual acuity in each of the six patients undergoing pars plana vitrectomy. CONCLUSIONS: Pars plana vitrectomy is effective in managing vitreous incarceration in glaucoma implant tubes. Previous anterior vitrectomy does not prevent incarceration.

Adult↗
PubMed1999

Randomized clinical trial of the 350-mm2 versus the 500-mm2 Baerveldt implant: longer term results: is bigger better?

OBJECTIVE: To report the longer term results of a randomized, clinical trial comparing the 350-mm2 and the 500-mm2 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 or the 500-mm2 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-mm2 group and 70% for the 500-mm2 group (P = 0.05). Average follow-up was 37 months (range, 1-76 months) for the 350-mm2 group and 34 months (range, 5-77 months) for the 500-mm2 group. The life-table success rates declined over time for both implant groups, from a high of 98% for the 350-mm2 group and 92% for the 500-mm2 group at 1 year to a cumulative success rate of 79% for the 350-mm2 group and 66% for the 500-mm2 group at 5 years. Visual acuities were better or remained the same in 50% of the patients in the 350-mm2 group and 46% of those in the 500-mm2 group. Complications during the 5-year follow-up were also statistically similar. CONCLUSIONS: The longer term results show that the 350-mm2 Baerveldt implant is more successful than the 500-mm2 implant for overall IOP control. Interval comparisons indicate a higher rate of success for the 350-mm2 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.

Adolescent↗
PubMed1999

Glaucoma drainage devices: pros and cons.

Glaucoma drainage devices are an option in the management of complicated glaucomas that carry a high risk of failure from conventional filtering surgery. Examples include the glaucomas associated with aphakia or pseudophakia, neovascular glaucoma, and glaucomas associated with trauma, uveitis, epithelial downgrowth, iridocorneal endothelial syndrome, vitreoretinal disorders, and penetrating keratoplasty. Modifications in the various implant designs have been developed to limit the occurrence of postsurgical complications such as hypotony, serous and hemorrhagic choroidal detachment, tube and plate avulsion, tube exposure, and corneal endothelial damage.

Equipment Design↗
PubMed1998

Trabeculectomy with intraoperative 5-fluorouracil.

BACKGROUND AND OBJECTIVE: To investigate the outcome and complication rates of trabeculectomy following the combined use of intraoperative, topical 5-fluorouracil (5-FU) and low-dose, postoperative subconjunctival 5-FU injections. PATIENTS AND METHODS: Forty-one eyes of 41 patients with advanced, medically uncontrolled glaucoma underwent trabeculectomy with intraoperative episcleral application of 5-FU (50 mg/ml for 5 minutes). A variable number of subconjunctival 5-FU injections were administered postoperatively at the discretion of the operating surgeon. RESULTS: Six-, 12-, and 15-month life-table success rates (5 mm Hg < or = intraocular pressure [IOP < or = 21 mm Hg) were 100%, 97%, and 83%, respectively. Mean postoperative IOP was 12.1 +/- 4.3 mm Hg. An average of 2.2 +/- 1.6 (range 0 to 7) supplemental subconjunctival 5-FU injections were administered postoperatively. Corneal epithelial erosions developed in 7 (17%) of the eyes. Five of 7 patients who underwent subsequent surgical procedures maintained successful control of IOP at an average of 11.0 +/- 4.8 (range 5 to 16) months after the secondary surgery. CONCLUSION: Trabeculectomy with intraoperative 5-FU is effective in controlling IOP while possibly minimizing the need for frequent postoperative injections and the occurrence of corneal epitheliopathy.

Adult↗
PubMed1997

Annular peripheral choroidal detachment simulating aqueous misdirection after glaucoma surgery.

PURPOSE: The purpose of the study was to define a newly recognized complication after glaucoma surgery and to recommend a therapeutic regimen. METHODS: Eighteen patients diagnosed initially as having aqueous misdirection after glaucoma surgery, but who subsequently were found by ultrasonography to have an annular peripheral choroidal detachment that resulted in secondary angle closure glaucoma, were studied. Ten of these patients were treated with topical cycloplegics and corticosteroids, and 8 were treated with drainage of suprachoroidal fluid. Outcomes of these two treatment methods were compared. RESULTS: Annular peripheral choroidal detachment reliably was diagnosed with ultrasonography. Of the variables studied, time elapsed before resolution of the annular peripheral choroidal detachment was noted to be statistically significant (P < 0.00005). Immediate resolution followed drainage of suprachoroidal fluid, whereas a mean of 19.6 days was required for resolution after medical therapy. CONCLUSIONS: Annular peripheral choroidal detachment should be considered in the differential diagnosis of a flat or shallow anterior chamber with normal or high intraocular pressure after glaucoma surgery. The diagnosis of annular peripheral choroidal detachment can be confirmed most reliably by ultrasonography. Medical therapy is as effective as is surgery, although a significantly longer time to resolution is required.

Adult↗
PubMed1996

Aqueous humor dynamics in rats.

BACKGROUND: In order to determine normal outflow facility and aqueous humor production values in Lewis rats, we established methods of measuring aqueous humor dynamics in this animal. METHODS: Outflow facility was determined using anterior chamber infusion with constant pressure. Aqueous humor production was determined by a technique of dilution with FITC-albumin. RESULTS: The mean outflow facility was 0.044 +/- 0.01 microliter/min/mmHg. Rats weighing less than 300 g had lower values than did rats weighing more than 300 g (0.034 +/- 0.006 microliter/min/mmHg vs 0.050 +/- 0.015 microliter/min/mmHg, P = 0.009). The mean aqueous humor production was 0.350 +/- 0.110 microliter/min. The turnover rate of aqueous humor production per minute was 2.23%. CONCLUSIONS: Anterior chamber infusion with constant pressure and the FITC-albumin method allow measurement of the outflow facility and aqueous humor production in Lewis rats. These methods may be useful in assessing aqueous humor dynamics when rats are used as a glaucoma model.

Animals↗
PubMed1996

Spontaneous collapse of primary acquired iris stromal cysts.

PURPOSE: To describe the spontaneous collapse of primary acquired iris stromal cysts. METHODS: We reviewed the medical records, clinical findings, and ultrasonography of two patients who had been followed up for primary acquired iris stromal cysts. RESULTS: During follow-up, both patients experienced spontaneous collapse of their cysts, which resulted in membrane formation on the peripheral corneal endothelium, localized peripheral anterior synechiae, ectropion uveae, and slightly peaked pupil. CONCLUSION: Primary acquired iris stromal cysts may undergo spontaneous collapse, resulting in clinical findings similar to other anterior segment disorders.

Anterior Eye Segment↗
PubMed1996

Laser suture lysis after mitomycin C trabeculectomy.

PURPOSE: To evaluate the timing, efficacy, and complications of laser suture lysis (LSL) after mitomycin C trabeculectomy in patients with glaucoma at high risk for failure of filtering surgery. METHODS: The authors retrospectively reviewed the charts of 62 consecutive patients who underwent a total of 66 sessions of LSL after trabeculectomy with mitomycin C. RESULTS: The interval from surgery to LSL ranged from 2 to 65 days (mean +/- standard deviation, 17.9 +/- 14.9 days). The average intraocular pressure (IOP) reduction after LSL was 11.9 +/- 8.9 mmHg (range, 3-40 mmHg). A longer interval to LSL was correlated with a lesser degree of pressure reduction (P=0.0004, Wilcoxon rank-sum test). After LSL, hypotony developed in 13 (21%) patients (IOP < 6 mmHg on 2 consecutive measurements at least 24 hours apart). This resolved spontaneously after 7 to 304 days (104.1 +/- 109.1 days) in 12 (92%) of the 13 patients. Life-table success rates (success defined as 6 mmHg </= final IOP </= 21 mmHg) for the hypotony and no hypotony groups were 100% and 86% (at 6 months) and 96% and 86% (at 12 months), respectively. The final visual acuity worsened in a significantly greater percentage of patients in the hypotony group (46%) compared with the no-hypotony group (18%) (P = 0.06), Fisher's exact test). CONCLUSIONS: Laser suture lysis is safe and effective in augmenting aqueous filtration after mitomycin C trabeculectomy. A longer time interval between surgery and LSL may result in both a lesser degree of IOP reduction and a lower incidence of subsequent hypotony.

Adolescent↗
PubMed1996

Effects of intraoperative mitomycin-C on the function of Baerveldt glaucoma drainage implants in rabbits.

PURPOSE: The purpose of this study was to assess the effects of intraoperative mitomycin-C (MMC) on the function of Baerveldt glaucoma implants in rabbits. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Administration, Topical↗
PubMed1996

Suprachoroidal hemorrhage after Molteno implantation.

PURPOSE: The objective of this study is to identify the rate and the associated risk factors for suprachoroidal hemorrhage (SCH) after Molteno drain implantation. METHODS: Data from the Molteno pilot study and single versus double-plate Molteno study were reviewed retrospectively for the occurrence of SCH. Follow-up intervals, demographic variables, ocular data, and medical history were collected. RESULTS: SCH occurred in 6% of the patients enrolled in the Molteno studies; all cases were delayed and none were intraoperative. Significantly associated factors in a multiple logistic regression for SCH were the extent of intraocular pressure (IOP) drop after surgery, the post-operative IOP, a diagnosis of angleclosure glaucoma, and possibly the number of prior surgeries as well. Eyes with SCH did significantly less well in terms of visual acuity outcomes and were more likely to have inadequately controlled IOP. CONCLUSIONS: This study suggests that SCH occurs at the same frequency after Molteno implantation as after filtering surgery with antimetabolite use and that eyes with SCH do less well.

Adult↗
PubMed1996

Long-term histologic studies of the Baerveldt implant in a rabbit model.

PURPOSE: The Baerveldt glaucoma implant is an aqueous shunting device with large surface area that is installed through a single-quadrant conjunctival incision. A rabbit model of the Baerveldt implant was created to obtain serial histology and clinical information over 1 year. METHODS: Modified versions of the Baerveldt implant (110 or 160 mm2) were implanted in 18 normal New Zealand white rabbit eyes. The rabbits were examined periodically and their intraocular pressures (IOPs) recorded. They were killed at monthly intervals to obtain histology of the bleb capsules. RESULTS: Thin capsules were present at 1 month, which consisted of lamellar collagen deposition surrounded by a granulomatous reaction with multinucleate giant cells. Inflammatory cells (probably macrophages) were scattered on the inner bleb surface. The granulomatous reaction resolved after 4 months. Subsequently, capsule thickness and cellularity remained relatively stable, although the collagen stroma became less compact over time. Sixteen rabbit eyes had initial IOP reductions of > or = 3 mm Hg compared with fellow eyes, which persisted up to 4 weeks postoperatively. Seven eyes (39%) exhibited a hypertensive phase (IOP exceeded that of fellow eye by > or = 3 mm Hg) from 2 weeks to 3 months postoperatively. CONCLUSION: The Baerveldt explant is surrounded by a fibrous capsule that matures over time. The bleb histology in the rabbit model is similar to that described with the Molteno implant in primates and humans, except for the eventual development of a fibroblastic inner lining in the rabbit model. This contrasts with primate and human models, in which the inner lining remains an open mesh.

Animals↗
PubMed1996

Cataract surgery after trabeculectomy.

BACKGROUND AND OBJECTIVE: To determine the effect of cataract surgery on glaucomatous eyes with good intraocular pressure (IOP) control after trabeculectomy. PATIENTS AND METHODS: Twenty-two eyes with functional blebs that underwent cataract extraction were retrospectively analyzed. RESULTS: The mean (+/- SD) preoperative IOP was 11.0 +/- 4.3 mm Hg. The mean (+/- SD) postoperative IOPs at 1, 2, 6, and 9 months were 15.5 +/- 4.9, 12.6 +/- 4.7, 14.6 +/- 5.6, and 19.0 +/- 7.9 mm Hg, respectively. At each interval except for the second month, the mean IOP was statistically significantly higher than the preoperative value (P = .0003, .24, .02, and .0009, respectively). The total number of medications was also higher (3 preoperatively versus 27 postoperatively). The interval between the two surgeries had no influence on IOP control. Intraoperative complications during cataract surgery, particularly vitreous loss, were associated with poor IOP control. Phacoemulsification had less of an effect on the postoperative IOP control than did extracapsular cataract extraction. CONCLUSIONS: Eyes with previous successful trabeculectomies had higher IOPs and required more medications after subsequent cataract surgeries.

Aged↗
PubMed1995

Pars plana Baerveldt tube insertion with vitrectomy in glaucomas associated with pseudophakia and aphakia.

PURPOSE: We reviewed the course of intraocular pressure, visual acuity, and complications in patients with shallow anterior chambers or vitreous prolapse who underwent insertion of glaucoma drainage tubes through the pars plana (after a complete posterior vitrectomy). METHODS: Thirteen patients (13 eyes) with uncontrolled glaucoma associated with shallow anterior chamber or vitreous prolapse and aphakia or pseudophakia underwent pars plana Baerveldt tube insertion after vitrectomy. RESULTS: In 11 eyes the intraocular pressure was less than or equal to 15 mm Hg at a minimum follow-up of one year; the other two eyes underwent additional glaucoma surgery. Two of the 11 eyes with controlled intraocular pressure had limitation of ocular motility postoperatively. No retinal complications had occurred in any of the 13 eyes. CONCLUSION: This technique of combined pars plana vitrectomy and pars plana insertion of a Baerveldt tube provides intraocular pressure control in eyes with shallow anterior chamber or vitreous prolapse and glaucoma associated with pseudophakia or aphakia.

Adolescent↗
PubMed1995

Echographic evaluation of primary cysts of the iris pigment epithelium.

PURPOSE: Primary cysts of the iris pigment epithelium frequently appear to be focal elevations of the peripheral iris. To differentiate them from other anterior segment tumors requires the ability to assess the distribution, tissue characteristics, and progression of such lesions, which we accomplished by using anterior segment echography. METHODS: We reviewed the medical records of 49 consecutive patients referred to the Doheny Eye Institute for echographic evaluation of focal bulging of the peripheral iris. Echography of the anterior segment was performed on each patient by using an immersion technique. Clinical examination was also performed on 20 (41%) patients at the time of initial examination. RESULTS: We identified 52 iris pigment epithelial cysts in 52 eyes of the 49 patients studied. All lesions were single, localized to the posterior iris surface, and demonstrated a well-circumscribed, echolucent structure on B-scan echography. Average maximal sagittal thickness was 1.6 +/- 0.4 mm. Cysts were most frequently located in the inferotemporal quadrant (31%). Minimal increase in size or regression of lesions was noted in the nine patients (ten eyes) for whom follow-up echographic examinations were available. CONCLUSIONS: Primary iris pigment epithelial cysts possess characteristic features with regard to location, size, and internal structure, which can be accurately documented with echography. Clinically evident lesions tend to be between 1 and 4 mm in maximum sagittal thickness, conform to the contour of posterior chamber structures without distortion, produce anterior bulging of the peripheral iris, are preferentially located in the inferotemporal quadrant, and demonstrate limited potential for growth.

Adolescent↗
PubMed1995

Experience with the Baerveldt glaucoma implant in treating neovascular glaucoma.

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Adult↗
PubMed1995

[Prostaglandins E2 and F2-alpha in uveitic glaucoma in the Lewis rat].

PURPOSE: In the preinflammatory phase of S-antigen (S-ag) induced uveitis, an ocular hypotension occurs between day 2 and day 6 after S-ag injection. To better understand this phenomenon, we studied the levels of prostaglandin E2 (PGE2) and prostaglandin F2-alpha (PGF2-alpha) in the aqueous humor of S-ag injected rats at various time points after induction of disease. METHODS: Twenty-five female Lewis rats weighting 150 to 175 gm were injected in the hind foot-pad with 50 micrograms of S-antigen. IOP was measured each day at 9 am with a Tono-Pen tonometer. Aqueous humor was collected at days 0, 2, 4, 6, 9, 14 and 18 after S-ag injection. PGE2 and PGF2-alpha were assayed in the aqueous humor using an enzyme immunoassay method. RESULTS: The concentration of PGE2 increased after day 6 and peaked at day 14 after S-ag injection (45.6 +/- 9.0 mu/ml vs 1.1 +/- 0.1 mu/ml in controls, P = 0.04). The peak of PGE2 corresponded to the maximum inflammation and ocular hypertension. PGF2-alpha was increased from day 2 to day 6, with a peak at day 6 after S-ag injection (128.0 +/- 51 pg/ml vs 56 +/- 2.0 pg/ml in controls, P = 0.047), which corresponded to the preinflammatory ocular hypotension. A second peak was observed at day 18 after S-ag injection (3643 +/- 824 pg/ml, P = 0.049), which corresponded to the cessation of intraocular inflammation and ocular hypertension. CONCLUSIONS: The early increased concentration of PGF2-alpha in the aqueous humor of rats with S-ag induced uveitis may explain the ocular hypotension observed from day 2 to day 6 after S-ag injection.

Animals↗