Mary Ann Lloyd

Which Is Better? One or Two?: A Randomized Clinical Trial of Single-plate versus Double-plate Molteno Implantation for Glaucomas in Aphakia and Pseudophakia

PURPOSE Previous studies have suggested that primary double-plate Molteno implantation may be beneficial. Therefore, the authors performed a randomized clinical trial to evaluate the relative effectiveness and safety of single- versus double-plate Molteno implantation. METHODS From March 1988 to February 1990, 132 patients who underwent Molteno implantation for medically uncontrollable non-neovascular glaucomas in aphakia or pseudophakia were randomly assigned to receive either single- or double-plate implants. RESULTS The 1- and 2-year life-table success rates (success [survival] defined as 6 mmHg < or = final intraocular pressure [IOP] < or = 21 mmHg without additional glaucoma surgery or devastating complication) were 55% and 46% with single-plate implantation and 86% and 71% with double-plate implantation, respectively. The final postoperative visual acuities were within one line of the preoperative visual acuities or had improved in 73% and 80% of patients, respectively. Choroidal hemorrhages and/or effusions, corneal decompensation, flat anterior chambers, and phthisis bulbi were more common in the patients who had undergone double-plate Molteno implantation; however, transient elevations of IOP during the first few postoperative months were more common in the patients who had undergone single-plate Molteno implantation. CONCLUSIONS Double-plate Molteno implantation more frequently affords IOP control than single-plate Molteno implantation; however, double plates are associated with greater risks of choroidal hemorrhages and/or effusions, corneal decompensation, flat anterior chambers, and phthisis bulbi.

Clinical experience with the single-plate Molteno implant in complicated glaucomas. Update of a pilot study.

Ninety-six patients who had undergone single-plate Molteno implantation for glaucomas with poor surgical prognoses were re-evaluated for long-term results. Control of intraocular pressure was achieved with one single-plate implant to a level less than 22 mmHg (but greater than 5 mmHg) without reoperation or devastating complications in 46% of the aphakic/pseudophakic eyes, 25% of eyes after failed filters, 25% of eyes with neovascular glaucomas, and 26% of eyes in patients younger than 13 years of age (life-table analysis at 5 years). Five-year success rates improved to 53%, 71%, 40%, and 56%, respectively, when data from second plates were included. Visual acuities improved or remained the same after one or two plates were implanted in 47% of aphakic/pseudophakic eyes, 17% of eyes after failed filters, 65% of eyes with neovascular glaucomas, and 63% of eyes in patients younger than 13 years of age on whom Snellen acuity was available. The most frequent overall complications after implantation of one or two plates included: corneal edema (19%), corneal graft decompensation (13%), and cornea-tube touch, retinal detachment, and cataract (8% each).

Intermediate-term Results of a Randomized Clinical Trial of the 350- versus- the 500-mm2 Baerveldt Implant

BACKGROUND The Baerveldt glaucoma implant is a large equatorial aqueous shunting device that is installed through a single-quadrant conjunctival incision. The intermediate-term results of a randomized study comparing the 350- and 500-mm2 Baerveldt implants are reported. METHODS Seventy-three patients with medically uncontrollable, nonneovascular glaucomas associated with aphakia, pseudophakia, or failed filters were enrolled in a randomized, prospective study comparing 350- and 500-mm2 Baerveldt implants. Surgical success was defined as 6 mmHg < or = final intraocular pressure < or = 21 mmHg without glaucoma reoperation or devastating complication. RESULTS Of patients with 350- and 500-mm2 implants, 93% and 88%, respectively, achieved surgical success (18-month life-table analysis, P = 0.93). The 500-mm2 implants afforded intraocular pressure control with significantly fewer medications (0.7 versus 1.3; P = 0.006). The postoperative visual acuities remained within one line of the preoperative visual acuities or improved in 62% and 66% of patients in the 350- and 500-mm2 groups, respectively (P = 0.93). Complication rates were statistically similar. The most frequent ones in the 350- and 500-mm2 groups, respectively, were serous choroidal effusion (16% and 32%), strabismus (16% and 19%), anterior uveitis (14% and 11%), and corneal or corneal graft edema (11% each). CONCLUSION The intermediate-term results of the 350- and 500-mm2 Baerveldt implants were statistically comparable with respect to surgical and visual outcomes, as well as complications, although the larger implant was associated with a higher rate of some complications. However, the 500-mm2 Baerveldt implant afforded intraocular pressure control with fewer medications than the 350-mm2 implant.

Initial Clinical Experience with the Baerveldt Implant in Complicated Glaucomas

BACKGROUND The Baerveldt glaucoma implant is an aqueous shunting device with a large surface area that is installed through a conjunctival incision in one quadrant of the eye. This study presents the initial results of the first 13 patients who underwent Baerveldt implantation as part of the Food and Drug Administration approval process. METHODS Thirteen patients with medically uncontrollable complicated glaucomas underwent one-stage implantation of either a 200- or 350-mm2 Baerveldt implant without postoperative systemic antifibrosis therapy. Surgical success was defined as intraocular pressure greater than or equal to 6 and less than or equal to 21 mmHg without glaucoma reoperation or devastating complication. RESULTS Eight patients (62%) had successful surgical outcomes, with a mean follow-up of 17.3 +/- 7.0 months (+/- standard deviation) (range, 6-24 months). Seven (70%) of the ten patients with glaucomas associated with aphakia or pseudophakia had successful outcomes, whereas only one (50%) of the two patients with neovascular glaucomas had a successful outcome. One patient with glaucoma associated with nanophthalmos and an unsuccessful filtering procedure had a failed outcome. The postoperative visual acuities remained within one line of the preoperative visual acuities or improved in 62% of the patients. The most frequent complications among all patients were transient serous choroidal effusion (23%) and hyphema (15%). CONCLUSION Initial results of the Baerveldt implant generally are comparable with other implants. It is easier to install and requires less extensive conjunctival dissection than other large implants. Additional studies are needed to evaluate the effectiveness of the Baerveldt implant in affording long-term intraocular pressure control.

INCIDENCE AND MANAGEMENT OF GLAUCOMA AFTER INTRAVITREAL SILICONE OIL INJECTION FOR COMPLICATED RETINAL DETACHMENTS

BACKGROUND Intravitreal silicone oil injection used for managing complicated retinal detachments can be associated with elevated intraocular pressure (IOP). This study was undertaken to determine the incidence of glaucoma in patients who underwent silicone oil injection, as well as to evaluate the effectiveness of medical and surgical therapy in patients in whom glaucoma developed. METHODS The postoperative courses of 50 eyes of 47 consecutive patients who underwent pars plana vitrectomy and silicone oil injection for the management of complicated retinal detachments were reviewed retrospectively. The outcomes of patients who underwent silicone oil removal and/or glaucoma surgery also were evaluated. RESULTS The mean overall postoperative IOP before any glaucoma surgery was 16.7 +/- 9.3 mmHg (range, 0 to 45 mmHg), with a mean follow-up of 16.6 +/- 12.1 months (range, 2 to 51 months). Twenty-four (48%) eyes had postoperative IOPs of at least 25 mmHg and IOP elevations of at least 10 mmHg above the preoperative levels. Twenty-one (42%) eyes underwent complete removal of silicone oil and/or glaucoma surgery to effect IOP control. The IOPs were controlled to 21 mmHg or less (but > 5 mmHg) in 8 of 14 eyes that underwent removal of silicone oil alone, in 3 of 5 eyes that underwent Molteno implantation, and in 1 eye that underwent Nd:YAG transscleral cyclophotocoagulation, but not in 1 eye that underwent a modified Schocket procedure (mean follow-up, 13.5 +/- 11.0 months; range, 0.2 to 33 months). CONCLUSION Intraocular pressure elevation is a common occurrence after intravitreal silicone oil injection. The underlying mechanism may often be multifactorial in nature. Patients in whom uncontrolled IOP develops may benefit from aggressive medical and/or surgical treatment with silicone oil removal, glaucoma implants, or cyclodestructive procedures.

Randomized clinical trial of the 350-mm2 versus the 500-mm2 Baerveldt implant: longer term results: Is bigger better?1☆

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.

Combined Molteno implantation and Pars Plana Vitrectomy for Neovascular Glaucomas

Ten patients underwent combined Molteno implantation and pars plana vitrectomy as the primary nonlaser surgical treatment of neovascular glaucoma associated with diabetic retinopathy (9 patients) or central retinal vein occlusion (1 patient). Combined surgery was performed most frequently because media opacities precluded adequate preoperative retinal ablation. Follow-up ranged from 3 to 43 (mean +/- standard deviation, 18.0 +/- 13.2) months. Six patients achieved final intraocular pressures less than 22 mmHg. Visual acuities remained the same or improved in four patients. Four patients had uncomplicated courses. Among the other patients, complications included: recurrent vitreous hemorrhage and retinal detachment (3 patients each); hyphema (2 patients); and tube block, extensive fibrin formation, epiretinal membrane, and total retinal necrosis (1 patient each).

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.

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.

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

PurposeThe 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. MethodsModified 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. ResultsThin 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 ≥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 ≥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.