Satisfactory Intraocular Pressure Control Research Articles

Combined Virna Glaucoma Implant (VGI) Implantation and Pars Plana Vitrectomy for Refractory Aphakic Glaucoma

Introduction : Glaucoma drainage devices (GDDs) implantation are frequently indicated for refractory glaucoma. The preferable anterior chamber may be inaccessible for patients with anterior chamber abnormalities.
 Case Illustration : A 6-year-old boy presented with high intraocular pressure (IOP) on the right eye (RE) four months before admission. Cataract surgery on both eye was done four years prior, due to congenital cataract. On examination, the visual acuity of the RE was hand movement with IOP 61mmHg with medications. Anterior chamber was shallow, posterior synechiae was found and posterior segment was hard to be evaluated. The fellow eye was nonfunctional with IOP 31mmHg. Pars plana vitrectomy (PPV) was performed followed by implantation of GDD (Virna Glaucoma Implant) with posterior chamber sulcus tube placement without adding a new incision. Post-operatively, IOP was 3mmHg and choroidal detachment was found. With steroid medication, satisfactory IOP control was achieved within three weeks of follow-up. Visual acuity of RE was improved to 0.5/60.
 Discussion : In eyes with shallow anterior segments, tube placed in the anterior chamber may increase the risk of corneal endothelial injury. Placement of the silicone tube in the posterior chamber sulcus is an effective alternative technique. Although it is relatively safe in experienced hands, vitrectomy and insertion of the tube into the posterior segment carries significant risks, including choroidal detachment. Careful monitoring and management is needed to control IOP and maintain vision.
 Conclusion : Combined GDD implantation and PPV may be considered for refractory aphakic glaucoma, showing favorable outcomes with a relatively safe procedure.

Size Matters: Ab Interno Canaloplasty Revision with Suture Trabeculotomy.

To report the efficacy of the revision of failed ab interno canaloplasty with micro-invasive suture trabeculotomy (MIST) over a follow-up period of 24 months. A retrospective analysis was performed on 23 eyes with open-angle glaucoma (OAG), on whom an ab interno canaloplasty revision with MIST was performed for glaucoma progression. The primary outcome was the proportion of eyes with a significant intraocular pressure (IOP) reduction at 12 months post trabeculotomy, defined as an IOP ≤ 18 mm Hg or ≥20% reduction in IOP without any secondary intervention (SI), and with the same or fewer number of glaucoma medications (NGM). All parameters, including best corrected visual acuity (BCVA), IOP, NGM, and SI, were evaluated at 1, 6, 12, 18, and 24 months. At 12 months, eight out of 23 eyes (36.4%) achieved complete success, maintained in six eyes (27.3%) at 24 months. A significantly lower mean IOP was recorded at all visits [14.3 ± 4.0 mm Hg at 24 months vs 23.1 ± 6.8 mm Hg at baseline (BL)] with a percent IOP change of up to 27.3% at 24 months postoperatively. NGM and BCVA did not significantly decrease from BL. A total of 11 eyes (47.8%) needed an SI throughout the follow-up period. Ab interno trabeculotomy in patients with failed canaloplasty was not shown to be effective in providing a satisfactory control of IOP in OAG patients, possibly due to the small suture gauge used in the initial canaloplasty. Further research is needed to optimize the surgical outcome. Seif R, Jalbout NDE, Sadaka A, et al. Size Matters: Ab Interno Canaloplasty Revision with Suture Trabeculotomy. J Curr Glaucoma Pract 2022;16(3):152-157.

Mitomycin C-loaded PTMC15-F127-PTMC15 hydrogel maintained better bleb function after filtering glaucoma surgery in monkeys with intraocular hypertension.

There is an unmet need for a safer and more effective approach for antimetabolite application to prevent bleb fibrosis after glaucoma filtering surgery. Here, we utilized our previously developed thermosensitive sustained-release agent, mitomycin C-loaded poly(trimethylene carbonate)15-F127-poly(trimethylene carbonate)15 (MMC-hydrogel), aiming to further evaluate the efficacy and safety of MMC-hydrogel in high intraocular pressure (IOP) primate eyes. Twelve primate eyes after high IOP induction were randomly divided into three groups, which respectively received phosphate-buffered saline (PBS)-hydrogel, MMC-hydrogel, and MMC treatment during trabeculectomy. IOP and bleb volume were measured using a Tonopen and anterior segment optical coherence tomography over 28 days. At the end of the experiment, all experimental primate eyes were enucleated. Histopathology and immunohistochemistry were performed to reveal myofibroblast cells and collagen deposition of filtering blebs. The MMC-hydrogel group had satisfactory IOP control (9.25 ± 4.80 mmHg) and maintained well-functioning blebs for a longer time. Fibrosis and scarring were significantly alleviated in this MMC-hydrogel group. There was no obvious toxicity to ocular surfaces or intraocular structures. Taken together, these data suggest that PTMC15-F127-PTMC15-loaded MMC-hydrogel plays a role in functional maintenance and scarring inhibition, showing high efficacy in reducing post-filtering surgery bleb fibrosis. This MMC-hydrogel may offer a new solution for filtering bleb management after glaucoma surgery.

Canaloplasty in Pseudoexfoliation Glaucoma. Can It Still Be Considered a Good Choice?

Purpose: The aim of this study was to assess the long-term outcomes of canaloplasty surgery in pseudoexfoliation glaucoma (PEXG) patients. Material and Methods: A total of 116 PEXG patients with an intraocular pressure (IOP) > 21 mm/Hg and maximum tolerated local medical therapy who underwent canaloplasty from February 2008 to January 2022 were considered. Every six months, all subjects underwent a complete ophthalmic examination. The period of follow-up ranged from 2 to 167 months. Inclusion criteria included only patients for whom the entire procedure could be completed with a follow-up of at least 2 years. Results: Amongst the 116 PEXG patients, the entire procedure could not be performed in 10 eyes (8.6%), and thus they were not considered in the analysis. Twenty-three patients did not reach the two-year follow-up and another 16 patients during this time period were lost. A total of 67 patients with a mean follow-up of 49 ± 32.3 months were considered in the analysis. The pre-operative mean IOP was 31.2 ± 8.7 mm/Hg (range 20–60). The mean IOP at the two-year follow-up was 17.2 ± 6.7 mmHg, with a mean reduction from baseline of 44.9%. After two years, the qualified success rates according to three different criteria (IOP ≤ 21, ≤18 and ≤16 mmHg) were 80.6%, 73.1% and 61.0%, respectively. The total number of medications used pre- and at the follow-up at 2 years was 3.5 ± 0.8 and 1.2 ± 1.4, respectively. Early complications included: hyphema, in about 30% of cases; Descemet membrane detachment (4.9%); and IOP spikes > 10 mmHg (9.7%). A late failure with an acute IOP rise of up to 50 mmHg was observed in 41 cases (61.2%) after 3 to 72 months. Conclusions: Long-term post-operative outcomes of canaloplasty in PEXG patients appear to be quite good on average; however, an acute rise in IOP can be observed in more than 60% of the cases after a long period of satisfactory IOP control. For this reason, canaloplasty may not be suitable in eyes with PEXG, especially in patients with severe functional damage.

Retrospective Analysis of 12 Months Glaucoma Implant Efficacy: XEN45 and PreserFlo Microshunt.

Several new implant devices have recently been introduced to glaucoma surgery using various techniques for reducing intraocular pressure (IOP). Two implants introduced during the past couple of years, XEN45 and PreserFlo Microshunt, are both designed to control subconjunctival filtration. There are two Swiss multicenter studies that collected the data retrospectively to analyze the efficacy and safety of these two devices separately. In this study, we report the analysis of the combined data subset from the University Hospital of Basel. The XEN45 implantation technique was introduced to Basel University Hospital in 2016 and PreserFlo Microshunt in 2018. Sixty operated patients, thirty in each group, were operated on by one surgeon, clinically followed up, and their data retrospectively analyzed from medical records. Only standalone procedures, without combined phacoemulsification, were considered in this analysis; the lens status, however, was neither an inclusion nor an exclusion criterion. Further inclusion criteria were the diagnosis of open-angle glaucoma, no previous glaucoma surgery, other than laser trabeculoplasty, and complete medical records during the 12 months of follow-up. IOP reduction during a 12-month postoperative period was the primary outcome measure as well as the number of IOP reducing drugs. The number of subsequent surgical interventions and complications/adverse events are descriptively reported. Patient age, gender, ophthalmological diagnosis, and initial preoperative IOP were well balanced between the two groups. Postoperative IOP course was comparable between the two methods for the first 12 months. IOP measurements were taken preoperatively and then on the first postop day, week 1, month 1, and months 3, 6, and 12 for the PreserFlo Microshunt vs. XEN45 (mmHg): 23.6 vs. 24.9, 9.0 vs. 8.9, 11.4 vs. 10.6, 13.0 vs.18.3, 16.8 vs.15.1, 15.9 vs.15.0, and 15.4 vs.14.5, respectively. IOP reducing medications were also comparable between the two groups. The study showed that subsequent interventions were more frequent in the XEN45 (13) than in the PreserFlo Microshunt group (7). Both methods demonstrate satisfactory IOP control within a 12-month postoperative period with practically no serious adverse events/complications, but with relatively high numbers of subsequent interventions (needlings), particularly in the XEN45 group.

Causes of Hypertensive Anterior Uveitis in Thailand

ABSTRACT Purpose To determine the prevalence of viral infections in patients with hypertensive anterior uveitis in Thailand from polymerase chain reaction (PCR) of aqueous humor. Methods Thirty-one patients with anterior uveitis with intraocular pressure (IOP) above 25 mmHg were included for PCR analysis for cytomegalovirus (CMV), herpes simplex (HSV), varicella-zoster (VZV), rubella, chikungunya and Zika virus. Results The prevalence of PCR-positive results was 32%, including 19% for CMV, 10% for HSV, and 3% for VZV; PCR for other tested viruses demonstrated negative results. PCR-positive patients exhibited satisfactory IOP control with antiviral and anti-glaucomatous treatment compared to PCR-negative patients, and more than half of PCR-negative patients required glaucoma surgery within 12 months (P = .01). Conclusion PCR evidence of infection with herpes group viruses was found in one-third of patients with hypertensive anterior uveitis; CMV being the most common pathogen. The PCR-positive group generally responded well to a combination of antiviral and anti-glaucoma treatment.

Combined trabeculotomy-trabeculectomy using the modified Safer Surgery System augmented with MMC: its long-term outcomes of glaucoma treatment in Asian children.

This study aimed to study the long-term surgical outcomes of combined trabeculotomy-trabeculectomy (CTT) using the modified Safer Surgery System in treating childhood glaucoma at a tertiary medical center in Taiwan. Retrospective, consecutive, noncomparative case series. We retrospectively reviewed medical records of 42 pediatric patients (age 0-18years) who had CTT performed on their 65 eyes using the modified Safer Surgery System. The study period spanned 18years (from January 1, 1997, to December 31, 2014). We evaluated the outcome in terms of postoperative intraocular pressure (IOP), axial length growth, disc cupping reversal, and use of antiglaucoma medications. The surgical success was rated using the Kaplan-Meier survival analysis and based on the incidence of complications. The mean follow-up period was 85.05 ± 32.17months (range 14-200). After operation, IOP dropped significantly from 35.76 ± 9.44mmHg (mean ± SD) to 16.18 ± 7.20mmHg together with a significant reversal of optic disc cupping. Similarly, the use of antiglaucoma medications was also significantly reduced in number from 1.26 ± 0.50 to 0.43 ± 0.70. Most of the axial lengths of the eyes measured at the last follow-up visit showed growths within the average ± 2 SDs in comparison with the healthy, age-matched population. After surgery, the qualified success rate was 90.77% at the end of the first year, 90.77% at the second year, 87.64% at the fifth year, 84.51% at the 10th year, and 81.38% at the 15th year. No serious intraoperative or postoperative complications were found. For Taiwanese children, the combined trabeculotomy-trabeculectomy using the modified Safer Surgery System offered an efficient and safe surgical option for treating glaucoma with long-term satisfactory control of IOP.

Aqueous misdirection syndrome in persistent fetal vasculature (PFV)

We report a case of a 5-year-old girl with persistent fetal vasculature who presented with unilateral acute angle closure caused by aqueous misdirection syndrome that was apparently associated with regression of cycloplegia. Initial treatment with topical steroids, anti-glaucomatous drops, and atropine showed insufficient control of the intraocular pressure (IOP). Surgical treatment with lensectomy and vitrectomy resulted in satisfactory IOP control and no complications at the 6-month follow-up.

Additive Effect of Risk Factors for Trabeculectomy Failure in Glaucoma Patients: A Risk-group From a Cohort Study.

The purpose of the study was to assess the role of significant risk factors and develop a risk-group category related to the trabeculectomy (Trab) failure. A retrospective cohort study was developed between January 2009 and June 2014. In total, 120 eyes included in this study had a glaucoma diagnosis and undergone to Trab with mitomycin. The main outcome measures were surgical success and failure rate. Multivariate (Cox proportional hazards regression model) analyses were used to examine the predictive value of significant factors. A risk-group category was build based on the number of significant risk factors for patients. The risk group category was tested using the Kaplan-Meier method and log-rank test. With a median follow-up of 33 months (3 to 72 mo), the complete surgical success in 1, 2, 3, and 4 years was 82%, 63.5%, 52%, and 27.6%, respectively. The probability of freedom from a complete surgical failure was 88%, 84.5%, 78%, and 70% in 1, 2, 3, and 4 years, respectively. Glaucoma type (P=0.008), previous ophthalmic surgery (P=0.04), glaucoma medication use ≥3 years (P=0.010) and 4 glaucoma medication use pre-Trab (P=0.038) were identified as risk factors for surgical failure. The probability of freedom of surgical failure in 3 years was 93%, 83%, and 37.6% (P=0.003), for low (no factors), intermediate (1 to 2 factors), and high-risk group (3 to 4 factors). Trab with mitomycin produces satisfactory intraocular pressure control over time. However, several risk factors influence the efficacy of the surgical procedure. Our data show that there seems to exist an additive effect among risk factors with similar pathophysiology.

Long-term Efficacy of Trabeculectomy on Chinese Patients with Pigmentary Glaucoma: A Prospective Case Series Observational Study.

Background:Though trabeculectomy is often performed on patients with medically refractive pigmentary glaucoma (PG), the clinical outcomes of surgical treatment on PG remain unknown. The aim of this study was to summarize the long-term efficacy and safety of trabeculectomy on PG.Methods:This was a prospective case series observational study. Eighteen consecutive PG patients were followed up for 8 years after trabeculectomy from May 2006 to April 2007. Visual acuity (VA), best-corrected visual acuity (BCVA), slit lamp biomicroscopy, intraocular pressure (IOP) measurement, Humphrey visual field analysis (VFA), and stereoscopic funduscopy were performed on admission and every 6 months after the surgery. Postoperative IOP, VA, BCVA, VFA, adjunctive anti-glaucoma medication, treatment-related side-effects, changes in blebs, and main clinical findings in the anterior segment of PG were recorded and compared with the baseline.Results:Eighteen PG eyes from 18 patients, with average preoperative IOP of 34.5 ± 4.7 mmHg (range: 21–47 mmHg, 1 mmHg=0.133 kPa) were enrolled in this study. All enrolled patients completed the follow-up visits and required examinations. Eight years after trabeculectomy, all surgical eyes (18/18) had satisfactory IOP control with an average of 13.7 ± 2.5 mmHg (range: 9–19 mmHg), which was significantly lower than baseline (P = 0.001). Majority (15/18) of the PG eyes had stable VA, BCVA, VFA, and optic disc cupping parameters. Functional blebs still existed in 12/18 of the PG eyes at the last follow-up visit. Unanimously, pigmentation in the anterior segment attenuated with time after surgical treatment. No severe side-effects were recorded in any of the surgical eyes.Conclusions:All surgical PG eyes in this study had satisfactory IOP control 8 years after the surgery with well-preserved visual function. The long-term efficacy and safety of trabeculectomy are promising in PG patients.

Long-term outcomes of laser peripheral iridectomy for primary angle closure glaucoma

To explore the long-term efficacy and safety of laser peripheral iridectomy for primary angle closure glaucoma (PACG). It was a retrospective case series study. Data were collected from those patients who received laser peripheral iridectomy (LPI) for acute or chronic PACG from April 1992 through October 2002 at the Peking Union Medical College Hospital. Only patients who were followed for at least 5 years were included in this study. The control of intraocular pressure (IOP), visual acuity and managements after LPI were analyzed. All of the studied eyes were re-classified into three categories according to the status of anterior chamber angle, optic nerve head and visual field before LPI: primary angle closure suspect (PACS), primary angle closure (PAC) and primary angle closure glaucoma (PACG). Satisfactory control of IOP was defined as the IOP was less than 21 mm Hg (1 mm Hg = 0.133 kPa) without any medications after LPI. No satisfactory control of IOP was defined as the IOP was greater than 21 mm Hg after LPI, yet could be controlled below 21 mm Hg by anti-glaucoma medications. A failure in IOP control was defined as an acute attack of angle closure developed or filtering surgery was required to control IOP after LPI. Chi-square analysis was used for comparison of IOP control in different groups. One hundred and thirty one patients (251 eyes) with PACG were eligible for this study. The mean follow-up period was (9.2 +/- 3.7) years. Of the 251 eyes, 18 eyes (7.2%) were identified as PACS, 98 eyes (39.0%) PAC, 129 eyes (51.4%) PACG, and 6 eyes (2.4%) could not be classified owing to the lack of the information on the optic nerve head and visual field before LPI. The rates of satisfactory control of IOP were 27.1% in all eyes, and 88.9% (16/18), 38.8% (38/98) and 10.9% (14/129) in PACS, PAC and PACG eyes respectively. The rates of no satisfactory control of IOP were 59.8% in all eyes, and 5.6% (1/18), 48.0% (47/98) and 75.2% (97/129) in PACS, PAC and PACG eyes respectively. The rates of failure in IOP control were 13.1% in all eyes, and 5.6% (1/18), 13.3% (13/98) and 14.0% (18/129) in PACS, PAC, PACG eyes respectively. The difference in IOP control between PACS, PAC and PACG eyes was statistically significant (chi(2) = 59.08, P = 0.000). Only 8 eyes had an acute attack of angle closure after LPI. No long-term complications after LPI were observed in all eyes. The IOP control after LPI in PACG eyes is not so good as expected. However, most of PACG eyes after LPI are free of acute attack of angle closure. PACG eyes should be given close and regular follow-up in a long-term to monitor the IOP control and the progression of PACG after LPI.

Micro-trephination Glaucoma Surgery In Nigerians: 10 Years Outcome

The aim of this study was to show the effectiveness of microtrephination glaucoma surgery in Nigerians followed up for up to 10 years. Eight eyes of 5 Nigerian patients who had microtrephination glaucoma surgery at DDS Eye Surgery, Benin City and the University of Benin Teaching Hospital Benin City were followed up for at least 10 years. The visual acuity, cup disc ratio and intraocular pressures were monitored in each eye. Intraocular pressure was measured by applanation tonometry in all cases. Two eyes (25%) had adequate intraocular pressure control and did not require additional medications after 10 years. The remaining 6 eyes (75%) did not have satisfactory intraocular pressure control and needed additional antiglaucoma medication. Micro-trephination appears to be unsatisfactory for effective control of intra-ocular pressure in Nigerian eyes. However the great potential of microtrephination making glaucoma surgery affordable and available to Nigerians and other developing countries may still be realizable. What may be required is to determine the appropriate diameter of the trephine that strikes adequate balance between preventing hypotony and obliteration.

Ex-PRESS R-50 miniature glaucoma implant insertion under the conjunctiva combined with cataract extraction

To evaluate the efficacy and safety of the Ex-PRESS R-50 implant (Optonol Ltd.) in eyes operated on for open-angle glaucoma combined with phacoemulsification. Glaucoma Unit, Ophthalmology Department, University of Lausanne, Lausanne, Switzerland. Between November 2000 and June 2002, the Ex-PRESS R-50 shunt was implanted in 35 eyes of 35 patients. The best corrected visual acuity (BCVA), intraocular pressure (IOP), number of medications, and complications were recorded preoperatively as well as postoperatively at 1 and 7 days and 1, 2, 3, 6, 9, 12, 24, 36, and 48 months. Temporal clear corneal phacoemulsification with intraocular lens implantation was performed first. The ophthalmic viscosurgical device was not removed, and the Ex-PRESS R-50 was implanted under the conjunctiva into the anterior chamber. The mean follow-up was 36.9 months +/- 18.2 (SD) and the mean age of the patients, 74.6 +/- 10.9 years. The mean preoperative IOP of 19.3 +/- 6.3 mm Hg decreased postoperatively to 15.3 +/- 6.2 mm Hg, 15.1 +/- 4.6 mm Hg, 13.8 +/- 2.8 mm Hg, 14.6 +/- 2.9 mm Hg, and 13.3 +/- 2.0 mm Hg at 6 months, 12 months, 24 months, 36 months, and 48 months, respectively (P<.005). At 48 months, the mean BCVA was 0.74 +/- 0.34 and the number of medications was reduced by 57% (P<.005). The microtube was removed in 10 patients, and bleb management was performed in 10 eyes. Ten patients (32%) had satisfactory IOP control (mean 13.2 +/- 2.2 mm Hg) without medication; minor transient complications were observed in 10 patients. Based on the cumulative survival curve after 48 months, the complete success rate was 32.7% and the qualified success rate, 53.7% (P<.05). Ex-PRESS R-50 implantation under the conjunctiva was associated with a relatively high number of complications, despite good IOP control in the uncomplicated cases. Refinement in the tube design and implantation technique would increase the success rate.

Sclérectomie profonde non perforante au Brésil: Étude rétrospective sur trois ans

Nonpenetrating deep sclerectomy with external trabeculectomy has been proved to be an effective alternative to classic trabeculectomy for surgical treatment of primary open-angle glaucoma. However, this procedure is not well known nor well accepted among Brazilian ophthalmic surgeons. The aim of this study was to assess the results and success rate of this new filtering surgical procedure in a Brazilian population, with a 3-year follow-up.One-hundred eleven primary open-angle glaucoma patients underwent deep sclerectomy with external trabeculectomy between 1999 and 2002 (the surgery was performed by two different surgeons using the same procedure). The antimetabolite mitomycin C (0.2 mg/ml) was applied intraoperatively in 80 patients with high surgical risk of failure (80 patients under 45 years of age, black, and having had previous ocular surgery). The postoperative follow-up included assessment of visual acuity, measure of intraocular pressure (IOP), evaluation of the filtration site and optic nerve head using biomicroscopy, and analysis of visual field deficits. Complete success was defined as IOP less than 18 mmHg without medical treatment, while relative success was defined as IOP less than 18 mmHg with medical treatment.The mean age was 63.7 +/- 13.1 years and 42.3% of patients were black. Mean follow-up was 19.4 months (+/- 11.7). The mean preoperative intraocular pressure was 22.57 +/- 4.92 mmHg, while mean IOP at the last follow-up visit was 14.22 +/- 2.89 mmHg, so that at the end of the follow-up, complete success was 82.7% and relative success was 93.3%. The cumulative probability of complete success was 76% at 3 years. The complication rate was low: intraoperative microperforations (14.4%), conjunctival seidel (12.5%), hyphema (3.8%), flat anterior chamber (2.9%), choroidal detachment (1%), and filtering bleb fibrosis (17.3%).These results demonstrate that deep nonpenetrating sclerectomy with external trabeculectomy is a safe and efficient filtering procedure that provides satisfactory IOP control with a minimal rate of complications, even in patients with high surgical risk of failure such as the highly mixed Brazilian population. The results suggest that this revolutionary procedure could be used as first-intention treatment in Brazilian glaucomatous patients that do not have access to expensive medical treatment.

Surgical revision of filtration blebs: a follow-up study.

To assess the clinical outcome of one technique for surgical revision of filtration blebs in terms of bleb function and intraocular pressure control. Retrospective analysis of 36 consecutive cases of leaking, overfiltrating, or oversized blebs treated with bleb excision and conjunctiva and Tenon advancement in a glaucoma referral center between January 1991 and December 1999. Surgical success was defined as a final intraocular pressure between 6 and 22 mm Hg with or without topical antiglaucoma medication, resolution of the bleb leak, hypotony maculopathy and symptoms, and no need for repeat glaucoma surgery. With a minimum of 12 months and an average of 29.5 months of follow-up, the overall success rate was 86.1%, with 51.6% of patients not requiring medication. In the success group, mean (SD) intraocular pressure was 23.7 (5.9) mm Hg before the original trabeculectomy, 4.3 (3.7) mm Hg prior to revision surgery, and 13.5 (SD 3.8) mm Hg at the last follow-up visit after the revision surgery. Mean number of antiglaucoma medications was 2.1 (range, 1-4) before the original trabeculectomy, none before the revision surgery, and 0.8 (range, 0-3) at the last follow-up visit. The surgical revision technique offers a definitive solution for most of these bleb complications and a satisfactory intraocular pressure control in the majority of patients.

Baerveldt implant in refractory glaucoma: long-term results and factors influencing outcome.

To evaluate the clinical outcome of patients who received a Baerveldt implant for refractory glaucoma and to identify factors which may influence the outcome. Retrospective study including 51 eyes of 51 patients with medically uncontrolled glaucoma who underwent Baerveldt implant surgery between June 1994 and December 1998. Criteria for success were intraocular pressure (IOP) < or = 21 mmHg and > 6 mmHg, necessity of further antiglaucoma medications, absence of additional glaucoma surgery and no loss of light perception. Over a mean follow-up of 37.6 (SD: +/-18.8) months, the mean intraocular pressure decreased from 34.8 (+/-12.5) mmHg to 14.0 (+/-4.3) mmHg at month 60. Qualified success rate, achieved when IOP was below 21 mmHg and higher than 6 mmHg with medications was 25/48 (52%), complete success rate (same IOP limits without medication) was 14/48 (29%). Seven eyes had major complications or lost light perception. Postoperative visual acuity improved or remained within one Snellen line of the preoperative visual acuity in 35 patients (73%). Factors associated with a better prognosis were a preoperative visual acuity better than 20/400 and etiology of glaucoma. The Baerveldt implant is effective in lowering intraocular pressure in most patients with refractory glaucoma. Long-term results are promising with satisfactory IOP control.

Nitric oxide mediates excitotoxic and anoxic damage in rat retinal ganglion cells cocultured with astroglia.

Nitric oxide has been implicated in the process of retinal ganglion cell death in glaucoma. To investigate the role of nitric oxide in mediating retinal ganglion cell death in a culture system that models glial-neuronal interactions at the level of the optic nerve head. Dissociated retinal ganglion cells from neonatal rats were plated on monolayers of astroglia and identified by retrograde labeling with the fluorescent marker 1.1-dioctadecyl-,3,3,3,tetramethylindocarbocyanineperchlorate. Two days after dissociation, cocultures of retinal ganglion cells and glia were treated with graded concentrations of the nitric oxide synthase inhibitor N-nitro-L-arginine (NNA), and exposed to either anoxia for 1 to 24 hours or excitatory amino acids for 6 hours. Surviving retinal ganglion cells were counted with fluorescence microscopy and expressed as a percentage of retinal ganglion cells surviving in control cultures. Cell survival after anoxia increased in a dose-dependent fashion with exposure to NNA. Mean +/- SD survival rate of retinal ganglion cells after 6 hours of anoxia was 57%+/-10% with NNA treatment compared with 31%+/-3% without treatment (P<.01). When treated with excitatory amino acids, cell survival was 31%+/-6% after administration of N-methyl D-aspartate, 500 micromol/L, and 27%+/-8% after administration of sodium glutamate, 500 micromol/L. Survival was increased in cultures with exposure to NNA, 100 micromol/L, to 53%+/-11% and 69%+/-11%, respectively (P<.01). In this coculture of retinal ganglion cells and astroglia, reduction of the glial source of nitric oxide through nitric oxide synthase inhibition provided partial but significant protection against the lethal effects of anoxia and excitatory amino acids on retinal ganglion cells. Neuroprotective agents may play a role in patients with glaucoma who have progressive visual field loss, despite satisfactory control of intraocular pressure. Inhibition of nitric oxide synthase at the level of the optic nerve head may contribute to a clinically significant level of neuroprotection.

Surgical Management of the Symptomatic Overhanging Filtering Bleb

Large filtering blebs that evolve after trabeculectomies can be bothersome to the patient, especially when overhanging the cornea. Partial bleb excision is warranted to relieve the patient from discomfort or even visual impairment. Surgical partial excision of the overhanging corneal part of the bleb was performed in four patients who had undergone earlier trabeculectomy without application of antimetabolites. Duration of follow-up after excision ranged from 9 months to 4 years. Successful reduction of the excessive bleb and continued satisfactory control of intraocular pressure (IOP) were achieved in all four cases. Partial excision of the corneal part of the bleb did not lead to bleb leakage in any of the cases. Surgical blunt dissection of the overhanging the morphologic features of the bleb and ensuring continued control of IOP and relief of symptoms. Alternative methods, such as autologous blood injection, cryoapplication, application of trichloracetic acid, or application of Nd:YAG laser, are noninvasive but do not allow precise rearrangement of bleb architecture.

Management of large, leaking, and inadvertent filtering blebs with the neodymium: YAG laser

Objective The purpose of the study was to test the efficacy of the neodymium:YAG (Nd:YAG) laser for repairing filtering blebs. Design The study design was a prospective study. Participants Five eyes of five patients with leaking blebs (group 1), five eyes of five patients with large irritating blebs (group 2), and four eyes of four patients with inadvertent filtering blebs in the surgical wound after cataract surgery (group 3) were studied. Intervention The thermal mode of the Lasag Microrupter II Nd:YAG laser was used to treat the filtering blebs. The area of the bleb targeted for treatment was “painted” with methylene blue and then exposed to Nd:YAG laser treatment with an energy level of 2.5 to 3.75 J in a grid pattern. The aiming beam was focused on the conjunctiva, but the laser beam was offset according to the height of the bleb (offset of 0.9–1.5 mm, 4–5 on the Lasag) to selectively treat the internal surface of the bleb. Main outcome measures Symptomatology, intraocular pressure (IOP), and complications were measured. Results After the laser treatment, all the leaks in group 1 were healed, all the patients in group 2 reported relief of their symptoms, and all blebs in group 3 shrank considerably. The IOP increased significantly ( P < 0.001) after laser treatment in all three groups. This elevation appeared to diminish over time, with the major increase in IOP being recorded within the first month after the laser treatment. However, satisfactory IOP control was maintained in nearly all patients (13 of 14) who received none or one antiglaucoma medication. The visual acuity of one patient decreased significantly because of cataract formation. Complications included transient pressure rise (1 eye), bleb failure (1 eye), pupillary retraction toward the bleb (6 eyes), iatrogenic bleb leak (6 eyes), and cataract (1 eye). Conclusion The continuous wave Nd:YAG laser is an effective tool for repairing bleb-related problems while maintaining successful filtration.

Tube-shunt Surgery versus Neodymium:YAG Cyclophotocoagulation in the Management of Neovascular Glaucoma

To determine the relative effectiveness of neodymium:YAG (Nd:YAG) cyclophotocoagulation (CPC) and tube-shunt surgery on intraocular pressure (IOP) control in eyes with neovascular glaucoma (NVG). Retrospective, case-by-case matched, comparative group study. Twenty-four patients with NVG treated with noncontact Nd:YAG-CPC were matched with 24 patients who underwent tube-shunt surgery. Matching criteria included the underlying disorder causing angle neovascularization, the lens status, and patient's age. Tube-shunt surgery or Nd:YAG-CPC. Postoperative IOP (IOP > or = 6 and < or = 25 mmHg), visual acuity, and presence of any postoperative complications. Satisfactory IOP control (IOP < or = 25 mmHg and > or = 6 mmHg) was achieved in 9 eyes (37.5%) treated with Nd:YAG-CPC compared with 16 eyes (66.7%) receiving a tube-shunt procedure (P = 0.04) over a mean follow-up of 16.9 +/- 14.6 and 15.2 +/- 11.8 months, respectively. In the matched pairs in both groups that had nonequivalent outcomes, the proportions with persistently high IOP or hypotony were both greater in the CPC group than in the tube-shunt group. The cumulative proportion of failure in the CPC group was 20.8% at 6 months, 35.4% at 1 year, and 71.2% at 3 years postoperatively. In the tube-shunt group, the cumulative proportions of failure at 6 months and 1 year were close to those in the CPC group (12.5% and 29.2%, respectively), but lower 3 years after surgery (43.3%). Eleven eyes (45.8%) in the CPC group lost light perception versus four eyes (16.7%) in the tube-shunt group. Complication rate was higher in the tube-shunt group. This study suggests that, in the management of NVG, tube-shunt surgery more frequently controls IOP in a satisfactory range, with less hypotony and less visual loss, than noncontact Nd:YAG-CPC.