Long-term Comparison of Primary Trabeculectomy With 5-Fluorouracil Versus Mitomycin C in West Africa:

The outcomes of a low-cost, non-valved glaucoma drainage device using mitomycin-C: 1-year results

PURPOSE

To evaluate the indications, outcomes, and complications of the usage of Aurolab Aqueous Drainage Implant (AADI) using mitomycin-C.

METHODS

A retrospective case series of patients who underwent AADI placement using mitomycin-C between April 2018 and June 2020 at Ain Shams University Hospitals, Cairo, Egypt. The data was extracted from the records of the patients with a minimum of 1 year of follow-up. Complete success was defined as IOP ≥ 5 mmHg and ≤ 21 mmHg or reduction of IOP by ≥ 20% from baseline without antiglaucoma medications (AGMs). Qualified success was defined as reaching the same IOP range with the aid of AGM.

RESULTS

A total of 50 eyes of 48 patients were included. Neovascular glaucoma represented the commonest indication (13 patients, 26%). The mean preoperative IOP was 34.0 ± 7.1 mmHg, with a median number of AGM of 3 (mean ± SD = 2.84 ± 1), while the mean IOP after 12 months was 14.3 ± 4 with a median number of AGM of 0. (mean ± SD = 0.52 ± 0.89) (p < 0.001). Complete success was achieved in 33 patients (66%). Qualified success was achieved in 14 patients (28%). Thirteen eyes (26%) had variable postoperative complications; none of them required explantation of the device or affected the visual acuity (except one patient).

CONCLUSION

AADI with using mitomycin-C and ripcord during the surgery is an effective and relatively safe method of control of IOP in refractory and advanced cases of glaucoma, with an overall success rate of 94%.

Racial Disparities Affecting Black Patients in Glaucoma Diagnosis and Management

Black patients are more affected by glaucoma and suffer from more advanced disease. Diagnostic challenges among black patients with glaucoma include lower rates of diagnostic testing and thinner average central corneal thickness, the latter of which affects intraocular pressure measurement. Treatment challenges include poor follow-up, medication adherence, and trust in providers. Black patients undergoing trabeculectomy have higher rates of failure compared to white patients. Race is not a definitive factor affecting success for tube shunts, laser trabeculoplasty, cyclophotocoagulation, and micro-invasive glaucoma surgeries, but the body of evidence is limited by low inclusion of black patients in these studies. Future steps should include increased attention toward improving trust between patients and providers, improving access to care, and increased representation of black patients in glaucoma research to better understand factors affecting racial disparities in glaucoma management and outcomes in this population disproportionately affected by the disease.

Racial Disparities Affecting Black Patients In Glaucoma Diagnosis And Management

Black patients are more affected by glaucoma and suffer from more advanced disease. Diagnostic challenges among black patients with glaucoma include lower rates of diagnostic testing and thinner average central corneal thickness, the latter of which affects intraocular pressure measurement. Treatment challenges include poor follow-up, medication adherence, and trust in providers. Black patients undergoing trabeculectomy have higher rates of failure compared to white patients. Race is not a definitive factor affecting success for tube shunts, laser trabeculoplasty, cyclophotocoagulation, and micro-invasive glaucoma surgeries, but the body of evidence is limited by low inclusion of black patients in these studies. Future steps should include increased attention toward improving trust between patients and providers, improving access to care, and increased representation of black patients in glaucoma research to better understand factors affecting racial disparities in glaucoma management and outcomes in this population disproportionately affected by the disease.

Differences in the Surgical Outcomes of Glaucoma Surgery in Patients of African Caribbean Descent

PURPOSE

People of African Caribbean Descent (ACD) have a higher prevalence of glaucoma compared to people of European Descent (ED) and there is uncertainty if treatment outcomes are equivalent between the two groups. To assess surgical failure rates comparing ACD with ED focusing on trabeculectomy, aqueous shunt implantation, non-penetrating filtering surgery (NPFS), and minimally invasive glaucoma surgery (MIGS) by performing a systematic review in accordance with the PRISMA guidelines and to determine whether there is any evidence in to show a difference in success rates based on race.

METHODS

A systematic review of articles using the CENTRAL, Ovid MEDLINE, PubMed, EMBASE, and ClinicalTrials.gov databases was completed. Additional studies were identified by contacting clinical experts and searching bibliographies. All retrospective and prospective studies on trabeculectomy, aqueous shunt implantation, NPFS, and MIGS that included at least 20% ACD were included. Two review authors independently screened search results for eligibility and inclusion and extracted the data using pre-determined fields.

RESULTS

A total of 76 studies were identified for inclusion in the review. Glaucoma surgical outcomes in ACD appear to be poorer compared to ED overall, particularly for trabeculectomy. Data on NPFS are limited, but the studies completed thus far demonstrate surprisingly good results for ACD, particularly when compared to ED, who have significantly lower pre-operative IOPs. Evidence from studies investigating aqueous shunts does not suggest that ACD have poorer outcomes than ED. There is not enough data on MIGS to provide a significant conclusion.

CONCLUSION

In a population where trabeculectomy may no longer be the gold standard, sufficiently powered studies assessing surgical outcomes in aqueous shunts, NPFS, and MIGS are needed to guide clinicians.

Comparison of Outcomes Following Glaucoma Drainage Tube Surgery Between Primary and Secondary Glaucomas, and Between Phakic and Pseudophakic eyes

PURPOSE

To report outcomes of glaucoma drainage device (GDD) surgery based on primary or secondary glaucoma diagnosis and lens status.

DESIGN

Single-center, retrospective, consecutive cohort study.

METHODS

University of Florida patients aged 18 to 93 years who underwent nonvalved GDD surgery between 1996 and 2015 with a minimum of 1-year follow-up were examined. Of the 186 eyes of 186 patients enrolled, 108 had a primary glaucoma and 78 a secondary glaucoma diagnosis. Excluding 13 aphakic patients, 57 eyes were phakic and 116 pseudophakic. Mean intraocular pressure (IOP), mean number of medications, visual acuity (VA), surgical complications, and failure (IOP ≥18 mm Hg, IOP <6 mm Hg, reoperation for glaucoma, or loss of light perception) were the main outcome measures.

RESULTS

No significant difference was noted in mean IOP and mean medication use (12.8 ± 4.5 and 13.0 ± 6.6 mm Hg on 2.0 ± 1.2 and 1.5 ± 1.1 medication classes, respectively), mean VA (1.08 ± 0.98 and 0.94 ± 0.89, respectively), failure, or numbers of complications and reoperations (P > 0.05) between eyes with primary and secondary glaucomas at up to 5 years postoperatively. Comparison of phakic and pseudophakic eyes showed a statistically significant higher success rate for the pseudophakic patient group at the ≥18 mm Hg upper limit and <6 mm Hg lower limit (P = 0.01), and significantly fewer eyes required reoperation to lower IOP (6.9% vs 23%).

CONCLUSIONS

GDD surgery appears equally effective for secondary glaucomas as for primary glaucomas, and has a better outcome for pseudophakic eyes than phakic eyes.

Outcomes of Primary Trabeculectomy From Two Same-centre Cohorts 10 Years Apart

PRECIS

Trabeculectomy can effectively lower intraocular pressure (IOP). A more junior surgeon profile is emerging. Mitomycin C (MMC) has replaced 5-fluorouracil (5-FU) intraoperatively with comparable success rates and a decrease in postoperative antimetabolite administration.

PURPOSE

We compare 2-year outcomes for primary trabeculectomy in 2 cohorts, 10 years apart, performed at a large UK teaching hospital.

METHODS

Consecutive case series of trabeculectomies at Manchester Royal Eye Hospital between 2004-2005 (Cohort 1/C1) and 2014-2015 (Cohort 2/C2). Preoperative and postoperative data was collected for IOP outcomes and complications. Success was defined as IOP ≥6 and ≤21, ≤18, ≤16, ≤14, or ≤12 mm Hg with/without a ≥20% decrease from preoperative IOP. The need for and absence of postoperative antihypertensive medication defined qualified and complete success, respectively.

RESULTS

A total of 186 cases were analyzed [52 (C1), 134 (C2)]. Mean preoperative IOP was 24±10 mm Hg (C1) and 21±7 mm Hg (C2) (P=0.01). Overall, 34 (79%), 33 (77%), 33 (77%), 29 (67%), and 25 (58%) patients in C1 and 88 (70%), 82 (65%), 73 (58%), 64 (51%), and 40 (32%) patients in C2 achieved complete success for IOP ≤21 mm Hg (P=0.33), ≤18 mm Hg (P=0.22), ≤16 mm Hg (P=0.04), ≤14 mm Hg (P=0.09), or ≤12 mm Hg (P=0.004). Similarly, 43 (93%), 40 (87%), 40 (87%), 35 (76%), and 27 (59%) in C1 and 123 (98%), 116 (92%), 106 (84%), 87 (69%), and 58 (49%) in C2 achieved qualified success (P=0.34, 0.37, 0.83, 0.48, and 0.19). In all, 32 (74%), 31 (72%),31 (72%), 28 (65%), and 24 (56%) in C1 and 64 (51%), 63 (50%), 61 (48%), 54 (43%), and 39 (31%) in C2 achieved complete success with ≥20% reduction from preoperative IOP and IOP of ≤21 mm Hg (P=0.01), ≤18 mm Hg (P=0.02), ≤16 mm Hg (P=0.01), ≤1 mm Hg (P=0.02), or ≤12 mm Hg (P=0.006). By same definition, 37 (80%), 36 (78%), 36 (78%), 33 (72%), and 26 (57%) in C1 and 94 (75%), 93 (74%), 90 (71%), 75 (60%), and 58 (46%) in C2 achieved qualified success (P=0.55, 0.69, 0.48, 0.20, and 0.30). Mean IOP at 2 years was 13±5 mm Hg (C1) and 13±4 mm Hg (C2) (P=0.35). Overall, 62% had intraoperative 5-FU in C1; only MMC was used in C2 (P<0.0001). Postoperative 5-FU was administered in 54% versus 22% in C1 and C2, respectively (P<0.0001). Needling rates were not statistically different [42% (C1), 54% (C2)] (P=0.22).

CONCLUSIONS

Trabeculectomy is effective in lowering IOP with success comparable across various definitions. MMC replaced 5-FU as intraoperative antimetabolite resulting in reduced need for postoperative antimetabolite but not increased complications.

What Glaucoma Surgical Rate could Serve as a Target for West Africa? A Systematic Review

AIM AND OBJECTIVE

This study aimed to use the available evidence to model a glaucoma surgical rate (GSR), which could serve as a target for West Africa.

MATERIALS AND METHODS

A comprehensive literature search was performed in Medline, Embase, Global Health, and CINAHL, and studies published between January 1, 2000, and June 19, 2020, were retrieved. Study selection, quality appraisal, and data extraction were performed and the results of individual studies aggregated and presented using a narrative synthesis. Using these data, we aimed to construct a target GSR per million population per year that is sufficient to offer trabeculectomy to most patients with glaucoma who are diagnosed, and for whom other treatment options are either ineffective or inappropriate. The findings were then used to develop a trabeculectomy target for West Africa.

RESULTS

Initial searches returned 633 references, of which 33 unique studies were eligible for inclusion. The glaucoma prevalence population-based surveys identified, reported a wide range of prevalence of primary open-angle glaucoma (POAG) ranging from 1.0 to 8.4%. The studies on glaucoma medications reported intraocular pressure (IOP)-lowering effects ranging from 12.8% (beta-blockers) to 63.7% (Timolol-Latanoprost combinations). The adherence rate to antiglaucoma medications spanned from 10.3 to 82.3%. Regarding selective laser trabeculoplasty (SLT), only two studies were found. All the studies on trabeculectomy showed a significant reduction in IOPs at different follow-up periods with many reporting the absence of vision-threatening complications. From these available data, a GSR of 50 trabeculectomies was suggested for countries in West Africa.

CONCLUSION

This trabeculectomy target metric is expected to minimize POAG blindness in the West African subregion.

CLINICAL SIGNIFICANCE

The proposed GSR will enable eye care workers involved in glaucoma care in West Africa to assess their efforts compared with the proposed target. The gap will signal the potential for improvement.

HOW TO CITE THIS ARTICLE

Eni EN, Nolan W, Eval B, et al. What Glaucoma Surgical Rate could Serve as a Target for West Africa? A Systematic Review. J Curr Glaucoma Pract 2021;15(1):19-27.

Safety and effectiveness of primary transscleral diode laser cyclophotoablation for glaucoma in Nigeria

Importance

To investigate the safety, effectiveness and follow‐up rates after transscleral diode laser cyclophotocoagulation as primary treatment for seeing eyes with primary open angle glaucoma in Bauchi, Nigeria.

Background

There is a high prevalence of primary open angle glaucoma in Africa where adherence to medical treatment and acceptance of surgery are poor.

Design

Prospective case series.

Participants

New glaucoma patients where surgical intervention was recommended.

Methods

A diode 810 nm laser G‐probe was used under retrobulbar anaesthesia to deliver approximately 20 shots for 2000 ms, titrating the power. If both eyes were treated the first was the study eye. Repeat treatment offered if the intraocular pressure (IOP) was >21 mmHg on two consecutive visits.

Main Outcome Measures

IOP < 22 mmHg, change in ≥2 lines of Snellen visual acuity (VA), and complications.

Results

201 out of 204 eyes with complete data analysed. Mean age 52 years, 17 (8.3%) eyes were re‐treated. Mean pre‐treatment IOP was 39 (SD 11) mmHg. 106 (53%) attended at 12 months when the mean IOP was 19 (7–45) mmHg; 77 (73%) had IOP < 22 mmHg. VAs were better in 13 (12.3%) and worse in 23 (21.7%) eyes. Postoperative complications included mild uveitis (5.5%), corneal oedema (2.5%), severe uveitis (0.5%) and transient hypotony (2.0%). No hypotony at 12 months.

Conclusions and Relevance

Transscleral diode laser cyclophotocoagulation controlled IOP in almost three quarters of eyes at 12 months with short‐term preservation of vision and minimal complications. Poor follow‐up in this setting highlights the need for an effective, safe and acceptable treatment where regular follow‐up is less critical.

Glaucoma Surgery Outcome in Rwanda

PURPOSE

To assess long-term intraocular pressure (IOP) outcome after adult trabeculectomy surgery in Central Africa.

PATIENTS AND METHODS

All adult glaucoma patients who underwent trabeculectomy surgery in the Kabgayi Eye Unit, Rwanda between August 2003 and March 2008 were invited for a follow-up visit. Surgical and clinical data were collected from medical records. At the study visit, best-corrected visual acuity was measured and Goldmann applanation tonometry and biomicroscopy were done. Good IOP outcome was defined as both an IOP<21 mm Hg and achieving ≥30% reduction from the preoperative IOP. Considering first operated eyes, univariate and multivariate logistic regression was used to investigate risk factors for failure.

RESULTS

Of 163 individuals operated 3 had died, 118 (74%) participated. Preoperatively, the mean IOP was 31 mm Hg (SD=11; range, 12 to 60). At the time of the follow-up study visit the mean postoperative IOP was 13 mm Hg (SD=5; range, 4 to 35). Good IOP outcome was achieved in 132 eyes (84%). Univariate analysis suggested a protective effect against failure of use of antimetabolites [odds ratio (OR)=0.39; 95% confidence interval (CI), 0.14-1.11; P=0.07] and a decrease in success with length of follow-up (OR=3.57; 95% CI, 1.09-12.50; P=0.03). The latter remained borderline significant with multivariate analysis. Seven eyes went from previously better vision (at least hand movements) down to perception of light or no perception of light after trabeculectomy. Particularly a flat anterior chamber in the first postoperative week (OR=0.07; 95% CI, 0.01-0.49; P<0.001) and late hypotony (OR=0.04; 95% CI, 0.002-0.99; P=0.004) were significant risk factors for severe visual loss.

CONCLUSIONS

Trabeculectomy with antimetabolites is one of the best available options for glaucoma management in Africa. However, the IOP control reduced at a follow-up duration beyond 2 years, highlighting the importance of regular long-term follow-up.

Is Beta Radiation Better than 5 Flurouracil as an Adjunct for Trabeculectomy Surgery When Combined with Cataract Surgery? A Randomised Controlled Trial

INTRODUCTION

In an African setting surgery is generally accepted as the treatment of first choice for glaucoma. A problem with trabeculectomy surgery for the glaucomas is the frequent co-existence and exacerbation of cataract. We report a randomized controlled trial to compare the use of beta radiation with 5FU in combined cataract and glaucoma surgery.

PARTICIPANTS AND METHODS

Consenting adults aged >40 years with glaucoma, an IOP>21mmHG and cataract were enrolled and randomised to receive either 1000cG β radiation application or sub-conjunctival 5fluorouracil (5FU) at the time of combined trabeculectomy and phaco-emulsification with lens implant surgery.

RESULTS

385 individuals were eligible for inclusion of whom 301 consented to inclusion in the study (one eye per patient). 150 were randomised to the 5FU arm and 151 received β radiation. In the 12 months following surgery there were 40 failures (IOP>21mmHg) in the 5FU arm and 34 failures in the beta arm. The hazard ratio for the beta radiation arm compared to the 5FU arm, adjusted for IOP at baseline, was 0.83 (95% c.i. 0.54 to 1.28; P = 0.40). The improvement from mean presenting visual acuities of 0.91 and 0.86 logMAR to 0.62 and 0.54 in the 5FU and beta arms respectively was comparable between groups (P = 0.4 adjusting for baseline VA). Incidence of complications did not differ between the two groups.

DISCUSSION

This study highlights several important issues in the quest for a therapeutic strategy for the glaucomas in an African context. Firstly, there is no evidence of an important difference between the use of 5FU and beta radiation as an anti-metabolite in phacotrabeculectomy. Secondly phacotrabeculectomy is a successful operation that improves visual acuity as well as controlling IOP in a majority of patients. Although the success of trabeculectomy in lowering IOP is reduced when combined with phacoemulsification compared with trabeculectomy alone, this finding has to be set against the possible need for subsequent cataract surgery following trabeculectomy alone, which represents a second trip and expense for the patient and results in 10-61% failure of the trabeculectomy at one year post-cataract surgery.

TRIAL REGISTRATION

ISRCTN Registry ISRCTN36436933.

Current and Future Techniques in Wound Healing Modulation after Glaucoma Filtering Surgeries

Filtering surgeries are frequently used for controlling intraocular pressure in glaucoma patients. The long-term success of operation is intimately influenced by the process of wound healing at the site of surgery. Indeed, if has not been anticipated and managed accordingly, filtering surgery in high-risk patients could end up in bleb failure. Several strategies have been developed so far to overcome excessive scarring after filtering surgery. The principal step involves meticulous tissue handling and modification of surgical technique, which can minimize the severity of wound healing response at the first place. However, this is usually insufficient, especially in those with high-risk criteria. Thus, several adjuvants have been tried to stifle the exuberant scarring after filtration surgery. Conventionally, corticosteroids and anti-fibrotic agents (including 5-fluorouracil and Mitomycin-C) have been used for over three decades with semi-acceptable outcomes. Blebs and bleb associated complications are catastrophic side effects of anti-fibrotic agents, which occasionally are encountered in a subset of patients. Therefore, research continues to find a safer, yet effective adjuvant for filtering surgery. Recent efforts have primarily focused on selective inhibition of growth factors that promote scarring during wound healing process. Currently, only anti-VEGF agents have gained widespread acceptance to be translated into routine clinical practice. Robust evidence for other agents is still lacking and future confirmative studies are warranted. In this review, we explain the importance of wound healing process during filtering surgery, and describe the conventional as well as potential future adjuvants for filtration surgeries.

Trabeculectomy With Mitomycin-C Versus Trabeculectomy With Amniotic Membrane Transplant: A Medium-term Randomized, Controlled Trial

PURPOSE

To evaluate the intraocular pressure (IOP)-lowering effect of trabeculectomy with the use of amniotic membrane transplant (AMT) compared with the standard trabeculectomy with Mitomycin-C (MMC) in patients with primary open-angle glaucoma.

PATIENTS AND METHODS

This study was a patient-masked, randomized, controlled comparison trial involving 52 eyes of 52 patients with bilateral primary open-angle glaucoma. Patients were randomized to receive trabeculectomy with AMT or trabeculectomy with MMC. The main outcome for comparison was the IOP-lowering effect of both procedures. Surgical success was considered if the patient's IOP was <22 mm Hg, and the IOPs were lowered by >20% without the use of any medication.

RESULTS

All surgeries passed uneventfully without intraoperative complications, and all patients showed significantly (P<0.05) lower IOP on the first postoperative day compared with their respective preoperative IOP with nonsignificant (P>0.05) difference between both study groups. All patients, irrespective of the operative procedure maintained significantly (P<0.05) lower IOP compared with their respective preoperative IOP till the end of 24 months follow-up. Moreover, patients of the AMT group showed lower IOP compared with those included in the MMC group throughout the follow-up period; however, the difference was not statistically significant at any point of the study period.

CONCLUSIONS

AMT exhibits potential as an alternative to MMC in trabeculectomy surgery. Over 24 months of follow-up, the use of AMT with trabeculectomy was safe and effective with an IOP-lowering effect comparable to that achieved with the use of MMC, and a reduced rate of postoperative complication.

Different strategies and cost-effectiveness in the treatment of primary open angle glaucoma

Glaucoma is the second highest cause of blindness worldwide with an estimated half of the glaucoma population unaware of their disease. To date, intraocular pressure is the most important modifiable risk factor and lowering it has been proven to reduce progression of visual field loss associated with glaucoma. Different strategies are available to lower intraocular pressure and include medical, laser, or surgical treatment in the form of topical or systemic medications, argon or selective laser trabeculoplasty, and glaucoma drainage surgery such as trabeculectomy, deep sclerectomy, or other drainage devices. The effectiveness of these treatments has been well documented however their cost-effectiveness between the developed world and third world remains unclear.

Glaucoma drainage implant surgery--an evidence-based update with relevance to sub-Saharan Africa

Glaucoma represents a leading cause of preventable vision loss in Sub-Saharan Africa. Recent studies evaluating outcomes of glaucoma drainage implant (GDI) surgery suggest an important role for this approach in the African patient population. The Tube Versus Trabeculectomy study demonstrated a higher success rate with non-valved GDI surgery compared to trabeculectomy with mitomycin C after five years. The Ahmed Baerveldt Comparison study showed no difference in surgical failure rates between the Ahmed Glaucoma Valve and the Baerveldt Glaucoma Implant (BGI) but better intraocular pressure outcomes with the BGI at one year. The Ahmed Versus Baerveldt study demonstrated a lower failure rate for the BGI, but also a requirement for more post-operative interventions. Further study of GDI surgery in the Sub-Saharan Africa is necessary to determine its optimal place in the treatment paradigm for glaucoma patients in the region.

[Long-term results after trabeculectomy with 5-fluorouracil]

PURPOSE

Trabeculectomy is among the first choice surgical treatments for glaucoma. Antimetabolites, especially mitomycin C, have improved the success rate. The aim of this study is to present the results of trabeculectomy with 5-fluorouracil (5-FU).

METHODS

A total of 71 consecutive trabeculectomies with 5-FU for decompensated glaucoma with at least 1 year follow-up data were retrospectively evaluated. The absolute (without therapy) and relative (with therapy) success rates for glaucoma medication were determined for intraocular pressure (IOP) levels of ≤ 21 mmHg, ≤ 18 mmHg, ≤ 15 mmHg and ≤ 12 mmHg respectively. Postoperative 5-FU administration rates, needling procedures and complications were recorded.

RESULTS

Sufficient follow-up data were available for a total of 55 patients. The average IOP was preoperatively 29.6 ± 7.3 mmHg (3 ± 1.4 active ingredients, partly acetazolamide), after 6 months 13.2 ± 4.1 mmHg and after 1 year 13.7 ± 4.3 mmHg. Complete success at 6 months postoperatively for the given pressure levels: were 92 %, 87 %, 79 % and 52% and at 1 year 87 %, 84 %, 51 % and 56%, respectively. Postoperative relative success for these pressure levels at 6 months were 96 %, 90 %, 81 % and 54% and at 1 year 96 %, 93 %, 58 % and 58%, respectively. Administrations of 5-FU postoperatively were no intervention (n=30 patients), subconjunctival 5-FU administration (n=25) and needling procedures (n=6). A temporary hypotension with a shallow anterior chamber was seen in 6 patients, cataract development in 5 patients and 1 patient developed corneal decompensation (multiple previous operations before trabeculectomy).

CONCLUSION

Trabeculectomy with intraoperative 5-FU administration showed very high success rates after 1 year. Serious complications were rarely seen. Intraoperative 5-FU administration can be considered as an alternative treatment to trabeculectomy with intraoperative use of mitomycin C.

Long-term outcomes and risk factors for failure with the EX-press glaucoma drainage device

PURPOSE

To report on the long-term outcomes and risk factors for failure with the EX-PRESS shunt implanted under a scleral flap.

SETTINGS

Eye Department, University of Ancona, Ancona, Italy and the Oxford Eye Center, University of Witwatersrand, Johannesburg, South Africa.

METHODS

The medical records of glaucoma patients who underwent consecutive EX-PRESS implantations under a scleral flap between 2000 and 2009 were reviewed. The operations were performed by two experienced surgeons using an identical surgical technique. The potential risk factors for failure that were analysed included age, sex, race, glaucoma type, previous antiglaucoma medications, previous glaucoma surgeries, diabetes, and smoking. Complete success was defined as postoperative intraocular pressure (IOP) 5 mm Hg>IOP<18 mm Hg without antiglaucoma medications. Qualified success was defined as 5 mm Hg>IOP<18 mm Hg with or without antiglaucoma medications.

RESULTS

Two hundred and forty-eight eyes of 211 consecutive patients were included. The mean IOP was reduced from 27.63 ± 8.26 mm Hg preoperatively (n=248) to 13.95 ± 2.70 mm Hg at 5 years (n=95). The mean follow-up was 3.46 ± 1.76 years. Complete and qualified success rates decreased gradually from 83% and 85% at 1 year to 57% and 63% at 5 years follow-up, respectively. The risk factors for failure were diabetes, non-Caucasian race, and previous glaucoma surgery. Complete success rates of diabetic patients and non-Caucasian patients decreased from 63% and 75% at 1 year to 42% and 40% at 5 years follow-up, respectively.

CONCLUSIONS

EX-PRESS success rates decrease over time but compare favourably with trabeculectomy literature data. The main identifiable risk factors for failure are diabetes, non-Caucasian race, and previous glaucoma surgery.

The role of the Ex-PRESS glaucoma filtration device in glaucoma surgery

The Ex-PRESS glaucoma filtration device is a safe and effective alternative to standard trabeculectomy in the surgical management of glaucoma patients. This latest modification of glaucoma filtration surgery has been shown to be equally efficacious to trabeculectomy in lowering intraocular pressure. With its unique features of small incision surgery, consistent lumen size with more uniform filtration, and no tissue removal, this technique has been shown to reduce both intraoperative and postoperative complications. This review updates clinical outcomes of this new variation of glaucoma filtration surgery and its current role in the glaucoma surgical armamentarium.

Epidemiological properties of primary open angle glaucoma in Nigeria

Background. Primary open angle glaucoma (POAG) is progressive chronic optic neuropathy in adults in which intraocular pressure (IOP) and other currently unknown factors contribute to damage. POAG is the second commonest cause of avoidable blindness in Nigeria. Pattern of Presentation. POAG is characterized by late presentation. Absence of pain which is a driving force for seeking medical help, inadequacy of trained eye care personnel, paucity of facilities, misdistribution of resources, lack of awareness, poor education, and poverty may all contribute to this. Medical and surgical treatment options available are challenging and tasking. Screening for Glaucoma. Screening is the presumptive identification of unrecognized disease (POAG) by applying test(s) which can be applied rapidly. Such test(s) should be of high reliability, validity, yield, acceptable, and cost effective. The test should ideally be sensitive, specific, and efficient. It is difficult to select a suitable test that meets these criteria. Intraocular pressure (IOP) appears to be the easiest option. But, high IOP is not diagnostic nor does normal value exclude the disease. Health education is a possible strategy in early case detection and management. Treatment of POAG. Glaucoma treatment can either be medical or surgical (this includes laser). Considering unavailability, potency, cost, and long-term effects of medication, surgery (trabeculectomy) could be a better option. Laser trabeculoplasty is available in a few centers. Viscocanalostomy is not routinely performed. Patient education is vital to success as management is for life. Conclusion. POAG remains a cause of avoidable blindness in Nigeria. There is need for long-term strategy to identify patients early and institute prompt management. Improvement in training of eye care personnel and provision of up to date equipment is essential in achieving this goal.

Advanced glaucoma: management pearls

A significant proportion of glaucoma patients present late, particularly in the developing world, and unfortunately, in an advanced stage of the disease. They are at imminent danger of losing remaining vision, and may also be afflicted with various socioeconomic and health challenges. The encounter with such a patient is typically characterized by anxiety/fear and sometimes hopelessness from the patient's perspective. The physician may also feel that they are in a difficult position managing the patient's disease. When dealing with such cases, we suggest a holistic, individualized approach taking into account the 'biopsychosociospiritual' (BPSS) profile of each patient. The BPSS model takes into account relevant ocular as well as systemic biology (factors such as the mechanism of glaucoma, level of intraocular pressure [IOP], rate of progression, life expectancy, general health), psychological considerations (e.g., fear, depression), socio-economic factors and spiritual/cultural values and beliefs before being able to decide with the patient and their care partner(s) what treatment goals should be and how they can best be approached. Treatment for advanced glaucoma can be highly effective, and patients and their care partners should be informed that aggressive IOP lowering to the low teens or even single digits offers the best chance of protecting remaining vision. This can be achieved safely and effectively in most cases with trabeculectomy (including an antimetabolite), and in some cases with medical and/or laser therapy. Vision rehabilitation and psychosocial support should also be considered in order to optimize remaining vision, replace fear with hope as appropriate, and thus improve the overall quality of life.

Wound modulation after filtration surgery

Filtration surgery is the standard invasive procedure for the management of intraocular pressure in advanced glaucoma. The key to a successful outcome is to modulate the normal wound healing cascade that leads to closure of the newly created aqueous outflow pathway. Antifibrotic agents such as mitomycin C and 5-fluorouracil have been increasingly used to modulate the wound healing process and increase surgical success. Although these agents have proven efficacy, they also increase the risk of complications. Efforts have centered on the identification of novel agents and techniques that can influence wound modulation without these complications. We detail new agents and methods under investigation to control wound healing after filtration surgery.

Effect of Qingguangan on the expressions of MMP-2 and MMP-9 in filtering bleb after trabeculectomy in rabbits

AIM

To explore the effect of Qingguangan on the expressions of MMP-2 and MMP-9 in filtering bleb scarring area after trabeculectomy in rabbit model.

METHODS

Thirty-two New Zealand rabbits were randomized into four groups: control group, experimental group, MMC group (ocular trabeculectomy in combination with MMC), and Qingguangan group. Trabeculectomy was performed on both eyes in each group except control group. Qingguangan group was mouth-fed with Qingguangan (solution). On postoperative day 14, the appearances of MMP-2 and MMP-9 on filtrating blebs were observed by immunohistochemistry.

RESULTS

Statistical differences of the expressions of MMP-2 and MMP-9 were noted among groups on day 14 following surgery. Histology immunohistochemistry showed significant differences on the expressions of MMP-2 and MMP-9 between each group (P<0.05).

CONCLUSION

Qingguangan can promote the expressions of MMP-2 and MMP-9.

Surgical outcomes of the Ex-PRESS glaucoma filtration device in African American and white glaucoma patients

Purpose

To compare the surgical outcomes of the Ex-PRESS glaucoma filtration device in African American and white glaucoma patients.

Design

Retrospective comparative case series.

Methods

This was a comparative case series of 36 eyes of 36 African Americans and 43 eyes of 43 whites that underwent placement of the Ex-PRESS glaucoma filtration device under a partial-thickness scleral flap for uncontrolled glaucoma. All eyes received intraoperative mitomycin C. The primary outcome measures were intraocular pressure (IOP), number of postoperative glaucoma medications, and surgical success. Surgical success was defined as IOP between 5 and 18 mm Hg, with or without glaucoma medications, without further glaucoma surgery, or loss of light perception vision.

Results

Average follow-up was 31.9 ± 9.8 (range, 14.6–47) months for African Americans and 30.7 ± 8.6 (range, 14.3–47) months for whites. At 33 months, surgical success was 80.0% in the African American group and 83.3% in the white group (P = 1.00). Reasons for surgical failure included increased IOP (3 eyes, 3.8%), persistent hypotony with maculopathy (1 eye, 1.3%), and further surgery (4 eyes, 5.06%). Compared with preoperative values, the mean postoperative IOP and number of glaucoma medications were significantly reduced in both groups, and no statistical difference was observed between the two groups at 33 months. Postoperative complications were similar in the two groups.

Conclusions

Similar surgical outcomes were observed in African American and white glaucoma patients after implantation of the Ex-PRESS glaucoma filtration device. This latest modification of glaucoma filtration surgery may be a better surgical option for African Americans given its potential advantages of no tissue removal, predictable outcomes related to consistent lumen size and controlled flow, fewer postoperative complications, and overall reduced inflammation.

Outcomes and bleb-related complications of trabeculectomy

PURPOSE

To determine rates of success and complications of trabeculectomy surgery.

DESIGN

Case series.

PARTICIPANTS

Consecutive patients undergoing trabeculectomy by 2 surgeons between May 2000 and October 2008.

INTERVENTION

By using the Wilmer Institute's billing database, we identified all patients at least 12 years of age coded as having undergone trabeculectomy between May 2000 and October 2008 by 1 of 2 glaucoma surgeons and whose surgery was not combined with another operation. From the chart, we abstracted demographic information on the patients and clinical characteristics of the eyes. The Kaplan-Meier product-limit method and Cox proportional hazard models were used to look at success rates and characteristics associated with inadequate intraocular pressure (IOP) reduction. Complications were tabulated.

MAIN OUTCOME MEASURES

(1) Success rate of trabeculectomy, as determined by the achievement of each of 4 different IOP goals, with or without IOP-lowering medications; and (2) incidence of surgical complications.

RESULTS

During the study period, 797 eyes of 634 persons underwent trabeculectomy without concurrent surgery. The success rates 4 years after surgery, with or without the use of IOP-lowering eye drops, were 70%, 72%, 60%, and 44%, for achievement of target IOP, ≤18 mmHg and ≥20% IOP reduction, ≤15 mmHg and ≥25% reduction, and ≤12 mmHg and ≥30% reduction, respectively. Increased chance of success was associated with European-derived race; use of mitomycin C (MMC); higher concentrations of MMC, when used; and higher preoperative IOP. Age and previous intraocular surgery were not associated with surgical success. Complications included worsening lens opacity in 242 of 443 phakic eyes (55%), loss of ≥3 lines of acuity (Snellen) in 161 eyes (21%), surgery for bleb-related problems in 70 eyes (8.8%), and infection occurring >6 weeks after surgery in 27 eyes (3.4%). A total of 101 eyes of 94 patients had at least 1 subsequent operation for inadequate IOP control.

CONCLUSIONS

Trabeculectomy surgery performed by 2 experienced glaucoma specialists achieved target IOP at 4 years in 70% of those operated and was associated with progressive cataract and small risks of bleb-related complications. These results are comparable to those reported in smaller series.

A watertight acrylic-free titanium recording chamber for electrophysiology in behaving monkeys

Neurophysiological recording in alert monkeys requires the creation of a permanent aperture in the skull for repeated insertion of microelectrodes. Most laboratories use polymethyl methacrylate to attach a recording chamber over the skull opening. Here, we describe a titanium chamber that fastens to the skull with screws, using no polymethyl methacrylate. The gap between the base of the chamber and the skull is filled with hydroxyapatite, forming a watertight gasket. As the chamber base osseointegates with the skull, the hydroxyapatite is replaced with bone. Rather than having a finite lifetime, the recording chamber becomes more firmly anchored the longer it is in place. It has a small footprint, low profile, and needs little maintenance to control infection. Toilette consists of occasional application of betadine to clean the scalp margin, followed by application of neomycin, polymyxin, and bacitracin ointment. Antibiotic is also placed inside the chamber to suppress bacterial proliferation. Thickening of the dura within the chamber can be prevented by regular application of mitocycin C and/or bevacizumab, an antibody against vascular endothelial growth factor. By conducting an e-mail survey, this protocol for chamber maintenance was compared with procedures used in 37 other vision research laboratories. Refinement of appliances and techniques used for recordings in awake monkeys promises to increase the pace of scientific discovery and to benefit animal welfare.

Augmenting trabeculectomy in glaucoma with subconjunctival mitomycin C versus subconjunctival 5-fluorouracil: a randomized clinical trial

Objective:

The aim of this study was to compare the efficacy of augmenting trabeculectomy with subconjunctival mitomycin C (TMMC) versus 5-fluorouracil (T5-FU) in lowering intraocular pressure (IOP).

Methods:

Forty eyes from 40 patients referred to the Nikoukari Ophthalmology University Hospital, Tabriz University of Medical Sciences, Tabriz, Iran, were enrolled in a randomized clinical trial. Patients with high-risk open angle glaucoma were allocated to receive either subconjunctival TMMC or T5-FU.

Results:

Mean overall preoperative IOP was 30.8 mmHg. Mean preoperative IOPs in the TMMC and T5-FU groups were 31.2 ± 9.8 and 30.6 ± 9.9 mmHg, respectively. Postoperatively, mean IOPs were 11.4.3 ± 4.9 and 13.6 ± 3.9 mmHg, respectively for TMMC and T5-FU groups after 6 months. In spite of some existing descriptive differences in IOP between the groups, statistical tests showed no difference in mean and median IOP. Three cases of hypotonia (IOP < 6 mmHg) and 1 case of epithelial keratitis were detected.

Conclusion:

TMMC and T5-FU appeared to have similar efficacy in lowering IOP.

Combined trabeculotomy and trabeculectomy: outcome for primary congenital glaucoma in a West African population

PURPOSE

To evaluate the surgical outcome of combined trabeculotomy-trabeculectomy in Ghanaian children with primary congenital glaucoma.

MATERIALS AND METHODS

A retrospective case series involving 19 eyes of 12 consecutive children with primary congenital glaucoma who had primary trabeculotomy-trabeculectomy from 12 August 2004 to 30 June 2008, at the Korle-Bu Teaching Hospital, Ghana. Main outcome measures were preoperative and postoperative intraocular pressures, corneal diameter, corneal clarity, bleb characteristics, duration of follow-up, surgical success, and complications.

RESULTS

A total of 19 eyes of 12 patients met the inclusion criteria. Six of the patients were males. Mean age at diagnosis was 4.4 (range 2-8) months. Mean age at surgery was 5.9 months (range 3-16). Eight (67%) infants had bilateral disease. Mean duration of follow-up was 13.1 (range 5-38) months. The preoperative mean horizontal corneal diameter was 13.4 ± 1.1(range 12-16) mm. Complete success (intraocular pressure <21 mm Hg) was obtained in 15 (79%) eyes. The probability of success was 94.4, 83.3, 66.7, 44.4, 38.9, 33.3, and 13.3% at 3, 6, 9, 12, 15, 18, and 21 months, respectively (Kaplan-Meier analysis). All eyes had corneal oedema preoperatively. Seventeen eyes (90%) had clear cornea at their last follow-up. Mean preoperative and postoperative intraocular pressures were 30.3 ± 8.8 and 18.1 ± 6.8 mm Hg respectively (P<0.001, t-test). Twelve (63%) eyes had well-functioning blebs at the last follow-up. One eye (5%) developed seclusio pupillae and cataract postoperatively.

CONCLUSION

The overall success for combined trabeculotomy-trabeculectomy in Ghanaian children with primary congenital glaucoma was 79%. The probability of success reduced from more than 66% in the first 9 months postoperatively to below 45% after that.

Paclitaxel inhibits growth, migration and collagen production of human Tenon's fibroblasts--potential use in drug-eluting glaucoma drainage devices

OBJECTIVE/AIM

One of the factors limiting the long-term success of glaucoma drainage devices and traditional filtering surgery is the tendency of bleb encapsulation. Glaucoma shunts present an opportunity of introducing drug-eluting mechanisms for a lasting exposure of the bleb to anti-proliferative substances. The aim of this in vitro study was to investigate the effects of short- and long-term exposure of primary cultures of human Tenon's fibroblasts to different concentrations of paclitaxel on cell proliferation, migration, collagen production and cytotoxicity, in order to evaluate the suitability of the drug for the use in such a device.

MATERIALS/METHODS

Seven individual primary cultures of human Tenon's fibroblasts were observed over the course of 1 week after administering paclitaxel concentrations varying from 10(-9) mol/l to 10(-6) mol/l for either 1 hour or continuously. Relative cell count and migration across a cell-free area introduced by scratching through a confluent cell layer were determined every 24 hours, using photomicrographs of the cells for each concentration and exposure time. Soluble collagen concentration in the cell culture medium was determined using a Sircol collagen assay 72 hours after paclitaxel exposure. Cytotoxicity of the compound was assessed by flow cytometry using dual staining with annexin V-FITC and propidium iodide.

RESULTS

Paclitaxel dose-dependently inhibited both proliferation and migration of the cells. Cell count was reduced at all concentrations and both exposure times (p = 0.001); similarly, all but two concentrations of paclitaxel caused a significant reduction of cell migration (p < 0.001). This may be explained in part by the dose- and time-dependent induction of apoptosis in up to 23.7% of the cells (maximal effect at 10(-6) mol/l, 7 days after exposure). Collagen production was significantly reduced at all concentrations and at both exposure times. However, no statistically significant difference was observed between any of the concentrations, indicating that this inhibition may be an indirect effect.

CONCLUSION

Paclitaxel may be a useful addition to the repertoire of anti-proliferative substances currently in use in glaucoma filtering surgery and shunt implantation. Further studies of the compound and its effects on Tenon's fibroblasts as well as other ocular tissues are warranted.