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

Glaucoma Treatment Outcomes in Open Angle Glaucoma Patients of African Descent

Open angle glaucoma (OAG), characterized by structural changes to the optic nerve head and retinal nerve fiber layer, is a progressive multifactorial optic neuropathy and a leading cause of irreversible blindness globally. Currently, intraocular pressure is the only modifiable risk factor; however, others have been identified, including genetics and race. Importantly, OAG is much more prevalent in persons of African descent (AD) compared with those of European descent (ED). OAG patients of AD are also known to have a more severe course of the disease, a finding potentially explained by structural and/or vascular differences within eye tissues. In addition, disparities in treatment outcomes have been identified in OAG patients of AD. Specifically, prostaglandin analogues have been suggested to be more effective in patients of AD than in those ED, while beta-adrenergic receptors have been suggested to be less effective, although the evidence is inconsistent. AD has also been identified as a risk factor for trabeculectomy failure while laser trabeculoplasty has been conversely found to be very effective in lowering intraocular pressure in patients of AD. Alternative surgical options, including Ex-Press shunt implantation, viscocanalostomy, and canaloplasty are promising in equivalence but require further research to evaluate disparity in outcome properly. In addition to treatment outcomes, social disparities affecting clinical care also exist for AD persons in the form of reduced adherence, access, and choice. Overall, data suggest the need for properly designed prospective trials with AD populations as a primary focus to identify the potential mechanisms driving disparities in treatment and address overall potential bias in glaucoma management.

ExPress mini shunt device with trabeculectomy surgery in patients with uncontrolled glaucoma of Middle Eastern descent

PURPOSE:

The aim of this study is to assess the efficacy and safety of ExPress mini shunt in glaucoma patients of Middle Eastern descent.

METHODS:

This is a prospective cohort study. Uncontrolled glaucoma patients were subjected to ExPress mini-shunt implant. Pre- and post-operative glaucoma clinical indices were measured and compared. Both intra- and postoperative complications and surgical success rates were assessed. In addition to comparing a group of combined ExPress mini-shunt implant with cataract surgery versus ExPress mini-shunt implant alone.

RESULTS:

A total of 35 eyes of 31 patients were involved. The most common type of glaucoma was primary open-angle glaucoma in 13 eyes (37.1%). Fourteen eyes (40.0%) were combined ExPress device with cataract surgery. The mean intraocular pressure (IOP) (±standard deviation) at the last visit dropped from 24.6 mmHg (±8.3) to 13.9 mmHg (±4.5). There was a significant reduction in the number of postoperative glaucoma medications from 3.0 ± 0.5 to 1.3 (±0.7). In cases combined with cataract extraction, the patients required fewer anti-glaucoma medications. Complete success was achieved in 22 eyes (63%) and qualified success was achieved in 9 eyes (26%), whereas 4 eyes (11%) were considered a failure. The two most common complications encountered were hypotony (28.6%) and hyphema (11.4%).

CONCLUSION:

Among the studied population of patients, ExPress offers IOP reduction that is comparable to reported rates following standard trabeculectomy. Postoperative hyphema was encountered at a slightly higher rate.

Observational Outcomes of Initial Trabeculectomy With Mitomycin C in Patients of African Descent vs Patients of European Descent: Five-Year Results

Importance

There is evidence that patients of African descent (AD) experience higher surgical failure rate after trabeculectomy without antimetabolites.

Objective

To compare outcomes of initial trabeculectomy with mitomycin C in AD patients with those of patients of European descent (ED) and to identify prognostic factors for failure.

Design, Setting, and Participants

In this retrospective matched cohort study, 135 eyes of 105 AD patients were matched with 135 eyes of 117 ED patients by age (within 5 years), surgeon, lens status, and follow-up time (within 1 year) from a single tertiary academic center.

Interventions

Initial trabeculectomy with mitomycin C.

Main Outcomes and Measures

Criteria A, B, and C defined qualified success rates as final intraocular pressure of 18 mm Hg or less, 15 mm Hg or less, and 12 mm Hg or less, respectively, in addition to 20% or more, 25% or more, and 30% or more reduction of intraocular pressure or reduction of 2 or more medications. Kaplan-Meier survival curves were compared with log-rank test in AD and ED patients, and Cox proportional hazard models were used to estimate the influence of race/ethnicity on surgical success accounting for confounding variables.

Results

Of the 105 AD patients, 56 (53.3%) were female, and the mean (SD) age was 67.5 (10.4) years; of the 117 ED patients, 64 (54.7%) were female, and the mean (SD) age was 68.2 (10.0) years. For AD patients compared with ED patients, the qualified success rates at 5 years for criteria A were 61% and 67%, respectively (difference, 7.3%; 95% CI, 4.4-10.4); for criteria B, 43% and 60% (difference, 17.6%; 95% CI, 15.2-20.0); and for criteria C, 25% and 40% (difference, 15.8%; 95% CI, 11.1-20.5). On multivariable Cox regression analyses, AD was associated with higher failure rate with criteria B and C for qualified success and with all criteria for complete success (ie, no need for medications). Incidence of bleb leaks was higher in the AD group (29 vs 11 eyes; P = .002). Additionally, AD patients required additional glaucoma surgeries more often than ED patients (47 vs 26 eyes; P = .004).

Conclusions and Relevance

African descent was associated with higher failure rates and higher incidence of bleb leaks after initial trabeculectomy with mitomycin C compared with European descent. If this is subsequently shown to be a cause and effect, the findings need to be considered when surgical treatment of glaucoma is contemplated in AD patients.

Factors influencing the filtration-bleb volume after Ex-PRESS® surgery

Purpose

The aim of this study was to investigate the factors influencing the volume of the filtration bleb after Ex-PRESS^® surgery.

Methods

This was a retrospective non-randomized study. After excluding patients who had undergone an additional glaucoma surgery, 99 glaucoma patients who underwent Ex-PRESS^® surgeries and were followed up for >2 years were analyzed. We used anterior segment optical coherence tomography to measure the bleb volume, and compared the volume at 1 year with that at 2 years after surgery. We also examined potential influencing factors, including age, number of medications, central corneal thickness, type of glaucoma, preoperative intraocular pressure (IOP), postoperative IOP, reduction ratio of IOP, history of trabeculotomy, and operation method (Ex-PRESS^® surgery only or simultaneous cataract surgery).

Results

Ex-PRESS^® surgeries significantly decreased the IOP from 26.3±9.7 mmHg to 11.6±3.7 mmHg after 24 months (P<0.001). The success rate at 2 years was 81.2% (IOP ≥21 mmHg or ≥20% reduction from the baseline IOP). The results showed that age, postoperative IOP, glaucoma type, and simultaneous cataract surgeries influenced the filtration-bleb volume.

Conclusion

Advanced age, higher postoperative IOP, pseudo-exfoliation glaucoma, and simultaneous cataract surgeries were all found to decrease the volume of the filtration bleb.

Primary Open-Angle Glaucoma Genetics in African Americans

PURPOSE OF REVIEW

Individuals of African descent are at highest risk for developing primary open-angle glaucoma (POAG), a devastating disease and major contributor of blindness worldwide. Currently, there is a large dearth of knowledge in this area despite a critical need for better understanding the underlying genetic and environmental factors afflicting this population. Here we highlight the current literature exploring the genetics of POAG in African Americans.

RECENT FINDINGS

Current studies have yet to replicate European POAG index variants (i.e. CDKN2B-AS1 and SIX1/SIX6) in African Americans or to definitely exclude that these loci contribute to risk in African descent populations. Recent studies have evaluated clinical features that may account for some differences in POAG risk between African Americans and European Americans.

SUMMARY

In summary, little headway has been made in elucidating the genetics of primary open-angle glaucoma in African Americans and other individuals of African descent.

Outcomes of Ex-PRESS and Trabeculectomy in a Glaucoma Population of African Origin: One Year Results

Aim

To compare the efficacy and safety of Ex-PRESS glaucoma filtration surgery to trabeculectomy in African origin patients.

Materials and methods

A retrospective chart review was performed on 56 African American patients undergoing Ex-PRESS glaucoma shunt (E) or trabeculectomy (T) between 2004 and 2012. Data collected included intraocular pressure (IOP) and glaucoma medication use at baseline and postoperative week 1, Month (M) 1, M3, M6, M12. Postoperative interventions including laser suture lysis (LSL) and 5FU injections were analyzed. Complete and qualified success rate, and eyes failing and requiring more surgery were determined. Means, SD, chi-square, and Student’s t-test were performed.

Results

A total of 56 subjects (E 28, T 28) were included in the analysis. There was a statistically significant reduction (p < 0.05) in IOP and number of glaucoma medications at all time points compared to baseline for both groups. Extent of IOP reduction between groups was not statistically significant at any time point, except postoperative week 1. Mean number of glaucoma medications between groups was not significant, except at 3 months (lower in EXP group). The cumulative number of postoperative interventions within 3 months (LSL and 5-FU) was significantly greater for the TRAB than EXP (3.89 ± 2.4 vs 2.36 ± 2.2, p = 0.007). Success rates were comparable between both groups (Table 2).

Conclusion

Our study is unique in patients of African origin showing statistical significance in the requirement of less postoperative 5-FU injections during the first 3 months following surgery in the Ex-PRESS group vs the trabeculectomy group. The Ex-PRESS shunt was as effective as trabeculectomy in reducing IOP and use of glaucoma medications up to 1 year.

Clinical significance

The possible benefit of this article is to help guiding ophthalmologists to select the type of glaucoma filtration surgery to undergo in an African American patient with glaucoma.

How to cite this article

Bustros YD, Fechtner R, Khouri AS. Outcomes of Ex-PRESS and Trabeculectomy in a Glaucoma Population of African Origin: One Year Results. J Curr Glaucoma Pract 2017;11(2):42-47.

Evaluation of ExPress glaucoma filtration device in Indian patients with advanced glaucoma

ExPress glaucoma filtration device (GFD) has recently become available in India as a surgical option for glaucoma patients. We retrospectively evaluated the outcome of ExPress GFD in 12 eyes with advanced glaucoma with intraocular pressures (IOPs) not controlled on maximal tolerable medical therapy. The mean preoperative IOP of 29.58 ± 7.13 mmHg decreased to 17.0 ± 2.67 and 17.40 ± 0.89 mmHg at 6 and 12 months after surgery. Absolute success (IOP ≤ 18 mmHg, with no additional glaucoma medications) was achieved in eight cases (66.7%) and qualified success (IOP ≤ 18 mmHg, with additional glaucoma medications) in two cases (16.7%) at 1-year after surgery. Early intervention was needed in 4 patients; two underwent anterior chamber reformation while the other two required needling. Two patients required resurgery. There was no significant change in the best corrected visual acuity postoperatively (P = 0.37). ExPress GFD does not seem to offer a benefit over standard trabeculectomy in patients with advanced glaucomatous disease in terms of IOP control or complication rate. However, due to the small sample size with a heterogeneous mixture of primary and secondary glaucoma's, we await further studies with a larger sample size and long-term follow-up, to see how the device performs.

Glaucoma surgery: taking the sub-conjunctival route

We are currently in the midst of a surge in interest in glaucoma surgery. Novel pathways for reducing intraocular pressure (IOP) have been tried with various levels of success over the last few years. While the trabecular bypass and suprachoroidal approaches have captured much of the attention, filtering aqueous into the sub-conjunctival space remains the gold standard for lowering IOP. This review attempts to focus on current research in surgical methods to enhance filtration by potentially improving on tried and tested methods like the trabeculectomy, deep sclerectomy, and tube surgeries.

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.