EX-PRESS Glaucoma Filtration Device: efficacy, safety, and predictability

Comparison of bleb morphologies between phacoemulsification combined with Ex-PRESS mini shunt implantation, phacotrabeculectomy and trabeculectomy alone: a two-year retrospective in vivo confocal microscopy study

BACKGROUND

To compare the bleb morphologies of phacoemulsification combined with Ex-PRESS implantation (Phaco-ExPRESS), phaco trabeculectomy (Phaco-Trab), and trabeculectomy (Trab) in postoperative two years.

METHODS

Patients with primary open-angle glaucoma (POAG) with or without cataracts were included in this study. All patients underwent surgeries of either Phaco-ExPRESS, Phaco-Trab, or Trab. The morphologic structures of the filtering bleb, including microcysts area, hyperreflective dot density, and stromal connective tissue under in vivo confocal microscope (IVCM), were compared between the three groups. The data were collected preoperatively and postoperatively at 2 weeks, 1 month, 3 months, 6 months, 12 months, 18 months, and 24 months.

RESULTS

Eighty-nine eyes from 89 patients were enrolled, including 32 in the Phaco-ExPRESS group, 25 in the Phaco-Trab group, and 32 in the Trab group. In a 24-month follow-up, bleb morphologies in Phaco-ExPRESS were similar to the Trab group. The area of epithelial microcysts was significantly increased in Phaco-ExPRESS and Trab groups while significantly decreased in Phaco-Trab. At postoperative 24 months, the complete success rate was 65.1% in Phaco-ExPRESS, 32.0% in Phaco-Trab, and 59.4% in the Trab group (P = 0.03). The phaco-Trab group had more postoperative anti-glaucoma medications than the other two groups (P < 0.05).

CONCLUSIONS

Phaco-ExPRESS group and Trab group had similar blebs morphologies in IVCM, with larger microcyst area, looser connective tissue, and less inflammation than Phaco-Trab, indicating that the function of blebs in the Phaco-ExPRESS and Trab group, was more potent than that of Phaco-Trab. All these surgical methods provided adequate IOP control, but Phaco-Trab required more anti-glaucoma medications.

Development and material characteristics of glaucoma surgical implants

Background

Glaucoma is the leading cause of irreversible blindness worldwide. The reduction of intraocular pressure has proved to be the only factor which can be modified in the treatment, and surgical management is one of the important methods for the treatment of glaucoma patients.

Main text

In order to increase aqueous humor outflow and further reduce intraocular pressure, various drainage implants have been designed and applied in clinical practice. From initial Molteno, Baerveldt and Ahmed glaucoma implants to the Ahmed ClearPath device, Paul glaucoma implant, EX-PRESS and the eyeWatch implant, to iStent, Hydrus, XEN, PreserFlo, Cypass, SOLX Gold Shunt, etc., glaucoma surgical implants are currently undergoing a massive transformation on their structures and performances. Multitudinous materials have been used to produce these implants, from original silicone and porous polyethylene, to gelatin, stainless steel, SIBS, titanium, nitinol and even 24-carat gold. Moreover, the material geometry, size, rigidity, biocompatibility and mechanism (valved versus nonvalved) among these implants are markedly different. In this review, we discussed the development and material characteristics of both conventional glaucoma drainage devices and more recent implants, such as the eyeWatch and the new minimally invasive glaucoma surgery (MIGS) devices.

Conclusions

Although different in design and materials, these delicate glaucoma surgical implants have widely expanded the glaucoma surgical methods, and improved the success rate and safety of glaucoma surgery significantly. However, all of these glaucoma surgical implants have various limitations and should be used for different glaucoma patients at different conditions.

Modified Technique of Ex-PRESS® Filtration Device Combined with a Scleral Pocket for Hereditary Transthyretin Amyloidosis (hATTR) Secondary Open-Angle Glaucoma

Purpose

To evaluate the effectiveness and safety of a modified approach using the Ex-PRESS^® implant combined with a scleral pocket in the management of secondary open-angle glaucoma in hereditary transthyretin amyloidosis (hATTR) at our department.

Methods

This was a retrospective analysis. The primary endpoints included Intraocular pressure (IOP) evaluation (baseline, 1st day, 1st week, 1, 3, 6, 12 months and at last follow-up) and number of hypotensive drugs (baseline, 6th, 12th months and at last follow-up). As secondary endpoints surgical complications, the need for additional glaucoma surgery and LogMAR BCVA were evaluated. Qualified and complete success were defined as ≥ 30% IOP decrease from baseline, with or without additional medications, respectively. The minimum follow-up was 12 months.

Results

A total of 32 eyes were included with a mean follow-up of 2.4±2.9 years. IOP decreased significantly from baseline (27.4±4.4 mmHg) to 1st day (5.00±2.9 mmHg), 1st week (6.9±4.1 mmHg), 1st month (11.7±7.8 mmHg), 3rd month (11.6±6.1 mmHg), 6th month (13.1±6.8 mmHg), 12th month (12.0±3.5 mmHg) and last visit (11.8±2.4 mmHg), p<0.001. There was also a significant reduction in the number of antiglaucoma medications from baseline (3.8±0.6) and last follow-up (0.4±0.8), p<0.001. LogMAR BCVA remained stable (0.25±0.26 at baseline and 0.25±0.24 at last follow-up), p=0.767. Transient hypotony occurred in 17 eyes (53.1%), but only 11 (34.4%) exhibited anterior chamber shallowing and needed additional care, namely cycloplegic drops and viscoelastic injection. Complete surgical success was achieved in 22 eyes (68.8%) and qualified success in 6 eyes (18.8%). Four eyes (12.5%) needed additional glaucoma surgery.

Conclusion

The modified ExPRESS^® technique appears to be effective, especially when low levels of IOP are required. Additionally, fewer anti-glaucoma drugs were necessary. In the other hand, hypotony was a common side effect with this procedure, although all patients were properly handled, preserving the surgical outcomes.

Ex-PRESS® surgery versus trabeculectomy for primary open-angle glaucoma with low preoperative intraocular pressure

PURPOSE

To compare surgical outcomes between Ex-PRESS® surgery (EXP) and trabeculectomy (Trab) for primary open-angle glaucoma (POAG) with low preoperative intraocular pressure (IOP).

PATIENTS AND METHODS

This was a retrospective non-randomized study. We included POAG patients with preoperative IOP ≤ 16 mmHg who were taking tolerance glaucoma medications. We compared the surgical outcomes, postoperative IOP, number of glaucoma medications, reduction rate of corneal endothelial cell density (ECD), visual acuity, and postoperative complications between POAG patients who underwent EXP (34 eyes) or Trab (38 eyes) and could be followed up for > 2 years.

RESULTS

Both surgeries significantly decreased the IOP (p < 0.001): At 2 years, EXP provided decreases from 13.4 ± 2.3 to 10.2 ± 3.1 mmHg, and Trab provided decreases from 13.5 ± 2.0 to 8.9 ± 3.2 mmHg. No significant differences were observed in the postoperative IOP (p = 0.076), number of postoperative medications (p = 0.263), success rate (p = 0.900), reduction rate of ECD (p = 0.410), or difference in visual acuity (p = 0.174). The reduction rate of IOP was significantly high in the Trab group (p = 0.047).

CONCLUSIONS

Both surgeries significantly decreased IOP and were useful surgical methods for low-IOP glaucoma. Our results suggest that trabeculectomy can decrease IOP more than Ex-PRESS surgery but might have more complications.

Comparison of Ex-PRESS implantation versus trabeculectomy combined with phacoemulsification in primary open-angle glaucoma: a retrospective in vivo confocal microscopy study

BACKGROUND

To compare the efficacy of Ex-PRESS implantation versus trabeculectomy combined with phacoemulsification.

METHODS

A retrospective 12-month study on patients with coincident primary open-angle glaucoma (POAG) and cataract. The patients underwent combined phacoemulsification and Ex-PRESS implant (Phaco-ExPRESS, n = 35) or phacotrabeculectomy (Phaco-Trab, n = 35). The morphological structures of the filtering bleb were examined by slit-lamp, anterior segment optical coherence tomography (AS-OCT) and in vivo confocal microscopy (IVCM). Complete success was defined as postoperative intraocular pressure (IOP) < 18 mmHg without the use of anti-glaucoma medication. Qualified success was defined as postoperative IOP < 18 mmHg with or without anti-glaucoma medications. The data were collected preoperatively and postoperatively at 2 weeks, 1 month, 3 months, 6 months, and 12 months.

RESULTS

No significant difference in the variables such as age, IOP and perimetry was found between the groups of Phaco-ExPRESS and Phaco-Trab. At the one-year postoperative visit for filtering blebs, Phaco-ExPRESS increased the mean area of epithelial microcysts significantly from 0.10 ± 0.05 to 0.20 ± 0.09 μm² per μm², while Phaco-Trab decreased the mean area significantly from 0.08 ± 0.04 to 0.04 ± 0.06 μm² per μm². Notably, the hyperreflective dots detected by IVCM decreased by 84.9% in Phaco-ExPRESS but increased by 36.3% in Phaco-Trab. The hyperreflective dots were further identified as neutrophil- and monocyte-like cells. The number of these cells were negatively correlated with the microcysts area (r =  - 0.7, P < 0.01) but positively associated with the grade of connective tissue (r = 0.5, P < 0.01). By creating different microstructural changes in the filtering blebs, Phaco-ExPRESS produced a higher complete success rate (84.9% vs. 41.2%, P < 0.01) and significant decrease in the number of anti-glaucoma medications (P < 0.01) when compared with those in Phaco-Trab. However, the qualified success showed no significant difference between the two groups (100.0% vs. 91.2%, P = 0.24).

CONCLUSIONS

At the one-year follow-up, Phaco-ExPRESS generated better filtering bleb with larger area of microcysts, looser connective tissues, and less inflammation than that of Phaco-Trab, providing adequate IOP control and less IOP-lowering medications. These findings indicate that Phaco-ExPRESS could be more preferred than Phaco-Trab for the treatment of patients with coincident POAG and cataract.

Comparison of Ex-PRESS P-200 mini-shunt implantation and standard trabeculectomy for open-angle glaucoma: four-year follow-up

INTRODUCTION

The study aimed to evaluate the efficacy and safety in 4-year follow-up of Ex-PRESS P-200 mini-shunt implantation versus standard trabeculectomy.

MATERIAL AND METHODS

A single-center retrospective study on patients diagnosed with open-angle glaucoma with failed medical treatment and who underwent Ex-PRESS device implantation or standard trabeculectomy was conducted. Seventy-three eyes were included in the analysis, 33 with Ex-PRESS P-200 implantation and 40 with standard trabeculectomy.

RESULTS

Significant decreases in the intraocular pressure (IOP) were observed after surgery and at all follow-ups in both groups (p < 0.001) with no significant difference between the two groups (p > 0.40). No significant differences with regard to post-operative medications were observed (p > 0.10). Excepting the 3-year follow-up, when just a borderline significant difference regarding the visual acuity between the Ex-PRESS and standard trabeculectomy group was observed (p = 0.0504), the Ex-PRESS groups showed significantly better visual acuity at 6 weeks (p = 0.0324), 1 year (p = 0.0168), 2 years (p = 0.0162), and 4 years (p = 0.0111). Hypotony occurred more frequently among the Ex-PRESS group, while cataract occurred more frequently among those with standard trabeculectomy, without significant differences between groups (p > 0.09). No difference in hazard of failure was observed between interventions (HR = 0.72, p = 0.523).

CONCLUSIONS

Both procedures provided good control of IOP and decreased the number of postoperative medications. The advantage of the Ex-PRESS shunt is the better visual acuity, but its main limitation is the cost.

Impending extrusion of Ex-PRESS shunt treated by shunt-position adjustment: a case report

Background

To report a case of impending extrusion of Ex-PRESS shunt treated by shunt-position adjustment.

Case presentation

A 56-year-old Asian woman presented with impending extrusion and malposition of Ex-PRESS shunt in her left eye. The bleb of the left eye was shallow and diffuse. In the past, the patient was treated by Ex-PRESS shunt implantation under the scleral flap in both eyes. There had been no Ex-PRESS shunt-related complication in her right eye, and she reported no history of left-eye trauma. Based on these findings, we hypothesized that the source of the left-eye problem was a loosely fixed Ex-PRESS shunt spur. It was thought, furthermore, that this inadequate scleral resistance during the Ex-PRESS shunt implantation was due to the low scleral rigidity resulting from high myopia and insufficient maintenance of the anterior chamber. We proceeded to make an incision in the area adjacent to the Ex-PRESS shunt using a super sharp blade. The shunt was then pushed into the anterior chamber with forceps, and the spur was fixed firmly. Pushing the shunt to the anterior chamber was found to have been sufficient to fix it firmly. In fact, when the sclera was palpated with a sponge, aqueous outflow was observed with no shunt displacement. Postoperative intraocular pressure (IOP) was managed well, and the bleb had formed with diffuse, prominent shapes. The Ex-PRESS shunt was well sustained with good positioning.

Conclusions

When an Ex-PRESS shunt operation is performed on a patient who shows a tendency for low scleral rigidity, shunt implantation should be accomplished carefully and with force adequate for firm spur fixation.

Comparison between the EX-PRESS P-50 implant and trabeculectomy in patients with open-angle glaucoma

Purpose

To evaluate the EX-PRESS P-50 implant compared to standard trabeculectomy (TBC).

Methods

Single-center prospective randomized study; 20 eyes of 20 patients were treated with the EX-PRESS P-50 implant, and 20 eyes of 20 patients with TBC, over a 19-month period. Records of all patients were reviewed and compared. Success was defined as intraocular pressure (IOP) <21 and >5 mmHg or a decrease of 30% of IOP. Failure was defined as >21 mmHg or decline in visual acuity. Statistical analysis was made with Student’s t-test and χ² test analyzed with SPSS version 13.0.

Results

The average follow-up was 8.6 months (±4.9 months) for the EX-PRESS P-50 group and 9.6 months (±5.3 months) for the TBC group. The postoperative visual acuity and IOP were not significantly different. We report more complications in the EX-PRESS P-50 group. At 3, 6, and 12 months follow-up, the control group was found to be free of complications, whereas multiple complications were observed in the EX-PRESS P-50 group at 3 and 6 months follow-up. We found no differences in either group with respect to success.

Conclusion

Both procedures are equally effective for the treatment of glaucoma, with 80% success in the EX-PRESS P-50 group and 72.7% in the control group.

CURRENT OPTIONS FOR SURGICAL TREATMENT OF GLAUCOMA

The purpose of this study is to review current surgical treatment and new and better alternatives for patients with glaucoma. Glaucoma refers to a group of related eye disorders that have in common an optic neuropathy associated with visual function loss. It is one of the leading causes of irreversible blindness worldwide. Optic nerve damage and glaucoma-related vision loss can be prevented or limited by early diagnosis and treatment. Surgery offers a better control of the intraocular pressure then medical therapy. Nowadays, research continues for improving current surgical alternatives for treatment.