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

Minimally Invasive Glaucoma Surgery: A Review of the Literature

Minimally invasive glaucoma surgery (MIGS) has emerged as a novel approach in the glaucoma treatment spectrum, offering a range of diverse procedures and devices aimed at reducing intraocular pressure (IOP). MIGS can be broadly classified into several categories: those that enhance trabecular outflow (Trabectome, iStent, Hydrus Microstent, Kahook Dual Blade, high frequency deep sclerotomy, and gonioscopy-assisted transluminal trabeculotomy), those that augment suprachoroidal outflow (CyPass Microstent and iStent Supra), those that target Schlemm's canal (TRAB360 and the OMNI Surgical System, Streamline, and Ab Interno Canaloplasty), and conjunctival bleb-forming procedures (EX-PRESS Glaucoma Filtration Device, Xen Gel Stent and PreserFlo MicroShunt). MIGS is considered to have a shorter surgical time and fewer severe complications when compared to traditional glaucoma surgeries such as trabeculectomy and glaucoma drainage device implantation (Ahmed, Baerveldt, and Molteno valves). This literature review comprehensively examines the distinct MIGS devices and procedures, their underlying mechanisms, and clinical outcomes, emphasizing the importance of evaluating the efficacy and complications of each approach individually. As the field of MIGS continues to evolve, it is crucial to prioritize high-quality, long-term studies to better understand the safety and effectiveness of these innovative interventions in glaucoma management.

Ex-PRESS shunt implantation for intractable glaucoma with posterior chamber phakic intraocular lens: a case report

Background

Implantation of the posterior chamber phakic intraocular lens has been widely performed to correct high and extreme myopia. Chronic intraocular pressure (IOP) elevation may occur in its late postoperative period. For medically uncontrolled cases, surgical treatment is necessary, and benefits should be weighed against risks when determining whether to remove the lens.

Case presentation

A 32-year-old man with extremely high myopia presented with progressive blurred vision and medically uncontrolled IOP in the right eye. His past ocular history was significant for bilateral implantable collamer lens (ICL) implantation ten years ago. On ophthalmic examination, the ICL was well placed with a vault height of 456 µm in the right eye. The anterior chamber angles were open but narrow, and mild to moderate trabecular pigmentation was noted. Ex-PRESS glaucoma filtration surgery without ICL removal was performed to control IOP. During surgery, an Ex-PRESS P50 shunt was inserted into the anterior chamber via the front edge of the blue-grey transition zone between the sclera and cornea. Transient hypotony and shallow anterior chamber occurred in the first week after surgery, along with an ICL tilt towards the cornea with reduced vault height. No other complications related to either the ICL or the Ex-PRESS shunt were noted. IOP remained stable at 12 ~ 14 mmHg at the first 3-month follow-up.

Conclusions

Ex-PRESS glaucoma filtration surgery might be a safe and effective alternative treatment for intractable glaucoma with high myopia and ICL implantation. Careful assessment of the ICL position and anterior chamber angle is necessary to plan the appropriate surgical procedure. A postoperative shallow anterior chamber may result in ICL dislocation.

Comparison of ExPress Implantation and Partial Deep Sclerectomy Combined with ExPress Implantation and Simultaneous Phacoemulsification

Background

To compare the effectiveness and safety profile of ExPress implantation versus partial deep sclerectomy combined with ExPress implantation and simultaneous phacoemulsification.

Patients and Methods

A prospective, randomized control study with 24-month follow-up was performed. 114 eyes were included, of which 42 eyes underwent phacoemulsification with simultaneous implantation of the Ex-Press device (ExPress), and deep sclerectomy with phacoemulsification and simultaneous implantation of the Ex-Press device (DS-ExPress) was performed in 72 eyes. The main outcome measures were intraocular pressure (IOP), corrected distance visual acuity (CDVA), the number of antiglaucoma medications, and the rate of complications. Surgical success was defined as complete (without antiglaucoma medications) with IOP ≤18 mmHg in criterion A, IOP ≤16 mmHg in criterion B, and IOP ≤12 mmHg in criterion C. Satisfactory success was defined as the same IOP levels for individual criteria with a maximum of 2 antiglaucoma medications.

Results

Before the procedure, mean IOP in the ExPress group was 17.5 ± 4.7 mmHg; after 24 months, it decreased by 13% to 16.0 ± 3.0 mmHg (P < 0.05). In the DS-ExPress group, mean IOP reduced from 16.3 ± 4.4 mmHg to 14.3 ± 3.3 mmHg (P < 0.05), which was a 9% reduction compared to the initial value. In the DS-ExPress group, 65.9% of the patients did not use topical pharmacotherapy, and the same is true for 29.2% of the ExPress group (P=0.004).

Conclusions

This modification is efficient in surgical treatment of glaucoma, especially when very low postoperative IOP is needed. A less amount of antiglaucoma medicines are needed.

Twenty-Four-Hour Contact Lens Sensor Monitoring of Aqueous Humor Dynamics in Surgically or Medically Treated Glaucoma Patients

Aim

This study assessed the 24 h circadian rhythm of intraocular pressure (IOP) using a contact lens sensor in three groups of patients with open-angle glaucoma.

Methods

This study was a monocentric, cross-sectional, nonrandomized, prospective, pilot study. Eighty-nine patients were enrolled: 29 patients previously underwent an Ex-PRESS mini glaucoma device procedure (Group 1), 28 patients previously underwent Hydrus microstent implantation (Group 2), and 32 patients were currently being treated medically for primary open-angle glaucoma (Group 3). Circadian rhythm patterns were considered with five circadian indicators: fluctuation ranges, maximum, minimum, acrophase (time of peak value), and bathyphase (time of trough value). A two-tailed Mann–Whitney U-test was used to evaluate differences between groups.

Results

All subjects exhibited a circadian rhythm and a nocturnal pattern. The signal fluctuation range was significantly smaller in the surgical groups than in the medically treated group (Group 1 vs. Group 3, p=0.003; Group 2 vs. Group 3, p=0.010). Subjects who underwent the Ex-PRESS procedure (Group 1) exhibited significant differences compared with the drug therapy group (Group 3) with regard to the minimum value (p=0.015), acrophase (p=0.009), and bathyphase (p=0.002). The other circadian indicators were not significantly different among groups.

Conclusions

Patients who underwent IOP-lowering surgery had an intrinsic nyctohemeral rhythm. Both surgical procedures, Ex-PRESS and Hydrus, were associated with smaller signal fluctuations compared with medical treatment.

Long-term efficacy and safety of ExPress implantation for treatment of open angle glaucoma

AIM

To compare the long-term efficacy and safety of ExPress implantation and standard trabeculectomy in patients with primary open angle glaucoma (POAG).

METHODS

In this retrospective study, we compared 17 eyes treated by ExPress implantation with 23 eyes treated by trabeculectomy. Efficacy was assessed according to the relevant intraocular pressure (IOP) values and success rates during the first year of follow-up. Postoperative corneal endothelial cell loss was also compared.

RESULTS

The number of antiglaucoma medications and the IOP reduction were similar between the 2 groups during the follow-up period. Although the mean IOP was similar, the IOP-fluctuation rate during the early postoperative period was significantly lower in the ExPress group than in the trabeculectomy group (P=0.038). A Kaplan-Meier survival curve analysis showed no significant success-rate difference between the groups (P=0.810). The corneal endothelial cell loss rate, moreover, was significantly lower in the ExPress group (P=0.05).

CONCLUSION

ExPress implantation compared with trabeculectomy showed similar IOP-reduction and success rates along with lower IOP fluctuation and endothelial cell loss rates. For this reason, it can be considered to be the treatment of choice for patients with advanced glaucoma or low corneal endothelial cell density.

Ex-PRESS implantation versus trabeculectomy in Chinese patients with POAG: fellow eye pilot study

AIM

To compare the outcomes of Ex-PRESS implantation in one eye versus trabeculectomy with mitomycin C in the fellow eye in Chinese patients with primary open-angle glaucoma (POAG).

METHODS

This was a prospective, non-randomized comparative study. Forty-eight eyes of 24 patients with bilateral POAG necessitating surgery were included and underwent Ex-PRESS implantation under the scleral flap in one eye and trabeculectomy in the other eye according to patients' choice. Primary outcome measures included mean intraocular pressure (IOP) and success rate. Secondary outcome measures were aqueous flare, postoperative medication use, visual acuity, and incidence of complications.

RESULTS

All 24 patients finished a 1-year follow-up. Both groups maintained significant reductions in IOP after surgery throughout the follow-up period. At any point in time, the IOP of the two groups did not differ significantly. The Kaplan-Meier survival curve analysis showed no significant differences in success between the two groups (P=0.289). The mean number of anti-glaucoma medicines and visual acuity in both groups were not significantly different. Eyes with Ex-PRESS implantation had lower aqueous flare values on days 1 and 3 (both P<0.05). Instances of early postoperative hypotony and choroidal effusion were significantly fewer in frequency after Ex-PRESS implantation under the scleral flap compared with those after trabeculectomy (P<0.001).

CONCLUSION

Ex-PRESS is comparable to trabeculectomy in terms of IOP, success rate, number of glaucoma medications used, and visual acuity. However, Ex-PRESS resulted in fewer cases of inflammation and a lower rate of complications.

Evaluation of Ex-PRESS mini glaucoma shunt implantation with preoperative intracameral bevacizumab injection in refractory neovascular glaucoma

PURPOSE

To evaluate the efficacy and safety of Ex-PRESS mini glaucoma shunt implantation with preoperative intracameral bevacizumab injection in eyes with refractory neovascular glaucoma.

METHODS

A retrospective chart review of patients with medically uncontrolled neovascular glaucoma who had received 50-µL intracameral bevacizumab (1.25 mg) before undergoing Ex-PRESS mini glaucoma shunt implantation was performed. Success was defined as a postoperative intraocular pressure (IOP) between 5 and 21 mm Hg without (complete success) or with or without (qualified success) glaucoma medications and no additional glaucoma surgery, or loss of light perception.

RESULTS

In total, 33 eyes of 33 patients (15 female, 18 male) were enrolled in the study. The mean age of the study population was 61.2 years (range 36-78). The mean IOP decreased from 41.0 mm Hg (range 24-72) to 17.6 mm Hg (range 8-28) over a mean follow-up of 20.9 months (range 6-60) (p&lt;0.001; Wilcoxon signed-rank test). Complete and qualified success rates were 36.4% and 66.7%, respectively. The average number of antiglaucoma medications decreased from 3.5 (range 2-4) preoperatively to 1.8 (range 1-4) postoperatively (p&lt;0.001; Wilcoxon signed rank test). In 81.8% of cases, the decrease in IOP was 30% or more postoperatively.

CONCLUSIONS

Ex-PRESS mini glaucoma shunt implantation with preoperative bevacizumab injection may be an effective alternative procedure for refractory neovascular glaucoma.

Comparison of ExPress Mini-Device Implantation Alone or Combined with Phacoemulsification for the Treatment of Open-Angle Glaucoma

We propose comparative assessment of the effectiveness of two surgical methods for the treatment of open-angle glaucoma: (1) ExPress mini-device implantation combined with phacoemulsification and (2) ExPress mini-device implantation alone. In this prospective study, 81 patients (88 phakic eyes) with uncontrolled open-angle glaucoma enrolled for surgery. They were assigned two groups, those with coexisting cataracts (46 eyes; P-ExPress group) and those with glaucoma alone (42 eyes; ExPress group). The follow-up period was 12.9 ± 0.4 months in P-ExPress and 12.2 ± 0.6 months in ExPress group. In both groups the following parameters were measured: best corrected visual acuity (BCVA), intraocular pressure (IOP), number of complications and necessary postoperative interventions, and number of glaucoma medications. The IOP at the end of follow-up was similar in both groups (18.8 ± 5.9 versus 18.1 ± 4.8 mmHg; P = 0.814). There were no statistical differences in the average number of glaucoma medications between ExPress and P-ExPress groups (0.9 ± 1.65 versus 1.3 ± 1.7; P = 0.419) as well as in the number of postoperative complications (26 versus 21%; P = 0.179 in the P-ExPress and ExPress groups, resp.). Both methods are safe and effective for the surgical treatment of open-angle glaucoma. Coexistence of cataracts does not constitute a compelling contraindication for combined surgery.

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

Trabeculectomy has been the traditional primary surgical therapy for open-angle glaucoma. While trabeculectomy is effective in lowering intraocular pressure, complications associated with the procedure have motivated the development of alternative techniques and devices, including the EX-PRESS Glaucoma Filtration Device. This review describes the efficacy, safety, complication rates, and potential advantages and disadvantages of the EX-PRESS Glaucoma Filtration Device. EX-PRESS implantation is technically simpler compared with that of trabeculectomy, with fewer surgical steps. Vision recovery has been more rapid after EX-PRESS implantation compared with trabeculectomy. Intraocular pressure variation is lower during the early postoperative period, indicating a more predictable procedure. While efficacy of the EX-PRESS implant has been comparable to trabeculectomy, postoperative complications appear less common after EX-PRESS implantation compared with trabeculectomy. The EX-PRESS Glaucoma Filtration Device appears to be safe and effective in the surgical management of open-angle glaucoma.

Prospective Randomized Study Comparing Combined Phaco-ExPress and Phacotrabeculectomy in Open Angle Glaucoma Treatment: 12-Month Follow-Up

Purpose of the Study. To compare the efficacy and safety of phacotrabeculectomy (P-Trab) and phacoemulsification with the ExPress (P-ExPress) mini glaucoma shunt implantation. Study Plan. Prospective randomized study. Material and Methods. 85 eyes with cataract and unregulated open angle glaucoma. There were 46 eyes in the P-ExPress and 39 the P-Trab group. Intraocular pressure (IOP), the number of antiglaucoma medications, qualified and complete surgical success (defined as IOP ≤ 18.0 mmHg), visual acuity (CDVA), the number of endothelial cells, and postoperative complications and additional procedures were assessed. Results. After 12 months of observation, the average IOP in the P-Express group went from 26.4 ± 9.3 down to 17.1 ± 5 mmHg (P < 0.05) and from 27.9 ± 12.9 down to 15.9 ± 2.7 mmHg in the P-Trab group (P < 0.05). No significant differences in the amount of medications used after surgery and CDVA were discovered between the groups. In the P-ExPress group, greater loss of endothelial cells was noted (CD_loss%), compared to the P-Trab group. Conclusions. Both P-ExPress and P-Trab have comparable efficacy and similar early postoperative complication profile. The presence of additional implant (as is the case of the ExPress mini glaucoma shunt implantation) may cause progressive loss of endothelial cells.