ExPRESS Shunt Surgery Research Articles

Aqueous Flare Changes in Ex-PRESS Glaucoma Shunt Eyes After 4.7 Tesla High-Field Magnetic Resonance Imaging

Ex-PRESS glaucoma shunt stainless steel devices have been used worldwide for glaucoma treatment. The purpose of this study was to evaluate the safety of high-field magnetic resonance imaging (MRI) for Ex-PRESS-inserted eyes. Using rabbits, we performed Ex-PRESS shunt surgery in one eye in each rabbit and divided the rabbits into MRI and non-MRI groups. In the MRI group, 1 week after Ex-PRESS shunt surgery under low specific absorption rate (SAR) conditions and 1 week later under high SAR conditions, high-field 4.7-Tesla MRI was performed. Aqueous flare counts were measured before and after the Ex-PRESS shunt surgery and each MRI examination. The rabbits in the non-MRI group received only general anesthesia, and aqueous flare counts were measured as for those of the MRI group. Aqueous flare counts were expressed in photon counts per millisecond. No dislocation of the Ex-PRESS shunt device was observed after MRI. The flare count ratio (MRI/non-MRI) in Ex-PRESS-inserted eyes 2 hours after high SAR MRI increased significantly compared with that before MRI (0.8 ± 0.3 vs 2.7 ± 0.8; pre-high SAR MRI vs 2 hours after high SAR MRI, respectively; P = 0.01). The day after MRI, the flare count improved spontaneously to the same level as that before MRI. Our results indicate that high-field MRI can be performed relatively safely after Ex-PRESS shunt surgery. This study demonstrates the safety of high-field MRI for Ex-PRESS-inserted eyes using a rabbit model.

Ex-PRESS Miniature Glaucoma Shunt Versus Ahmed Glaucoma Valve in the Surgical Treatment of Glaucoma in Pseudophakic Patients.

The aim of this study was to compare the 3-year outcome of Ex-PRESS miniature glaucoma shunt versus Ahmed glaucoma valve in pseudophakic patients. We retrospectively reviewed the records of patients with a history of clear corneal phacoemulsification alone, or failed trabeculectomy following phacoemulsification, who subsequently underwent Ahmed glaucoma valve (AGV) implantation or Ex-PRESS shunt surgery. The main outcome measure, surgical success, was defined as an intraocular pressure between 5 and 21 mm Hg and a 20% intraocular pressure reduction from baseline (with/without glaucoma medications) without glaucoma reoperation. In total, 92 patients (92 eyes) were included (43 AGV, 49 Ex-PRESS). Overall success at 3 years was 92.7% for AGV and 66.1% for Ex-PRESS (P=0.006). AGV had a higher success rate in patients with prior phacoemulsification and failed trabeculectomy (96% AGV vs. 64.1% Ex-PRESS; P=0.023). There was no difference in success rate for patients with only previous phacoemulsification (87.5% AGV vs. 69.4% Ex-PRESS; P=0.205). Glaucoma reoperation rates were 4.6% and 30.6% in the AGV and Ex-PRESS group, respectively (P=0.001). Both procedures had similar complication rates. AGV compared with Ex-PRESS shunt, had a higher success rate for secondary surgeries but not primary surgeries, in patients with prior clear corneal phacoemulsification. The AGV surgery also had a lower overall glaucoma reoperation rate.

Prevalence of glaucoma in the Israeli Arab population.

We describe the prevalence and treatment of glaucoma in a Muslim Arab population in Israel. Based on the medical records of 15 122 persons, the overall prevalence of glaucoma was 3.9%. Prevalence rates of primary open angle glaucoma (POAG) and primary angle-closure glaucoma (PACG) were 3.0% and 0.42%, respectively. Prevalence rates of women were 135% that of men considering all types of glaucoma, 143% for POAG, and 96% for PACG. Prostaglandin analogs and beta blockers, alone or combined with carbonic anhydrase inhibitors, were the preferred medications. Of 68 patients who underwent trabeculectomy, 27 (39.7%) required medications, postoperatively, for treatment of glaucoma; following Ex-Press shunt surgery, 3/11 (27.3%) required medications. During the last three years, 16 (1.3%) individuals with POAG were recorded as legally blind as a result of glaucoma.

Subconjunctival implantation of ologen Collagen Matrix to treat ocular hypotony after filtration glaucoma surgery.

PurposeTo report the results of subconjunctival ologen Collagen Matrix implantation to manage ocular hypotony after filtration glaucoma surgery.Patients and methodsThis retrospective observational case series included 12 consecutive implantations of ologen in nine eyes of nine Japanese subjects (five men, four women; mean age±SD, 72.1±12.7 years) who underwent subconjunctival implantation of the device to treat hypotony after glaucoma filtration surgery. Demographic data and surgical results were collected by chart review.ResultsThe subjects included six patients who underwent trabeculectomy and three who underwent an EX-PRESS shunt surgery. The duration between the last glaucoma surgery and the initial ologen implantation was longer than 2 years in seven (78%) eyes. Bleb leakage in five (56%) eyes preoperatively stopped in all cases by 8 days after the device implantation. After the initial implantation, three (33.3%) eyes required a second implantation of ologen because of insufficient efficacy. After a mean follow-up of 12.6±6.8 months, the mean preoperative intraocular pressure (IOP) of 3.8±2.7 mmHg increased significantly (P=0.0001) to 9.0±3.2 mmHg; no eye required glaucoma medication to control the IOP. No vision-threatening complications developed in association with the treatment.ConclusionWhen conservative management failed, subconjunctival implantation of ologen Collagen Matrix in combination with bleb revision can be a useful therapeutic option for ocular hypotony after glaucoma filtration surgery.

Outcomes of Bleb Revision With Mitomycin C After Ex-PRESS Shunt Surgery.

Investigate efficacy and safety of bleb revision using mitomycin C after Ex-PRESS shunt surgery. We performed chart reviews of 36 consecutive eyes from 34 patients with previous Ex-PRESS shunt surgery who underwent subsequent bleb revision with mitomycin C. The mean follow-up time was 13.5 months. The primary outcome measure was surgical success. Secondary outcomes included visual acuity, intraocular pressure, number of medications, and complications. Twenty-four eyes had open-angle glaucoma (61.1%). Mean time from Ex-PRESS to bleb revision was 8.8 months. Complete success rate for the immediate 3-month postoperative period was 94.4% and qualified success rate was 97.2%. Complete and qualified success rates for the entire follow-up period were 40% and 65.7%, respectively. Visual acuity remained stable throughout the study period, and at 1 year, average intraocular pressure was 14.7 mm Hg on an average of 1.7 medications. No major complications were reported. Bleb revision in eyes with an Ex-PRESS shunt is a safe and efficacious procedure. The surgical outcomes are within the range of published outcomes for bleb needling after trabeculectomy. Further research with larger sample size and longer follow-up is needed to confirm these results.

Bubble mirror technique for express shunt surgery

Surgical techniqueThe bubble mirror technique consists of the stabilization of the anterior chamber by means of a plug made with a combination of conveniently placed air and viscoelastic material. A line arises at interface between the air and viscoelastic where the anterior chamber angle reflected can be seen as in a mirror (bubble mirror). DiscussionThe viscoelastic–air plug offers three advantages in glaucoma surgery with the Ex-PRESS implant: (1) plug effect of viscoelastic, giving stability to the anterior chamber and preventing it from collapsing; (2) toning effect of the air bubble; and (3) specular effect at the interface, which allows the surgeon to visually control the chamber angle during the Ex-PRESS implantation.

Ex-PRESS outcomes using mitomycin-C, Ologen alone, Ologen with 5-fluorouracil

To compare the complication rate and effectiveness of mitomycin C (MMC), Ologen alone, and Ologen with 5-fluorouracil (5-FU) as adjunctives with Ex-PRESS mini shunt for medically uncontrolled glaucoma. Retrospective comparative study of 59 Ex-PRESS mini shunt trabeculectomy operations coupled with Ologen implantation alone, transient MMC application or Ologen implantation with 5-FU as adjunctive treatment. Eight eyes (7 patients) received Ologen alone, 37 eyes (34 patients) received MMC, and 14 eyes (14 patients) received Ologen with 5-FU as adjunctive therapy. Baseline characteristics, adjunctive used during operation, along with outcomes including intraocular pressure (IOP), number of anti-hypertensive drops, visual acuity, and complications were documented and compared. The primary outcome was IOP at 12 months. Variables were compared with r × c Fisher tests. The Ologen only group had a significantly higher IOP at 12 months (20.5 ± 10.23 mmHg) compared with Ologen combined with 5-FU (12.2 ± 1.47 mmHg) or MMC (13.8 ± 4.37 mmHg) (p = 0.015, linear mixed model). The Ologen only cohort also had a higher re-operation rate (p = 0.01, Fisher's Exact Test) and higher rate of bleb leak (p = 0.02, Fisher's Exact Test). Visual acuity was similar among all three groups. 5-FU with Ologen is as effective as MMC in maintaining IOP following Ex-PRESS shunt surgery at 1 year. However, Ologen alone may not be as effective as the other two adjunctive agents.

Trabeculectomy Versus ExPRESS Shunt Surgery in Residency Training

The core curriculum for an ophthalmology residency training program should include surgical procedures relevant to a comprehensive ophthalmologist. Considerations include outcomes (success and complications), technical skill required, applicability to a wide range of disease, and cost. Using these metrics, trabeculectomy should be favored over ExPRESS shunt surgery.

ExPRESS Shunt Surgery: Preferred Glaucoma Surgery in Residency Training?

It is important to equip future ophthalmic surgeons with appropriate surgical skills without compromising patient care. The ExPRESS implant surgery is very similar to trabeculectomy surgery in both efficacy and technique, but is less traumatic and may be prone to less postoperative hypotony and require less postoperative hypotensive medications. although affording a way to teach a novice surgeon the steps and technique of trabeculectomy and minimizing patient risk, ExPRESS implantation is a more expensive surgery that involves placing a foreign body in the eye. Further, needling an ExPRESS is a more technically challenging procedure than needling a trabeculectomy and more limited in its scope.