Glaucoma surgery: taking the sub-conjunctival route

Effects of Postoperative Atropine Eye Drops on Visual Quality in Patients Undergoing Trabeculectomy

The aim of this study was to investigate the effects of atropine on patients' perception of visual quality after trabeculectomy. Forty patients undergoing standard trabeculectomy with mitomycin C were enrolled in this prospective randomized study. All surgeries were conducted at the ophthalmology department of the University Medical Center of Mainz, Germany. All patients received the same postoperative treatment with ofloxacin and dexamethasone eye drops. Following randomization of patients into two groups of 20 patients, the intervention group also received atropine eye drops three times daily for the first 2 days after surgery to stabilize the anterior chamber. All patients completed a visual quality questionnaire before surgery and 2 and 6 weeks after surgery. Results were compared using the Wilcoxon test. After surgery, there was a reduction in visual quality in all patients. Patients who received atropine eye drops described a greater and longer-lasting reduction in visual quality than those who did not receive atropine eye drops. Trabeculectomy often leads to a transient reduction in visual quality. This reduction was greater in severity and duration in patients who received postoperative atropine eye drops. Thus, unless there is an underlying medical necessity, we would discourage the application of atropine as a standard therapy for trabeculectomy surgery.

PreserFlo® MicroShunt: An Overview of This Minimally Invasive Device for Open-Angle Glaucoma

For moderate-to-severe glaucoma, trabeculectomy remains the “gold standard” intraocular pressure (IOP)-lowering treatment; nonetheless, this method requires extensive post-operative maintenance. Microinvasive glaucoma surgery (MIGS) treatments are designed to lessen intra- and post-operative care burden while offering an acceptable IOP decrease for individuals with mild to moderate glaucoma. The PreserFlo® MicroShunt (previously InnFocus MicroShunt) is an 8.5 mm glaucoma drainage device manufactured from poly(styrene-block-isobutylene-block-styrene) (SIBS), an extremely biocompatible and bioinert material. The lumen is narrow enough to prevent hypotony, but big enough to avoid being obstructed by sloughed cells or pigment. The device is implanted ab externo, as a stand-alone procedure or in conjunction with cataract surgery, with intraoperative mitomycin C, and a bleb is produced under the conjunctiva and Tenon’s capsule. The MicroShunt was CE-marked in 2012 and designed for primary open-angle glaucoma, the IOP of which remains uncontrolled after maximally tolerated topical treatment. Several clinical trials evaluating the MicroShunt’s long-term safety and effectiveness have been conducted, highlighting the effectiveness of the device over time, along with a tolerable safety profile. The present review aims to gather evidence of PreserFlo’s effectiveness and safety results almost 10 years after its introduction, and furthermore, to compare it with other MIGS and with the gold-standard trabeculectomy for glaucoma management.

High-Frequency Deep Sclerotomy, A Minimal Invasive Ab Interno Glaucoma Procedure Combined with Cataract Surgery: Physical Properties and Clinical Outcome

Background: The efficiency and safety of primary open-angle glaucoma with high-frequency deep sclerotomy (HFDS) combined with cataract surgery has to be investigated. Methods: Right after cataract surgery, HFDS was performed ab interno in 205 consecutive patients with open angle glaucoma. HFDS was performed with a custom-made high-frequency disSection 19 G probe (abee tip 0.3 × 1 mm, Oertli Switzerland). The bipolar current with a frequency of 500 kHz is applied. The nasal sclera was penetrated repetitively six times through the trabecular meshwork and consecutively through Schlemm’s canal. Every time, a pocket of 0.3 mm high and 0.6 mm width was created. Results: Mean preoperative intraocular pressure (IOP) was 24.5 ± 2.1 mmHg (range 21 to 48 mmHg). After 48 months, the follow up average IOP was 15.0 ± 1.7 mmHg (range 10 to 20 mmHg). Postoperative IOP has been significantly reduced compared to preoperative IOP for all studied cases (p < 0.001). After 48 months, the target IOP less than 21 mmHg reached in 84.9%. No serious complications were observed during the surgical procedure itself and in the postoperative period. Conclusions: HFDS is a minimally invasive procedure. It is a safe and efficacious surgical technique for lowering IOP combined with cataract surgery.

The Efficacy and Safety of High-Frequency Deep Sclerotomy in Treatment of Chronic Open-Angle Glaucoma Patients

Purpose

Highlights the high-frequency deep sclerotomy as a competing ab interno surgery in open-angle glaucoma patients and evaluates the efficacy of high-frequency deep sclerotomy in lowering IOP of chronic open-angle glaucoma patients, in addition to the evaluation of the safety of the procedure on the corneal endothelium.

Design

A prospective study. It was performed in the Research Institute of Ophthalmology, Cairo.

Participants

43 eyes were enrolled for the study. All eyes were diagnosed with chronic open-angle glaucoma.

Methods

The procedure was performed using the abee® glaucoma tip of Oertli phacoemulsification machine (OS3, Switzerland) and goniolens performing nasal six pockets penetrating 1 mm deep into the trabecular meshwork and Schlemm's canal. Patients were followed up regarding vision and intraocular pressure (IOP) for 9 months. Endothelial cell count and coefficient of variation were calculated using specular microscopy preoperatively and 9 months postoperatively.

Results

The mean preoperative IOP was 31.4 ± 4.71 mmHg (range: 22 to 42 mmHg). All patients were followed up for nine months. The mean IOP was 19.06 ± 1.907 mmHg (range: 15 to 26 mmHg) by the end of the study. The reduction across the follow-ups was statistically significant (P < 0.0001). The percentage of total success was 90.7% (39 eyes). Four eyes (9.3%) had IOP > 21 (failed) after surgery and continued on antiglaucoma therapy.

Conclusion

High-frequency deep sclerotomy is a safe and promising minimally invasive procedure which successfully achieves a lower IOP for chronic open-angle glaucoma patients, but not adequate for advanced glaucoma patients. This trial is registered with PACTR201910823824561.

Ab externo implantation of the MicroShunt, a poly (styrene-block-isobutylene-block-styrene) surgical device for the treatment of primary open-angle glaucoma: a review

Trabeculectomy remains the ‘gold standard’ intraocular pressure (IOP)-lowering procedure for moderate-to-severe glaucoma; however, this approach is associated with the need for substantial post-operative management. Micro-invasive glaucoma surgery (MIGS) procedures aim to reduce the need for intra- and post-operative management and provide a less invasive means of lowering IOP. Generally, MIGS procedures are associated with only modest reductions in IOP and are targeted at patients with mild-to-moderate glaucoma, highlighting an unmet need for a less invasive treatment of advanced and refractory glaucoma. The PRESERFLO® MicroShunt (formerly known as InnFocus MicroShunt) is an 8.5 mm-long (outer diameter 350 μm; internal lumen diameter 70 μm) glaucoma drainage device made from a highly biocompatible, bioinert material called poly (styrene-block-isobutylene-block-styrene), or SIBS. The lumen size is sufficiently small that at normal aqueous flow hypotony is avoided, but large enough to avoid being blocked by sloughed cells or pigment. The MicroShunt achieves the desired pressure range in the eye by draining aqueous humor from the anterior chamber to a bleb formed under the conjunctiva and Tenon’s capsule. The device is implanted ab externo with intraoperative Mitomycin C via a minimally invasive (relative to incisional surgery) surgical procedure, enabling precise control of placement without the need for gonioscopy, suture tension control, or suture lysis. The implantation procedure can be performed in combination with cataract surgery or as a standalone procedure. The MicroShunt received Conformité Européenne (CE) marking in 2012 and is intended for the reduction of IOP in eyes of patients with primary open-angle glaucoma in which IOP remains uncontrolled while on maximum tolerated medical therapy and/or in which glaucoma progression warrants surgery. Three clinical studies assessing the long-term safety and efficacy of the MicroShunt have been completed; a Phase 3 multicenter, randomized clinical study comparing the MicroShunt to primary trabeculectomy is underway. In preliminary studies, the MicroShunt effectively reduced IOP and use of glaucoma medications up to 3 years after implantation, with an acceptable safety profile. This article summarizes current literature on the unique properties of the MicroShunt, the preliminary efficacy and safety findings, and discusses its potential use as an alternative to trabeculectomy for glaucoma surgery.

Prospective study of filtering blebs after XEN45 surgery

OBJECTIVE

To qualitatively analyse the evolution of filtering blebs after XEN surgery, by using anterior segment optical coherence tomography (AS-OCT).

METHODS

A prospective study was performed on filtering blebs of 30 eyes with cataracts and glaucoma, surgically operated on using phacoemulsification and XEN45 implantation (PHACO-XEN). AS-OCT was used to analyse bleb morphology and reflectivity at 3, 6, and 12 months after surgery. Functionality was studied considering an intraocular pressure (IOP)≤18mmHg without antihypertensive medication.

RESULTS

The IOP enabled the blebs to be classified into non-functional: flat (6.67%) and encapsulated (3.33%); and functional (90%), which were then divide by their morphology into cystic (5/27), diffuse (2/27), and layered (20/27). Cystic types had a mean IOP of 12.8, 12.6, and 14.0mmHg at 3, 6 and 12 months, respectively. In the diffuse type, the mean IOP was 13.0, 11.5 and 13.0mmHg at 3, 6 and 12 months, respectively. In the layers pattern the mean IOP was 14.45, 14.55 and 14.8mmHg at 3, 6 and 12 months respectively. The percentage of blebs with high reflectivity was 48.15%, 62.96%, and 77.78%, at 3, 6 and 12 months, with a mean IOP of 14.23, 14.59, and 15.14mmHg in each time period, respectively.

CONCLUSION

AS-OCT could be a good predictor of bleb functionality in PHACO-XEN surgery. Those with a cystic pattern or low reflectivity seem to have better post-operative success. Nevertheless, more long-term studies are required.

Combined phacoemulsification and XEN45 surgery from a temporal approach and 2 incisions

OBJECTIVE

To assess the safety and effectiveness of phacoemulsification combined with XEN45 implant surgery in patients with cataract and open-angle glaucoma, with 12-month follow-up.

METHODS

A prospective study conducted on 30 eyes requiring phacoemulsification with, at least, 2 medications to control intraocular pressure (IOP). Phacoemulsification combined with XEN45 implant surgery was performed within 15minutes of administering subconjunctival mitomycin C. Surgery was performed through 2 temporal incisions, separated by 90°, using the inferior to enter the XEN45 and to implant it in the superior nasal region. A record was made of the best corrected visual acuity, IOP before and 1 day, 1 month, 3 months, 6 months, 9 months, and 12 months after surgery, the number of antiglaucomatous medications, and complications.

RESULTS

The best corrected visual acuity was 0.37±0.2 and 0.72±0.15 before and 12 months after surgery, respectively. The pre-operative IOP was 21.2±3.4mmHg, with 3.07 drugs, decreasing by 61.65% on the first day, 37.26% at 1 month, 35.05% at 3 months, 31% at 6 months, 30.6% at 9 months, and 29.34% at 12 months. The number of medications decreased by 94.57%. Complications occurred in 3 eyes, 2 of them were excluded because we could not complete the implantation (280° subconjunctival haemorrhage and XEN extrusion when trying to reposition). In a third case, the bleb was encapsulated at 5 months after surgery.

CONCLUSIONS

The phacoemulsification combined with XEN45 implant surgery can effectively reduce IOP and the number of drugs in mild-moderate open-angle glaucoma, as they rehabilitate the VA. The use of only 2 micro-invasive incisions makes it simple, quick and safe, with few complications at 12 months follow-up from surgery.