Aqueous Drainage Device Erosion: A Review of Rates, Risks, Prevention, and Repair

Surgical techniques for Baerveldt glaucoma implant removal

Purpose

To describe two surgical techniques for removing Baerveldt-350 Glaucoma Implants (BGI-350).

Observations and plan

A 91-year-old female with history of bilateral BGI-350s and prior history of tube associated endophthalmitis in the left eye requiring tube removal and resultant phthisis was referred for tube erosion and hypopyon in the right only-seeing eye, and we recommended tube removal. On exam, the left phthisical eye still had a BGI-350 plate attached under the lateral rectus muscle by one anchoring stalk, as it had not been fully removed previously, and the patient recalled severe pain during attempted tube removal in the left eye. We performed concurrent removal of both BGI-350s under general anesthesia. We describe a surgical technique for removing a BGI-350 when the conjunctiva does not need to be spared for future surgery. We also present a second case of BGI-350 removal with a different technique that aims to spare the conjunctiva for future surgery.

Conclusions and importance

BGI-350s can develop complications requiring repositioning, revision, or removal. Improper removal of BGI-350s can lead to patient discomfort and future complications. We highlight two different techniques to remove a BGI-350, depending on whether the conjunctiva is intended to be spared for future surgery or not. With either technique, we advocate for general anesthesia and a posterior scleral traction suture to provide patient comfort and optimal exposure of the surgical field.

Long-term outcomes of Baerveldt glaucoma implant surgery in Japanese patients

This study evaluated the long-term surgical outcomes of Baerveldt glaucoma implant (BGI) surgery in patients with refractory glaucoma (204 eyes/204 patients). Surgical failure was defined by: < 20% reduction in preoperative intraocular pressure (IOP), or criterion A (IOP > 21 mmHg), criterion B (IOP > 17 mmHg), or criterion C (IOP > 14 mmHg). Reoperation, loss of light perception vision, or hypotony also denoted failure. The probability of success at 5 years postoperatively using criteria A, B, and C was 72.4%, 49.7%, and 24.4%, respectively. The mean IOP decreased significantly from 32.7 ± 9.7 mmHg preoperatively to 13.1 ± 3.9 mmHg at 5 years; the mean number of glaucoma medications also decreased from 3.7 ± 1.2 to 1.8 ± 1.9 (both P < 0.01). The number of previous intraocular surgeries was significantly associated with failure in the multivariable analysis for criterion B (hazard ratio 1.30; P < 0.01) and criterion C (hazard ratio 1.19; P = 0.031). Early and late postoperative complications occurred in 82 (40.2%) and 28 (13.7%) eyes, respectively. Postoperative interventions were performed in 44 eyes (21.6%). BGI surgery resulted in significant long-term decreases in IOP and the number of glaucoma medications. BGI surgery is effective for refractory glaucoma. However, postoperative interventions due to complications are required in numerous cases.

Ahmed Glaucoma Valve Implantation to Reduce Intraocular Pressure: Updated Perspectives

Trabeculectomy and glaucoma drainage device implantation are the most commonly performed glaucoma surgeries worldwide. Although trabeculectomy is the gold standard, at the present time there is an increase in the use of glaucoma drainage devices. The Ahmed glaucoma valve is one of the most widely used glaucoma drainage devices worldwide. Corneal endothelial cell loss and eventually corneal decompensation is one of the serious complication of glaucoma drainage device implantation. To avoid this, drainage tube can be inserted into the ciliary sulcus instead of the anterior chamber, especially in eyes with high risk for corneal decompensation. Tube/plate exposure, hypertensive phase, endophthalmitis, cataract formation, diplopia and ocular hypotony are the other potential complications that can develop after Ahmed glaucoma valve implantation.

Glaucoma Surgical Outcomes in Patients with a History of Scleritis

PURPOSE

To assess the outcomes of glaucoma surgery in patients with a history of scleritis at a tertiary medical center.

METHODS

The retrospective case series included patients with a history of scleritis who required glaucoma surgery between 4/2006 and 8/2021.

RESULTS

Two hundred and eighty-one eyes of 259 patients had glaucoma and scleritis with 28 eyes (10%) of 25 patients requiring glaucoma surgery. Post-operatively, one eye (4%) had infectious scleritis. Eleven (39%) surgeries failed: 5 tube shunts, 5 cyclophotocoagulation, and 1 gonioscopy-assisted transluminal trabeculotomy. Five (18%) eyes required tube revisions due to tube exposures without infection (3), iris blocking the tube (1), or to shorten tube length (1).

CONCLUSIONS

Patients with a history of scleritis have a low risk of scleritis recurrence or scleral perforation after glaucoma surgery but should be counseled appropriately on the higher risk of reoperation.

Corynebacterium ocular infection after Baerveldt glaucoma implant surgery: treatment involving immediate tube withdrawal and temporary subconjunctival tube placement: a case report

Background

We report a case of Corynebacterium endophthalmitis secondary to tube exposure following Baerveldt glaucoma implant surgery that was successfully treated with prompt tube withdrawal and temporary subconjunctival tube placement without removing the glaucoma drainage device.

Case presentation

A 65-year-old Japanese man with secondary glaucoma underwent glaucoma drainage device surgery with a donor scleral patch graft in the inferonasal quadrant of his right eye. Ten months after surgery, he presented with tube exposure due to dehiscence of the overlying conjunctiva and erosion of the scleral patch graft. Eleven days later, mild inflammation was found in the anterior chamber and anterior vitreous body, with the root of the tube surrounded by a plaque at the site of insertion in the anterior chamber. He was diagnosed with infectious endophthalmitis secondary to tube exposure. Two days later, since medical therapy was ineffective, the tube was withdrawn from the anterior chamber and irrigated with a polyvinyl alcohol-iodine solution, and the tube was tucked into the subconjunctival space. Complete resolution of the infection was achieved 1.5 months later. The tube was reinserted nasally into the anterior chamber and covered with a scleral patch graft and a free limbal conjunctival autograft. Thereafter, there has been no recurrence of infection or tube exposure. Twenty eight months after tube reinsertion, his right best-corrected visual acuity was 20/50 and intraocular pressure was 12 mmHg.

Conclusion

Prompt tube withdrawal and temporary subconjunctival tube placement followed by tube reinsertion may be effective for endophthalmitis associated with tube exposure after glaucoma drainage device surgery.

Assessing patient cosmetic satisfaction after glaucoma drainage device surgery for different patch grafts

BACKGROUND

The use of a tissue patch graft is common practice with a glaucoma drainage device (GDD). Patch grafts can be visible in the palpebral fissure and may be cosmetically displeasing for some patients. The aim of this study was to report the cosmetic satisfaction of pericardial, scleral, and corneal patch grafts related to superior GDD surgery.

METHODS

Baseline clinical data were collected for consecutive patients with glaucoma operated between 2014 and 2019 at two tertiary eye care institutions (for superiorly-placed) Ahmad glaucoma valve implant using sclera, cornea and pericardium patch graft. A patient questionnaire that contained 4 concise questions, with a Likert-scale grading relating to cosmetic satisfaction was administered by a telephone-based interview. Responses and scores for each question were compared across patients who received the three different types of graft. A binominal logistic regression analysis was used to assess the effects of age, gender, type of graft, number of previous ocular surgeries, and final visual acuity to explain differences.

RESULTS

We included 92 patients who met our inclusion criteria (24 patients received a corneal patch graft, 30 who received sclera and 38 who received pericardium). The mean (±SD) age was 50 (±17.5) years, and the average follow up was 20.7 (± 18.6) months. Regardless of the type of patch graft, most (67-84%) of patients were satisfied with the appearance of their eyes. Patients who received cornea or sclera were more likely to report that their eye looked 'abnormal' by others. Younger age was significantly associated with the response to this question.

CONCLUSION

Patients are generally satisfied with the appearance of their eye following GDD surgery with each of the patch grafts for superiorly-placed GDDs. Younger patients with cornea or sclera were more likely to report that their eyes looked abnormal.

Repair of Tube Erosion by Modifying the Tube Extender

Supplemental Digital Content is available in the text.

We describe here a case report of a novel technique for tube erosion repair, which modifies and utilizes the commercially available tube extender (Model TE). The modification of the tube extender makes the commercially available tube extender more compact and is useful in cases where conjunctival mobility and space are limited. This debulking of the tube extender may reduce the risk of future tube exposure and dellen formation.

New developments in tube shunt surgery

PURPOSE OF REVIEW

This article reviews recent studies related to tube shunt surgery.

RECENT FINDINGS

Medical claims data and surveys of glaucoma surgeons demonstrate that tube shunts are being selected with increasing frequency as an alternative to trabeculectomy. A 5-year pooled analysis of the Ahmed Baerveldt comparison study and Ahmed versus Baerveldt study found a higher rate of surgical success with the Baerveldt glaucoma implant compared with the Ahmed glaucoma valve, but Baerveldt implantation carried a higher risk of hypotony. The primary tube versus trabeculectomy study showed trabeculectomy with mitomycin C produced greater intraocular pressure reduction with fewer glaucoma medications compared with tube shunt surgery as a primary procedure at 1 year, but trabeculectomy had a higher rate of postoperative complications. Adjunctive use of antifibrotic agents may enhance the success of tube shunt surgery. Implantation of a second tube shunt is effective in lowering intraocular pressure following primary tube shunt failure, but good results have also been reported with cyclophotocoagulation. Endothelial cell loss, diplopia, and tube shunt erosion are complications associated with these devices.

SUMMARY

The popularity of tube shunts has grown in recent years. Clinical trials and retrospective studies have provided valuable information to guide surgeons in the use of tube shunts. Increased efficacy of glaucoma procedures generally occurs at the cost of a higher risk of surgical complications.

Autologous Partial-thickness Scleral Flap and Donor Corneal Graft in Management of Tube Erosion of Glaucoma Drainage Device

PURPOSE

To evaluate the outcomes of autologous limbus-hinged partial-thickness scleral flap and half-moon-shaped split-thickness donor corneal allograft in management of tube erosion of glaucoma drainage device.

METHODS

Consecutive patients who had undergone a limbus-hinged partial-thickness scleral flap and half-moon-shaped split-thickness corneal graft were reviewed. Primary outcome was surgical success of coverage of the exposed tube without complications or additional surgeries. Secondary outcomes were visual acuity (VA), intraocular pressure, number of glaucoma medications, surgical complications, and additional surgeries.

RESULTS

From March 1, 2016 to August 30, 2017 (18 mo), 8 consecutive cases (7 patients) of tube erosions were included for analysis. Mean follow-up and age were 16.6±5.4 months and 74.4±15.2 years, respectively. Mean number of intraocular surgeries was 4.8±1.6 (range: 3 to 6 surgeries) and intraocular glaucoma surgeries was 2.9±1.7 (range: 1 to 6 surgeries) before tube erosion. There were no intraoperative or postoperative complications or recurrence of tube erosion in any patient. Differences between the preoperative and postoperative number of medications (2.6±1.8, 2.9±1.8, respectively; P=0.171) and intraocular pressure (12.9±6.9, 10.8±3.5 mm Hg, respectively; P=0.209) were not statistically significant. Preoperative and 3-month postoperative VA were identical in all eyes except in 1 eye that the VA improved from 20/300 to 20/70 after repair.

CONCLUSIONS

Combination of limbus-hinged partial-thickness scleral flap and half-moon-shaped split-thickness corneal allograft is a viable surgical option to repair tube erosion.