Infective Necrotizing Scleritis After XEN Gel Stent With Mitomycin-C

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.

Complications of XEN gel stent implantation for the treatment of glaucoma: a systematic review

Aim

This study was aimed to summarize the complications and their management associated with XEN gel stent implantation.

Methods

A systematic review of literature was conducted using Medline (via PubMed), EMBASE, the Cochrane Library databases, and China National Knowledge Infrastructure, from their inception to February 1, 2024.

Results

A total of 48 studies published between 2017 and 2024 were identified and included in the systematic review, including 16 original studies (retrospective or prospective clinical studies), 28 case reports, and 4 case series, which followed patients for up to 5 years. Early postoperative complications of XEN gel stent implantation include hypotony maculopathy (1.9-4.6%), occlusion (3.9-8.8%), suprachoroidal hemorrhage (SCH), choroidal detachment (0-15%), conjunctival erosion, and exposure of the XEN gel stent (1.1-2.3%), wound and bleb leaks (2.1%) and malignant glaucoma (MG) (2.2%). Mid-postoperative complications of XEN gel stent implantation included migration of XEN (1.5%), ptosis (1.2%), endophthalmitis (0.4-3%), macular edema (1.5-4.3%), hypertrophic bleb (8.8%) and subconjunctival XEN gel stent fragmentation (reported in 2 cases). Late postoperative complications reported in cases included spontaneous dislocation and intraocular degradation.

Conclusion

XEN gel stent implantation is a minimally invasive glaucoma surgery (MIGS) procedure for glaucoma, known for its potential to minimize tissue damage and reduce surgical duration. However, it is crucial to note that despite these advantages, there remains a risk of severe complications, including endophthalmitis, SCH, and MG. Therefore, postoperative follow-up and early recognition of severe complications are essential for surgical management.

Computer-aided drug repurposing to tackle antibiotic resistance based on topological data analysis

The progressive emergence of antimicrobial resistance has become a global health problem in need of rapid solution. Research into new antimicrobial drugs is imperative. Drug repositioning, together with computational mathematical prediction models, could be a fast and efficient method of searching for new antibiotics. The aim of this study was to identify compounds with potential antimicrobial capacity against Escherichia coli from US Food and Drug Administration-approved drugs, and the similarity between known drug targets and E. coli proteins using a topological structure-activity data analysis model. This model has been shown to identify molecules with known antibiotic capacity, such as carbapenems and cephalosporins, as well as new molecules that could act as antimicrobials. Topological similarities were also found between E. coli proteins and proteins from different bacterial species such as Mycobacterium tuberculosis, Pseudomonas aeruginosa and Salmonella Typhimurium, which could imply that the selected molecules have a broader spectrum than expected. These molecules include antitumor drugs, antihistamines, lipid-lowering agents, hypoglycemic agents, antidepressants, nucleotides, and nucleosides, among others. The results presented in this study prove the ability of computational mathematical prediction models to predict molecules with potential antimicrobial capacity and/or possible new pharmacological targets of interest in the design of new antibiotics and in the better understanding of antimicrobial resistance.

A case of mitomycin C toxicity after XEN gel stent implantation with the XEN air technique in a glaucoma patient

BACKGROUND

To discuss the first case of mitomycin C (MMC) toxicity after XEN® gel stent implantation in a glaucoma patient, conducted using the XEN "air" technique with an ophthalmic viscosurgical device (OVD).

CASE PRESENTATION

A 44-year-old Asian male presented with increased intraocular pressure (IOP; 52 mmHg) accompanied by keratic precipitates and an edematous cornea. He was diagnosed with uveitic glaucoma in the left eye, and the IOP was controlled with a topical anti-glaucoma agent. However, glaucoma progression was revealed by Humphrey visual field (HVF) and optical coherence tomography (OCT) examinations. The patient underwent uneventful XEN gel stent implantation using the XEN air technique and an MMC (0.02%, 0.1 mL) injection, with subconjunctival air and OVD injection provided prior to XEN implantation in the left eye. The patient exhibited a decreased IOP (11 mmHg), elevated bleb, and extensive subconjunctival hemorrhage on postoperative day 1. On postoperative day 18, diffuse conjunctival injection and a large avascular bleb was noticed around the XEN gel stent. The patient complained of severe eye pain and discomfort, suggestive of MMC toxicity, and the IOP was 12 mmHg. The patient was treated with a topical steroid and antibiotics tapered over a 6-month period. Finally, the toxicity was successfully controlled, with the IOP stabilizing at around 15 mmHg.

CONCLUSIONS

Although significantly greater lowering of the IOP can be expected with the use of subconjunctival OVD injection and MMC during XEN gel stent implantation, a cautious approach and a longer monitoring period are required.

Management of XEN Gel Stent Exposure with Conjunctival Erosion via Rotational Conjunctival Flap and Amniotic Membrane Transplantation—A Case Report

Background: Despite its proven effectiveness and safety profile, the XEN gel stent (Allergan Inc., CA, USA) for minimally invasive glaucoma surgery (MIGS) has a probability of postoperative complications, including postoperative hypotony, hyphema, stent migration, stent obstruction, bleb fibrosis, and fibrin formation. In particular, the use of adjunctive Mitomycin-C (MMC) might be associated with bleb-related complications, including conjunctival erosion, XEN gel stent exposure, and blebitis. However, there are few studies on XEN gel stent exposure and its management. We describe a case of XEN gel stent exposure with conjunctival erosion 18 months postoperatively, which resolved effectively after combination treatment with a rotational conjunctival flap and amniotic membrane transplantation. Case presentation: A 74-year-old Korean male patient with diabetes and hypertension underwent uncomplicated ab interno XEN gel stent implantation with a subconjunctival injection of 0.1 cc of 0.02% MMC and presented with low intraocular pressure (IOP) with a well-functioning filtering bleb. Periocular pain and tearing developed 18 months after the initial operation, with mild deterioration of visual acuity to 20/100. Despite conservative medical treatment, the conjunctival erosion was not relieved. Anterior segment optical coherence tomography (AS-OCT) revealed an exposed XEN gel stent with conjunctival erosion. We performed bleb revision surgery using a rotational conjunctival flap and amniotic membrane transplantation. Slit-lamp examination and AS-OCT showed a well-formed moderate bleb without leakage, and IOP continued to be well controlled (14 mm Hg with latanoprost) until six months after bleb revision. Conclusions: This case report highlights the importance of careful examination, including slit-lamp examination, the Seidel test, and AS-OCT, to identify accurate anatomical positioning and to monitor ocular surface changes after XEN gel stent implantation with MMC or 5-FU. Combination treatment (rotational conjunctival flap and amniotic membrane transplantation) may be relatively safe for persistent XEN gel stent exposure.