Glaucoma drainage devices in children: an updated review.

Implantation of glaucoma drainage devices is a valuable therapeutic option, particularly in children with glaucoma refractory to primary surgical treatment. Glaucoma drainage devices are typically used when conjunctival scarring hampers filtration surgery or prior angle procedures are not effective in controlling intraocular pressure. Despite known complications, the use of glaucoma drainage devices in children has increased in recent years, even as the primary surgical option. In this review, we evaluate the results of recent studies involving the implantation of glaucoma drainage devices in children, discussing new advances, and comparing the success rates and complications of different devices.

A comparative study of cystoid macula edema following glaucoma drainage device surgery versus trabeculectomy.

PURPOSE: To assess and compare the risk for development of cystoid macula edema (CME) after glaucoma drainage device (GDD) implantation versus conventional trabeculectomy with mitomycin (trab) for glaucoma. METHODS: Retrospective review of consecutive patients receiving trab or GDD implantation between 2016 and 2018. Inclusion criteria were availability of pre- and postoperative spectral domain optical coherence tomography (SD-OCT) of the macula. SD-OCT images were evaluated for presence of CME qualitatively, central subfield thickness (CST) and macular volume (MV). RESULTS: 73 eyes could be included, 42 received trab and 31 GDD surgery. Eyes receiving trab on average had 0.8 ± 0.8 previous intraocular operations, while eyes with GDD implantation had 3.1 ± 1.9 (p < 0.001). Occurrence of postoperative CME was significantly more frequent after GDD implantation (6 out of 31 (19.4%)) than after trab (2 out of 42 eyes = 4.8%), (p = 0.049). Mean preoperative CST as well as MV was comparable in both groups (CST before trab: 282.7 ± 23.0 µm, CST before GDD 284.2 ± 27.3 µm, p = 0.287; MV before trab: 7.8 ± 1.1 mm3, MV before GDD: 8.0 ± 0.8mm3, p = 0.305). Mean postoperative CST and MV were significantly higher after GDD (CST 338.5 ± 129.3 µm, MV 8.8 ± 2.6 mm3) than after trabeculectomy (CST 290.6 ± 60.2 µm, p = 0.038; MV 7.8 ± 1.2mm3, p = 0.039). CONCLUSIONS: In real-life conditions, GDD surgery seems to be associated with a higher risk to develop CME when compared to conventional trabeculectomy. This information may be helpful for glaucoma surgeons to advise the patients on postoperative risks of surgery.

Bilateral total iris atrophy, corneal decompensation and glaucoma following bilateral cosmetic artificial iris implantation: A case report of severe sequela and successful management.

PURPOSE: Cosmetic iris implants have a record of high ocular complications and are no longer in use. These complications include glaucoma, corneal decompensation, iris atrophy, uveitis, cataract and retinal detachment. CASE PRESENTATION: We report a case of a 44-year-old lady presented with bilateral total iris atrophy, glaucoma and corneal decompensation after cosmetic artificial iris implantation. The patient underwent bilateral artificial iris removal, glaucoma drainage device for the right eye, and micropulse laser for the left eye. In addition, she underwent phacoemulsification with iris-diaphragm intraocular lens implant for the right. The cornea of the right eye ended up with successful Boston keratoprosthesis after rejection of previous 2 grafts. CONCLUSIONS: To the best of our knowledge, we describe the first report of bilateral total iris atrophy following a cosmetic iris implant accompanied by bilateral glaucoma and corneal decompensation.

Evaluation of early ocular discomfort after glaucoma surgery: trabeculectomy versus Ahmed glaucoma valve implantation.

PURPOSE: This study aims to compare the initial ocular discomfort symptoms resulting from trabeculectomy and Ahmed glaucoma valve implantation surgeries. METHODS: A prospective comparative study was conducted. The evaluation of ocular discomfort employed a questionnaire designed to identify the frequency and severity of distinct symptoms: ocular pain, general discomfort, tearing, foreign body sensation, and burning. This questionnaire was administered prior to surgery as a baseline, and subsequently at 7, 30, and 90 days post-surgery. Simultaneously, the Ocular Surface Disease Index (OSDI) was applied at these same time intervals. RESULTS: The study encompassed a total of 17 patients (9 undergoing trabeculectomy and 8 undergoing Ahmed glaucoma valve implantation). The Ahmed glaucoma valve implantation group exhibited higher tearing levels at baseline (p=0.038). However, no statistically significant differences in symptoms were observed between the two surgeries at 7 and 30 days post-surgery. At the 90-day mark following surgery, patients who had undergone trabeculectomy reported a significantly higher foreign body sensation (p=0.004). Although OSDI scores did not differ between groups at baseline, the trabeculectomy group showed significantly higher OSDI scores than the Ahmed glaucoma valve implantation group at 7, 30, and 90 days after surgery (p<0.05). CONCLUSION: Post-surgery, patients who had undergone trabeculectomy experienced increased foreign body sensation. Trabeculectomy appears to cause greater early postoperative ocular discomfort compared to the Ahmed glaucoma valve implantation group.

Complications after CyPass® Micro-Stent explantation: a case series.

PURPOSE: To describe the in toto explantation of the CyPass® Micro-Stent and its conceivable complications. METHODS: This is a case series of eighteen eyes from fourteen patients who underwent CyPass® Micro-Stent implantation due to mild to moderate glaucoma and who subsequently suffered from loss of endothelial cell density. Consequently, the CyPass® Micro-Stent was in toto explanted. The surgical procedure and its complications are described and compared with trimming of the CyPass® Micro-Stent. RESULTS: A postoperative hyphema was developed in 8 of the 18 eyes. In four of them the hyphema was self-limiting, while in two patients an anterior chamber irrigation was necessary. One patient suffered from a severe intracameral bleeding and iridodialysis during explantation, so that the base of the iris had to be scleral fixated. The remaining explantations were without complications. CONCLUSION: Dealing with implanted CyPass® Micro-Stents poses a challenge for ophthalmic surgeons. An in toto removal can be traumatic, since the CyPass stent often is fibrotic encapsulated and fused with the surrounding tissue. Alternatively, trimming of the CyPass is also a viable option to avoid further endothelial damage. Reported complications of CyPass trimming are consistent with those that can occur after explantation. Further data on the development of the endothelial cells after trimming or explantation are not yet available. Therefore, it remains open whether trimming of the CyPass, in contrast to complete removal, carries the risk of further endothelial cell loss.

In vivo evaluation of a nanotechnology-based microshunt for filtering glaucoma surgery.

To carry out the preclinical and histological evaluation of a novel nanotechnology-based microshunt for drainage glaucoma surgery. Twelve New Zealand White rabbits were implanted with a novel microshunt and followed up for 6 weeks. The new material composite consists of the silicone polydimethylsiloxane (PDMS) and tetrapodal Zinc Oxide (ZnO-T) nano-/microparticles. The microshunts were inserted ab externo to connect the subconjunctival space with the anterior chamber. Animals were euthanized after 2 and 6 weeks for histological evaluation. Ocular health and implant position were assessed at postoperative days 1, 3, 7 and twice a week thereafter by slit lamp biomicroscopy. Intraocular pressure (IOP) was measured using rebound tonometry. A good tolerability was observed in both short- and medium-term follow-up. Intraocular pressure was reduced following surgery but increased to preoperative levels after 2 weeks. No clinical or histological signs of inflammatory or toxic reactions were seen; the fibrotic encapsulation was barely noticeable after two weeks and very mild after six weeks. The new material composite PDMS/ZnO-T is well tolerated and the associated foreign body fibrotic reaction quite mild. The new microshunt reduces the IOP for 2 weeks. Further research will elucidate a tube-like shape to improve and prolong outflow performance and longer follow-up to exclude medium-term adverse effects.

A computational fluid dynamics investigation of endothelial cell damage from glaucoma drainage devices.

Glaucoma drainage devices (GDDs) are prosthetic-treatment devices for treating primary open-angle glaucoma. Despite their effectiveness in reducing intraocular pressures (IOP), endothelial cell damage (ECD) is a commonly known side-effect. There have been different hypotheses regarding the reasons for ECD with one being an induced increase in shear on the corneal wall. A computational fluid dynamics (CFD) model was used to investigate this hypothesis in silico. The Ahmed Glaucoma Valve (AGV) was selected as the subject of this study using an idealised 3D model of the anterior chamber with insertion angles and positions that are commonly used in clinical practice. It was found that a tube-cornea distance of 1.27 mm or greater does not result in a wall shear stress (WSS) above the limit where ECD could occur. Similarly, a tube-cornea angle of 45° or more was shown to be preferable. It was also found that the ECD region has an irregular shape, and the aqueous humour flow fluctuates at certain insertion angles and positions. This study shows that pathological amounts of WSS may occur as a result of certain GDD placements. Hence, it is imperative to consider the associated fluid force interactions when performing the GDD insertion procedure.

Inferior implant of XEN63 Gel stent in a refractory open-angle glaucoma due to silicone oil tamponade: A case report.

BACKGROUND: To discuss the efficacy of an inferior implant of XEN 63 gel stent in a patient with refractory glaucoma after trabeculectomy failure and vitreoretinal surgery with silicone oil tamponade. CASE DESCRIPTION: We report the case of a 73-year-old man with a history of refractory open glaucoma with trabeculectomy failure. He experienced recurrent retinal detachments with silicone oil tamponade, with uncontrolled intra-ocular pressure (IOP) after silicone oil removal. Due to the presence of oil emulsion in the anterior chamber, the chosen location for XEN 63 implantation was the infero-temporal quadrant. Mild hyphema and vitreous hemorrhage were seen post-operatively, but were self-limiting. At week 1, the intraocular pressure was 8 mmHg with a well-formed bleb seen in anterior segment optical coherence tomography (AS-OCT). At 6 month follow up, the patient maintained a IOP of 12 mmHg without topical hypotensive drugs. Slit lamp examination revealed a widespread, developed bleb with no signs of inflammation. CONCLUSION: In this case of refractory glaucoma in a vitrectomized eye with previous oil tamponade, the inferior placement of the XEN 63 gel stent delivered an adequate intraocular pressure even at 6-months follow up, with a diffuse functional infero-nasal bleb seen with AS-OCT.

Effect of Early Aqueous Suppression After Valved Tube Shunt Surgery for Uveitic Glaucoma.

PURPOSE: To compare outcomes of early aqueous suppression (EAS) and standard therapy (ST) after Ahmed Glaucoma Valve (AGV) implantation for uveitic glaucoma. DESIGN: Retrospective comparative cohort study. PARTICIPANTS: All patients with uveitic glaucoma underwent AGV implantation from January 2010 to October 2020 at Northwestern Medicine. METHODS: Excluding the first postoperative day 1 (POD1), only eyes with IOP 10-15 mmHg at their first visit with IOP ≥ 10 mmHg were included in the main analysis. Early aqueous suppression (EAS) was defined as initiation of ocular hypotensive therapy when IOP was first 10-15 mmHg. Standard therapy was initiation of therapy at any later time. Failure was defined as IOP > 21 mmHg, < 5 mmHg, or < 20% reduction in IOP from baseline after 3 months, for 2 consecutive study visits. Hypotony was defined as IOP ≤ 5 mmHg for ≥ 2 visits. Hypertensive phase was defined as IOP > 21 mmHg for 2 consecutive visits in the first 3 months. MAIN OUTCOME MEASURES: Proportion achieving overall success; incidence of hypotony and hypertensive phase. RESULTS: Twenty-eight eyes of 26 patients were in the EAS group and 20 eyes of 19 patients were in the ST group, with a mean follow-up of 17.7 and 28.2 months, respectively. Baseline IOP was similar in the EAS (31.2 ± 10.1 mmHg) and ST (34.6 ± 12.2 mmHg) groups; P = 0.18. Final IOP was lower in the EAS group (12.9 ± 4.6 mmHg) than the ST group (16.4 ± 5.7 mmHg; P = 0.02) on 2.6 ± 0.9 medications in the EAS group and 1.8 ± 1.5 in the ST group (P = 0.07). Overall success was achieved in 87% of EAS eyes and 74% of ST eyes (P = 0.43). There were no statistically significant differences in the occurrence of additional glaucoma surgery (4% for EAS, 20% for ST; P = 0.11), hypotony (7% for EAS, 0% for ST; P = 0.50), or hypertensive phase (4% for EAS, 21% for ST; P = 0.09). CONCLUSIONS: EAS was associated with a lower final IOP after AGV in uveitic glaucoma eyes; however, more medications were in use at the final visit. No statistically significant differences in overall success or the incidence of adverse events were observed. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Efficacy and Safety of an Adjustable Glaucoma Drainage Device (eyeWatch System) for Refractory Glaucoma: A 2-Year Prospective Study.

PRCIS: In this study, we report a 2-year follow-up after implantation of an adjustable glaucoma drainage device combined with a novel orbital filtering plate. The IOP was efficiently controlled postoperatively with limited complications and an excellent safety profile. PURPOSE: To report the clinical results at 2 years after implantation of an eyeWatch (eW) system, which comprises an adjustable glaucoma drainage device (eW implant) combined with a novel orbital filtering plate (eyePlate), in refractory glaucoma. PATIENTS AND METHODS: Monocentric, prospective, noncomparative clinical trial. Patients suffering from refractory glaucoma after several failed surgeries were operated using the eW system. The primary outcome was the success rate, defined as an IOP ≤18 mm Hg and reduction of more than 20% from baseline, IOP ≥6 mm Hg. Secondary outcomes were mean IOP, visual acuity, the number of antiglaucoma medications, and the number and type of complications. RESULTS: Forty-two eyes from 42 patients were included. The mean follow-up time was 22.0±4.0 months. The mean baseline IOP decreased from 23.2±7.2 mm Hg before surgery to 11.9±4.4 mm Hg at 12 months ( P <0.001) and 11.5±3.0 at 24 months. The mean number of glaucoma medications decreased from 2.9±0.9 before surgery to 0.7±0.9 at 12 months ( P <0.001) and 1.0±0.9 at 24 months. The qualified success rate was 93% at 12 months and 90% at 24 months whereas the complete success rate was 46% and 40% at 12 and 24 months, respectively. Complications occurred in 7 patients. CONCLUSIONS: Implantation of the eW system effectively lowered IOP and reduced glaucoma medications for a 2-year period in patients who had previously failed glaucoma surgery. Persistent hypotony was not observed and the number of complications was low.

Short- to intermediate-term surgical outcome of Keiki Mehta valve implantation in refractory glaucoma.

BACKGROUND: Keiki Mehta body pressure (BP) valve is a glaucoma drainage device that works on the simple mechanism of body pressure. PURPOSE: To evaluate the short- to intermediate-term efficacy and safety of Keiki Mehta valve implantation in treating refractory glaucoma. METHODS: This was a prospective, interventional, institution-based study. Adult patients (age >18 years) having refractory glaucoma who underwent Keiki Mehta valve implantation from May 2019 to December 2019 in a tertiary hospital in eastern India were followed up to 18 months. RESULTS: Twenty patients (20 eyes) with refractory glaucoma who underwent Keiki Mehta valve implantation were followed up on postoperative day 1 and at 1, 3, 6, 12, and 18 months postoperatively. Visual acuity, intraocular pressure (IOP), antiglaucoma medications, and success rate were measured at every visit. There was significant reduction in mean IOP from the preoperative values at every postoperative follow-up ( P < 0.05). Kaplan-Meier survival analysis demonstrated a probability of 50% complete success and 20% qualified success at 18 months. Hypotony was the most common postoperative complication. CONCLUSION: Keiki Mehta valve implantation is an effective and safe treatment for refractory glaucoma.

The effects of the first versus second glaucoma drainage implant surgery in patients with primary open-angle glaucoma.

BACKGROUND: To investigate the outcome of non-valved glaucoma drainage implant surgery (GDIS) in primary open-angle glaucoma (POAG) patients divided in the first GDI group (patients who underwent the first GDIS) and the second GDI group (patients who underwent the second GDIS because of the failed first GDIS). METHODS: Intraocular pressure (IOP), visual acuity (VA), visual field defect (VFD), medication score (MS), survival rate of GDIS, complications, and patient background was retrospectively analyzed. Two success criteria were set: Criteria (1) IOP reduction ≥ 20% and 5 < IOP ≤ 21, Criteria (2) IOP reduction ≥ 20% and 5 < IOP ≤ 14. RESULTS: There were 136 eyes of 109 patients in the first GDI group and 32 eyes of 27 patients in the second GDI group. In the first GDI group and II, mean preoperative IOP was 26.7 ± 6.7 mmHg and 23.7 ± 3.5 mmHg, respectively (P = 0.09). No statistically significant difference in postoperative IOP reduction was found between the two groups (P = 0.39). At 5-years postoperative, the Criteria 1 (Criteria 2) survival rate in the first GDI group and the second GDI group was 60.4% (31.7%) and 61.2% (25.6%), respectively (Criteria 1: hazard ratio [HR]: 0.64, 95% confidence interval [CI]: 0.30-1.35 [P = 0.24]; Criteria 2: HR: 0.81, 95% CI: 0.46-1.44, P = 0.48). No significant difference in VA, VFD change, MS, or complications was observed. Young patient age was the only significant factor for failure in the first GDI group (odds ratio: 0.95, 95% confidence interval: 0.91-1.00, P = 0.03). CONCLUSION: The second GDIS may be as effective as the first GDIS for IOP reduction in POAG patients, however, there is a high risk of failure in young-age patients and the surgery may be ineffective in eyes requiring Criteria 2.

[Micro-invasive glaucoma surgery]. / Mikroinvazivnaya khirurgiya glaukomy.

Glaucoma is a severe, rapidly progressing disease that in the absence of proper treatment leads to blindness in 20% of patients. According to the World Glaucoma Association, this disease is the most socially significant in modern ophthalmology and requires searching for new and effective methods of treatment. This article presents the results of research and reviews on this issue, considers both conservative therapy and surgical methods of treatment, analyzes in detail modern methods of micro-invasive eye surgery actively used in clinical practice. The article also describes indications for a various types of interventions, as well as the effect achieved by them and the possible complications, and presents the conclusions about the possibility of using these procedures in wide clinical practice.

Spontaneous resolution of long-standing choroidal effusion after glaucoma drainage implant surgery without significant visual deterioration : a case report.

BACKGROUND: Choroidal effusion is a common complication of glaucoma surgery. Although most cases of choroidal effusions resolve spontaneously with observation or medical management alone as intraocular pressure normalizes, surgical drainage might be needed in severe or persistent cases. Herein, we report a case of spontaneous resolution of long-standing severe choroidal effusion after Ahmed glaucoma valve implantation. CASE PRESENTATION: An 85-year-old man with uncontrolled primary open-angle glaucoma and medical history of chronic kidney disease underwent uneventful Ahmed glaucoma valve implantation. On postoperative day 8, transient hypotony occurred, and large 360° peripheral choroidal detachments developed. Although the intraocular pressure increased to normal levels on postoperative day 15, choroidal effusion did not resolve. Fundus examination over 8 months showed that the large choroidal effusion persisted despite a well-controlled intraocular pressure. Laboratory test performed at preoperatively and follow-up period revealed persistently elevated potassium and creatinine levels. On postoperative 9 months, the lesion resolved spontaneously without any surgical intervention. We found that the patient's creatinine level was normalized, pre-existing hyperkalemia was corrected, and accordingly his general condition was improved. CONCLUSIONS: Considering the underlying medical condition may be helpful in patients with persistent choroidal effusion of an unclear etiology following glaucoma filtering surgery.

Outcomes of reimplantation of a new Glaucoma Drainage Device after explantation of an older implant from exposure-related complications.

Purpose: To describe the clinical outcome of a series of seven eyes with an explanation of an original Glaucoma Drainage Device (GDD) arising from the complication of plate exposure and consequent reimplantation of another GDD at a second setting. Methods: This was a retrospective, interventional, and non-comparative study at two tertiary eye care hospitals in eastern and southern India. Electronic medical record data of the seven eyes where a GDD was explanted and a 2nd GDD was reimplanted over October 2010 and May 2021 was analyzed. Statistical analysis was done by SPSS (ver. 26). Results: The first GDD survived for a mean of 168 days only till the plate got exposed and thereby got explanted. Possible predisposing factors noted were conjunctival and scleral thinning, ischemic conjunctiva, etc., The reimplantation surgery was technically easy in the absence of hypotony-opposite to what is reported in the literature. The final IOP (mean +/- SD) values (mm Hg) were 18.9 (+/-7.9), range = 10-30. The mean number of glaucoma medications reduced from 3.9 (+/-1.2; range, 2 to 5) after the explanation to 3.1 (+/-0.7; range, 2 to 4) after the 2nd GDD implantation, in the final follow-up. The second GDD was found to be stable till the last follow-up (mean = 1149 days). No other significant intraoperative or postoperative complications were seen. Conclusions: Reimplantation of a second GDD in a separate setting after explanations of an original implant due to exposure-related complication is both a safe and effective method.

Long scleral tunnel technique for prevention of drainage tube-related complications during Ahmed glaucoma valve implantation.

To evaluate the safety and efficacy of modified Ahmed glaucoma valve (AGV) implantation (long scleral tunnel technique) in the treatment of neovascularization glaucoma (NVG). This retrospective observational case series included 23 patients (23 eyes) diagnosed with NVG secondary to proliferative diabetic retinopathy from January 2020 to June 2021. All 23 cases received anti-vascular endothelial growth factor treatment. Then, after 3 to 7 days, these cases were treated with modified AGV implantation (long scleral tunnel technique) and were followed up for at least 6 months. The best corrected visual acuity, intraocular pressure, numbers of antiglaucoma medications used, and postoperative complications were observed at 1 week and 1, 3, and 6 months after treatment. With treatment, the mean best corrected visual acuity improved significantly (P < .001) from 1.62 ±â€…0.52 logMAR preoperatively to 1.29 ±â€…0.36 logMAR at the 6-month follow-up. The mean postoperative intraocular pressure was significantly lower than that before modified AGV implantation during follow-up period, decreasing from 45.48 ±â€…7.86 mm Hg preoperatively to 14.87 ±â€…1.96 mm Hg at 1 week, 18.39 ±â€…2.25 mm Hg at 1 month, 16.61 ±â€…1.47 mm Hg at 3 months, and 17.48 ±â€…1.38 mm Hg at 6 months (F = 256.646, P < .001). The median number of antiglaucoma medications used by patients also significantly decreased from 3 (3-4) preoperatively to 0 (0-1) at the 6-month follow-up after surgery (Z = -4.248, P < .001). Postoperative complications included hyphema in 2 cases and vitreous hemorrhage in 1 case, and all 3 patients achieved satisfactory recovery with treatment. No drainage tube-related complications occurred among our patients. Long scleral tunnel technique is a safe and effective surgical treatment for NVG with fewer drainage tube-related complications.

Combining Perfluorobutylpentane (F4H5) with Glaucoma Drainage Device Implantation for Silicone Oil-Induced Glaucoma: A Pilot Study.

Objectives: Our aim was to perform a perfluorobutylpentane (F4H5) washout in conjunction with glaucoma drainage device (GDD) placement in patients with silicone oil (SO)-induced glaucoma. In this report we present our preliminary results concerning the effectiveness in clearing the SO and the safety of the procedure. Materials and Methods: Eight patients who previously underwent pars plana vitrectomy with SO tamponade due to retinal detachment were selected. Removal of SO was performed on average 10 months after initial surgery. All patients developed glaucoma with evidence of SO remnants in the anterior chamber (AC) and angle. Removal of the remaining SO with F4H5 washout was performed in all cases with concomitant insertion of a GDD to treat the refractory glaucoma. Intraocular pressure (IOP), SO remnants, endothelial cell count, and need for glaucoma medications were evaluated up to 12 months after the surgical procedure. Results: All patients had uneventful surgery with no major complications 12 months postoperatively. A marked reduction of SO remnants in the AC and angle was observed in all cases after surgery. There was a 60.9% decrease in mean IOP 12 months postoperatively (p<0.05) and the need for glaucoma medication was lower in all patients (mean topical medicines: 4 preoperatively vs. 0.75±0.89 postoperatively; p<0.05). Endothelial cell density showed no significant change (mean 2012±129 cells/mm2 preoperatively vs. 1985±134 cells/mm2 postoperatively; p>0.05), and there were no signs of corneal edema. Conclusion: F4H5 is an effective emulsifier for removing SO remnants and may be safely used in conjunction with GDD placement in order to control IOP in eyes with silicone oil-induced glaucoma.

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.