L’implant XEN® pour la prise en charge du glaucome chronique à angle ouvert : une revue de la littérature

Navigating hypotony challenges with XEN gel implantation

INTRODUCTION

The XEN Gel, a hydrophilic tube meticulously crafted to adhere to the principles of the Hagen - Poiseuille law, is designed to facilitate efficient aqueous shunting without inducing hypotony. Implantable ab interno or ab externo, with or without conjunctival opening, the device shows no significant outcome differences. Despite numerical hypotony signaling failure, patients may fare well below 6 mmHg.

AREAS COVERED

This review provides insights into device variability, challenges related to hypotony, associated risk factors, and hypotony management.

EXPERT OPINION

The progressive evolution of the XEN Gel constitutes a significant advancement in the field of glaucoma management. Comparative studies investigating diverse implantation methodologies, particularly the ab interno and closed conjunctival approaches, highlight the device versatility in addressing individual patient needs. Exploring hypotony from both statistical and clinical perspectives challenges the traditional view of intraocular pressure as a straightforward success or failure indicator. The incidence of hypotony-related issues varies between device models, emphasizes the need for an individualized approach during device selection. Overall, understanding the dynamics of hypotony is crucial for optimizing the outcomes of XEN Gel implantation.

Preliminary results of Preserflo Microshunt versus Preserflo Microshunt and Ologen implantation

PURPOSE

To report preliminary 6-month results on the use of the Preserflo Microshunt implant with and without Ologen in 50 pseudophakic eyes with moderate to advanced primary open-angle glaucoma (POAG).

METHODS

Fifty pseudophakic eyes underwent ab externo Preserflo Microshunt implantation. Data was gathered retrospectively and two groups were then created, group A with application of MMC 0.2 mg/ml and group B with MMC 0.2 mg/ml and Ologen collagen matrix (OCM) implantation. Absolute success was regarded as the percentage of eyes achieving: a) 5 ≤ intraocular pressure (IOP) ≤ 13 mmHg, b) 5 ≤ IOP ≤ 16 mmHg, and c) 5 ≤ IOP ≤ 21 mmHg without additional medication or surgery and qualified success was regarded as the percentage of eyes achieving a) IOP ≤ 13 mmHg, b) IOP ≤ 16 mmHg, and c) IOP ≤ 21 mmHg with or without medication. Evaluation was performed using a log-rank Kaplan-Meier test. A scatterplot analysis presented the treatment effect data of all eyes with a minimum of 20% IOP reduction per case. Failure was defined as requiring additional surgery, IOP greater than 21 mmHg with or without medication and failure to reach 20% IOP reduction.

RESULTS

Mean postoperative IOP was significantly lower in both groups. IOP decreased by 49.06% in group A and by 53.01% in group B at 6 months (P < 0.88), respectively. Medication use was lower in both groups (Wilcoxon test, P < 0.001). The absolute and qualified success rates were not statistically significant between the groups (all P > 0.05). Cumulative IOP results per case were not statistically different in group A compared with group B. One revision surgery in group A (4% failure rate) and three in group B (12% failure rate) were performed.

CONCLUSIONS

Both groups showed equal results in terms of cumulative and mean IOP reduction, medication reduction as well as in absolute and qualified success rates. No significant difference was found in any parameters tested between Preserflo Microshunt with MMC 0.2 mg/ml and with or without OCM implantation at 6 months. Long-term follow-up is required to further evaluate this data.

[Micropulsed diode laser transscleral cyclophotocoagulation: An effective technique whose role remains to be defined]

Micropulse Transscleral Cyclophotocoagulation (MP-TSCP) is a recently developed cyclodestructive procedure less aggressive than conventional TSCP. In this study, we aimed to evaluate the safety and efficacy of MP-TSCP in a real-life setting.

MATERIAL AND METHODS

We retrospectively included all MP-TSCP cases performed in the Bicêtre Hospital Ophthalmology department between January 2017 and September 2019. Intraocular pressure (IOP) and hypotensive medications were recorded preoperatively, at month 1, 3, 6 and at the conclusion of follow-up, as well as postoperative adverse events. Success was defined as an IOP between 6 and 21mmHg with a decrease of at least one medication or an IOP reduction>20%.

RESULTS

Thirty eyes (28 patients) were included. Preoperative IOP was 27.2±10.6mmHg, with 3.5±0.6 hypotensive medications, the mean deviation on the Humphrey 24-2 visual field was -21.9±6.9dB, and 43% of eyes had a past history of filtering surgery. The mean follow-up was 13.5±8.1 months. Eleven patients (37%) had to be retreated with MP-TSCP during follow-up. At 3 and 6 months and at the conclusion of follow-up, the IOP was 18.3±7.3mmHg (-33%; P<0.0001), 22.5±11.8mmHg, (-17%; P=0.052), 22.7±12.0mmHg (-16,5%; P<0.050), respectively. The success rates were 57%, 50% et 53% at 3 months, 6 months and at the conclusion of follow-up, respectively. Severe adverse events included 3 cases of corneal ulcers and 2 cases of severe but transient ocular hypotony without visual impairment.

CONCLUSION

MP-TSCP is an effective procedure for severe and/or refractory glaucoma, but retreatments are required in more than one-third of cases. Further studies are warranted to define factors predictive of success and indications for retreatment.