Intra-Ocular Pressure Response to Dexamethasone Implant Injections in Patients with a History of Filtering Surgery: The TRABEX Study

Abstract

Patients with both macular edemas, of various etiologies such as diabetes and glaucoma, may suffer serious loss of vision if either disease goes untreated. Where no effective alternative therapies are available, dexamethasone implant (DEX-I) injections may be the only choice of treatment, despite the risk of a possible increase in intraocular pressure (IOP) when using steroids. Although many studies have reported on IOP evolution in eyes treated with DEX-I, little is known specifically about eyes with a history of filtering surgery. The aim of this observational series was to evaluate the IOP response following DEX-I injection in eyes presenting conventional filtering surgeries or microinvasive glaucoma surgeries (MIGS). Twenty-five eyes were included in this study. A total of 64% of the eyes did not experience OHT during follow-up. Additional IOP-lowering therapy was needed for 32% of eyes, and 20% of eyes (all showing bleb fibrosis) required further filtering surgery: 50% of eyes in the MIGS group and 10.5% of eyes in the conventional filtering surgery group. A significant positive correlation was found between IOP at baseline and the maximum IOP throughout follow-ups after DEX-I (r = 0.45, p = 0.02). In conclusion, if DEX-I is used when there are no alternative therapies for treating macular edema, IOP in eyes with a history of filtering surgery is generally manageable. Those eyes which previously underwent conventional therapy with effective blebs obtained better IOP control after DEX-I injections and mostly did not require any additional IOP-lowering therapy or surgery.

Refractory intraocular hypertension after dexamethasone-implant intravitreal injection treated with Preserflo MicroShunt implantation

“…Preserflo ® MicroShunt is a 8.5 mm long tube, made of flexible polymer, that drains aqueous humour into the subconjunctival space [6] . Our team previously reported cases of DEX-I induced OHT managed with XEN45 implantation [7][8] . A 78-year-old man with a history of bilateral open angle glaucoma was previously treated with IOP-lowering eyedrops.…”

Current Treatments and Innovations in Diabetic Retinopathy and Diabetic Macular Edema

“…Concerns of adverse effects such as ocular hypertension and the necessity of filtration surgery for secondary glaucoma may be a bias toward the preference for anti-VEGF treatment, but in a randomized clinical trial the need for glaucoma filtering surgery was 0.3% and no patient needed removal of implants for IOP control [ 71 ]. The safety profile has been widely studied in the literature [ 72 , 73 ]. There are clinical trials that have shown some benefits of intravitreal steroids in the progression of DR [ 74 ].…”