Optical Coherence Tomography Angiography Characteristics Serve as Retinal Vein Occlusion Therapeutic Biomarkers for Dexamethasone Intravitreal Implant

Abstract

Background. Retinal vein occlusion (RVO) is the second most common vision-threatening retinal vascular disease. Intravitreal dexamethasone implant has been applied to treat macular edema secondary to RVO (RVO-ME). However, the alteration of morphologic features detected with optical coherence tomography angiography (OCTA) has not been fully studied in RVO-ME patients before and after the treatment. Objective. This study is aimed at identifying potential therapeutic targets in RVO with integrative bioinformatic analysis and compares the OCTA characteristics alterations in patients with RVO-ME receiving injection of dexamethasone intravitreal implant. Methods. Bioinformatic analysis was analyzed in GSE101398 dataset from the Gene Expression Omnibus database. Multiple functional enrichment analyses were performed, and protein-protein interaction network was constructed to visualize the key node genes. Eleven eyes with RVO-ME were examined with OCTA before and after intravitreal dexamethasone implant. The OCTA parameters, including macular thickness, vessel density, foveal avascular zone parameters, the number of hyperreflective foci (HRF), area of cystoid edema, and subretinal fluid (SRF), were compared. The correlation was analyzed between best-corrected visual acuity (BCVA) and OCTA parameters. Results. A total of 79 differentially expressed genes were identified. Functional enrichment analyses revealed the enriched inflammatory events in RVO. In RVO-ME, Pearson correlation revealed that baseline BCVA was positively correlated with the area of SRF and central macular thickness, while no correlation was detected between baseline BCVA and HRF number or the area of cystoid edema. The visual acuity improved, and the central macular thickness was decreased after intravitreal dexamethasone implant injection. Besides, the number of HRF, the area of cystoid edema, and SRF were significantly alleviated after dexamethasone intravitreal injection. Conclusion. Retinal inflammation plays a crucial role in RVO pathogenesis. The imaging biomarkers of RVO including Müller glial intracellular edema, and retinal pigment epithelium dysfunction, could be assessed in OCTA and attenuated by intravitreal dexamethasone implant effectively.

Evaluation of off‐label anti‐vascular endothelial growth factor and steroid implant medication uses in macular edema due to retinal vein occlusion in Turkey

“…Dexamethasone implant (Dexamethasone implant, Allergan Inc, California) is the only corticosteroid licensed for the treatment of RVO in Turkey. With a single intravitreal injection, it shows rapid efficacy in the first 2 weeks 23 . Although its effectiveness has been reported to last up to 6 months, usually ending in 3 or 4 months 22 .…”

“…Although its effectiveness has been reported to last up to 6 months, usually ending in 3 or 4 months 22 . It reduces the number of injections due to its longer duration of action than anti‐VEGF drugs, is effective against inflammatory and vasogenic steps that contribute to the formation of macular edema, and is an effective treatment alternative in patients with recalcitrant macular edema unresponsive to anti‐VEGFs 23,24 . However, steroids are not generally preferred as the first‐line treatment option due to the risk of cataracts and glaucoma development 16 …”

“…With a single intravitreal injection, it shows rapid efficacy in the first 2 weeks. 23 Although its effectiveness has been reported to last up to 6 months, usually ending in 3 or 4 months. 22 It reduces the number of injections due to its longer duration of action than anti-VEGF drugs, is effective against inflammatory and vasogenic steps that contribute to the formation of macular edema, and is an effective treatment alternative in patients with recalcitrant macular edema unresponsive to anti-VEGFs.…”

“…22 It reduces the number of injections due to its longer duration of action than anti-VEGF drugs, is effective against inflammatory and vasogenic steps that contribute to the formation of macular edema, and is an effective treatment alternative in patients with recalcitrant macular edema unresponsive to anti-VEGFs. 23,24 However, steroids are not generally preferred as the first-line treatment option due to the risk of cataracts and glaucoma development. 16 Regulatory agencies may approve the dosages of medications at the licensing stage less than what is needed in clinical practice.…”