Correlation of Aqueous, Vitreous, and Plasma Cytokine Levels in Patients With Proliferative Diabetic Retinopathy.

Purpose: To investigate the relationship between proangiogenic and inflammatory cytokines in concurrent vitreous, aqueous, and plasma samples from patients with proliferative diabetic retinopathy (PDR). Methods: Vitreous, aqueous, and plasma samples were analyzed using multiplex immunoassay for 10 PDR-related cytokines (IL-6, IL-8, TNF-α, monocyte chemoattractant protein-1 [MCP-1], macrophage inflammatory protein-1ß [MIP-1ß], VEGF receptor 1 [Flt-1], placental growth factor [PlGF], VEGF-A, VEGF-C, VEGF-D). A total of 17 patients with PDR and 7 controls were included. The primary outcome was correlation of cytokines in vitreous, aqueous, and plasma. The secondary outcome was the comparison of cytokine levels in controls and diabetics with and without recent anti-VEGF injection. Results: The following factors were elevated in diabetics compared with controls: vitreous IL-6, IL-8, TNF-α, MCP-1, MIP-1ß, PlGF, and VEGF-A; and aqueous IL-6, IL-8, PlGF, and VEGF-C (all P < 0.05). Vitreous and aqueous IL-8, PlGF, and VEGF-A were significantly correlated in patients with PDR (all P < 0.05). Plasma cytokines were not correlated with those in vitreous and aqueous (all P > 0.05). Vitreous and aqueous IL-6, IL-8, TNF-α, PlGF, and VEGF-A differed among controls and diabetics with and without recent anti-VEGF injection (all P < 0.05). In one-to-one comparisons, aqueous VEGF-A levels were lower in diabetic patients who had recent anti-VEGF injection compared with those who did not (P = 0.01). Conclusions: In this proof-of-concept study, IL-8, VEGF-A, and PlGF demonstrated a strong correlation in vitreous and aqueous of patients with PDR. The aqueous may serve as a proxy for vitreous for some cytokines involved in PDR. Recent anti-VEGF injections decreased VEGF-A levels in aqueous, but did not significantly affect other cytokines, suggesting a role for other targeted therapies in PDR management.

Dexamethasone Intravitreal Implant Injection in Eyes with Comorbid Hypotony.

PURPOSE: To evaluate outcomes in patients with hypotony treated with intravitreal dexamethasone implant (Ozurdex). DESIGN: Retrospective cohort study. PARTICIPANTS: Thirteen patients (15 eyes) that received a total of 99 dexamethasone implant injections on occasions at which the intraocular pressure was low, meeting the definition of statistical hypotony. METHODS: The medical records of 13 patients (15 consecutive eyes) receiving 1 or more intravitreal dexamethasone implants between December 2014 and April 2017 were reviewed retrospectively. Hypotony was defined as intraocular pressure less than 6.5 mmHg. The indications for intravitreal dexamethasone implant injection were intermediate or posterior uveitis (86.7%), diabetic macular edema (13.3%), and/or cystoid macular edema (6.7%). MAIN OUTCOME MEASURES: The primary outcome measures were safety outcomes and best visual acuity within 6 months of the final intravitreal dexamethasone implant injection in a hypotonous eye. RESULTS: In 15 eyes (13 patients), 99 injections were administered to eyes under circumstances of hypotony. Uveitic cystoid macular edema or diabetic macular edema was reduced after treatment in all cases. No complications were noted during the injection procedure. Three complications were noted in 2 patients after injection. Pseudophakodonesis and mild vitreous hemorrhage immediately after injection were noted in 1 patient, and a case of delayed-onset vitreous hemorrhage with pigment release was noted in another. All 3 complications resolved without intervention. The primary end point of this study-mean visual acuity-was stable over the follow-up period. In patients with hypotony whose intraocular pressure normalized during the follow-up period, this was attributable to management of glaucoma surgery-related complications rather than an effect of the intravitreal dexamethasone implant. CONCLUSIONS: Intravitreal dexamethasone implant injection is a reasonable treatment option for patients with comorbid hypotony in whom clinical findings warrant treatment with a sustained-delivery intravitreal steroid implant. Further studies, including imaging of zonules before and after intravitreal dexamethasone implant injection in a hypotonous eye, could help define risks to intraocular lens stability with this procedure.