Clinical features, management and outcomes of patients with sterile endophthalmitis associated with intravitreal injection of antivascular endothelial growth factor

Reduced Incidence of Intravitreal Injection-Related Endophthalmitis With Prefilled Syringes

Purpose: To evaluate the incidence and clinical characteristics of intravitreal injection-related endophthalmitis cases with antivascular endothelial growth factor (anti-VEGF) medications manufactured as prefilled syringes or non-prefilled preparations. Methods: This retrospective chart review comprised eyes that received intravitreal anti-VEGF at a single-specialty retina practice from January 1, 2014, to December 31, 2019. Eyes diagnosed with injection-related endophthalmitis were identified. Demographic and clinical data were abstracted from medical records, including the type of anti-VEGF agent, baseline and follow-up corrected visual acuity (VA), and microbiologic findings. Results: The review identified 88 cases of intravitreal anti-VEGF injection-related endophthalmitis and 325 990 total injections. Total injections included 32 045 (9.8%) bevacizumab (BEV), 93 073 (28.6%) ranibizumab (RAN), 122 947 (37.7%) aflibercept (AFL), and 77 925 (23.9%) ranibizumab prefilled syringe (RANPFS). Ten of the endophthalmitis cases were related to BEV, 21 to RAN, 45 to AFL, and 12 to RANPFS. The endophthalmitis rate was lowest for RANPFS (0.0154%) (BEV, 0.0312%; RAN, 0.0226%; AFL, 0.0366%) (P = .030). Thirty-four (41.5%) of 82 samples were culture positive. RANPFS had a significantly lower rate of culture-proven postinjection endophthalmitis than the other agents (P = .003). The mean VA for endophthalmitis cases related to RANPFS vs non-prefilled agents was similar at presentation (Snellen 20/2092 vs 20/2327) and at the 3-month follow-up (Snellen 20/201 vs 20/272) (both P > .05). Conclusions: Anti-VEGF medications in prefilled syringes may reduce the risk for medication contamination during injection preparation. RANPFS was associated with a lower rate of injection-related endophthalmitis than non-prefilled anti-VEGF medications.

Differential diagnosis of endophthalmitis after intravitreal drug injection for age related macular degeneration: Sterile vs. infectious

The recent release of brolucizumab and the development of new antiangiogenic molecules as abicipar pegol has increased the interest towards inflammatory complications after intravitreal drug injection. Those drugs are associated to a higher rate of inflammatory adverse events compared to classic drugs. In this context it is essential to differentiate between sterile and infectious cases for a fast and effective treatment. The clinical similarities between infectious and sterile cases, the high rate of culture negative patients and the heterogeneity in the terminology used are obstacles for a correct diagnosis and report of these complications. Sterile cases appear early after the injection, before 48 hours; or 20 days after in brolucizumab-related vasculitis cases. Infectious cases show up around the third day after injection and up to a week after it. A severe visual impairment, severe pain, severe hyperemia, hypopyon and a more severe intraocular inflammatory process are signs of a likely infectious origin. If the cause of the inflammation is uncertain we must follow up the patient closely or "tap and inject" antimicrobial agents in order to prevent the eventual complications of an infectious endophthalmitis. On the other hand, sterile endophthalmitis might be observed in mild cases or treated with steroids according to the severity of the inflammation.

Current Situation and Challenges in Vitreous Substitutes

Vitreo-retinal disorders constitute a significant portion of treatable ocular diseases. These pathologies often require vitreo-retinal surgery and, as a consequence, the use of vitreous substitutes. Nowadays, the vitreous substitutes that are used in clinical practice are mainly divided into gases (air, SF₆ , C₂ F₆ , C₃ F₈ ) and liquids (perfluorocarbon liquids, silicone oils, and heavy silicone oils). There are specific advantages and drawbacks to each of these, which determine their clinical indications. However, developing the ideal biomaterial for vitreous substitution continues to be one of the most important challenges in ophthalmology, and a multidisciplinary approach is required. In this sense, recent research has focused on the development of biocompatible, biodegradable, and injectable hydrogels (natural, synthetic, and smart), which also act as medium and long-term internal tamponade agents. This comprehensive review aims to cover the main characteristics and indications for use of the extensive range of vitreous substitutes that are currently used in clinical practice, before going on to describe the hydrogels that have been developed recently and which have emerged as promising biomaterials for vitreous substitution.