Intravitreal Injections

PurposeThere is an urgent need to address how to best provide ophthalmic care for patients with retinal disease receiving intravitreal injections with anti-vascular endothelial growth factor agents during the ongoing global COVID-19 pandemic. This article provides guidance for ophthalmologists on how to deliver the best possible care for patients while minimizing the risk of infection.MethodsThe Vision Academy's Steering Committee of international retinal disease experts convened to discuss key considerations for managing patients with retinal disease during the COVID-19 pandemic. After reviewing the existing literature on the issue, members put forward recommendations that were systematically refined and voted on to develop this guidance.ResultsThe considerations focus on the implementation of steps to minimize the exposure of patients and healthcare staff to COVID-19. These include the use of personal protective equipment, adherence to scrupulous hygiene and disinfection protocols, pre-screening to identify symptomatic patients, and reducing the number of people in waiting rooms. Other important measures include triaging of patients to identify those at the greatest risk of irreversible vision loss and prioritization of treatment visits over monitoring visits where possible. In order to limit patient exposure, ophthalmologists should refrain from using treatment regimens that require frequent monitoring.ConclusionManagement of patients with retinal disease receiving intravitreal injections during the COVID-19 pandemic will require adjustment to regular clinical practice to minimize the risk of exposure of patients and healthcare staff, and to prioritize those with the greatest medical need. The safety of patients and healthcare staff should be of paramount importance in all decision-making.

PurposeTo determine whether the co-injection of extracellular matrix degrading enzymes improves retinal transduction following intravitreal delivery of adeno-associated virus-2 (AAV2).MethodsAAV2 containing cDNA encoding enhanced green fluorescent protein (GFP), under the control of a chicken β-actin promoter, was delivered by intravitreal injection to adult mice in conjunction with enzymes including collagenase, hyaluronan lyase, heparinase III, or chondroitin ABC lyase. Two weeks later, retinal flatmounts were examined for GFP expression using confocal microscopy.ResultsWithout the addition of enzymes, transduction was limited to occasional cells in the retinal ganglion cell layer. The addition of heparinase III or chondroitin ABC lyase greatly enhanced transduction of the retinal ganglion cell layer and increased the depth of transduction into the outer retina. Hyaluronan lyase had a limited effect and collagenase was ineffective. Electroretinograms survived with higher concentrations of heparinase III and chondroitin ABC lyase than were required for optimal retinal transduction.ConclusionsAAV2-mediated retinal transduction is improved by co-injection of heparinase III or chondroitin ABC lyase. Improved transduction efficiency may allow intravitreal injection to become the preferred route for delivering gene therapy to both the inner and outer retina.

Sterile endophthalmitis appears as an infrequent complication of intravitreal injections and seems to develop mainly in the context of the off-label use of drugs that have not been conceived for intravitreous administration. The aetiology of sterile endophthalmitis, independently of the administered drug, remains uncertain and a multifactorial origin cannot be discarded. Sterile inflammation secondary both to intravitreal triamcinolone acetonide and to intravitreal bevacizumab share many characteristics such as the acute and painless vision loss present in the big majority of the cases. Dense vitreous opacity is a common factor, while anterior segment inflammation appears to be mild to moderate. In eyes with sterile endophthalmitis, visual acuity improves progressively as the intraocular inflammation reduces without any specific treatment. If by any chance the ophthalmologist is not convinced by the sterile origin of the inflammation, this complication must be treated as an acute endophthalmitis because of the devastating visual prognosis of this intraocular infection in the absence of therapy.

PurposeIntravitreal injections (IVIs) are among the most frequently performed ophthalmic procedures and have been associated with a substantial carbon footprint. Travel-associated emissions are considered a key driver of IVIs' carbon footprint; however, no study in a country with a decentralised healthcare system has assessed IVI-related emissions. Here, the IVI-associated carbon footprint in an urban German tertiary referral centre was investigated.MethodsIn total, 340 patients were included. The carbon footprint was assessed based on the distance travelled by patients and accompanying persons, the mode of transport, and postoperative follow-up visits. Demographic data, treatment indication, and the injected medication were collected.ResultsThe average travel-associated CO2 equivalent (CO2eq) for a single IVI was 11.1 kg. Of this, 9.1 kg CO2eq and 2 kg CO2eq were due to travel to the injection clinic and to follow-up visits, respectively. Anti-VEGF treatment for common diseases such as age-related macular degeneration and diabetic macular edema was associated with a lower CO2eq compared with treatment of patients suffering from less prevalent conditions such as uveitis (10.8 kg vs. 15.6 kg). The majority of patients (49%) travelled by public transport (median distance: 22.4 km); patients travelling by car (33%) usually covered longer distances (median distance: 61.5 km).ConclusionTravel is a meaningful contributor to the carbon footprint of IVIs. Mitigation may be achieved by various approaches, such as longer-acting therapeutic agents or bilateral injections. To implement strategies for more sustainable IVIs, ophthalmologists may be encouraged by local and national bodies to incorporate environmental criteria into their practice.