Endophthalmitis following Intravitreal Anti-Vascular Endothelial Growth Factor Therapy: Changes in Incidence and Outcomes over a 9-Year Period

Impact of Prefilled Syringes and Masking on Postintravitreal Injection Endophthalmitis

Purpose: To compare rates of endophthalmitis (1) following intravitreal injection of antivascular endothelial growth factor therapies with glass-vial preparation (GVP) vs prefilled syringes (PFS) and (2) before and after masking protocols were implemented. Methods: Medical records within a multicenter retina practice in Houston, Texas, from January 2015 to August 2021 were retrospectively reviewed. The primary outcome was rate of endophthalmitis after intravitreal injection. Results: A total of 307 349 injections were performed during the study period and 101 cases of endophthalmitis were identified (0.033%). PFS use was associated with a decreased risk of endophthalmitis (relative risk [RR], 0.320; 95% CI, 0.198-0.518, P < .001); 54 cases of endophthalmitis occurred in the GVP group of aflibercept and ranibizumab (0.052%) compared with 24 in the PFS group (0.017%). There was no difference in the endophthalmitis rates with or without universal masking (RR, 0.953; 95% CI 0.616-1.473, P = .91). Discussion: PFS use was associated with a significant reduction in the rate of endophthalmitis while the use of surgical face masks did not appear to significantly impact the rate of endophthalmitis.

[Clinical features and treatment of endophthalmitis after cataract surgery]

PURPOSE

The study analyzes the frequency of acute endophthalmitis occurrence after cataract surgery, the risk factors, characteristic symptoms, and the effectiveness of peri-operative prevention measures.

MATERIAL AND METHODS

The study retrospectively analyzed 59 670 cases of patients operated for cataract in 2017-2021. To prevent infections, patients received four instillations of third generation fluoroquinolone (quinolone antibiotic) in the course of two days prior to cataract phacoemulsification (PE), and two instillations immediately (1 hour and 30 minutes) before the surgery; three-minutes treatment of the cornea, conjunctival sac and periocular skin with 5% povidone iodine before the surgery; and as the last step of surgery, patients received subconjunctival injection of 0.05 g cefazolin with 2 mg dexamethasone. Follow-up after surgery included four injections of 0.5% levofloxacin in the course of 7-10 days, and 0.1% dexamethasone for two weeks, or fixed combination of tobramycin and dexamethasone four times per day for two weeks. The criteria for acute endophthalmitis are: loss of spatial vision, absence of red reflex, pronounced thickening of the choroid, suspended particulates in the retrovitreal space and the vitreous observed with ultrasonography in the early postoperative period (day 4-7 after surgery).

RESULTS AND DISCUSSION

There were 32 patients (0.054%) diagnosed with acute endophthalmitis. Posterior capsule rupture was the main complicative risk factor of endophthalmitis development (OR=11.75, p=0.026). Main diagnostic criteria of acute endophthalmitis were hypopyon (OR=22.5, p=0.001) and absence of red reflex (OR=19.59, p<0.001). The use of the fixed combination of tobramycin and dexamethasone was associated with 5.8-times higher risk of acute endophthalmitis than separate application of levofloxacin and dexamethasone (p=0.042).

CONCLUSIONS

Povidone iodine and third generation fluoroquinolone as a method of acute endophthalmitis prevention after cataract surgery demonstrate comparable efficacy to intracameral antibiotic injections.

Preventive factors, diagnosis, and management of injection-related endophthalmitis: a literature review

BACKGROUND

Intravitreal medication injections represent the gold standard treatment for a variety of potentially blinding chorioretinal vascular diseases. Despite their excellent safety profile, they are associated with the feared complication of injection-related endophthalmitis (IRE). Though the overall incidence of IRE is low, due to the ever-increasing number of injections being performed, it is a complication that all retina specialists are likely to encounter. This article reviews various factors that could potentially influence the risk of IRE and discusses evidence-based strategies for management.

METHOD

PubMed was searched for keywords "intravitreal injection" and "endophthalmitis" from the period of 1995-2021. Relevant articles were reviewed and selected articles were analyzed with respect to the incidence, potential preventive factors, clinical presentation, microbial profile, management, and outcomes for IRE.

RESULTS

There is strong consensus supporting the use of povidone iodine topical antiseptic, eyelid retraction away from the injection site, and avoiding treatment of eyes with active surface or eyelid disease, but there is less agreement on the use of face masks versus "no-talking" policies and optimal anesthetic technique. Current evidence comparing tap and inject or early vitrectomy for treatment of IRE is inadequate to determine an optimal treatment strategy.

CONCLUSION

Intravitreal injections are sight saving, but even using established prophylactic measures there remains a small but real risk of infectious injection-related complications. Further investigations comparing tap and inject versus vitrectomy may help to establish optimal treatment, although the rarity of IRE makes designing adequately powered prospective trials a difficult task.

A novel, minimally invasive implant to assist in repeated intraocular drug delivery

The standard of care for posterior segment disorders such as wet age-related macular degeneration, diabetic macular oedema and retinal vascular occlusions is pharmacotherapy by intravitreal drug delivery. Since the therapeutic effect of these drugs lasts only around 4 to 8 weeks, repeated intravitreal injections are required. Pain is experienced by the patients during injection as the needle courses through the sclera and choroid. The current work describes the design and development of a novel anodized titanium alloy implant that allows for intravitreal injections through the implant so that the needle transverses only the conjunctiva, thus minimizing discomfort to the patient. Both ex-vivo testing of the implant in enucleated goat's eye as well as in-vivo validation in rabbit eyes was carried out. The implant was placed through pars plana via a minor surgical procedure and was sutured to the sclera and covered with conjunctiva. Subsequent intravitreal injections were administered under topical anaesthesia with a 30-gauge needle through the implant thus delivering the drug into the vitreous cavity. Repeated intravitreal injections were administered every 2 weeks via the implant for 3 months in 4 rabbits. Apart from cataract in 1 rabbit, no complications were observed. There was no evidence of intra-ocular inflammation or infection at final follow-up. Histopathological analysis did not reveal any inflammation or necrosis around the area of implant. The implants were subsequently removed at 5 months and scleral wound was closed with a single suture. The sclera and overlying conjunctiva healed well and no intraocular complications were observed after removal.

Complications of intravitreal injections: 2022

PURPOSE OF REVIEW

This review highlights the complications of both intravitreal injection procedure as well as different intravitreal medications including antivascular endothelial growth factors, antibiotics, antivirals, antifungals, methotrexate, and steroids. Techniques for reducing rates of endophthalmitis will also be discussed.

RECENT FINDINGS

Intravitreal vancomycin can cause hemorrhagic occlusive retinal vasculitis resulting in severe vision loss. Intravitreal brolucizumab is associated with intraocular inflammation and retinal vasculitis resulting in significant vision loss. Face mask use by both patient and physician is not associated with increased risk of endophthalmitis and may decrease culture positive endophthalmitis.

SUMMARY

Intravitreal injections continue to be one of the most commonly performed procedures by ophthalmologists. Although the injections are generally well tolerated, sight-threatening complications can occur including endophthalmitis, retinal detachment, and/or retinal vasculitis. Adverse events associated with specific medications are outlined below. Several safety measures have been shown to reduce rates of endophthalmitis, the most concerning complication of this procedure.

Suprachoroidal delivery of bevacizumab in rabbit in vivo eyes: Rapid distribution throughout the posterior segment

PURPOSE

To test the in-vivo bio-distribution and safety of bevacizumab delivery into the suprachoroidal space (SCS) using a novel injection system in a large eye model.

METHODS

Bevacizumab (1.25 mg) was injected into the vitreous (IVT, 50 µL, n = 12) or the SCS, (150 µL, n = 37) of live rabbits. Immunofluorescence and ELISA were used to assess bevacizumab distribution. Intraocular pressure (IOP) measurements, SD-OCT and fundus imaging, electroretinogram, and histology analysis were performed for safety assessment.

RESULTS

Bevacizumab was observed throughout the choroid layers up to the retinal pigment epithelium (RPE), within 1 h following SCS injection. The C_max of bevacizumab in the retina/choroid was 1043 ± 597 μg/gr tissue (mean ± standard error), 40-fold higher than in IVT injected eyes (p = 0.0339). One day following SCS injection, bevacizumab was detected throughout the posterior pole with a two-fold lower concentration. One week post-SCS injection, bevacizumab concentration in the retina/choroid dropped to 2.36 ± 1.32 μg/gr tissue (p = 0.034 vs. 1 h), with a half-life of 20 h. No suprachoroidal blebs, retinal detachment, hemorrhages, inflammation or changes in retinal function were observed up to 2 months following SCS injection. Elevated IOP (+16 mmHg) was observed two minutes post-SCS injection and spontaneously returned to baseline levels within 10 minutes.

CONCLUSIONS

The novel injection system enabled a minimally invasive, safe, and consistent delivery of bevacizumab with rapid distribution throughout the choroid layers up to the RPE in large eyes. Large volumes of anti-angiogenic are delivered in close proximity to the retina due to the high volume distribution.