In conducting the present retrospective, single-center cohort study, the electronic medical records of the Torfeh University Eye Hospital (Tehran, Iran), affiliated with the Shahid Beheshti University of Medical Sciences, were accessed and queried for all cases of acute endophthalmitis following IVB injections, performed during two distinct periods, i.e., March 1st, 2013 to October 31st, 2019, and March 1st, 2020 to April 1st, 2021. The former period is from now on referred to as the “pre-COVID era”, and the latter as the “COVID era” – constituting approximately 80 and 12 months, respectively.
The study protocol was approved by the local ethics committee and adhered to the tenets of the declaration of Helsinki. The records of all patients who had undergone IVB injection during those periods were extracted from the hospital data archives using the international classification of the disease-10 (ICD-10) codes. Subsequently, among those records, all cases with acute post-IVB endophthalmitis were identified and extracted using the ICD-10 code of endophthalmitis. The acquired information included basic demographic data, injection indications, treatments and outcomes, bacterial smear and culture results, best-corrected visual acuity scores (BCVA) before the injection, after the onset of endophthalmitis symptoms, and three months after the treatment.
Post-IVB endophthalmitis cases were excluded if I) their bevacizumab administration was part of another surgical procedure, II) had any other intraocular procedures during the last six weeks before the IVB injection, and III) their acute endophthalmitis was secondary to other causes such as trauma or post-cataract surgery. Acute endophthalmitis after IVB was defined as a progressive inflammation in the vitreous cavity with or without inflammation of the anterior chamber, occurring in six weeks after the injection. The diagnosis was confirmed by a vitreoretinal surgeon.
All injections in the Torfeh University Eye hospital were performed in the operating room under strict aseptic techniques. All of the patients studied in the COVID era wore face masks. Before the procedure, physicians scrubbed their hands and wore face masks and sterile gloves. Topical tetracaine 0.5% drops were used to achieve local anesthesia. After cleaning the skin around the eye with a solution of povidone-iodine 10% and instilling a single drop of povidone-iodine 5% in the cul-de-sac, a sterile lid speculum was placed. The rubber covering of the bevacizumab vial was wiped with cotton soaked in 5% betadine; 1.25mg (0.05 ml) bevacizumab (Avastin®; Genentech, Inc., South San Francisco, CA, USA) was drawn into an insulin syringe for each injection. The needle was changed, and a 30-gauge needle was used for injection at 3–4 mm posterior to the limbus. Topical antibiotic eye drops were prescribed for three days after injection (12).
In the case of post IVB endophthalmitis, immediate anterior chamber and vitreous tap was performed for all patients, followed by intravitreal injection of vancomycin (1 mg) and ceftazidime (2.25 mg). Early standard three-port pars plana vitrectomy (PPV) was performed within 24 hours of diagnosis in all cases. Fortified antibiotic eye drops (vancomycin and ceftazidime) and systemic intravenous vancomycin and ceftazidime were initiated for all patients. Oral prednisolone 1 mg/kg was prescribed 24 hours after PPV and continued for ten days.
Finally, to investigate the effect of the pandemic-associated adjustments in health protocols on the incidence of this complication, data from the two periods, i.e., the Pre-COVID and the COVID eras, were compared and analyzed. Normal continuous variables were described as mean and standard deviation, and qualitative variables as frequency and percentage. Chi-square (κ2) test, Wilcoxon signed-rank test, and Kruskal-Wallis test were used to evaluate visual acuity changes in relation to other variables. Fisher’s exact test was applied when comparing variables from the Pre-COVID era with those from the COVID era. A P-value of less than 0.05 was considered statistically significant. Data were gathered and analyzed using IBM SPSS v.23.0. for Windows.