[Complaints and complications after intravitreal injection (IVI) and potential risk factors].

Background: Intravitreal injections (IVI) are the most commonly used procedure worldwide in the treatment of retinal vascular diseases.

Objective: This study investigates the endophthalmitis rate, the frequency of subjective complaints and potential risk factors associated with IVI.

Material and methods: In the first part of this monocentric study the number of cases of endophthalmitis and potential risk factors were analyzed based on routine hospital documentation of 123,373 IVI procedures from 2013 to 2022. In the second part, subjective complaints and potential risk factors following IVI were investigated through a survey involving 584 patients.

Results: From 2013 to 2022 a total of 27 cases of endophthalmitis occurred following IVI (0.02%). The analysis of potential risk factors (age, gender, disinfection method, number of prior injections, day of the week, year, bilateral injection) revealed that none of these factors were associated with an increased risk of endophthalmitis. The initial identification of bilateral injection as a risk factor was disproven through further analysis and classified as a statistical artifact. More than 10% of patients reported complaints the day after the injection, such as foreign body sensation (18%), seeing air bubbles (17%), itching (12%) and reddening of the eyes (11%). Subconjunctival hemorrhage (4%) or severe pain the day after the injection (2%) occurred less frequently. Male patients reported severe pain the day after less often (odds ratio 0.18, 95% confidence interval 0.03-0.72). Nearly 2% of patients sought unplanned ophthalmologist visits or considered treatment discontinuation due to the complaints.

Conclusion: Subjective complaints are more prevalent than severe complications and can jeopardize treatment adherence. Therefore, providing information about expected discomfort is advisable.