Comparison of Two Different Intravitreal Injection Techniques

OBJECTIVE: To compare the effectiveness, procedure time and safety outcomes of two different intravitreal injections (IVI) techniques. METHODS: This was a prospective, single-center, randomized clinical trial of 200 adult eyes receiving intravitreal medications for various indications. Eyes were assigned (1:1) to undergo IVI using either an intravitreal injection guide (IIG) (n= 100) or conventional dual blade speculum plus surgical caliper (DBS) (n=100). All IVI were administered using a 30-gauge needle placed 4 mm posterior to the inferior limbus. The main outcome measures were rate of successful IVI administration, procedure time (seconds) as measured by a stopwatch from application to removal of IIG or DBS, patient preference for IVI technique and adverse events. RESULTS: The two groups were similar in terms of mean age (P=0.398), laterality (P=0.671), indication for treatment (P=0.175) and medication type (P=0.489). All IVI procedures were successfully completed in both groups. The mean procedure time was shorter using the IIG (9.94 ± 2.87 seconds) versus DBS (21.85 ± 7.25 seconds) technique (P ≤ 0.01). The incidence of post-injection subconjunctival hemorrhage was higher when the DBS was applied (OR = 2.35, 95% CI = 1.22–4.53). Patients with previous history of IVI preferred the IIG over the DBS. No other injection-related adverse events were observed in both groups. CONCLUSION: DBS and IIG techniques are similarly effective and safe for the administration of intravitreal medications. The IIG appears to significantly reduce procedure time, be associated with a lower incidence of subconjunctival hemorrhage and engender better patient acceptance. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov (NCT04455399).