Study Shows Advantage of Using Intravitreal Injection Guide

Syringes and needles filled with the Moderna coronavirus vaccine for Covid-19 are seen before being administered to employees of Japan’s Mori Building Company, a property management firm, during the company’s workplace vaccination campaign in Tokyo on June 21, 2021. (Photo by Behrouz MEHRI / AFP) (Photo by BEHROUZ MEHRI/AFP via Getty Images)
The study quantifies differences between the instrument and a dual blade speculum.

While a dual blade speculum (DBS) and an intravitreal injection guide (IIG) are similarly safe and effective instruments to aid in the  administration of intravitreal medications, investigators have found that the IIG appears to reduce procedure time significantly. It is also associated with a lower incidence of subconjunctival hemorrhage, and is better tolerated by patients, according to the team’s findings, published in Clinical Ophthalmology.

Intravitreal injections (IVI) are among the most commonly performed procedures in ophthalmology, according to the researchers. To keep up with demand, health care systems have employed administrative changes, streamlined IVI techniques, and used IVI assistive devices.

Recently introduced, the IIG is a single-use, IVI assistive instrument that features a single blade lash guard, curved footplate with a distance marker, cylindrical chamber to control scleral needle insertion, and a handle. This study compared the effectiveness, procedural time, patient acceptability, and safety of the IIG vs DBS.

This prospective, single-center, randomized clinical trial included patients’ 200 adult eyes receiving intravitreal medications for various indications. Eyes were assigned (1:1) to undergo IVI using either an IIG (n=100) or conventional DBS plus surgical caliper (n=100). All IVIs were administered using a 30-gauge needle placed 4 mm posterior to the inferior limbus. The participants in each group were similar in terms of mean age (P =.398), laterality (P =.671), indication for treatment (P =.175) and medication type (P =.489).

All IVI procedures were successfully completed in both groups. The mean procedure time was shorter using the IIG (9.94±2.87 seconds) compared with the DBS (21.85±7.25 seconds, P ≤.01). The incidence of postinjection subconjunctival hemorrhage was higher when the DBS was applied (OR=2.35, 95% CI=1.22–4.53). No other injection-related adverse events were observed in both groups. Patients with a previous history of IVI preferred the IIG. 

In this study, the use of the IIG decreased the procedural time by half for every case, according to researchers. The cost-benefit of using the IIG will be highly dependent on current institutional practice.

The study’s authors note several limitations to their work, including having a single treating investigator in an open-label study, which creates a potential for researcher bias. The short study duration and relatively small sample size in this study do not allow for detecting rare and late-onset complications. Additionally, researchers report that they did not account for systemic factors that may affect subconjunctival hemorrhage incidence. For purposes of uniformity, all treatments were administered in the inferior quadrant, so it is unclear what the effect would be in other injection locations.


Uy HS, Artiaga JCM. Comparison of two different intravitreal injection techniques. Clin Ophthalmol. 2021;15(6):2383-2389. doi:10.2147/OPTH.S309501.