Ocular decompression with cotton swabs lowers intraocular pressure elevation after intravitreal injection

Abstract

Objective: To determine the effect of preinjection ocular decompression by cotton swabs on the immediate rise in intraocular pressure (IOP) after intravitreal injections.

Methods: Forty-eight patients receiving 0.05 mL ranibizumab injections in a retina clinic were randomized to 2 anesthetic methods in each eye on the same day (if bilateral disease) or on consecutive visits (if unilateral disease). One method utilized cotton swabs soaked in 4% lidocaine applied to the globe with moderate pressure and the other 3.5% lidocaine gel applied without pressure. IOPs were recorded at baseline (before injection) and at 0, 5, 10, and 15 minutes after the injection until the IOP was ≤30 mm Hg. The IOP elevations from baseline were compared after the 2 anesthetic methods.

Results: The preinjection mean IOP (SD, mm Hg) was 15.5 (3.3) before the cotton swabs and 15.9 (3.0) before the gel (P=0.28). Mean IOP (SD, mm Hg) change immediately after injection was 25.7 (9.2) after the cotton swabs and 30.9 (9.9) after the gel (P=0.001). Thirty-five percent of gel eyes had IOP≥50 mm Hg compared with only 10% of cotton swab eyes immediately after the injection (P<0.001).

Conclusion: Decompressing the eye with cotton swabs during anesthetic preparation before an intravitreal injection produces a significantly lower IOP spike after the injection.

Trial registration: ClinicalTrials.gov NCT01087489.

Figure 1

Percentage of Eyes Prepared with the Gel and with Cotton Swabs Methods with Post-injection IOP ≥ 50 mmHg vs. time after the injection. A graph showing percentage of eyes prepared with gel and lidocaine-soaked cotton swabs with IOP ≥50 mmHg at zero through 15 minutes after 0.05-ml ranibizumab injection. Higher percentage of gel eyes prepared without softening by cotton swabs demonstrated IOP ≥ 50 mmHg immediately after the injection (P<0.001, McNemar's test) than the eyes softened by lidocaine-soaked cotton swabs.