Ocular Decompression Lowers IOP After Intravitreal Injection
Ocular Decompression Lowers IOP After Intravitreal Injection
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.
Repetitive intravitreal injections have become a common treatment modality in the management of many retinal diseases. Patients may receive injections as frequently as every 2 weeks. Because the globe is essentially a noncompliant sphere, injecting an additional volume produces an acute short-term intraocular pressure (IOP) elevation that carries a well-recognized risk of short-term occlusion of the central retinal artery. It has been documented that significant, and at times extreme, IOP elevations are common but are transient, usually taking <30 minutes to return to baseline. However, elevated IOP has been reported to persist for 2 hours, and there is a report of a patient who required a 1-week course of glaucoma medication to control IOP after bevacizumab. High IOP may lead to disruption in retinal and optic nerve head blood flow and has the potential for direct mechanical damage to the optic nerve axons. Consequences of transient IOP elevations are unknown. Patients with history of glaucoma have been shown to take significantly longer to normalize IOP. It is conceivable that these significant rises in IOP, repeated every month for many years, may lead to permanent damage, especially in patients with preexisting glaucoma. Some normotensive patients might also be susceptible to effects of repetitive IOP elevations, and these might be the patients who demonstrate sustained IOP elevation reported in the literature. Although the long-term effects of repetitive IOP elevations need to be studied further, ways to minimize postinjection IOP elevation should be considered. Lowering preinjection IOP with medications and ocular decompression has been suggested.
We conducted a prospective randomized clinical trial comparing IOP rise after 0.05 mL ranibizumab injections, where the same patients were subjected to 2 different preinjection anesthetic methods, one involving decompression with cotton swabs soaked with 4% lidocaine and the other using 3.5% lidocaine gel applied without decompression. This was done as part of a randomized clinical trial comparing pain control efficacy of the 2 anesthetic techniques, which has been published elsewhere. Secondary outcome measure was postinjection IOP change with and without pressure on the eye. These data are presented here.
Abstract and Introduction
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.
Introduction
Repetitive intravitreal injections have become a common treatment modality in the management of many retinal diseases. Patients may receive injections as frequently as every 2 weeks. Because the globe is essentially a noncompliant sphere, injecting an additional volume produces an acute short-term intraocular pressure (IOP) elevation that carries a well-recognized risk of short-term occlusion of the central retinal artery. It has been documented that significant, and at times extreme, IOP elevations are common but are transient, usually taking <30 minutes to return to baseline. However, elevated IOP has been reported to persist for 2 hours, and there is a report of a patient who required a 1-week course of glaucoma medication to control IOP after bevacizumab. High IOP may lead to disruption in retinal and optic nerve head blood flow and has the potential for direct mechanical damage to the optic nerve axons. Consequences of transient IOP elevations are unknown. Patients with history of glaucoma have been shown to take significantly longer to normalize IOP. It is conceivable that these significant rises in IOP, repeated every month for many years, may lead to permanent damage, especially in patients with preexisting glaucoma. Some normotensive patients might also be susceptible to effects of repetitive IOP elevations, and these might be the patients who demonstrate sustained IOP elevation reported in the literature. Although the long-term effects of repetitive IOP elevations need to be studied further, ways to minimize postinjection IOP elevation should be considered. Lowering preinjection IOP with medications and ocular decompression has been suggested.
We conducted a prospective randomized clinical trial comparing IOP rise after 0.05 mL ranibizumab injections, where the same patients were subjected to 2 different preinjection anesthetic methods, one involving decompression with cotton swabs soaked with 4% lidocaine and the other using 3.5% lidocaine gel applied without decompression. This was done as part of a randomized clinical trial comparing pain control efficacy of the 2 anesthetic techniques, which has been published elsewhere. Secondary outcome measure was postinjection IOP change with and without pressure on the eye. These data are presented here.