Abstract
Purpose: :
To evaluate an intravitreal injection technique and its effect on intraocular pressure (IOP) spikes
Methods: :
Patients who were scheduled to have an intravitreal injection had pressure placed over the injection site for a duration of 60 seconds with a Q-tip and had their intraocular pressure measured immediately after this. The intravitreal injection was then done and intraocular pressure was measured 15 minutes later by applanation tonometry.
Results: :
IRB approval was obtained. Data from 47 consecutive intravitreal injections to 43 eyes (3 patients were injected twice) was analyzed. Our study had 21 males, 22 females and a mean age of 73 years (range 32-92). At the time of injection, 4 patients had glaucoma and 4 were glaucoma suspects. Patients with glaucoma were all on topical IOP-lowering medication. Indications for intravitreal injections were: age related macular degeneration in 25 eyes, clinically significant diabetic macular edema in 9 eyes, central retinal vein occlusion in 6, hemiretinal vein occlusion in 3 and choroidal neovascular membranes secondary to multifocal choroiditis and panuvieits in 1. 2 eyes had no previous injection, 3 eyes had 1 prior injection and 42 eyes had a history of 2 or more prior intravitreal injections. Mean IOP prior to any intervention was 16.42 (SD 3.49, SEM 0.52). Mean IOP immediately following scleral indentation pressure was 10.79 (SD 2.87, SEM 0.49) with a statistically significant reduction in IOP (P <0.0001) compared to the initial readings. There was no statistically significant difference between the IOP measured prior to application of pressure and the IOP measured 15 minutes after the injection ( mean 17.87, SD 3.49, SEM 0.83, paired t-test).
Conclusions: :
We found a significant decrease in IOP following scleral indentation for 60 seconds and no significant increase in IOP between the preinjection and postinjection values. The occurrence of increased IOP after intravitreal injections is a recently recognized entity. Glaucoma has lifelong implications for patients in terms of quality of life, cost, and the ongoing treatments required. Therefore, it is imperative that we take every precaution to reduce acute pressure spikes following intravitreal injections, which may be a risk factor for the development of ocular hypertension and glaucoma. There is currently no standardization in the technique for intravitreal injection. Our findings advocate the adoption of this technique in the procedure of intravitreal injections.
Keywords: injection • intraocular pressure • vitreous