Impact of injection techniques on intraocular pressure (IOP) increase after intravitreal ranibizumab application

To examine the influence of different intravitreous injection techniques on the short-term intraocular pressure (IOP) in patients with exudative age-related macular degeneration (AMD) receiving 0.05 ml ranibizumab (Lucentis) in the supine position.

Forty-five eyes (45 patients, 16 male, 29 female, mean age: 78 years) received intravitreal ranibizumab injections for treatment of exudative AMD (0.05 ml = 0.5 mg). A total of 31 patients received a standard straight scleral incision, and 14 were injected using the tunneled sclera technique. IOP was measured by Schiøtz tonometry immediately pre-and postoperatively, and the amount of subconjunctival reflux was documented using a semi-quantitative scale. Twenty-three eyes were phakic, and the remaining 22 were pseudophakic. No history of glaucoma was present. The Wilcoxon matched-pairs test was used for comparisons.

The mean preoperative IOP was 22.4 +/- 5.5 mmHg in the supine position. Immediately after the injection, the IOP increased to 47.9 +/- 15.1 (range 23-82). The mean difference between preoperative IOP and immediately after the injection was 25.5 +/- 13.6 mmHg. The mean IOP increase in eyes receiving a standard straight scleral incision was 21.9 +/- 14.2 mmHg (median 22.3) versus 33.5 +/- 7.2 mmHg (median 34.7) in the tunneled scleral incision group (p = 0.001).

IOP increased significantly in a considerable number of patients after receiving 0.05-ml intravitreal ranibizumab injections. This increase was dependent on the intravitreal injection technique and was significantly higher if a tunneled scleral injection was performed.