Effect of quadrant switch on ıntraocular pressure change in ıntravitreal aflibercept or ranibizumab ınjection...

To evaluate the effect of injection quadrant switch on the intraocular pressure (IOP) change in intravitreal aflibercept or ranibizumab applications.

123 eyes of 123 patients who received intravitreal injection (IVE) into the superotemporal quadrant at least 10 times for age-related macular degeneration or diabetic macular edema have been recruited. The demographic data, lens status, IOP values (preoperative, postoperative 0th min, and postoperative 30th min), and amount of vitreous reflux (VR) following IVE have been recorded. Next IVE application was performed into the inferotemporal quadrant of the patient, which had never been injected before.

The mean IOP value at postoperative 0th min was 50.24 ± 7.66 mmHg after injections into the superotemporal quadrant and was 34.85 ± 4.96 mmHg after injections into the inferotemporal quadrant. No significant difference was observed between the preoperative and postoperative 30th min-IOP values (p > 0.05), while a significant difference was found between the postoperative 0th min-IOP values among quadrants (p < 0.001). VR was significantly higher in applications into the inferotemporal quadrant than those into the superotemporal quadrant (p < 0.001).

One of the most principal factors affecting the postoperative short-term IOP increase is the amount of VR, and this amount decreases the IOP following an IVE. The high amount of VR produced in the quadrant where the injection was applied for the first time caused a low-level IOP, while the low amount of VR formed in the quadrant where the repeated injections were applied caused a higher IOP.