Ocular Pulse Amplitude and Retinal Vessel Caliber Changes after Intravitreal Dexamethasone Implant

The purpose of this study is to evaluate possible changes in ocular pulse amplitude (OPA), retinal arteriole caliber (RAC), and retinal venule caliber (RVC), following the intravitreal injection of dexamethasone implants (DIs).

Thirty-four eyes of 34 patients with macular edema were included. All participants received a full ophthalmologic examination at baseline. RAC and RVC were measured via optical coherence tomography; OPA and intraocular pressure (IOP) were measured via dynamic contour tonometry at baseline, month 1, and month 3. Statistical analysis was performed for before-after comparison of OPA, IOP, RAC, and RVC measurements.

The mean OPA (in order to baseline, month 1, month 3) was 2.8 ± 0.8, 2.9 ± 1.0, 2.9 ± 0.9. The mean IOP was 16.8 ± 2.9, 17.3 ± 2.7, 18.4 ± 2.9 mmHg. The mean RAC was 97.8 ± 9.2, 97.2 ± 9.0, 97.6 ± 9.4. The mean RVC was 124.4 ± 8.2, 124.8 ± 8.8, 123.8 ± 8.2. There were no statistically significant changes in RAC (P = 0.688), RVC (P = 0.714), OPA (P = 0.348), and IOP (P = 0.115). There was also no correlation between RAC and OPA (r = 0.12, P = 0.62) or RVC and OPA (r = 0.16, P = 0.68) at the last visit.

The intravitreal injection of DI does not significantly affect RAC, RVC, or OPA, which indicates that the treatment does not alter overall retinal-choroidal vasculature or hemodynamics.