Retinal blood flow levels measured by laser speckle flowgraphy in patients who received intravitreal bevacizumab injection for macular edema secondary to central retinal vein occlusion.

Abstract

To report retinal blood flow levels measured by Laser speckle flowgraphy in three patients after they received an intravitreal bevacizumab injection (IVB) for macular edema secondary to central retinal vein occlusion (CRVO). Three patients (3 eyes) being treated with IVB (1.25 mg/0.05 mL) for secondary macular edema of CRVO were examined. Laser speckle flowgraphy analyses of the blood flow were based on the examinations of mean blur rate (MBR) at the major vessels of the optic disk. Central retinal thickness (CRT) was measured by optical coherence tomography using Macular Cube 512 × 128 scanning protocol. After the first IVB, Case 1 exhibited an increase in MBR and decrease in CRT. After 4 months, an additional injection was required because of a subsequent MBR decrease and CRT increase, which led to an increase in MBR and decrease in CRT similar to that observed after the first treatment. Subsequently, blood flow has continued to improve without additional IVB. Macular edema recurrence in Case 2 led to 3 further IVBs over a 6-month period. Although increases in MBR and decreases in CRT were noted, MBR values tended to decline after each IVB. In Case 3, macular edema recurrence led to 5 additional IVBs being carried out within a 1-year period. Continuous MBR increases and CRT decreases were observed in the patient after each IVB. By measuring MBR using laser speckle flowgraphy, we may predict the prognosis of CRVO. Mean blur rate increases after IVB were confirmed by laser speckle flowgraphy in three patients. Even though CRVO pathology backgrounds can vary, laser speckle flowgraphy may be useful in both determining the CRVO prognosis and in evaluating treatment efficacy.