Extension of peripheral nonperfusion in eyes with retinal vein occlusion during intravitreal dexamethasone treatment

To evaluate the change in peripheral perfusion status in patients with retinal vein occlusion (RVO) during dexamethasone treatment.

Thirty-five eyes of patients with macular oedema due to either branch or central retinal vein occlusion were included. At baseline, patients were treated with an intravitreal dexamethasone implant (Ozurdex^® ) and followed until month 6. Wide-field angiographies were classified as ischaemic and nonischaemic. Peripheral nonperfusion (PNP) was determined manually by calculating the percentage of nonperfusion area in relation to the total visible retina (ischaemic index).

Thirteen eyes showed evidence of >10 disc area of PNP at baseline and were graded as ischaemic RVO. In nonischaemic eyes, the mean area of PNP was 0.3% at baseline, 0.6% after 1 month, 0.6% after 3 months and 0.6% after 6 months, respectively (p > 0.05). In ischaemic RVO, the ischaemic index was calculated to be 18% at baseline. One month after treatment, mean area of PNP was 16% and after 3 months was 19% (p = 0.8; p = 0.6). After retreatment, total PNP area was 18% (month 6; p = 0.9). During treatment, best-corrected visual acuity (BCVA) increased and central retinal thickness (CRT) decreased from baseline to final follow-up with no differences between nonischaemic/ischaemic RVO. A significant negative correlation between the total area of PNP and visual acuity was identified (r = -0.6; p = 0.04).

Using 200° wide-field fluorescein angiography, the ischaemic index was shown to remain stable during dexamethasone treatment. This finding was consistent in ischaemic as well as in nonischaemic conditions.