Purpose: To investigate the vasomotor responses and diameter of retinal vessels in patients with macular edema secondary to retinal vein occlusion (RVO).
Methods: A total of 18 eyes of 18 RVO patients were consecutively included and compared with age- and sex-matched controls. Participants underwent an examination with optical coherence tomography and dynamic and static retinal vessel analyses using the Dynamic Vessel Analyzer.
Results: Dynamic vessel analysis in RVO showed mean maximum venous and arterial dilation of 2.22 ± 1.23% and 1.87 ± 1.41%, respectively, as compared with 5.05 ± 2.75% (P = 0.001) and 3.95 ± 1.44% (P = 0.0004), respectively, in controls. Static retinal vessel analysis in RVO revealed a mean arteriovenous ratio (AVR) of 0.74 ± 0.09 versus 0.90 ± 0.04 (P < 0.0001) in controls. Mean AVRs of occluded and nonoccluded quadrants in RVO were 0.71 ± 0.13 and 0.85 ± 0.19, respectively; in the corresponding quadrants of controls, mean AVRs were 0.90 ± 0.19 (P < 0.0001) and 0.86 ± 0.17 (P = 0.89), respectively. In branch RVO patients, mean AVRs of occluded versus nonoccluded quadrants were 0.70 ± 0.06 and 0.90 ± 0.22 (P = 0.002), respectively.
Conclusion: In patients with macular edema secondary to RVO, dynamic vessel analysis showed an impairment of both venous and arterial motility and/or reactivity and static vessel analysis showed a reduced AVR indicating a general enlargement of the retinal venous network. Moreover, in branch RVO patients, static analysis demonstrated that retinal vessels could actually be uninvolved by the occlusive process in areas spared by disease.