First Author: F.Corvi ITALY
Co Author(s): G. Querques C. La Spina R. Lattanzio G. Zerbini F. Bandello 0 0 0 0 0 0 0 0 0
Back to previous
To analyze dynamics of retinal vessel dilation response to flicker light in patients with retinal vein occlusion (RVO).
Ophthalmology, San Raffaele Scientific Institute, Vita-Salute University, Milan, Italy.
Twelve patients with RVO were consecutively included and compared to 12 age and sex matched healthy controls. The retinal vascular response to flicker light stimulation was assessed in each participant using the Dynamic Vessel Analyzer (DVA, IMEDOS, Jena, Germany). Relative dilations of selected arteriole and venule segments during flicker stimulation and resting diameters were measured automatically. Maximum vessel dilation was calculated as the percentage increase in vessel diameter relative to 50 sec baseline after 20 sec of flicker stimulation and non-ficker period for 80 sec. Three consecutive measurement cycles were averaged. Mean values for RVO patients and healthy controls were compared using Mann Whitney test.
In RVO patients, the mean diameter of arterial vessels studied was 120.50 ± 21.11μm; maximum arterial dilations during flicker stimulation was 1.97 ± 1.21%. The mean diameter of venous vessels studied was 144.70 ± 21.62μm; maximum venous dilations was 1.43 ± 0.90%. In healthy controls, the mean diameter of arterial vessels studied was 112.90 ± 11.58μm; maximum arterial dilations during flicker stimulation was significantly higher than RVO patients (4.73 ± 0.91%, p < 0.01). The mean diameter of venous vessels studied was 141.2 ± 14.71μm; maximum venous dilations was significantly higher than RVO patients (4.79 ± 2.10%, p < 0.01).
Retinal vascular dilation during flicker stimulation is reduced in patients with RVO. Interestingly, a significant reduction could be demonstrated in both venous and arterial vessels. Whether the above described changes in vascular dynamics could be involved in the development of different retinal signs related to RVO remain to be clarified by further studies.