Abstract
Abstract: :
Purpose:To assess the variations of retinal vessel widths in patients with Behçet’s Disease (BD) in response to warm and cold stimuli and compare with healthy people. Methods:Right eyes of nonsmoker and normotensive16 patients with BD [9 (age: 15–37 yrs.) with ocular findings (group B) and 7 (age: 19–40 yrs.) without ocular findings (group C)] and 9 (age:21–35 yrs.) healthy volunteers (group A) were examined. Exclusion criteria for B were: severe uveitis, retinal vasculitis, severe optic nerve involvement. All vessels (from digitally recorded 30° redfree fundus pictures) larger than 25 pixel (123 arterioles, 119 venules) were studied: 1) before, 2) after immersion of the hand into warm water (40–42ºC) and successively into 3) ice cold water (3–4ºC) 4) after 45 minutes of rest using vectorial analysis and image editing programs . We measured the line between 2 intersection points of each vessel edges with the circle drawn at 0.5 optic disk diamater from the optic disk margin (in pixel). We compared this relative value with 3 others of the same vessel taken at different procedures in the same way to obtain ratios of vessel caliber changes. We compared the measurements between each group and accepted a variation of ±10% as normal. Results:After warm stimulus arteriolar vasodilation (AVD) and vasoconstriction (AVC) rates were identical for each group; A: 23.8%, 19%; B: 27.3%, 18.2%; C: 29.7%, 24.3% and venular vasodilation (VVD) rates were found highly increased in all BD patients (A: 9.5%, B: 23.1%, C: 31.6%) and venular vasoconstriction (VVC) rates decreased (A: 21.4%, B: 7.7%, C: 13.1%). After cold provocation (compared to healthies) AVD rates increased for both BD patients group: A:23.8%, B:31.8%, C:37.8% and AVC rates increased too (A: 9,5%, B: 15.9%, C:13.5%); VVD rates were increased in non–ocular BD group (A: 16.6%, B: 17.9%, C: 26.3%) and VVC rates were decrased for the same group (A: 14.2%, B: 15.4%, C: 10.5%). After 45 minutes of rest the AVD and AVC rates were increased in group C (A: 31%, 11.9%; B: 31.8%, 6.8%; C: 43.2%, 18.9%), VVD rates were increased in all BD patients (A: 11.9%, B:30.8%, C:23.7%) and VVC rates were decreased in all BD groups (A:23.8%, B: 7.7%, C: 13.2%). Conclusions:Dysfunction of retinal vessels with evident abnormal and long lasting vasodilation of the venules after warm and cold stimuli in patients with BD are probably the first signs of ocular involvement and explain many pathologic processes in the eye.
Keywords: retina • autoimmune disease • blood supply