Vitreous Fluorophotometry for Clinical Research

Retinal Vascular Permeability in Diabetic Subjects without Retinopathy Compared with Mild Diabetic Retinopathy and Healthy Controls

“…Previous studies have used posterior vitreous fluorophotometry to assess blood-retinal barrier breakdown in patients with diabetes and either no DR, minimal DR, or both no and minimal DR, with mixed results that are difficult to compare because of the reliance on different techniques and fluorophotometers. 34 , 35 , 36 , 37 , 38 Chahal et al did not find any significant difference between the permeability coefficient ( p ), diffusion coefficient ( D ), or permeability index ( PI ) in insulin-dependent diabetic patients with no or minimal DR ( p = 1.94 ± 1.03 cm·s −1 ·10 −7 ; D = 1.74 ± 1.53 cm 2 s −1 ·10 −5 ; PI = 2.14 ± 1.21 cm·s −1 ·10 −7 ) and healthy control subjects ( p = 1.99 ± 0.95 cm·s −1 ·10 −7 ; D = 2.05 ± 1.03 cm 2 ·s −1 ·10 −5 ; PI = 1.15 ± 0.38 cm·s −1 ·10 −7 ), whereas in a comparable study conducted by Cunha-Vaz et al, the posterior vitreous fluorescein concentration and penetration ratio (i.e., ratio between posterior vitreous fluorescein concentration and free plasma fluorescein concentration) in diabetic patients with no or 1 aneurysm were both significantly higher compared with healthy control patients. 36 , 37 In a dual tracer study conducted on healthy Long Evans rats, the vascular permeability as represented by E was 0.08 at baseline (n = 13) and 0.15 post-mannitol infusion (n = 3), 10 which is significantly higher than the observed E s in this human study (0.04 ± 0.01, 0.07 ± 0.04, and 0.10 ± 0.04 for control, DMnoDR, and mild NPDR groups, respectively).…”

Retinal Vascular Permeability in Diabetic Subjects without Retinopathy Compared with Mild Diabetic Retinopathy and Healthy Controls

“…Previous studies have used posterior vitreous fluorophotometry to assess blood-retinal barrier breakdown in patients with diabetes and either no DR, minimal DR, or both no and minimal DR, with mixed results that are difficult to compare because of the reliance on different techniques and fluorophotometers. 34 , 35 , 36 , 37 , 38 Chahal et al did not find any significant difference between the permeability coefficient ( p ), diffusion coefficient ( D ), or permeability index ( PI ) in insulin-dependent diabetic patients with no or minimal DR ( p = 1.94 ± 1.03 cm·s −1 ·10 −7 ; D = 1.74 ± 1.53 cm 2 s −1 ·10 −5 ; PI = 2.14 ± 1.21 cm·s −1 ·10 −7 ) and healthy control subjects ( p = 1.99 ± 0.95 cm·s −1 ·10 −7 ; D = 2.05 ± 1.03 cm 2 ·s −1 ·10 −5 ; PI = 1.15 ± 0.38 cm·s −1 ·10 −7 ), whereas in a comparable study conducted by Cunha-Vaz et al, the posterior vitreous fluorescein concentration and penetration ratio (i.e., ratio between posterior vitreous fluorescein concentration and free plasma fluorescein concentration) in diabetic patients with no or 1 aneurysm were both significantly higher compared with healthy control patients. 36 , 37 In a dual tracer study conducted on healthy Long Evans rats, the vascular permeability as represented by E was 0.08 at baseline (n = 13) and 0.15 post-mannitol infusion (n = 3), 10 which is significantly higher than the observed E s in this human study (0.04 ± 0.01, 0.07 ± 0.04, and 0.10 ± 0.04 for control, DMnoDR, and mild NPDR groups, respectively).…”

Retinal Vascular Permeability in Diabetic Subjects without Retinopathy Compared with Mild Diabetic Retinopathy and Healthy Controls

“…Previous studies have used posterior vitreous fluorophotometry to assess blood-retinal barrier breakdown in patients with diabetes and either no DR, minimal DR, or both no and minimal DR, with mixed results that are difficult to compare because of the reliance on different techniques and fluorophotometers. 34 , 35 , 36 , 37 , 38 Chahal et al did not find any significant difference between the permeability coefficient ( p ), diffusion coefficient ( D ), or permeability index ( PI ) in insulin-dependent diabetic patients with no or minimal DR ( p = 1.94 ± 1.03 cm·s −1 ·10 −7 ; D = 1.74 ± 1.53 cm 2 s −1 ·10 −5 ; PI = 2.14 ± 1.21 cm·s −1 ·10 −7 ) and healthy control subjects ( p = 1.99 ± 0.95 cm·s −1 ·10 −7 ; D = 2.05 ± 1.03 cm 2 ·s −1 ·10 −5 ; PI = 1.15 ± 0.38 cm·s −1 ·10 −7 ), whereas in a comparable study conducted by Cunha-Vaz et al, the posterior vitreous fluorescein concentration and penetration ratio (i.e., ratio between posterior vitreous fluorescein concentration and free plasma fluorescein concentration) in diabetic patients with no or 1 aneurysm were both significantly higher compared with healthy control patients. 36 , 37 In a dual tracer study conducted on healthy Long Evans rats, the vascular permeability as represented by E was 0.08 at baseline (n = 13) and 0.15 post-mannitol infusion (n = 3), 10 which is significantly higher than the observed E s in this human study (0.04 ± 0.01, 0.07 ± 0.04, and 0.10 ± 0.04 for control, DMnoDR, and mild NPDR groups, respectively).…”

Retinal Vascular Permeability in Diabetic Subjects without Retinopathy Compared with Mild Diabetic Retinopathy and Healthy Controls

“…Previous studies have used posterior vitreous fluorophotometry to assess blood-retinal barrier breakdown in patients with diabetes and either no DR, minimal DR, or both no and minimal DR, with mixed results that are difficult to compare because of the reliance on different techniques and fluorophotometers. 34 , 35 , 36 , 37 , 38 Chahal et al did not find any significant difference between the permeability coefficient ( p ), diffusion coefficient ( D ), or permeability index ( PI ) in insulin-dependent diabetic patients with no or minimal DR ( p = 1.94 ± 1.03 cm·s −1 ·10 −7 ; D = 1.74 ± 1.53 cm 2 s −1 ·10 −5 ; PI = 2.14 ± 1.21 cm·s −1 ·10 −7 ) and healthy control subjects ( p = 1.99 ± 0.95 cm·s −1 ·10 −7 ; D = 2.05 ± 1.03 cm 2 ·s −1 ·10 −5 ; PI = 1.15 ± 0.38 cm·s −1 ·10 −7 ), whereas in a comparable study conducted by Cunha-Vaz et al, the posterior vitreous fluorescein concentration and penetration ratio (i.e., ratio between posterior vitreous fluorescein concentration and free plasma fluorescein concentration) in diabetic patients with no or 1 aneurysm were both significantly higher compared with healthy control patients. 36 , 37 In a dual tracer study conducted on healthy Long Evans rats, the vascular permeability as represented by E was 0.08 at baseline (n = 13) and 0.15 post-mannitol infusion (n = 3), 10 which is significantly higher than the observed E s in this human study (0.04 ± 0.01, 0.07 ± 0.04, and 0.10 ± 0.04 for control, DMnoDR, and mild NPDR groups, respectively).…”