Julián García Sánchez

Blood-aqueous barrier permeability determination in HLA B27-positive acute anterior uveitis patients

The blood-aqueous barrier (BAB) permeability was studied by fluorophotometry in 17 healthy control subjects and in 27 eyes from 27 patients with HLA-B27-positive acute anterior uveitis (HLA-B27 AAU). Twenty of these patients had an associated spondyloarthropathy. BAB permeability was studied during the ocular inflammatory crisis and in the disease-free periods in the same patients. Anterior chamber fluorophotometric scans were performed before and 30 minutes after the intravenous injection of 14 mg/kg of sodium fluorescein. The diffusion coefficient (Kd) was obtained from the ratio between the fluorescein concentration in the anterior chamber and the NPBF. Data were analyzed using the Students t test and analysis of variance. A statistically significant difference (P < 0.001) was found between the Kd of active HLA-B27 AAU (61.4±16.8×10−4 min−1) and the Kd of inactive HLA-B27 AAU (4.8±1.6×10−4 min−1). No statistically significant differences were found between the Kd of inactive HLA-B27 AAU and the Kd of the control subjects (4.3±1.0×10−4min−1). We also failed to detect significant differences between patients with and without spondyloarthropathy either during the acute attack or during the disease-free period. On the basis of these results we conclude that the permeability of the BAB remains intact in inactive HLA-B27-positive AAU. The parallel fluorophotometric behaviour of HLA-B27-positive AAU with spondyloarthropathy and without spondyloarthropathy suggests that both share a common pathogenetic mechanism.

An 18-month vitreous fluorophotometric follow-up study in juvenile diabetics.

Abstract. The authors assessed a fluorophotometry follow‐up study of 18 months in 24 juvenile insulin‐dependent diabetic patients with no retinopathy. The initial duration of diabetes was 5.96 ± 3.44 years and the glycosylated hemoglobin (HbAlc) was 10.12 ± 2.27%. The baseline Vitreous Penetration Ratio transmittance value (VPRt) was 4.13 ± 1.31 × 10–6 min‐1 and after 18 months was 5.36 ± 1.85 × 10–6 min‐1, yielding a statistically significant difference (p < 0.01). The average HbAlc during the follow‐up term was 9.80 ± 1.72%. VPRt values were significantly correlated with the duration of diabetes and HbAlc. During the follow‐up 3 patients developed foveal background diabetic retinopathy with respect to a high initial VPRt value (6.22 ± 0.27 × 10–6 min‐1), nevertheless, the other 7 patients with high baseline VPRt did not do so. We suggest that vitreous fluorophotometry could be a beneficial procedure in the management of insulindependent diabetic patients; however, there is not a cutoff value for VPRt values to help distinguish patients prone to develop retinopathy.

Clinical and metabolic factors associated with the blood retinal barrier permeability in insulin dependent diabetes mellitus without retinopathy

The authors assessed a study pointing out the relationship between the permeability of Blood Retinal Barrier (BRB), using vitreous fluorophotometry, and several risk clinical and laboratory data in Insulin Dependent Diabetes Mellitus (IDDM). Eighty eyes of 40 IDDM patients were evaluated. Their mean age was 14.8 ± 3.2 years. Twenty healthy volunteers served as control group (mean age 15.3 ± 3.2 years). Preexisting diabetic retinopathy was dismissed after funduscopy and fluorescein angiography. The studied risk factors were: age, duration of diabetes, HLA antigens, blood pressure, cholesterol and triglycerides levels, glycosylated hemoglobin, insulin dose/kg body weight and fructosamine. Vitreous and lens fluorophotometry was performed in both groups (VPRt). The mean VPRt in IDDM patients was 3.56 ± 1.47 × 10−6 min−1. In healthy subjects it was 2.53 ± 0.55 × 10−6 min−1, establishing a significant difference (p < 0.01). We found a statistically significant correlation between VPRt and duration of diabetes, insulin dose/kg body weight and HbAlc. No correlation was found between VPRt and the rest of parameters. We conclude that vitreous fluorophotometry is a valid method to measure BRB; and the three factors mentioned above are related to the BRB permeability.