Abstract: AIMS/BACKGROUND: Comparison of the diffusion coefficient through the blood-aqueous barrier of healthy volunteers measured in different cities with identical fluorophotometers using a standardised protocol. METHODS: Healthy volunteers aged between 20 and 70 years were studied in seven European cities. The fluorescein concentration in the anterior segment of each eye was measured with a commercial scanning fluorophotometer 30 and 40 minutes after intravenous fluorescein. The decay of non-protein bound fluorescein concentration in blood plasma was determined with the use of three blood samples taken at 7, 15, and 55 minutes after injection. The diffusion coefficient through the blood-aqueous barrier was calculated from the ratio between the fluorescein concentration in the anterior chamber and the time integral of non-protein bound fluorescein concentration in plasma using specially developed software. RESULTS: The mean values of the diffusion coefficient (SD) (X10(-4) min-1) were 4.76 (1.51) (n = 20, Brussels), 5.48 (2.33) (n = 17, Coimbra), 3.47 (2.09) (n = 12, Cologne), 6.09 (2.77) (n = 21, Frankfurt), 3.85 (1.59) (n = 11, Ghent), 4.99 (1.69) (n = 23, Leiden), and 4.87 (1.05) (n = 20, Madrid). The values between centres were similar (Kruskal-Wallis test p > 0.05) except for Cologne and Frankfurt (p = 0.013). No differences were found when repeating measurements (four centres, interval time 1-8 months, Wilcoxon paired test p > 0.39). CONCLUSION: The diffusion coefficients had similar values and standard deviations. The concerted action demonstrated the usefulness of a standardised protocol.

Abstract: Twenty-two patients with severe epiphora due to relative (n = 13) or absolute (n = 9) stenoses of the nasolacrimal duct were treated by means of radiologically guided balloon dacryocystoplasty. The recanalization was performed with a steerable microguide wire with flexible tip, which was advanced through the lacrimal draining system and manipulated out of the nasal cavity. A 3-mm PTA balloon was then introduced from the nasal site. In 20 of 22 cases the procedure was technically successful. Dacryocystography proved a normal lumen in 9 of 20 patients and an improvement without impairment of flow in another 8 cases. Two months after dilation a clear regression of epiphora could be demonstrated in 17 of 20 patients. The procedure was complicated by the occurrence of 2 reobstructions within the first 3 months; other serious side effects were not observed.

Abstract: For the evaluation of a possible malfunction of the blood-retinal (BRB) and the blood-aqueous barrier (BAB) in type I diabetes without manifest angiopathy, after i.v. injection of sodium fluorescein, the permeability of BRB (P) and the diffusion coefficient of BAB [P(a)] were studied simultaneously by fluorophotometry in 34 eyes of 34 type I diabetics (HbA1c = 6.6 +/- 0.9%) without retinopathy whose ages ranged from 19 to 38 years (30.5 +/- 5); diabetes' duration was between 5 and 18 years. Fluorescein angiography was performed to exclude nonperfused areas. In all, 34 eyes of 34 healthy volunteers whose ages ranged between 23 and 34 years (28.5 +/- 3.3) served as controls; in this group, fluorophotometry was performed twice to evaluate reproducibility. The mean BAB diffusion coefficient in diabetics [P(a) = 5.3 +/- 1.8/min] was significantly increased (p = 0.00003) as compared to controls [P(a) = 3.7 +/- 0.7/min]; BRB permeability in diabetes (P = 3.2 +/- 1.4 x 10(-7) cm/s) was raised with this elevation being of lower significance (p = 0.019; controls: P = 2.6 +/- 0.7 x 10(-7) cm/s). We found a decrease in BRB permeability depending on diabetes' duration (r = -0.15; p = 0.007) that was not significant in BAB (r = -0.1; p = 0.24). No correlation was found to exist between permeability and HbA1c values either in BAB or in BRB. The reproducibility in controls was 9% in BRB determinations and 12% in BAB measurements. These results may suggest that early structural alterations without the manifestation of retinopathy possibly cause elevation in BRB permeability and are even more obvious in BAB permeability. Whereas the reliability of vitreous fluorophotometry in detecting early BRB malfunction has to be judged critically, anterior segment fluorophotometry is a reliable procedure for the monitoring of BAB affection in type I diabetes without retinopathy.

Abstract: In ten patients with incomplete postsaccal stenosis radiology examined by digital subtraction dacryocystorhinography, an overpressure ballooning was done with a small foot vessel balloon with hydrophilic surface under image intensiver control. The balloon was inflated with a diluted suspension for visualization of the balloon and widening of the stenosis. In eight patients recovery was continuous without any treatment, in one with topical application of vasoconstrictor eye drops. In one patient there was a recurrence. Balloon of incomplete postsaccal lacrimal pathway dilatation stenosis is an adequate and minimally invasive therapy.

Abstract: BACKGROUND: The study was carried out to compare corneal endothelial permeability and aqueous flow values of healthy volunteers measured in different countries with identical fluorophotometers using a standardized protocol. METHOD: Healthy volunteers aged between 20 and 70 years were studied in five European cities. Fluorescence scans of the anterior segment of both eyes were made using a commercial fluorophotometer. Beginning 4 h after instillation of four drops of fluorescein 10%, 12 scans of the anterior segment of each eye were performed in 2 h. The values of corneal endothelial permeability and aqueous flow were calculated with standardized software from the decay of the fluorescein concentration in the cornea and anterior chamber. RESULTS: The mean permeability values (x 10(-4) cm.min-1) +/- SD were 3.7 +/- 1.6 (n = 19; Coimbra, Portugal), 4.3 +/- 1.1 (n = 19; Frankfurt, Germany), 3.9 +/- 0.9 (n = 19; Leiden, The Netherlands) and 5.4 +/- 1.2 (n = 10; Milan, Italy). The values were not significantly different (ANOVA, P > 0.3), except those in Milan. The mean flow values (microliters.min-1) +/- SD were 2.3 +/- 0.9 (n = 17; Coimbra), 1.9 +/- 0.7 (n = 10; Cologne, Germany), 2.6 +/- 1.2 (n = 19; Frankfurt), 2.0 +/- 0.6 (n = 19; Leiden) and 1.7 +/- 0.8 (n = 10; Milan). The values were not significantly different (Kruskal-Wallis test, P > 0.1). CONCLUSIONS: Permeability and flow values in the different cities had similar values and standard deviations. The Concerted Action demonstrated the usefulness of a standardized protocol.

Abstract: An intact posterior capsule between aqueous and vitreous may act as a barrier to substances of low and high molecular weight, e.g., prostaglandins, hyaluronic acid, or the angiogenic factor. After phacoemulsification followed by posterior YAG capsulotomy, an increased diffusion rate of such molecules into the vitreous and increased permeability of blood aqueous barrier (BAB) may occur. These barriers were quantified in eyes that underwent YAG capsulotomy after sulcus or intracapsular IOL implantation in order to determine the safest surgical procedure with respect of maintenance of these barriers. PATIENTS AND METHODS: Between 2 to 6 h after topical fluorescein application, the time-dependent decrease in dye concentration ratio between aqueous and anterior vitreous leads to the diffusion rate D(av) [10(-3)min-1] between aqueous and vitreous; D(av) was evaluated fluorophotometrically before and 3 weeks after capsulotomy (3 to 5 mm) in human eyes of each group. In order to quantify BAB function, aqueous laser flare was measured in eyes with sulcus and capsular fixation of IOL before, 3 h, and 3 weeks after YAG capsulotomy. RESULTS: After YAG surgery D(av) increased 2.7-fold (P < 0.001) in eyes with a sulcus implant compared to the values obtained in the group that had an intracapsular PCL. Aqueous laser flare was increased to 140% (P < 0.001) in eyes with sulcus fixation and to 95% (P < 0.001) in eyes with capsular fixation of PCL. Laser flare values became normal 3 weeks after laser treatment (P > 0.05). CONCLUSION: Intracapsular PCL implantation more effectively maintains the protective aqueous vitreous barrier and BAB after posterior capsulotomy than sulcus implantation. This possibly reduces the incidence of cystoid macular edema (diffusion of prostaglandins), retinal detachment (loss of hyaluronic acid of the vitreous), endophthalmitis (spread of bacteria) or rubeosis iridis (angiogenic factor) after YAG capsulotomy.

Abstract: BACKGROUND: Clinical findings in patients with retinitis pigmentosa (RP) frequently include cystoid macular edema (CME) and vitreous pigment dusting (VPD) indicating alterations of the blood-ocular barriers. It was the aim of this study to determine whether alterations of the blood-aqueous barrier (BAB) are present in RP. PATIENTS AND METHODS: Aqueous flare was quantitatively determined in 56 eyes of 29 patients (mean age 36.4 +/- 11.2 years) with RP using the noninvasive laser flare-cell photometer (Kowa FC-1000, Tokyo, Japan). All RP patients had common forms of RP with markedly reduced or nondetectable ERG. The presence of CME and VPD was determined semiquantitatively by biomicroscopy. Fifty-eight eyes of 58 normal controls (mean age 38.2 +/- 8.5 y.) were also examined. RESULTS: Aqueous-flare values were significantly higher in RP eyes (mean 9.65 +/- 3.24 photon counts/ms, range 4.0-18.1) than in the normal control eyes (mean 3.89 +/- 1.05, range 1.9-6.0, p < 0.0001, Mann-Whytney test). Forty-eight of the 56 RP eyes (86%) showed increased flare values (> 6.0 photon counts/ms). RP eyes with moderate to marked CME (n = 11) had significantly higher flare values (mean 14.66 +/- 1.92) than RP eyes without or with only questionable CME (8.52 +/- 2.18, p < 0.0001), and RP eyes with moderate to marked VPD (n = 17) had significantly higher (12.05 +/- 2.84) flare values than RP eyes without or with only minimal VPD (8.74 +/- 2.22, p < 0.0005). CONCLUSIONS: Our findings show that the majority of patients with RP have alterations of the BAB with consecutively increased aqueous protein concentrations. The impairment of the BAB appears to be associated with CME and VPD. Measurement of aqueous flare in RP allows quantification of the impairment of the BAB and may be helpful in the future in choosing and monitoring patients with RP and CMP for possible antiinflammatory or antiedematous therapeutic measures.

Abstract: For the evaluation of a possible malfunction of the blood-retinal barrier (BRB) and the blood-aqueous barrier (BAB) in type I diabetes without manifest angiopathy after i.v. injection of sodium fluorescein, the permeability of the BRB (P) and the permeability coefficient of the BAB [P(a)] were simultaneously determined by fluorophotometry in 34 eyes of 34 type-I diabetics [hemoglobin (Hb)A1c = 6.6% +/- 0.9%] without retinopathy whose age ranged from 19 to 38 years (mean, 30.5 +/- 5 years); the diabetes duration was between 5 and 18 years. Fluorescein angiography was performed to exclude nonperfused areas. In all, 34 eyes of 34 healthy volunteers whose age ranged between 23 and 34 years (mean, 28.5 +/- 3.3 years) served as controls; in this group, fluorophotometry was performed twice to evaluate reproducibility. The mean BAB permeability coefficient in diabetics [P(a) = 5.3 +/- 1.8 x 10(-4)/min] was significantly increased (P = 0.00003) as compared with control values [P(a) = 3.7 +/- 0.7 x 10(-4)/min]; BRB permeability in diabetics (P = 3.2 +/- 1.4 x 10(-7) cm/s) was raised, with this elevation being of lower significance (P = 0.019; controls, P = 2.6 +/- 0.7 x 10(-7) cm/s). We found a decrease in BRB permeability depending on diabetes duration (r = -0.15; P = 0.007) that was not significant in the BAB (r = -0.1; P = 0.24). No correlation was found to exist between permeability and hemoglobin (Hb)A1c values either in the BAB or in the BRB. The reproducibility in controls was 9% in BRB determinations and 12% in BAB measurements.(ABSTRACT TRUNCATED AT 250 WORDS)

Abstract: BACKGROUND: Possibly early functional disruption of the blood-ocular barrier in eyes of insulin dependent type I diabetics without manifestation of retinopathy can be detected using fluorophotometry and laser flare measurement. MATERIAL AND METHODS: In order to evaluate blood-retinal (BRB) and blood-aqueous-barrier (BAB) permeability fluorophotometry was performed in 34 eyes of 34 insulin-dependent type-I diabetics without retinopathy, additionally the aqueous laser flare was measured. 34 normal eyes of 34 age-matched subjects served as controls. RESULTS: BRB permeability (3.2 +/- 1.3 x 10(-7) cm/s) was increased with low significance (p = 0.019) in diabetic eyes (controls: 2.6 +/- 0.7). The permeability coefficient of BAB was found to be increased in diabetics (5.3 +/- 1.8 x 10(-4)/cm) with higher significance (controls: 3.7 +/- 0.7; p = 0.00003); laser flare values in diabetic eyes (5.0 +/- 1.2 photon counts/ms) were significantly higher than in controls (4.1 +/- 1.0; p = 0.003). In diabetics there was a significant correlation (r = 0.3; p = 0.014) between the laser flare values and the permeability coefficient of BAB. CONCLUSIONS: In type-I diabetics without retinopathy BRB permeability seems to be increased slightly as well as laser flare in the aqueous; the BAB permeability coefficient seems to be the most sensitive parameter in a beginning affection of the blood-ocular barrier.

Abstract: Fluorophotometry allows calculation of the permeability coefficient k(a) of the blood-aqueous barrier to fluoresceine after i.v. dye application; aqueous flare can be graded objectively by laser flare measurement and permits in vivo estimation of over-all protein concentration in the aqueous humor. To evaluate a formal relationship between both procedures we performed laser flare measurements on 40 eyes (clinically ranged from healthy to mild uveitis) before and during fluorophotometry. Laser flare count [mec-1] raises exponentially (r = 0.8; p = 0.05) with an increasing permeability coefficient to fluoresceine k(a) [10(-4)min-1]. Laser flare count during the fluorophotometry procedure is not increased (p = 0.05) compared to the prescan. Reproducability was 14% +/- 7.5% for laser flare measurements and 13% +/- 5% for fluorophotometry. Malfunction of the blood aqueous barrier possibly increases the permeability to molecules of high molecular weight not proportional to that of hydrophilic particles of low molecular weight. The exponential regression between the data achieved with both procedures suggests that fluorophotometry is more sensitive in detecting early changes in blood aqueous barrier function whereas laser flare detection could be appropriate in more severe cases of barrier dysfunction.