Sodium fluorescein influence on the hemorheological profile of non-insulin dependent diabetes mellitus patients.

Sodium fluorescein angiography is a widely used technology in ophthalmology, which allows us to visualise the chorioretinal microcirculation. Previous reports showed a prolongation of the retinal circulation time along with erythrocyte hyperaggregation and a decrease of erythrocyte acetylcholinesterase activity and a possible interference with the erythrocyte's membrane fluidity. The aim of the present work is to investigate the influence of sodium fluorescein on the hemorheological profile of a group of 23 non-insulin dependent diabetes mellitus (NIDDM) patients undergoing routine retinal angiography. Thirty minutes after the endovenous administration of the fluorescein there was: (I) an increase of whole blood viscosity (p = 0.015), erythrocyte elongation index (EEI, p < 0.05), whole blood pH (p < 0.001), methemoglobin (p < 0.001) and carboxyhemoglobin (p < 0.001) concentrations; (II) no variation of plasma osmolality and erythrocyte aggregation index (EAI); (III) a decrease of the erythrocyte acetylcholinesterase activity, p < 001; (IV) no variation in membrane lipid fluidity, although 1,6-diphenyl-1,3,5-hexatriene (DPH) correlated directly with the EEI, while 1,4-trimethyl-phenyl-1,3,5-hexatriene (TMA-DPH) and EAI correlated inversely, suggesting that the decreasing EEI (lower erythrocyte deformablity) might be associated with an increased rigidity of the external polar region and fluidification of the hydrophobic region of the erythrocyte membrane, with an increasing EAI. In conclusion, the endovenous administration of sodium fluorescein in NIDDM patients during the retinal angiography procedure interferes with the erythrocyte membrane and possibly with the microcirculatory blood flow.

Red blood cell membrane integrity in primary open angle glaucoma: ex vivo and in vitro studies.

PURPOSE: There is increasing evidence that abnormal perfusion of the optic nerve head is an important factor involved in the pathophysiology of glaucoma. Transport and distribution of oxygen to the tissues takes place through the erythrocyte membrane. Red blood cell (RBC) acetylcholinesterase (AChE) is a marker of RBC membrane integrity. The aim of this study was to find out whether RBC membrane integrity is preserved in primary open angle glaucoma (POAG), and whether it is modified by the use of topical timolol maleate and pilocarpine. METHOD: RBC AChE activity was determined ex vivo by Kaplan's spectrophotometric method in 19 POAG patients undergoing topical treatment for glaucoma with timolol, pilocarpine or a combination of the two drugs, and compared with that in 20 controls. To assess the effect of antiglaucomatous therapy in our findings, we carried out an in vitro study in 26 non-glaucomatous patients in which we measured RBC AChE activity after incubation of blood with either timolol maleate, pilocarpine or a combination of the two drugs, using the same spectrophotometric method. RESULTS: There was a significant increase in RBC AChE enzyme activity in POAG patients compared with the control group (p < 0.002). However, timolol and pilocarpine, individually or in combination, have the opposite effect, significantly decreasing RBC AChE activity (p < 0.05). CONCLUSION: This change in RBC AChE enzyme activity could suggest alterations in RBC membrane integrity in primary open angle glaucoma. Whether or not this finding has implications regarding the microcirculation at the optic nerve head needs to be investigated further.

The effect of sodium fluorescein angiography on erythrocyte properties.

Sodium fluorescein angiography is a widely used routine ophthalmological diagnostic procedure which enables the study of chorioretinal microcirculation and consists of the injection of sodium fluorescein into the systemic bloodstream. The aim of the present study was to evaluate whether or not fluorescein interferes with erythrocyte properties during the angiographic procedure. In a group of 37 patients, 26 with non-insulin-dependent diabetes mellitus (DM) with and without retinopathy, and 11 without diabetes mellitus (non-DM) although affected by other ophthalmological diseases, all undergoing routine angiography, blood samples were drawn before (T0) and 30 min (T30) after fluorescein injection. The erythrocyte aggregation index (EAI), membrane lipid fluidity and erythrocyte acetylcholinesterase activity were determined in both groups. After fluorescein injection there was no statistical change in EAI and erythrocyte membrane fluidity in either group. Erythrocyte acetylcholinesterase activity, a marker of membrane protein integrity, decreased significantly (p < 0.01) in the DM group. Membrane lipid fluidity did not change with fluorescein injection, however (i) in the DM group erythrocyte membranes became more rigid than in the non-DM (DPH: p < 0.01); (ii) EAI and membrane lipid fluidity became significantly correlated (r = 0.6263, p < 0.05) in non-DM patients at T30. In conclusion, fluorescein administration for angiographic procedures seems to interact with erythrocyte membrane, namely, in diabetic patients, which may interfere with the blood flow in the microcirculation.

[The effect of angiography with disodium fluorescein on the hemorheologic parameters of diabetics]. / Estudo da influência da angiografia com fluoresceína bissódica nos parâmetros hemorreológicos de doentes com diabetes mellitus.

Chorioretinal angiography with fluorescein is an auxiliary method widely used in Ophthalmology which enables us to study the blood/humour and blood/retina/choroid interface. The presence of a strange compound in circulation may interfere with blood flow homeostasis. With the aim of studying fluorescein influence in blood rheology, blood samples were drawn before, immediately after and 30 minutes after fluorescein bolus injection; from 10 patients with diabetes mellitus, with or without retinopathy, blood fluidity (hematocrit, erythrocyte aggregation and whole blood viscosity) and erythrocyte membrane functional properties were determined. After fluorescein injection there was erythrocyte hyperaggregation (37.7%, p = 0.004), was detected, hemoglobin concentration (p = 0.039) and hematocrit (p = 0.013) decrease, and a double time increase of methemoglobin concentration (p < 0.001) the erythrocyte membrane hydrophobic region became more rigid (p = 0.016). All these abnormalities normalized after 30 minutes. In conclusion, fluorescein angiography interferes acutely with the hemorheological parameters of patients with diabetes mellitus, with erythrocyte hyperaggregation which could interfere with the microcirculation of these patients.

Behçet's disease in Portugal.

During the last decades 156 patients with Behçet's disease were diagnosed and studied in Portugal. Until 1966 only two cases were referred in Portugal. In 1978 we reported 23 cases (18 males and 5 females) with multisystemic involvement, not different from that reported in other publications elsewhere. In 1987, 17 cases were reported from the Oporto region, diagnosed during a period of 5 years. In the region of Coimbra 15 cases were diagnosed (6 males and 9 females). In the Lisbon area from 1969 until 1990, 123 cases were studied altogether, 76 during the last decade (35 males and 41 females). All the cases studied had oral ulcerations and a high incidence of ocular involvement (clinical and sub-clinical, 87%). HLA-B5 was detected in 50% of the patients. At least four cases were fatal, three died with neuro-Behçet. Steroids, colchicine and thalidomide were the main form of treatment, for the patients in the Lisbon area, but in some cases chlorambucil, cyclophosphamide, azathioprine, cyclosporine-A, fibrinolytic therapy, plasmapheresis and isovolemic hemodilution were also used.

Uveomeningoencephalitis in a human immunodeficiency virus type 2-seropositive patient.

A 35-year-old woman developed longstanding uveitis and later a uveomeningoencephalitis of unknown origin and died of toxoplasmal brain abscesses. The presence of immunological impairment, human immunodeficiency virus type 2 (HIV-2) seropositivity, and multinucleated cells in the brain led us to suspect neurotropic properties for HIV-2 similar to those of HIV-1.

Haematological changes in retinal vasculitis.

Two selected cases of retinal vasculitis, apparently of unknown aetiology, are reported; one case without any systemic or laboratory manifestation and the second case with a clinical picture similar to VKH syndrome and immunodepression. Both cases showed abnormal haematological parameters related to blood viscosity in the early and acute phases which could be manipulated by therapy. Reduction or near normalisation of these haemorrheological parameters coincided with clinical and angiographic improvement. The second case with severe immunodepression was found to be retrovirus HIV-2 positive.