Cancer risk in healthy patients who underwent chest tomography comparing three different technologies.

This research aimed to estimate the risk of cancer associated with patients without previous disease undergoing chest tomography. Siemens CT scanners have 6, 64, and 128 detectors. The Biologic Effects of Ionizing Radiation Reports - BEIR VII methodology was used. The study presented a sample of 64 patients aged between 18 and 80 years, in the city of Belo Horizonte, Minas Gerais - Brazil. The IMPACT CT software and CalDose X CT Online were used to calculate the absorbed and equivalent dose from the Volumetric Computed Tomography Dose Index - CTDIvol (mGy) and Dose Length Product - DLP values provided by the equipment. CT-Expo Software was also used to estimate Specific Dose Estimates (SSDEs) values. The CTDvol results for the MG1, MG,2 and MG3 Diagnostic Centers in mGy were respectively 4.369 ± 1.352, 6.99 4 ± 1.53,3 and 9.984 ± 2.282 and the SSDE values were 3.800, 6.40,0 and 9,.500. The values for the equivalent dose, at the MG2 Diagnostic Center, by IMPACT CT, in (mSv) for the breasts, esophagus, heart, thyroid, lung and thymus were respectively 3.9, 5.7, 4.7, 1.0, 4.8 and 5.7. The CalDose Software, for the same equipment and the same organs, in mSv, estimated the values 7.4, 9.4, 11.1, 5.3, 10.8 and 11.3 for women and 7.1, 9.3, 11.0, 5.3, 10.2 and 10.9 for men. The estimated risk of cancer decreased according to the patient's age, but with a higher incidence for females. The use of each software must be carefully analyzed to avoid undue values due to the particularities of each one. The results also showed that the risk of developing cancer due to radiation decreases with patient age and is higher in females.

Evinacumab to treat hypercholesterolemia.

Cardiovascular disease is the most common cause of death worldwide and is mainly due to atherosclerosis. Elevated levels of low-density lipoprotein cholesterol (LDL-C) are the main risk factor for atherosclerosis. Treatment with existing therapies for dyslipidemia and life-style changes are often sufficient to reach the lipid targets and decrease the cardiovascular risk of patients. However, there are patients who cannot reach their targets. Especially patients with genetically caused dyslipidemias, such as familial hypercholesterolemia, often are not able to reach the targets, leading to an increased cardiovascular risk and higher mortality. Evinacumab is a human monoclonal antibody which binds and inhibits angiopoietin-like protein 3 (ANGPTL3). The inhibition of ANGPTL3 leads to increased activity of the lipoprotein lipase (LPL) and the endothelial lipase (EL). LPL is the main enzyme for hydrolyzation of triglyceride-rich lipoproteins. EL is a phospholipase which preferentially hydrolyzes high-density lipoprotein (HDL) but also decreases circulating LDL-C. The increased LPL and EL activity reduces circulating levels of very-low-density lipoprotein cholesterol, triglycerides, LDL-C and HDL-cholesterol. Evinacumab leads to a significant decrease in circulating lipids and attainment of lipid targets in these patients. Further studies with evinacumab to assess its lipid-decreasing potential and to evaluate its impact on cardiovascular risk and mortality are eagerly awaited.

The Impact of Tenofovir Disoproxil Fumarate on Reduced Bone Mineral Density and Fractures in Liver Transplant Recipients.

BACKGROUND: Tenofovir disoproxil fumarate (TDF) is associated with reduced bone density in patients with human immunodeficiency virus, but the effect of TDF on bone density in liver transplant (LT) recipients is unknown. METHODS: We performed a single-center, retrospective study of LT recipients with hepatitis B taking TDF compared to a control group with non-hepatitis B virus viral hepatitis. The primary outcome was reduced bone density, defined as femoral neck or lumbar T-score less than -1. Other outcomes included mean T-score and fractures. RESULTS: Three hundred ninety-three patients were studied: 52 patients in the TDF group and 341 patients in the control group; 64.3% patients in the TDF group had reduced bone density vs 71.4% in the control group (P = .58) before LT, compared to 75% and 81.5% (P = .57), respectively, after LT. Mean posttransplant lumbar T-scores were lower in the TDF group (-1.74 vs -0.75, P = .04). There was no difference between the 2 groups for the other outcomes. In a multivariate Cox proportional hazards model, TDF use did not affect the risk of post-LT reduced bone density (hazard ratio = 0.99; 95% confidence interval, 0.56-1.76; P = .97). CONCLUSION: TDF use was not associated with reduced bone mineral density or increased rates of fractures in LT recipients compared to controls in this study.

[Surgical treatment of lamellar macular hole]. / Operative Therapie bei Makulaschichtforamen.

PURPOSE: Vitrectomy and peeling in patients with lamellar macular hole was evaluated with regard to anatomical and functional outcome. PATIENTS AND METHODS: In a retrospective study, 10 patients with lamellar macular hole underwent vitrectomy, membrane-peeling (epiretinal membrane [ERM] and internal limiting membrane [ILM]) and gas (n=9) or silicone oil (n=1) endotamponade. In most patients (n=9), cataract surgery was also performed. Pre- and postoperative ocular coherence tomography (OCT) findings, visual acuity (ETDRS), and Birkhäuser near visual acuity were evaluated. RESULTS: Mean follow-up was 15+/-11 months after surgery with a minimum follow-up of 6 months. Best corrected visual acuity (BCVA) improved in all patients; the average BCVA gain was 3+/-2 lines. Preoperative mean BCVA was 0.35 (0.45+/-0.23logMAR), and postoperative BCVA was 0.64 (0.19+/-0.21logMAR). Eight of ten patients had a postoperative BCVA > or =20/40, and six patients had a postoperative BCVA > or =20/25. Mean near visual acuity was 0.5+/-0.26 (range 0.2-0.9). Postoperative OCT revealed a closed lamellar macular hole in six patients, with restored foveal contour in three of them. The other four patients showed a persistent inner retinal defect with an intact photoreceptor layer. CONCLUSION: Surgical treatment including vitrectomy, ERM-ILM-peeling and endotamponade appears to benefit patients with lamellar macular hole. All patients improved functionally. Surgical treatment can close the lamellar macular hole and restore foveal architecture.

[Intravitreal anti-VEGF therapy with bevacizumab for neovascular AMD]. / Intravitreale Anti-VEGF-Therapie mit Bevacizumab bei neovaskulärer AMD.

PURPOSE: To report on the efficacy of intravitreal bevacizumab as off-label therapy in different angiographic subtypes in neovascular age-related macular degeneration (AMD). METHODS: Seventy-five patients with neovascular AMD and recent disease progression were classified into different angiographic subtypes and were treated with intravitreal bevacizumab (1.25 mg/0.05 ml) at 6-week intervals. Patients with subfoveal classic choroidal neovascularization (CNV) also received photodynamic therapy. ETDRS visual acuity, ophthalmic exams, and optic coherence tomography (OCT) were performed before treatment, 1 week after treatment, and then on a 6-week basis. Fluorescein angiographies and medical check-ups were also done. RESULTS: Bevacizumab led to stabilization of visual acuity (loss of less than 15 letters) in all angiographic subtypes during a follow-up of 37+/-13 weeks. Patients with occult extrafoveal CNV (n=6) profited the most and gained 2+/-2 lines. Treatment with intravitreal bevacizumab was very well tolerated in all patients, with neither systemic nor intraocular side effects, with the exception of one retinal pigment epithelium tear. CONCLUSION: Intravitreal bevacizumab treatment is efficacious in all angiographic CNV subtypes and leads to reduction of macular edema and stabilization or improvement in visual acuity.

[Functional results after anatomically successful surgery for stage III/IV macular hole]. / Funktionelle Ergebnisse nach anatomisch erfolgreicher Makulaforamen-Stadium-III/IV-Chirurgie.

PURPOSE: To report the functional results after anatomically successful surgery for stage III/IV macular hole. METHODS: Follow-up examinations (ETDRS charts, Birkhäuser near visual acuity charts, OCT) were carried out in 29 patients 11+/-5 months after surgery for stage III/IV macular hole (hole size >400 microm); in all cases the foveal contour had been restored postoperatively . The surgery performed also included cataract surgery (n=26), vitrectomy, ICG-assisted ILM peeling (in which perfluorcarbon liquid was used to prevent ICG from coming in contact with the retinal pigment epithelium) and tamponade with intraocular gas (n=16) or silicone oil (n=13). Silicone oil had been removed by the time of the follow-up evaluation. RESULTS: Preoperative mean BCVA was 0.2 (0.64 logMAR+/-0.24) and postoperative BCVA, 0.5 (0.3 logMAR+/-0.19). None of the patients experienced any deterioration in sight; the average improvement in visual acuity was 3.5+/-2 lines. In 70% (n=20) of the patients the postoperative BCVA was > or =0.5. Visual acuity for near sight was 0.45+/-0.2. In 66% (n=19) a visual acuity of > or =0.4 was achieved for close work. The improvement in visual acuity was not related to the kind of endotamponade or to the size of the macular hole. Patients with macular hole diameters of 400-800 microm (n=20) gained 3.5+/-2.,4 lines, while in patients with macular hole diameters of 800-1135 microm the average gain was 3.6+/-1.3 lines. CONCLUSIONS: Anatomically successful macular hole stage III/IV surgery with ICG-assisted ILM peeling and protection of the retinal pigment epithelium from contact with ICG by perfluorcarbon liquid can yield good functional results.

Growth of Staphylococcus epidermidis in anaesthetic resuscitative drugs: implications for potential contamination.

This controlled laboratory study investigated the survival of Staphylococcus epidermidis (S. epidermidis) over a 24 hour period in four commonly drawn-up anaesthetic resuscitative drugs: suxamethonium, atropine, metaraminol and ephedrine. These drugs were prepared in typical therapeutic concentrations and then inoculated with S. epidermidis. Samples of the inoculated drug preparations were cultured on horse blood agar plates at 0, 2, 6, 12 and 24 hourly intervals and incubated for 24 hours. Colony counts were performed at the end of the incubation period. Suxamethonium, atropine and metaraminol all showed an inhibitory effect on colony counts within the first six hours. There was a more gradual decline of colony counts over a 24 hour period in the ephedrine solution. This decline was similar to that occurring in the normal saline. It is concluded that suxamethonium, atropine and metaraminol do not support the survival of the common skin contaminant, S. epidermidis over a 24 hour period.

Cannabinoid CB1 receptor-mediated modulation of evoked dopamine release and of adenylyl cyclase activity in the human neocortex.

1. The present study investigated the binding characteristics of various ligands to cannabinoid CB(1) receptors in human neocortex and amygdala. In addition, the functionality of CB(1) receptors in the human neocortex was assessed by examining the effects of CB(1) receptor ligands on evoked [(3)H]-dopamine (DA) release in superfused brain slices and on synaptosomal cAMP accumulation. 2. Saturation-binding assays in human neocortical and amygdala synaptosomes using a radiolabelled cannabinoid receptor agonist ([(3)H]-CP55.940) revealed pK(d) values of 8.96 and 8.63, respectively. The numbers of binding sites (B(max)) were 3.99 and 2.67 pmol (mg protein)(-1), respectively. 3. Various cannabinoid receptor ligands inhibited [(3)H]-CP55.940 binding with rank order potencies corresponding to those of previous studies in animal tissues. 4. Electrically evoked [(3)H]-DA release from human neocortical slices was inhibited by CP55.940 (IC(50) 6.76 nm, I(max) 65%) and strongly enhanced by the cannabinoid receptor antagonist AM251. However, [(3)H]-DA release was not influenced in rat neocortex. In human tissue, the estimated endocannabinoid concentration in the biophase of the release-modulating CB(1) receptors was 1.07 nm, expressed in CP55.940 units. 5. K(+)-evoked [(3)H]-DA release in the presence of tetrodotoxin (TTX) was strongly inhibited by CP55.940 in humans, but not in rats. 6. In human tissue, CP55.940 inhibited forskolin-stimulated cAMP accumulation (IC(50) 20.89 nm, I(max) 35%). AM251 blocked this effect and per se increased forskolin-stimulated cAMP accumulation by approximately 20%. 7. In conclusion, cannabinoids modulate [(3)H]-DA release and adenylyl cyclase activity in the human neocortex. CB(1) receptors are located on dopaminergic nerve terminals and seem to be tonically activated by endocannabinoids.

Diabetic macular oedema: the effect of photocoagulation on fluorescein transport across the blood-retinal barrier.

BACKGROUND/AIM: The visual loss secondary to diabetic macular oedema can be controlled to some extent by photocoagulation, though the mechanism of action is largely unknown. The purpose of the present study was to quantitate the effect of photocoagulation on the blood-retinal barrier using fluorescein as a tracer of passive and active transport. METHODS: A prospective study of 46 eyes in 34 patients with clinically significant macular oedema (CSMO) examined by vitreous fluorometry before and 6 months after macular photocoagulation treatment. RESULTS: In 23 eyes CSMO was not present at follow up (responding eyes), in another 23 other eyes CSMO was still present (non-responding eyes). With reference to the presence or absence of CSMO at follow up, the passive transport (permeability) for responding eyes decreased after photocoagulation in contrast with an increase in non-responding eyes; the difference between the groups at follow up was significant (p=0.03). The active transport for responding eyes decreased slightly at follow up, while it increased for non-responding eyes; the difference between the groups at follow up was not significant (p=0.09). CONCLUSION: Following photocoagulation a reduction of diabetic macular oedema, defined as disappearance of CSMO, is paralleled by a decrease of the passive permeability while the hypothesis of an increase in the active transport from the retina to the blood could not be supported by this study.

Diabetic macular oedema: a comparison of vitreous fluorometry, angiography, and retinopathy.

AIM: To evaluate the relation between the quantitative measurement of vitreous fluorescein with fluorescein angiography and retinopathy in diabetic patients with and without clinically significant macular oedema (CSMO). METHODS: In a prospective cross sectional study, passive permeability and active, outward transport of fluorescein across the blood-retinal barrier were quantitated with vitreous fluorometry in 61 eyes from 48 patients with CSMO and 22 fellow eyes without CSMO, after exclusion of eyes with previous macular laser treatment and vitreous liquification. All patients were recruited from the university hospital's outpatient clinic. Retinopathy and fluorescein angiograms were evaluated on 60 degree photographs. RESULTS: The passive permeability in CSMO was significantly correlated with the severity of leakage on fluorescein angiograms (r=0.73), the level of retinopathy (r=0.61), and visual acuity (r=0.45). Significant differences between eyes with CSMO and eyes without CSMO were found for passive permeability (p<0.001), fluorescein leakage (p<0.001), visual acuity (p=0.02), and retinopathy (p=0.002). CONCLUSION: Passive permeability of fluorescein quantitated with vitreous fluorometry was correlated both with semiquantitative fluorescein angiography and retinopathy, and a significant increase in passive permeability was found when comparing eyes with CSMO to eyes without CSMO. No such pattern was found for the active transport indicating that passive and not the outward, active transport is the factor of most importance in the development of CSMO.

Effects of ammonia nitrogen of H2 and CH4 production during anaerobic digestion of dairy cattle manure.

A number of researchers have verified the inhibitory effects of elevated H2 concentrations on various anaerobic fermentation processes. The objective of this work was to investigate the potential for using hydrogen gas production to predict upsets in anaerobic digesters operating on dairy cattle manure. In an ammonia nitrogen overload experiment, urea was added to the experimental digesters to obtain increased ammonia concentrations (600, 1,500, or 3,000 mg N/l). An increase in urea concentration resulted in an initial cessation of H2 production followed by an increase in H2 formation. Additions of 600, 1,500, or 3,000 mg N/l initially resulted in the reduction of biogas H2 concentrations. After 24 h, the H2 concentration increased in the 600 and 1,500 mg N/l digesters, but production remained inhibited in the 3,000 mg N/l digesters. Both methane and total biogas production decreased following urea addition. Volatile solids reduction also decreased during these periods. The digester effluent pH and alkalinity increased due to the increased NH4 formed with added urea. Based on these results, changes in H2 concentration could be a useful parameter for monitoring changes due to increased NH3 in dairy cattle manure anaerobic digesters.

Recurrent Methylobacterium mesophilicum sepsis associated with haemodialysis.

Methylobacterium mesophilicum is an environmental organism that has infrequently been implicated as a human pathogen. Most reported cases are in immunocompromised hosts. The natural ecology of this organism is related to vegetation or soil. We report the case of a 51-year-old man who developed a recurrent bacteraemia with this organism while receiving haemodialysis through an indwelling intravascular catheter. The literature on the clinical significance of this organism is reviewed together with specific microbiological identifying features which could be of use in the routine diagnostic laboratory.

The effect of acetazolamide on passive and active transport of fluorescein across the blood-retina barrier in retinitis pigmentosa complicated by macular oedema.

BACKGROUND: The carbonic anhydrase inhibitor acetazolamide (AZM) reduces macular oedema in some patients with retinitis pigmentosa. To better understand the oedema-reducing effect of AZM, the effect of AZM on passive permeability and active transport of fluorescein across the blood-retina barrier was studied in patients with retinitis pigmentosa and varying degrees of macular oedema. METHOD: The selection of patients was based on an introductory examination including vitreous fluorometry for qualitative assessment of the vitreous. Macular oedema was graded by fluorescein angiographic leakage. The effect of AZM on the transport properties of the blood-retina barrier was determined by differential spectrofluorometry, in a randomised, double-masked, cross-over study, comprising 2 weeks' treatment with AZM (500 mg/day) and 2 weeks' treatment with placebo. The penetration ratio, defined as the ratio between vitreous concentration 3 mm in front of the retina and the plasma integral, was determined for fluorescein and its metabolite fluorescein glucuronide at 30-60 min and at 120 min after fluorescein injection. Passive permeability and unidirectional permeability in the direction vitreous to blood, due to outward active transport of fluorescein, were determined in those cases where the curves for vitreous concentration of fluorescein could be fitted to a mathematical model. Visual acuity was tested by use of ETDRS standard logarithmic charts. RESULTS: Twenty-two patients volunteered to participate in the study. Signs of significant vitreous detachment/liquefaction caused the exclusion of ten patients after the introductory examination. Nine patients with approximately intact vitreous and varying degrees of oedema completed the cross-over study. AZM treatment was related to a decrease in the penetration ratio of 21% for fluorescein (P=0.01) and of 22% for fluorescein glucuronide (P=0.004). Passive permeability and unidirectional permeability were determined in seven patients. AZM caused a decrease of 27% in the passive permeability of fluorescein (from 1.1 x 10(1) nm/s, P=0.031), and a 95% increase in unidirectional permeability of fluorescein (from 1.2 x 10(2) nm/s, P=0.047). AZM led to a reduction in the grade of macular oedema as determined by fluorescein angiography in three out of seven patients. Only small improvements (< or =5 letters) in visual acuity were noted. CONCLUSION: The present study indicates that the oedema-reducing effect of AZM is due to decreased leakage and stimulated active transport across the blood-retina barrier.

Blood-retina barrier permeability is independent of trace substance lipid solubility in retinitis pigmentosa and in the healthy eye.

Differential ocular spectrofluorometry was used to assess the passive permeability of the blood-retina barrier in healthy subjects and in patients with retinitis pigmentosa by determination of the rate of inward leakage of fluorescein and fluorescein glucuronide after intravenous injection of fluorescein. In five healthy subjects we found permeabilities of 1.3 (0.6-2.8) nm/s [log-mean (range)] for fluorescein and 1.3 (0.6-3.1) nm/s for fluorescein glucuronide. Six patients with retinitis pigmentosa all had a markedly increased blood-retina barrier leakage, with inward permeabilities of 8.2 (3.4-25) nm/s for fluorescein and 8.2 (5.6-27) nm/s for fluorescein glucuronide. Since no detectable difference was found between the permeabilities of the two tracers the passive permeability of the blood-retina barrier appears to be independent of the 18-fold difference in lipid solubility between the two tracers, both in retinitis pigmentosa and in healthy subjects. Presumably, the structural substrate for leakage of small hydrophilic molecules through the blood-retina barrier is a water-filled pore, since diffusion through lipid cellular membranes would favor fluorescein over its more water soluble glucuronide.

Fluorescein transport across the human blood-retina barrier in the direction vitreous to blood. Quantitative assessment in vivo.

Inward and outward movement of flourescein across the human blood-retina barrier was studied in five healthy volunteers, using a differential spectrofluorometry method that eliminates the contribution of fluorescein glucuronide to the total fluorescence in the vitreous and in plasma. The inward permeability across the blood-retina barrier, which is presumed to be passive, and the diffusion coefficient in the vitreous for fluorescein was calculated from data obtained 1 h after intravenous injection of fluorescein. The rate of elimination of fluorescein from the vitreous across the blood-retina barrier was estimated from data obtained 7 to 12 h after injection of fluorescein. The calculations were based upon the free plasma fluorescein decay curve and the preretinal fluorescein gradient in the vitreous. The mean inward permeability of fluorescein was 1.39 x 10(-7) cm/sec (range: 0.70-2.06 x 10(-7) cm/sec), whereas the mean outward permeability was 1.51 x 10(-5) cm/sec (range: 1.14-1.73 x 10(-5) cm/sec). We have thus found that the movement of fluorescein across the blood-retina barrier is highly asymmetric, the outward transport being more than 100 times faster than the passive inward leakage. This could indicate the presence of an active pumping mechanism in the blood-retina barrier, responsible for fluorescein transport in the direction from the vitreous to the blood.

Probenecid inhibition of the outward transport of fluorescein across the human blood-retina barrier.

The effect of probenecid on the outward transport of fluorescein from vitreous to blood was studied in 13 insulin-dependent diabetic patients with background retinopathy in a randomised double-masked placebo controlled cross-over study. Fluorescein and fluorescein glucuronide was separated in the vitreous and in plasma by differential spectrofluorometry. The data for fluorescein were analysed using a simplified mathematical model of the eye. The inward permeability was estimated from data obtained 1 h after injection and the outward transport from data obtained 7 h after injection. During placebo treatment the mean inward permeability was 3.75 x 10(-7) cm/sec and the mean outward permeability was 2.25 x 10(-5) cm/sec. During probenecid treatment the mean inward permeability was 3.34 x 10(-7) cm/sec and the mean outward permeability was 1.44 x 10(-5) cm/sec. Thus, we found no significant change in inward permeability (p = 0.5879), whereas a significant decrease of 36% was found in the outward permeability of fluorescein (p = 0.0171). The demonstration that the outward permeability, which is more than 100-fold higher than the inward permeability in the healthy eye, is significantly decreased by probenecid, demonstrates that active transport is involved in movement of fluorescein across the blood-retina barrier from the vitreous to the plasma.

Predisposition to self-health care: who does what for themselves and why?

Data collected on a national sample of 714 respondents aged 55 years and over were used to investigate predisposition to self-health care. Three different indicators of self-health care were employed in this work, including a measure of actual self-care behavior (ASCB), a behavioral indicator, and two attitudinal indicators, normative self-care response (NSCR) and global self-care. In OLS regression modeling, predisposing characteristics from the health-behavior model yielded levels of variance consistent with those found in the extant literature on health- and social-services utilization among elderly Americans. Age showed limited utility as an explanatory variable; it appeared as a direct effect only on global self-care. Race was the only variable to achieve a statistically significant effect on NSCR, and being female showed direct effects on ASCB and global self-care.

Absence of foveal avascular zone demonstrated by laser scanning fluorescein angiography.

We present laser scanning fluorescein angiograms of abnormal foveal capillary patterns in a healthy subject and an insulin-dependent diabetic patient with mild diabetic retinopathy. In both subjects capillaries were seen to cross the central foveal area where capillaries are usually absent. The flow pattern of the foveal capillaries, which were visualised with the use of a laser scanning ophthalmoscope, was indistinguishable from that of the more peripheral capillaries, indicating that foveal vessels are functionally normal retinal capillaries. The two cases demonstrate that identification of abnormal capillary patterns induced by retinal disease such as diabetic retinopathy is made difficult by the marked interindividual variation in capillary anatomy. In prospective studies, however, the method may be capable of detecting subtle changes in early diabetic retinopathy with a high degree of sensitivity.

Early changes in diabetic retinopathy: capillary loss and blood-retina barrier permeability in relation to metabolic control.

In diabetic retinopathy capillary loss and blood-retina barrier leakage are prominent factors. We present a study with quantitative measurements of both capillary loss and leakage and their relation to cumulative metabolic control. Seventeen insulin-dependent diabetic patients with no retinopathy or only mild background retinopathy and 10 years' duration of the disease were included in the study. Status of metabolic regulation had been followed for at least 6 years. Seven healthy subjects were included as controls. In diabetic patients the perifoveal intervascular areas were found to increase significantly with the cumulative HbA1c index (p = 0.02) and in relation to the presence of moderate background retinopathy (p < 0.02). The blood-retina barrier leakage and the area of the foveal avascular zone were not significantly different from healthy subjects and no correlation was found between the HbA1c index and blood-retina barrier permeability. We conclude that perifoveal capillary loss occurs early in the course of diabetic retinopathy and that this loss is related to prior glycemic control and to the ophthalmoscopic retinopathy level.

Interferon alfa-2a modifies the course of subfoveal and juxtafoveal choroidal neovascularisation.

The first double masked placebo controlled trial of interferon alfa-2a for the treatment of overt choroidal neovascular membranes is presented. A total of 43 consecutive patients were randomised to double masked treatment with either interferon alfa-2a, 3 million IU subcutaneously three times a week or matching placebo, for a period of 8 weeks. End of study changes from baseline in distance and near visual acuity, macular visual field, contrast sensitivity, and macular morphology (fluorescein angiography) were assessed. The between group difference in distance visual acuity, the primary efficacy variable, was significant in favour of interferon alfa-2a (p = 0.023). Fluorescein angiograms, macular visual fields, and near vision all showed a trend in favour of interferon alfa-2a. It was concluded that, at the dosage used in this study, interferon alfa-2a is a reasonably well tolerated and apparently effective short term treatment of subfoveal and juxtafoveal choroidal neovascularisations.