Subclinical Edema Research Articles

Ciliary Body Edema after Scleral Buckling Surgery for Rhegmatogenous Retinal Detachment

Choroidal detachment and anterior chamber (AC) shallowing develop in some cases after scleral buckling surgery for rhegmatogenous retinal detachment (RD). Postoperative angle-closure glaucoma has been reported to occur in 4% of cases. It is supposed that compression by the local scleral buckling induces ciliary body edema and angle narrowing. This study aimed to evaluate quantitatively the time course of changes in ciliary body thickness and AC depth (ACD) before and after the scleral buckling procedure using ultrasound biomicroscopy. Prospective consecutive case series. Forty-six eyes of 44 patients (43.7+/-18.1 years old [mean +/- standard deviation]) undergoing rhegmatogenous RD surgery. Ciliary body thickness and ACD were measured before and 3, 7, 14, and 28 days after the procedure. Ultrasound biomicroscopy was used to evaluate ACD and ciliary body thickness. Time course of changes in ciliary body thickness and ACD. The surgery caused significant increases in ciliary body thickness at 3, 7, and 14 days postoperatively (P<0.0001, Bonferroni multiple comparison). Ciliary body edema reached its peak 3 days after surgery, followed by a gradual decrease thereafter. Ciliary body thickness in the encircling group was statistically greater than in the segmental buckling group at 3 and 7 days postoperatively (P<0.001, Student's t test). The ciliary body was significantly thicker in the direction of buckling than on the opposite side 3 days after surgery (P = 0.0079). In the encircling group, retinal reattachment surgery significantly decreased ACD 3 days after surgery (P = 0.018), whereas no significant fluctuations were found in the buckling group. Even without apparent choroidal detachment and a shallow AC, subclinical ciliary edema existed in all directions of all eyes for at least 1 month after the scleral buckling procedure. The ciliary body in the direction of scleral buckling showed greater edema than the other areas. Eyes treated with the encircling band showed greater ciliary edema than those treated with segmental buckling alone.

Cytokine response to diabetic ketoacidosis and its treatment

The objectives of this study were to monitor plasma cytokines as markers of cellular activation and as potential markers for the progression of the acute complications of diabetic ketoacidosis (DKA). Blood samples were obtained prior to, during and after treatment of severe DKA (pH < 7.2) in six children and adolescents. Plasma IL-10, IL-1β, TNF-α, IL-6, IL-8 and IL-2 cytokine levels were assayed by ELISA at each of the time points. Prior to treatment, elevations of multiple cytokines were found, the highest being IL-10. Treatment of DKA resulted in a significant decrease of IL-10 at 6–8 h ( p = 0.0062), and further increases in the inflammatory cytokines at 6–8 h and/or 24 h vs 120 h (baseline): IL-1β ( p = .0048); TNF-α ( p = .0188) and IL-8 ( p = .0048). This study strengthens the hypothesis that the metabolic crisis of DKA, and its treatment, have differential effects on cellular activation and cytokine release. The time frame for the increase in inflammatory cytokines correlates with the reported progression of subclinical brain edema, interstitial pulmonary edema and the development of clinical brain edema.

Diabetic ketoacidosis and its treatment increase plasma 3-deoxyglucosone

Objectives Highly reactive dicarbonyl compounds are known to be increased by hyperglycemia, ketone bodies and lipid peroxidation. This study was carried out to investigate the effect of diabetic ketoacidosis (DKA) and its treatment on the plasma concentration of 3 deoxyglucosone (3-DG) one of the dicarbonyl compounds. Design and methods 3-DG was measured in 7 children before, during and following correction of severe DKA. Results 3-DG was elevated before treatment (610 nmol/L ± 70) in comparison to baseline (120 h) (200 nmol/L ± 17) ( p < 0.05). At 6 to 24 h into treatment 3-DG was further elevated (1,080 nmol/L ± 80) in comparison to both pretreatment ( p < 0.05) and baseline ( p < 0.05). Conclusion 3-DG is significantly elevated before the treatment of DKA and increases further during the treatment of DKA. The time course of the increase of 3-DG coincides with the time of progression of subclinical brain edema, which occurs in DKA.

Acute activation of peripheral lymphocytes during treatment of diabetic ketoacidosis

Activated peripheral T-lymphocytes are increased in both pre-insulin-dependent diabetes mellitus (IDDM) patients and in recently diagnosed IDDM patients, as well as in various forms of acute stress. We studied the in vivo T-lymphocyte activation in six patients in severe diabetic ketoacidosis (DKA) prior to treatment, after 24 h of treatment and ≥5 days after admission. Five of the six patients showed an increased percentage of activated T-lymphocytes based on the expression of HLA-DR at 24 h of treatment when compared to the admission percentage of activation ( P<.05). There was no correlation to the admission serum glucose, osmolality, or electrolytes. Serum pH showed a trend toward an inverse correlation, but was not statistically significant. We speculate that T-lymphocyte activation plays a role in the progression of the acute complications of subclinical brain edema and interstitial pulmonary edema of DKA. This process could also be another factor in the progression of the chronic complications of IDDM in addition to the well-established effects of hyperglycemia and hypertension.

Computer Analysis of Magnetic Resonance Imaging of the Brain in Children and Adolescents After Treatment of Diabetic Ketoacidosis

Cerebral vascular accidents are one of the causes of morbidity and mortality in children with diabetic ketoacidosis. We investigated the possible occurrence of asymptomatic cerebrovascular infarcts and the course of subclinical brain edema in six patients. Neurologic examinations and computer analysis of magnetic resonance imaging were performed immediately after, and again at 14 days after, correction of DKA. None of the patients had clinical evidence of a neurologic deficit. Neither radiologic evaluation nor computer analysis of MRI identified changes indicating asymptomatic ischemic events. However, a computer analysis of the MRI identified a significant increase of the total ventricle area between Day one and Day 14. Our study does not establish whether this change is a return to the baseline prior to DKA or a new baseline, representing an early manifestation of diabetic encephalopathy.

Sub-clinical cerebral oedema does not occur regularly during treatment for diabetic ketoacidosis.

Fulminant cerebral oedema is an uncommon, fatal complication of diabetic ketoacidosis (DKA) in children. This study aimed to find out whether the sub-clinical compression of the brain ventricles found by an earlier study, is a general phenomenon during intravenous treatment for DKA. Four boys and four girls were examined. Blood glucose values ranged from 40 to 24.6 mmol/l, base excess -34.6 to -13.6 and capillary blood pH 6.89-7.22. The patients received fluids containing both glucose and electrolytes, and insulin intravenously. After about 10h, blood glucose was 8.7-21.8 mmol/l and base excess had decreased substantially (-9.5 to -2.9) in seven of the eight cases. Computerized tomography of the brain was then performed, and again after full recovery. Only two of the patients had an initial decrease in intercaudate distance, which exceeded the variability found in a reference group. Compression of the cerebral ventricles does not occur regularly during treatment for DKA.

Low Pulmonary Diffusing Capacity in Subjects With Acute Mountain Sickness

This study was conducted to investigate whether the changes in the pulmonary diffusing capacity found in individuals with acute mountain sickness (AMS) reflect the early stage of high-altitude pulmonary edema (HAPE). We measured the pulmonary diffusion capacity for carbon monoxide (DCO) by the single-breath method, arterialized capillary blood gas, and spirometry in a group of 32 healthy subjects (24 men, eight women) at an altitude of 2,260 m and after ascent to 4,700 m. Twelve subjects (10 men, two women) had symptoms of AMS (AMS group) by the second day after arrival at 4,700 m, but none had clinical signs of pulmonary or cerebral edema. In the non-AMS group, almost all subjects exhibited an increase in DCO at 2,260 to 4,700 m (delta DCO, 10.7 +/- 1.25 mL/min/mm Hg), while the degree of increase in DCO in the AMS group (n = 12) was significantly lower (delta DCO, 1.26 +/- 1.74 mL/min/mm Hg) than that of the non-AMS group (p < 0.01). In four of the 12 subjects with AMS who had a high AMS score, DCO decreased from 38.4 +/- 4.5 to 33.2 +/- 5.3 mL/min/mm Hg (delta DCO, -5.84 +/- 1.1 mL/min/mm Hg). The AMS group showed significantly lower vital capacity, forced expiratory flow during the middle half of FVC, PaO2, and a greater alveolar-arterial oxygen pressure difference at 4,700 m compared with the non-AMS group. DCO showed a significant negative correlation with AMS score (r = -0.885) and a positive correlation with PaO2 (r = 0.757) at 4,700 m. These results suggest that the decreased pulmonary diffusing capacity in subjects with AMS reflects the presence of pulmonary gas exchange abnormality, which is probably due to subclinical interstitial edema of the lung.

Exercise-induced VA/Q inequality in subjects with prior high-altitude pulmonary edema

Ventilation-perfusion (VA/Q) mismatch has been shown to increase during exercise, especially in hypoxia. A possible explanation is subclinical interstitial edema due to high pulmonary capillary pressures. We hypothesized that this may be pathogenetically similar to high-altitude pulmonary edema (HAPE) so that HAPE-susceptible people with higher vascular pressures would develop more exercise-induced VA/Q mismatch. To examine this, seven healthy people with a history of HAPE and nine with similar altitude exposure but no HAPE history (control) were studied at rest and during exercise at 35, 65, and 85% of maximum 1) at sea level and then 2) after 2 days at altitude (3,810 m) breathing both normoxic (inspired Po2 = 148 Torr) and hypoxic (inspired Po2 = 91 Torr) gas at both locations. We measured cardiac output and respiratory and inert gas exchange. In both groups, VA/Q mismatch (assessed by log standard deviation of the perfusion distribution) increased with exercise. At sea level, log standard deviation of the perfusion distribution was slightly higher in the HAPE-susceptible group than in the control group during heavy exercise. At altitude, these differences disappeared. Because a history of HAPE was associated with greater exercise-induced VA/Q mismatch and higher pulmonary capillary pressures, our findings are consistent with the hypothesis that exercise-induced mismatch is due to a temporary extravascular fluid accumulation.

Bronchial Hyperresponsiveness in Chronic Renal Failure Undergoing Hemodialysis

Background: Cardiogenic pulmonary edema increases nonspecific airway responsiveness in humans and animals. Increased extravascular lung water from overt pulmonary edema to subclinical interstitial edema is a common finding in patients with chronic renal failure. Several studies carried out to assess pulmonary function disturbances in this condition have documented a reduction in forced expiratory volume that usually reverses after hemodialysis, suggesting airway edema as the underlying mechanism. This interstitial edema may also lead to nonspecific bronchial hyperresponsiveness. We hypothesized that patients with chronic renal failure may present nonspecific bronchial hyperresponsiveness due to subclinical interstitial pulmonary edema. Methods: We studied 18 chronic renal failure undergoing regular hemodialysis 3 times a week(New York Heart Association Class II) without concomittent disease. These patients were checked pulmonary function test and metacholine provocation test before hemodialysis and same procedure was repeated if responsive, after hemodialysis. Results: 1) 12 out of 18 patients before hemodialysis were reactive in metacholine provocation test(66.7%) before hemodialysis. This airway hyperresponsiveness were decreased after hemodialysis. 2) Pulmonary function was improved after hemodialysis and change in was correlated with change in weight(r=-0.62, p and , which is one of the variables of the peripheral airways(r=0.58, p

An experimental model for subclinical edema disease (Escherichia coli enterotoxemia) manifest as vascular necrosis in pigs

Summary An experimental model for subclinical edema disease was developed in weanling pigs. In multiple experiments, 3-week-old pigs were weaned, then inoculated intragastrically with 1010 colony-forming units of an SLT-IIv-positive strain of Escherichia coli originally isolated from a pig with edema disease (principals). Control pigs were inoculated with a nonpathogenic E coli strain. Of 39 principals, 8 developed clinical edema disease within 14 days after inoculation. However, 20 of 21 principals that did not develop clinical signs of edema disease, but were submitted for necropsy examination at 14 days after inoculation, had characteristic vascular lesions of edema disease. Vascular lesions, found principally in ileum and brain, consisted of segmental necrosis of myocytes in the tunica media of small arteries and arterioles. None of the pigs inoculated with a nonpathogenic strain of E coli developed edema disease or vascular lesions. None of the principals necropsied at 2 days after inoculation had vascular lesions. Development of vascular lesions by 14 days after inoculation was used as the end point for detecting subclinical edema disease in the model.

Factors Affecting Light Scatter in Contact Lens Wearers

We measured forward light scatter at 3.5, 10, and 28 degrees using a portable stray light meter. Subjects included 66 normal subjects (age range 19 to 79 years), 17 established hydrophilic contact lens wearers, and 15 rigid gas permeable (RGP) contact lens wearers. Contact lens deposits were measured using a modified Rudko procedure and a Leitz/Wild Makroscope M240. Corneal health was assessed using slitlamp biomicroscopy. Results showed a significant increase in light scatter with age, particularly after the age of 40 years. Stray light scores were significantly lower in pigmented non-Caucasian subjects, particularly at larger angles. The stray light scores were significantly greater in contact lens wearers than in age-matched normals, but were not found to correlate with the amount of lens deposits. Scores from hydrophilic lens wearers after removal of their lenses were significantly higher than results from RGP wearers after removal of their lenses and from age-matched normals. This suggests the presence of subclinical corneal edema in some of these subjects.

Iodinated Contrast Media Effects on Extravascular Lung Water, Central Blood Volume, and Cardiac Output in Humans

Intravascular contrast media produce pulmonary edema in one rat model, but not in dogs or pigs. In humans, pulmonary edema after contrast media is rarely diagnosed, but subclinical edema could be more frequent than believed previously. Therefore, the authors prospectively studied the effects of diatrizoate (n = 5) and ioxaglate (n = 5) on extravascular lung water, central blood volume, and cardiac output in ten patients undergoing routine radiographic procedures. Variables were measured by thermal-dye dilution before and every 5 minutes after completion of the procedure for four repetitions. Extravascular lung water and central blood volume did not change significantly, indicating that pulmonary edema or pulmonary congestion did not occur. Cardiac output was elevated by 10.6% immediately after the procedure, but returned to baseline during the 10 following minutes. The authors conclude from this preliminary study in a small number of patients that intraarterial contrast media (less than 1.5 g/kg body weight of iodine) did not produce pulmonary edema or pulmonary congestion, even at a subclinical level.

Corneal thickness in nephropathic cystinosis.

Cystinosis is a rare autosomal recessive metabolic disorder in which non-protein cystine accumulates within cellular lysosomes owing to a defect in lysosomal cystine transport. The pathognomonic ocular manifestation of cystinosis is the deposition of distinctive iridescent crystals in the cornea, not associated with any inflammatory response or recognised change in corneal function. We measured corneal thickness in nine patients with infantile nephropathic cystinosis. We also studied a corneal button from one of these patients who underwent corneal transplantation. All nine patients had increased corneal thickness in comparison with an age matched control population. Electron microscopy analysis of the cystinotic button revealed structural changes of both epithelium and endothelium layers. Increased corneal thickness in patients with nephropathic cystinosis may reflect subclinical corneal oedema.

Changes in pulmonary diffusing capacity and closing volume after running a marathon

The purpose of this study was to evaluate changes in lung function after running a marathon. Pulmonary function tests were administered to 8 men before, immediately after, and the day following competition X ̄ run time = 3 hr 30 min ). Subjects completed maximum expiratory flow volume maneurvers breathing air and 80% He/20% O 2. Lung volumes were determined by N 2 washout and single breath He dilution. Closing volumes (CV) were determined using a single breath O 2 test. Pulmonary diffusing capacity (D L CO), pulmonary capillary blood volume (Vc), and membrane diffusing capacity (D M) were measured with the single breath technique. There were no changes in lung volumes or flow rates, except for an increase in FEV 1, after the marathon. The He/O 2 ΔV̇max 50, ΔV̇max 25, and isoflow values were similar pre- compared to post-race. There were significant decreases, however, in D L CO, D M and increases in CV prost-race. Vc remained similar to pre-race values. These results suggest that small airways obstruction does not occur after a marathon. The significant increase in alveolarcapillary membrane resistance, however, may reflect the occurence of subclinical edema. Such a change would decrease lung elastic recoil and could explain the increase in CV.

The investigation of the visualperformance of the contact lens wearer

The paper describes the assessment of a television system devised to investigate the visual performance of persons wearing an optical aid. It is suggested that a similar device could find application in hydrophilic contact lens practice. Introduction Despite the technological advances which have produced physiologically acceptable hydrophilic contact lenses, there still remain associated with this form of optical correction certain unpredictable factors; these include variable residual refractive errors (Grosvenor, 1972; Sarver, 1972) and subclinical epithelial oedema (Hess and Garner, 1977). Such effects, too subtle to be detected with the conventional letter chart, are nevertheless disruptive to vision, and the recording of visual acuity (i.e. the Snellen fraction) is only a limited measure of visual performance (Applegate and Massof, 1975). The present authors feel that aspects such as the quality and stability of visual correction which the optical aid provides must be considered. Rather than defining the limit of resolution (i.e. visual acuity), assessment of the quality of vision for object sizes within the resolution limit should be undertaken. An obvious approach is via contrast sensitivity threshold measurements (Schade, 1956; Campbell and Green, 1965), and indeed this has been at tempted in a contact lens context (Applegate and Massof, 1975; Rosenblum and Leach, 1975; Woo and Hess, 1979). The less well known technique of border enhancement (a special case of Mach-band formation) has also been suggested (Remole, 1977) as a means of quantifying contact lens performance. However, in the visual environment of contact lenses, where poor quality and instability is a consequence of lens movement and flexure, such tests as these including the use of Arden's (1978; 1979) book of contrast sensitivity gra t ings-are considered to be of limited application in resolving what is essentially an optical rather than a neural problem. Reverting to more clinically accepted techniques, consideration of the visual performance and illumination studies of Weston (1945) suggested the possibility of using a test procedure along the lines of Landolt ' s broken ring. After some initial trials it was found that the presentation of such test targets on a television screen facilitated a more accurate means of assessment (Larke and Pearson, 1977). In the resulting system, to be discussed here, single target presentation was utilised with a threshold technique of constant stimuli, and from the results obtained it has been found possible to specify visual performance in terms of threshold acuity and variability of vision. Apparatus The television system and the factors which affect its operat ion have been described more fully elsewhere (Pointer, Gilmartin and Larke, 1980). To summarize, an electronically generated angular version of Landolt ' s broken ring test figure was displayed on a monochrome television screen (Figure 1). This test figure was randomly presented within a central viewing area over a specific range of sizes (Table 1), with a choice of instrumental settings for contrast level, figure/ground relationship and presentation/ interval times. (Continued on page 158) Journal of the British Contact Lens Association 155 Figure 1 The television system, with the subject's hand control box in the foreground. The contrast level is set at 55%. Method of Operation The subject indicated the position of the break in the target, viewed at 9.7 metres, by pressing one of the four buttons on a hand control box (Figure 1). Instructions on the experimental procedure were given to each subject with the aid of a cassette tape recorder. The subject was instructed to respond promptly to each target, guessing being allowed in the event of any uncertainty, but it was stressed that only one response to each target was permitted. Experimental Procedure and Results Work to date has largely been concerned with optimizing the operational variables in what was Table 1 Physical Dimensions and Angular Subtense of the