Blur adaptation: clinical and refractive considerations

The human visual system is amenable to a number of adaptive processes; one such process, or collection of processes, is the adaptation to blur. Blur adaptation can be observed as an improvement in vision under degraded conditions, and these changes occur relatively rapidly following exposure to blur. The potential important future directions of this research area and the clinical implications of blur adaptation are discussed.     

Pseudoathetosis: report of three patients.

We report on 3 patients with pseudoathetosis, which are involuntary, slow, writhing movements due to loss of proprioception.     

Congenital diaphragmatic defects that present late.

Twenty two patients (age range: 1 month to 11 years) were treated for congenital diaphragmatic defects (excluding hiatus hernia) in the six year period 1983-8. Presenting features were failure to thrive (n = 7), abdominal pain and vomiting (n = 4), chronic respiratory symptoms (n = 3), and inability to wean from ventilatory support (n = 3). The defect was an incidental finding in five patients. Operative repair was performed with no mortality or serious postoperative morbidity. Dramatic improvement occurred in 15 of the 17 symptomatic patients. Awareness of the differential diagnosis should avoid delay in diagnosis or inappropriate treatment. Surgical correction is strongly recommended in all cases.     

The development of a comprehensive, institution-based patient risk evaluation program: II. Validity and reliability of questionnaire data

The accuracy of historical information derived from self-administered questionnaires must be confirmed. We report the results of studies conducted to assess the reliability and validity of data collected from a comprehensive cancer risk factor questionnaire developed at The University of Texas M.D. Anderson Cancer Center. A comparison of the basic demographic data of a randomly selected sample of 80 respondents and 70 nonrespondents revealed no fundamental ethnic or socioeconomic differences. We verified self-reported past illnesses, surgical procedures, and cancers by reviewing 72 patient charts, using stringent diagnostic criteria for verification. We noted substantial agreement between self-reported and documented illnesses and operations. With the exception of nine patients who misclassified metastatic disease, the verification of primary cancers was excellent. We determined reliability by interviewing 50 of these patients by telephone. Questions with a dichotomous outcome (e.g., smoking status) were reliably answered; however, those requiring quantification (e.g., amount of alcohol consumed) were less accurately reported on interview. While we recognize the limitations of self-administered questionnaires, we believe this program will develop into a comprehensive, standardized, easily accessible patient risk factor data base.     

Gastric transposition for esophageal substitution in children.

Fifty-four gastric transposition procedures have been carried out for esophageal substitution in the 10-year period 1981 through 1990. The indication for esophageal replacement was esophageal atresia in 36 (19 long-gap atresia with distal fistula and 17 isolated atresia), caustic stricture in 9, intractable peptic reflux stricture in 3, 2 achalasia and 1 each of prolonged foreign body impaction, diffuse leiomyoma, congenital esophageal stenosis, and congenital short esophagus. Eight patients had previously undergone an unsuccessful colonic replacement procedure. The age at gastric transposition ranged from 4 months to 16 years. The procedure of choice was posterior mediastinal transposition without thoracotomy in 37 cases. The esophagogastric anastomosis leaked in 7 patients (12.9%), all of which closed spontaneously, whereas 5 patients developed an anastomotic stricture that responded to bouginage. There were 5 deaths (9.2%). Major complications developed postoperatively in 12 patients: 4 required additional gastric drainage procedures, 2 required temporary tracheostomy, 2 developed adhesion obstruction, and 1 each developed paraesophageal hernia, leakage of the jejunal feeding tube, tracheomalacia, and major hemorrhage following resection of a colonic graft. Major but temporary feeding problems were encountered in 12 children. Medium-term results were assessed as excellent in 67%, good in 20%, fair in 6%, and poor in 6% of the 34 patients surviving longer than 1 year postoperatively (ie, excluding 7 patients lost to follow-up).     

Serum ionic fluoride levels in haemodialysis and continuous ambulatory peritoneal dialysis patients

High serum fluoride (F-) in patients with chronic renal failure (CRF) and end-stage renal disease (ESRD) is associated with risk of renal osteodystrophy and other bone changes. This study was done to determine F- in normal healthy controls and patients with ESRD on haemodialysis (HD) or peritoneal dialysis (PD). Seventeen healthy controls (12 males, 5 females) and 39 ESRD patients on dialysis (17 males, 22 females) were recruited in the study in a community with 47.4 +/- 3.28 microM/l (range 44-51 microM/l) of F- content in drinking water. Control subjects showed a mean serum F- concentration of 1.08 +/- 0.350 microM/l. Males in control group showed slightly higher F- levels (1.15 +/- 0.334, range 0.55-1.9 microM/l) than females (0.92 +/- 0.370, range 0.6-1.5 microM/l). Mean serum F- concentration did not correlate significantly with age and sex among control subjects, whereas such correlation was observed in patients with ESRD on dialysis. Mean serum F- concentration was significantly higher in patients on dialysis (2.67 +/- 1.09, range 0.8-5.2 microM/l) than normal controls. When grouped according to sex, the mean serum F- concentration in males (3.05 +/- 1.04, range 1.8-5.2 microM/l) was significantly higher than females (2.38 +/- 1.08, range 0.8-5.2 microM/l). When patients were grouped according to age, it was observed that F- concentration was significantly higher in patients with age groups 21-70 (2.86 +/- 1.05) than those with age group 13-20 years (1.42 +/- 0.531). Thus F- concentration correlated with age and sex, being higher in males and above 20 years. Despite appreciable clearance of F- (39-90%) across the peritoneum, patients on CAPD showed higher serum F- concentration than those on HD (3.1 +/- 1.97 vs 2.5 +/- 1.137 microM/l). Of the total 39 patients on dialysis 39% had their serum F- concentration above 3.0 microM/l, posing the risk of renal osteodystrophy.      

Gastro-oesophageal reflux and intestinal malrotation in children

In a series of 74 children undergoing Nissen fundoplication for persistent gastro-oesophageal reflux unresponsive to intensive medical treatment, there was an unexpectedly high incidence (54 per cent, n = 40) of intestinal malrotation. The series was not homogeneous, 25 of the children having reflux as a complication of a serious congenital abnormality (48 per cent incidence of intestinal malrotation), and 49 presenting with 'idiopathic' reflux (57 per cent incidence of intestinal malrotation). Intestinal malrotation is best detected pre-operatively by careful barium radiology, requiring clinicians to be aware of the association. In our experience, in children over the age of 3 months, both an antireflux operation and Ladd's procedure are often necessary to stop gastro-oesophageal reflux when an intestinal malrotation is present.