A251 VERY EARLY ONSET INFLAMMATORY BOWEL DISEASE IN CHILDREN: A SINGLE CENTER EXPERIENCE OVER 15 YEARS

Background

Very-early-onset inflammatory bowel disease (VEOIBD) refers to an IBD diagnosis established before the 6th year of life, including a subset of patients with disease onset before the age of 2 years, known as infantile-onset IBD (IO-IBD) (1). VEO-IBD accounts for 15% of pediatric IBD and infantile IBD in approximately 1% (2,3). VEOIBD is considered to be a unique entity, and compared to adults with IBD, VEO-IBD children are more likely to present with extensive and treatment-resistant disease (4).

Aims

To analyze the clinical characteristics and management of patients diagnosed with very early onset inflammatory bowel disease (VEO-IBD).

Methods

A retrospective analysis of children diagnosed with VEO-IBD (age <6 years) at the Montreal Children’s Hospital from 2003–2018 was performed. Clinical data for VEO-IBD patients was collected to identify the clinical, biochemical, endoscopic and histological features of these patients and their clinical course until 2018.

Results

A total of 28 VEO-IBD patients (71% male) were included in this study. The median age of disease onset was 52 months. A diagnosis of Crohn’s disease (CD) or CD-like intestinal manifestations accounted for 89% of the VEO-IBD cases. Most patients had Crohn’s colitis (36%) of whom 50% had evidence of granulomatous Crohn’s disease; 11 patients[NAD1] [AQAB2] (39%) had upper gastrointestinal involvement. Over their progress of the disease, 4 patients (14%) required surgical intervention, while 11 patients (39%) required biologic therapy for maintenance therapy. Genetic[NAD3] [AQAB4] results were available for 5 patients out of 28 (18%) and 3 of them were identified to have monogenic IBD.

Conclusions

In our center, the majority of patients with VEO-IBD had typical Crohn’s disease presentation. Most of the VEO-IBD patients responded well to the standard IBD treatment. Genetic studies were not done regularly for all of our patients, however, among those who had this testing performed 3/5 had an identifiable cause, suggesting that these patients should be investigated for an underlying genetic abnormality.

Funding Agencies

None

Neurotoxic sequelae of mercury exposure: an intervention and follow-up study in the Brazilian Amazon

Since 1995, the Caruso Project used an Ecosystem Approach to Human Health to examine mercury (Hg) exposure in fish-eating communities in the Brazilian Amazon and develop interventions to maximise nutrition from traditional diet and minimise toxic risk. In 1995, 2000 and 2006, this study followed fish consumption, Hg levels, and visual and motor functions in 31 villagers. Questionnaires gathered information on socio-demographics and diet. Hair Hg (H-Hg) levels were measured. Visual acuity, colour vision, manual dexterity and grip strength were assessed. Data was analysed using general linear models of repeated measures. Total fish consumption, similar in 1995 and 2000, decreased in 2006. Carnivorous fish consumption initially decreased and then remained stable, whereas non-carnivorous fish consumption first increased and then decreased. H-Hg declined from 17.6 to 7.8 μg/g. Visual functions showed a significant decrease over time, with those with H-Hg ≥ 20 μg/g in 1995 showing greater loss. Motor functions showed initial improvement and then returned to the 1995 performance level. Decrease in Hg exposure is attributed to the intervention and socio-economic changes in the village. While there may be a certain reversibility of motor deficits, visual capacities may decrease progressively with respect to exposure prior to the intervention.

Resistance of plastic ophthalmic lenses: the effect of base curve on different materials during static load testing

PURPOSE

This study was designated to evaluate, through a static load test, the influence of lens base curve on the fracture resistance of three common plastic materials.

METHODS

A JJ Lloyd load cell machine was used to test the fracture resistance of -4.00 D spherical lenses. The samples had a nominal center thickness of 2.0 mm and a base curve distributed in one of five groups (+0.50, +2.50, +4.50, +6.50, and +8.50 D). The lenses were manufactured in CR39, polycarbonate, and TL16, a high refractive index plastic (n = 1.599).

RESULTS

The lens base curve influenced fracture resistance for all materials. For these materials, resistance increased as the base curve varied from +0.50 to +8.50 D. The resistance of CR39, TL16, and polycarbonate lenses was found to be linearly dependent on lens base curve. The effect is stronger for polycarbonate. Fracture resistance was higher for TL16 than for CR39, and polycarbonate was much more resistant to breakage than the two other materials.

CONCLUSIONS

For a given power, the fracture resistance of an ophthalmic lens is reduced when its base curve has a low value. Consequently, the flattening of ophthalmic lenses for cosmetic purposes is not recommended as far as fracture resistance is concerned.

Visual dysfunction among former microelectronics assembly workers

Although known neurotoxins with potential ophthalmotoxic properties are commonly used in microelectronics assembly, there has been no systematic study of visual disturbances among past or present workers in this industry. The objective of the present study was to compare visual functions, using a matched-pair design, between former workers from a microelectronics plant and a local reference population. From an initial population of 180 former workers and 157 potential referents, 54 pairs were matched for age (+/- 3 y), education (+/- 2 y), sex, ethnic origin, and number of children. Near and far visual acuity, chromatic discrimination, and near contrast sensitivity were assessed monocularly. Paired comparisons (Signed-rank Wilcoxon test) revealed that the former microelectronics workers had significantly lower contrast sensitivity, particularly in the intermediate frequencies, independently of near visual acuity loss. There were no differences for far visual acuity in both eyes. Even though near visual acuity and color vision were compromised among the former workers, the differences were only significant for one eye, as was the prevalence of acquired dyschromatopsia (chi-square for matched pairs, p less than .001). These findings suggest a pattern of contrast sensitivity deficits consistent with impairment to foveal and/or neuro-optic pathways among these former microelectronics workers. Exposure to ophthalmotoxic chemicals is proposed as the most probable risk factor.

Contrast-sensitivity loss in a group of former microelectronics workers with normal visual acuity

The measurement of contrast sensitivity at varying grating frequencies is used increasingly to study visual and neural disorders. It provides more information than conventional acuity measures. Refractive errors initially affect high spatial frequencies, whereas lower spatial frequencies are affected only when these errors are pronounced. Neurophysiological alterations are reflected by depressed sensitivity to coarse gratings. Visual dysfunction has been associated with workplace exposures to a wide range of organic solvents. In microelectronics assembly where large quantities of organic solvents are used in many aspects of the work processes, visual deficits have been observed. The objective of the present study was to compare contrast sensitivity among former microelectronics assembly workers, with normal far and near visual acuity, and a reference group from the same region, with similar acuity. No significant differences were observed between scores at the two ends of the contrast sensitivity curves; however, at the intermediate spatial frequencies, the former microelectronics workers' scores were significantly lower (Student's t-test; p less than 0.05). For the microelectronics workers, no relation was observed between age and contrast sensitivity at any spatial frequency, whereas for the reference group, contrast sensitivity scores were progressively lower with age at spatial frequencies greater than or equal to 6.0 cpd (r2 = 0.15 at 6 cpd to r2 = 0.45 at 18.0 cpd), suggesting that for the former there is some form of interference with the expected contrast sensitivity loss with age. Lower contrast sensitivity scores in intermediate spatial frequencies, observed among the former microelectronics workers, possibly reflect neural alterations, which may have resulted from exposure to neurotoxic substances. These findings suggest the need for further studies on visual functions in microelectronics workers.

Measurement precision of a portable instrument to assess vibrotactile perception threshold

The objective of the present study was to evaluate the reliability of a modified version of the commercially available Biothesiometer, and to examine vibrotactile perception thresholds with respect to age and gender. A standardized protocol for measuring vibrotactile perception threshold was administered to 80 subjects, once a week over 4 weeks. Inter-session variability was stable (analysis of variance for repeated measures; P greater than 0.05) and correlations were high (Pearson's: 0.87 less than or equal to r less than or equal to 0.90; P less than or equal to 0.001). For sites on both hands and feet, there was a significant increase with age (0.19 less than or equal to r2 less than or equal to 0.52; P less than or equal to 0.001). Five factor analysis of variance model showed that vibrotactile perception threshold was significantly different with stimulus site, age category and gender; no differences were observed with alcohol consumption or smoking status. The findings indicate that the measurements from this device are highly reproducible and sensitive to expected threshold differences with age and gender. The authors attribute this to technical improvements of the original apparatus, rigid adherence to test protocol and maintenance of standard conditions. This type of instrument would be useful in assessing vibrotactile perception loss in occupational health studies.