Reproductive health of women with intellectual disability: antenatal care, pregnancies and outcomes in the Dutch population.

BACKGROUND: Research in a handful of countries found that women with intellectual disability (ID) faced barriers and risks regarding antenatal care and reproductive health. This study tested disparities between women in the Netherlands with and without ID in antenatal care, pregnancy rates and pregnancy outcomes. METHODS: Secondary analyses on the large representative panel of primary health patients in the Netherlands by the Netherlands Institute for Health Services Research (NIVEL) compared women in their reproductive age (18-49 years) with (n = 2397) and without (n = 228 608) indicators of ID. Bias due to underreporting and under-identification was reduced by linkage with an index of ID for the total Dutch population from Statistical Netherlands. RESULTS: Women with ID were more likely to receive contraceptive care [95% confidence interval (CI) for odds ratio (OR) = 1.37-1.61] and became somewhat more often pregnant (95% CI OR = 1.06-2.30) than women from the general population, adjusting for age difference and follow-up time. No statistical differences were found in medical complications during pregnancy, delivery and immediately after birth, but women with indicators of ID had a higher risk of losing their pregnancy, including through induced abortion (95% CI OR = 1.26-1.99). CONCLUSIONS: Women with ID have specific needs around contraceptive care and risks around their pregnancy that may require more awareness among practitioners and better understanding of the processes of care and decision-making.

Mortality of people with intellectual disabilities during the 2017/2018 influenza epidemic in the Netherlands: potential implications for the COVID-19 pandemic.

BACKGROUND: Data on the development of Covid-19 among people with intellectual disabilities (IDs) are scarce and it is uncertain to what extent general population data applies to people with ID. To give an indication of possible implications, this study investigated excess mortality patterns during a previous influenza epidemic. METHODS: Using Dutch population and mortality registers, a historical cohort study was designed to compare mortality during the 2017-2018 influenza epidemic with mortality in the same period in the three previous years. People with ID were identified by entitlements to residential ID-care services as retrieved from a national database. RESULTS: Data covered the entire adult Dutch population (12.6 million; GenPop), of which 91 064 individuals were identified with an ID. During the influenza epidemic, mortality among people with ID increased almost three times as much than in the GenPop (15.2% vs. 5.4%), and more among male individuals with ID (+19.5%) than among female individuals with ID (+10.6%), as compared with baseline. In both cohorts, comparable increases in mortality within older age groups and due to respiratory causes were seen. Particularly in the ID-cohort, excess deaths also occurred in younger age groups, due to endocrine diseases and ID-specific causes. CONCLUSIONS: During the 2017-2018 influenza epidemic, excess mortality among people with ID was three times higher than in the general Dutch population, appeared more often at young age and with a broader range of underlying causes. These findings suggest that a pandemic may disproportionally affect people with ID while population data may not immediately raise warnings. Early detection of diverging patterns and faster implementation of tailored strategies therefore require collection of good quality data.

Comparative Fe and Zn K-edge X-ray absorption spectroscopic study of the ferroxidase centres of human H-chain ferritin and bacterioferritin from Desulfovibrio desulfuricans.

Iron uptake by the ubiquitous iron-storage protein ferritin involves the oxidation of two Fe(II) ions located at the highly conserved dinuclear "ferroxidase centre" in individual subunits. We have measured X-ray absorption spectra of four mutants (K86Q, K86Q/E27D, K86Q/E107D, and K86Q/E27D/E107D, involving variations of Glu to Asp on either or both sides of the dinuclear ferroxidase site) of recombinant human H-chain ferritin (rHuHF) in their complexes with reactive Fe(II) and redox-inactive Zn(II). The results for Fe-rHuHf are compared with those for recombinant Desulfovibrio desulfuricans bacterioferritin (DdBfr) in three states: oxidised, reduced, and oxidised/Chelex-treated. The X-ray absorption near-edge region of the spectrum allows the oxidation state of the iron ions to be assessed. Extended X-ray absorption fine structure simulations have yielded accurate geometric information that represents an important refinement of the crystal structure of DdBfr; most metal-ligand bonds are shortened and there is a decrease in ionic radius going from the Fe(II) to the Fe(III) state. The Chelex-treated sample is found to be partly mineralised, giving an indication of the state of iron in the cycled-oxidised (reduced, then oxidised) form of DdBfr, where the crystal structure shows the dinuclear site to be only half occupied. In the case of rHuHF the complexes with Zn(II) reveal a surprising similarity between the variants, indicating that the rHuHf dinuclear site is rigid. In spite of this, the rHuHf complexes with Fe(II) show a variation in reactivity that is reflected in the iron oxidation states and coordination geometries.

The crystal structure of the Dps2 from Deinococcus radiodurans reveals an unusual pore profile with a non-specific metal binding site.

The crystal structure of recombinant Dps2 (DRB0092, DNA protecting protein under starved conditions) from the Gram-positive, radiation-resistant bacterium Deinococcus radiodurans has been determined in its apo and iron loaded states. Like other members of the Dps family, the bacterial DrDps2 assembles as a spherical dodecamer with an outer shell diameter of 90 A and an interior diameter of 40 A. A total of five iron sites were located in the iron loaded structure, representing the first stages of iron biomineralisation. Each subunit contains a mononuclear iron ferroxidase centre coordinated by residues highly conserved amongst the Dps family of proteins. In the structures presented, a distinct iron site is observed 6.1 A from the ferroxidase centre with a unique ligand configuration of mono coordination by the protein and no bridging ligand to the ferroxidase centre. A non-specific metallic binding site, suspected to play a regulative role in iron uptake/release from the cage, was found in a pocket located near to the external edge of the C-terminal 3-fold channel.

Performance testing of medical echo/Doppler equipment.

This paper describes the methods applied in a software package developed by the authors for use in a performance testing protocol for medical ultrasound equipment. The history of performance testing of medical ultrasound equipment is briefly reviewed. This paper is confined to the testing of performance of usage aspects, i.e. imaging performance and Doppler velocity estimation performance. Simple test objects are used which have a long life expectancy. The tests performed both in fundamental and in (tissue) harmonic modes when applicable are spatial resolution, contrast sensitivity, and clutter. The concept of a computational observer is used to define the lesion signal-to-noise ratio and the tissue-to-clutter ratio. Further imaging performance features are penetration depth, slice thickness and geometric conformity of display. Pulsed Doppler velocity measurement features tested are: sensitivity, depth and 3D size of the sample volume, velocity measurement, channel separation. The whole performance measurement protocol as well as the quantitative measurements in the digitized images are implemented in software, together with the graphs and data obtained from the measurements.

IDEA: a large-scale project on electronic identification of livestock.

The aim of the IDEA (Identification électronique des animaux) project is to collect information on the feasibility of the introduction into the European Union (EU) of an animal electronic identification system, as referred to in Directive 92/102 and Regulation 1760/2000. The project will run for a period of four years (1998-2001) and will include one million animals in six countries (France, Germany, Italy, The Netherlands, Portugal and Spain). The Joint Research Centre, as technical co-ordinator of the project, provides technical support in terms of testing and certification of electronic identification devices, establishment of the central database, transmission and recording of data and evaluation of results. Identification has been undertaken in cattle, sheep, goats and buffalo using three types of electronic tags (ruminal bolus, ear tag and injectable transponder). The performance of these tags is checked at defined intervals until recovery in the slaughterhouse. The evaluation of the results in terms of the performance of the device and the necessary organisational support structures will lead to recommendations for a system to trace animals from birth to slaughterhouse, including the appropriate technology to be applied in any generalised system for the livestock sector in the EU.

Fred Hollows lecture: digital screening for eye disease.

The purpose of this study was to explore progress, in the adaptation to community screening for blinding eye disease, of digital imaging devices and technology for storage and transmission. Available imaging systems were compared to gold standard clinical photography in terms of sensitivity and specificity for diagnosis of common blinding eye conditions. Since the use of expensive non-portable imaging devices is likely to be limited for widespread community screening purposes, a portable fundus camera (Nidek, Chiyoda-ku, Japan) and a prototype monocular digital indirect ophthalmoscope constructed at the Lions Eye Institute (LEI) were selected for comparative trials for the screening of optic disc cupping, glaucoma and clinical signs of diabetic retinopathy. Fifty-one eyes of 27 consecutive patients being assessed at the LEI clinic for glaucoma were dilated and photographed with a Zeiss retinal camera, and digital images were taken with the portable Nidek NM100 fundus camera (Carl Zeiss, Oberkochen, Germany) or with a prototype digital monocular indirect ophthalmoscope. Vertical cup: disc ratios (VCDR) were measured on the disc photographs by one ophthalmologist while three other clinicians were presented with compressed digital images in random order to estimate VCDR. Field trials were also carried out to demonstrate the practicality of compression, local storage and then transmission by mobile telephone ISDN lines and satellite, of optic discs and fundus images of patients with diabetes in either rural Western Australia or Surabaya, Indonesia. Kappa values of correlations of measurement of agreement between measured and estimated VCDR were 0.87, 0.45 and 0.84, respectively, for the three observers, corresponding to a specificity of 79-97% and a sensitivity of 70-95%. The portable Nidek fundus camera was also assessed for specificity and sensitivity in the diagnosis of diabetic retinopathy in comparison to standard Zeiss fundus camera photographs. Of 49 eyes in 25 consecutive patients attending the LEI clinic for assessment of diabetic retinopathy, three ophthalmologists assessed photographs and images in random order. When used for screening diabetic retinopathy, the digital images of the Nidek camera were graded as adequate quality in only 56% of eyes compared to 93% of the photographs. The kappa value of agreement in analysis of diabetic retinopathy was only 0.30. The prototype digital monocular indirect ophthalmoscope compared favourably with the Nidek camera. At 1:5 compression, images of size 36 kB transmitted from Surabaya to Perth took 29 s on the mobile telephone, while uncompressed images took 170 s. Images compressed 1:5 were transmitted in 60 s using the satellite telephone, while the uncompressed images took 240 s. Satellite transmission was more expensive but the lines were more stable than telephone connections from Indonesia. Digital imaging is becoming a powerful tool for ophthalmology in clinical records, teaching and research, and interoffice diagnostic opinions. It also has enormous potential for community screening for blinding eye diseases, such as glaucoma and diabetic retinopathy. Inexpensive portable imaging devices that are easy to use, and on which local health workers might be trained, must be developed and validated in terms of sensitivity and specificity of performance. The technology of image capture, image compression, transmission, data base storage and analysis is rapidly evolving and becoming less expensive.

Relationship between anticoagulant medication and massive intraocular hemorrhage in age-related macular degeneration.

BACKGROUND: A massive intraocular hemorrhage in the course of age-related macular degeneration (AMD) is a devastating event. We set out to determine the role of anticoagulant therapy prescribed for vascular or cardiac indications in the development of a massive hemorrhage. METHODS: A retrospective case-controlled study was conducted of 50 cases of age-related macular degeneration complicated by massive subretinal and vitreous hemorrhage. The control group consisted of 50 cases of AMD with small subretinal hemorrhage. RESULTS: There was a significant difference in the use of anticoagulant medication (warfarin sodium) between the groups. The difference in the use of antiplatelet medication (aspirin) between the groups was not significant. A patient with a massive intraocular hemorrhage and AMD is 11.6 times more likely to use anticoagulant medication. It appeared that more than 50% of the patients in the massive hemorrhage group were allowed to stop the anticoagulant medication. CONCLUSION: Anticoagulant medication poses a significant risk in the development of a massive intraocular hemorrhage in patients with exudative AMD. Antiplatelet medication poses a less significant risk. Physicians prescribing anticoagulant medication should be informed about the macular status of the patient. the In case of neovascular AMD, anticoagulant medication should be prescribed only for absolute systemic indications.

Tele-ophthalmology screening for retinal and anterior segment diseases.

A digital indirect ophthalmoscope (DIO) was developed and tested for use in tele-ophthalmology screening for posterior and anterior segment diseases. Using custom software, images from the DIO were digitized, compressed, stored and transmitted to a centralized eye clinic for interpretation. A total of 43 subjects were primarily screened for glaucoma using the DIO, a hand-held fundus camera and a stereo fundus camera. The photographic slides from the stereo fundus camera used as gold standards. Images (390 x 300 pixels x 3 bits) were stored using a laptop computer together with patient information. Image quality received at the central eye clinic was good and showed adequate diagnostic information. An ophthalmologist estimated cup-disc ratios and graded the quality of the images. The sensitivity and specificity of each instrument was calculated. A high sensitivity and specificity was found when using the DIO, indicating that it could be used in tele-ophthalmic screenings. Further modifications are needed to make the instrument more user-friendly and to enable it to be used with undilated pupils, so that it can be easily operated by health-care personnel in remote areas. The camera can also be used to image gross external eye pathology.

Assessment of myocardial velocities in healthy children using tissue Doppler imaging.

The objective was to determine the normal range of tissue velocities in paediatric hearts as measured by tissue Doppler imaging. A prospective study was carried out involving 160 healthy children (mean age 10.8 y, range 4.0-17.9 y). Using tissue Doppler imaging (TDI) from parasternal long axis and apical views, peak velocities and peak myocardial velocity differences across the right ventricular anterior wall, interventricular septum and left ventricular posterior wall were assessed during systole, early and late diastole. The existence of transmyocardial velocity differences between the left and right side of the interventricular septum, as well as between the endocardium and epicardium of the left ventricular posterior wall was observed throughout the heart cycle. With range-gated TDI from apical four-chamber view, peak velocities were measured within the basal, mid and apical parts of the interventricular septum, and the left and right free ventricular walls. The highest peak systolic, early and late diastolic velocities were measured within the basal parts of all myocardial walls. The ranges of the calculated velocity ratios (early-to-late diastolic velocity and early diastolic-to-systolic velocity) for the various wall parts appeared to be overlapping. The correlations of peak myocardial tissue velocities and their ratios with age and weight were weak and practically irrelevant. These normal values of peak myocardial velocities, transmyocardial velocity differences and the ratios of peak wall velocities can be used as reference values in future investigations of ventricular dysfunction in this age group.

Retinal blood flow changes in diabetic retinopathy measured with the Heidelberg scanning laser Doppler flowmeter.

BACKGROUND: Investigation of retinal blood flow in patients with and without diabetic retinopathy (DR). Retinal blood flow is measured with the non-invasive Heidelberg Retinal Flowmeter (HRF). The clinical suitability of the HRF in patients with diabetes mellitus is investigated, and measured blood flow is compared with blood flow in a group of non-diabetic persons. METHODS: Cross-sectional study of retinal capillary perfusion in eighty diabetic patients and forty-nine control persons, non-invasively measured with the Heidelberg scanning laser Doppler flowmeter. RESULTS: In the control group, HRF measurements could be performed in all subjects. In the diabetes group some patients had media opacities or were not able to maintain stable fixation. Therefore HRF measurement was only possible in 79%, 75% and 60% of the subjects for the nasal, papillo-macular and foveal areas respectively. Retinal blood flow as measured in the perifoveal and nasal areas was associated with the level of diabetic retinopathy. In patients with proliferative DR (levels 4 and 5) the blood flow was reduced, in comparison with that of the patients with exudative or non-proliferative DR (levels 1 and 2) and preproliferative DR (level 3). Blood flow was not correlated with age, systemic blood pressure, intra-ocular pressure and perfusion pressure in either group. A significant negative correlation with the actual blood glucose level was found in the perifoveal area (R = -0.585, P = 0.0001). CONCLUSIONS: The HRF offers an interesting non-invasive method for measurement of retinal blood flow. In this cross-sectional study variations in retinal blood flow could be detected in various stages of DR in relation to clinically visible funduscopic changes.

Comparison of optic disc image assessment methods when examining serial photographs for glaucomatous progression.

AIM: To assess serial, simultaneous stereo optic disc images by four methods for glaucomatous progression. METHODS: Using varying techniques, two ophthalmologists assessed serial optic disc images of 52 eyes from 27 patients with a mean duration between images of 18 months. The neuroretinal rim width was qualitatively assessed by four assessment methods and compared with quantitative rim measurements made using PC based software. RESULTS: The highest sensitivity of 83% was achieved using computerised stereo chronoscopy. CONCLUSION: Stereo chronoscopy improved the detection of subtle optic disc changes when compared with simpler assessment techniques.

Congenital heart defects and maternal derangement of homocysteine metabolism.

Methionine loading tests and folate, vitamin B(6), and vitamin B(12) analyses were performed in 27 mothers of children with congenital heart defects. Median fasting plasma homocysteine concentrations were significantly higher in the study group as compared with 56 control subjects (P =.0001). Maternal hyperhomocysteinemia may be a risk factor for congenital heart defects.

Predictive value of pattern VEP, pattern ERG and hole size in macular hole surgery.

OBJECTIVE: To describe pattern-reversal visual evoked response (PRVEP) and pattern electroretinogram (PERG) parameters in eyes with macular hole and their value for predicting postoperative visual outcome. METHODS: Prospectively we studied 27 eyes (27 patients) with a full-thickness macular hole. Preoperatively the hole and rim were measured and the PRVEP and PERG were recorded. The preoperative parameters were correlated with postoperative visual outcome. RESULTS: The macular hole was closed in 26 of 27 eyes. Sixteen eyes (59%) had an increase in visual acuity (VA) of two lines or more, 10 eyes (37%) remained within one line of preoperative VA and 1 eye (4%) had a decrease in VA of two lines. Duration of symptoms was negatively correlated with preoperative VA (R=-0.547, P=0.0038) and postoperative VA (R=-0.519, P=0.0065) and positively correlated with hole area (R=0.533, P=0.0061) and rim area R=0.633, P=0.0009). Only the PRVEP P100 latency of the 10' check size and the PERG N35 latency were significantly associated with visual outcome (P=0.022 and P=0.042 respectively). CONCLUSIONS: There was no association of either hole or rim size with postoperative visual outcome. Preoperative electrophysiology, however, is useful as a prognostic tool. Utilization is limited to the use of latency parameters of the response and is dependent on the check size of the stimulus.

Treatment of hyperopia with contact Ho:YAG laser thermal keratoplasty.

PURPOSE: To evaluate the effectiveness, safety, and stability of contact Ho:YAG laser thermal keratoplasty for low to moderate hyperopia. METHODS: Fifty-five hyperopic eyes of 39 patients were treated with a Technomed contact Ho:YAG laser; 23 eyes were treated a second time. Treatment parameters were 1 octagonal ring of 8 spots with a treatment diameter of 6 mm, 7 mm, or 8 mm. Efficacy of the Ho:YAG laser treatment was evaluated after 6 months, comparing 3 treatment zone diameters. Stability and efficacy after 12 months was evaluated comparing 7-mm and 8-mm treatment zone diameters. RESULTS: Mean reduction of spherical equivalent refraction after 6 months was not statistically significantly different between the 6-mm or 7-mm diameter zones: 1.42 (+/- 1.30) D versus 2.22 (+/- 0.44) D. An 8-mm diameter treatment zone was significantly less effective, 1.12 (+/- 0.47) D. Longer follow-up did not show stability: mean reduction of spherical equivalent manifest refraction was 1.58 (+/- 0.45) D for the 7-mm diameter treatment zone and 0.82 (+/- 0.61) D for the 8-mm diameter treatment zone after approximately 12 months. Retreatment had a limited additive effect. No clinically significant loss of spectacle-corrected visual acuity was reported. No eyes lost more than 1 line of visual acuity. CONCLUSION: Contact Ho:YAG laser thermal keratoplasty corrected hyperopia up to 2.50 D, but predictability was poor and a regression of initial effect occurred. Instability of refraction persisted to 1 year after surgery.

Prognostic value of pattern reversal visual-evoked potentials in idiopathic epiretinal membrane.

BACKGROUND: Prognostically favorable factors for epiretinal membrane removal have been described in the literature by several authors. Little information, however, is available about the objective assessment of the preoperative macular function. This study reports the results of idiopathic epiretinal membrane removal and the prognostic value of preoperative, pattern reversal visual-evoked potentials (PRVEPS) in recovery of visual acuity (VA). METHODS: In 60 patients (60 eyes) with idiopathic epiretinal membrane we performed PRVEP examination preoperatively. All eyes were operated on by standard three-port vitrectomy with membrane removal. Two eyes were excluded because of postoperative complications. Follow-up VA was compared with preoperative VA for the 58 study eyes and correlated with preoperative PRVEP parameters. RESULTS: The mean preoperative VA was 0.2, the mean postoperative VA, 0.4. The PRVEP was recordable in 74%, 67% and 36% of cases for check sizes of 17, 10 and 7 arcmin respectively. Twenty patients (50%) had an increase in VA of two lines or more, in 25 patients (43%) VA remained within one line of the preoperative value, and in 4 patients (7%) VA decreased by two lines or more. The mean preoperative VA was not significantly different between the group with an improved VA and the group that did not benefit from membrane removal. Of the PRVEP parameters, only the N80 latency for the 17' check size was significantly associated with postoperative visual outcome. CONCLUSION: The PRVEP is applicable as a predictor for visual outcome in cases of epiretinal membrane removal. For the 17' pattern size we found a significant association of the combination of recordability and delayed N80 latency with visual outcome.

The inverse problem in electroretinography: a study based on skin potentials and a realistic geometry model.

The problem of obtaining the retinal source distribution that generates the electroretinogram (ERG) from measured skin potentials is addressed. A realistic three-dimensional (3-D) volume conductor model of the head is constructed from magnetic resonance image (MRI) data sets. The skin potential distribution generated in this model by a dipole layer source at the retina is computed by using the boundary element method (BEM). The influence of the various compartments of the complete model on the results was investigated, and a simplified model was defined. An inverse procedure for estimating the source distribution at the retina from ERG's obtained from skin electrodes was developed. The procedure was tested on simulated potentials. A fair correspondence between the original and estimated source distribution was found. Furthermore, the ERG's measured at seven skin electrodes were used to estimate the source distribution at the retina. The ERG potential waveform at an additional skin electrode was computed from this source distribution and compared to the measured potential at this electrode. Again a fair correspondence was obtained. It is concluded that the methods may become a useful tool for clinical applications, i.e., for the assessment of localized defects in retinal function.

Pattern reversal visual evoked potentials in eyes with macular holes and their fellow eyes.

PURPOSE: To investigate whether the pattern reversal visual evoked potential can be useful in the diagnosis and management of macular hole patients. METHODS: The pattern reversal visual evoked potential was measured in 66 patients with a macular hole and in 43 healthy control subjects. Check sizes of 34', 17' and 10' were applied. RESULTS: Results showed that, for the check sizes of 34', 17' and 10', eyes with a macular hole had significantly prolonged N80 and P100 latencies and a significantly reduced P100 amplitude as compared to their fellow eyes. Furthermore, for the 10' check size, the fellow eyes appeared to have a significantly reduced P100 amplitude in comparison with the control eyes, whereas N80 and P100 latencies of the fellow eyes of the macular hole patients were not prolonged. CONCLUSION: Significant pattern reversal visual evoked potential alterations were shown in eyes with macular holes and fellow eyes for small check sizes.

Pattern-reversal visual evoked potentials in patients with epiretinal membrane.

PURPOSE: To determine the extent of pattern-reversal visual evoked potential parameter alteration by epiretinal membranes and to investigate the use of pattern-reversal visual evoked potential in the estimation of macular function in eyes with epiretinal membrane and in the fellow eyes. METHODS: In both eyes of 162 patients with epiretinal membrane, 92 of primary and 70 of secondary origin, pattern-reversal visual evoked potentials were recorded. Check sizes of 17', 10', and 7' (minutes of arc) were used. Parameters investigated were N80 and P100 latencies and P100 amplitude. RESULTS: No significant difference was detected between eyes with epiretinal membrane of primary and secondary origin regarding visual acuity and the pattern-reversal visual evoked potential parameters for the different check sizes. Compared with the fellow eyes, the eyes with epiretinal membrane had a significantly reduced visual acuity, prolonged N80 and P100 latencies, and a reduced P100 amplitude for the different check sizes. Compared with a separate control group (N = 20) with patients 50 to 59 years old, eyes with epiretinal membrane (N = 9) showed the same features as in the total group, but only for the 17' and 10' check sizes. The fellow eyes (N = 9) showed a significant reduction of the P100 amplitude (P < .05) for the pattern sizes of 17' and 10', but no difference in visual acuity or pattern-reversal visual evoked potential latency was found. CONCLUSIONS: In eyes with epiretinal membrane, pattern-reversal visual evoked potential latencies are prolonged, and amplitude is reduced. Relationships between clinical parameters and pattern-reversal visual evoked potential parameters require further study.