Johannes Schouten

Knowledge base and preferred methods of obtaining knowledge of glaucoma patients.

Purpose To gather information regarding patients understanding of glaucoma and the manner in which patients wish to learn about the disease with the intent of improving patient education. Methods Forty-four of sixty randomly selected ophthalmologists (73%) asked four of their patients consecutively to complete a questionnaire about glaucoma. The selection of questions was based on focus group interviews and suggestions from several experts. Topics included knowledge about glaucoma and its treatment, the need for information, and preferred providers and methods of patient education. Results Fifty percent of the patients had 49% or less correct answers to questions about glaucoma or its treatment. Per item the correct answers ranged from 5% to 90%. Lack of knowledge was associated with low level of education, short duration of glaucoma, high age, and no preference for the Internet as method of supplying information. These variables, however, did not identify groups with a considerable lack of knowledge sufficiently accurately to target patient education. A high need for information was observed and included information about the patients own glaucoma. Almost all patients preferred the ophthalmologist and many also a nurse or a representative of the Glaucoma Patient Society as providers of information. Written material was the preferred method. Conclusions Patient education should address all patients. A patient education program should cover a wide range of topics with a focus on general information through written material and information tailored to the individual glaucoma patients needs. The ophthalmologist is a key- person, but others could play an important role in patient education.

Corneal endothelial cell loss after Baerveldt glaucoma drainage device implantation in the anterior chamber

To investigate central and peripheral corneal endothelial cell density (ECD) in relation to Baerveldt (BV) glaucoma drainage device (GDD) tube corneal (TC) distance.

Correlation of structure and function of the macula in patients with retinitis pigmentosa

PurposeTo correlate the structure of the macula, as measured by spectral-domain optical coherence tomography (SD-OCT) and function, as measured by microperimetry (MAIA) in patients with retinitis pigmentosa (RP) and relatively good visual acuity.DesignProspective, cross-sectional, non-intervention study.SubjectsPatients with RP.MethodsThirty patients with RP and good central visual acuity were identified. Each patient underwent SD-OCT of the macula and microperimetry. The images were overlaid using the custom-designed software. The retinal sensitivity by microperimetry was correlated with corresponding retinal thickness, as measured by the SD-OCT. ELM, COST, and IS/OS junction were scored as intact, disrupted, or absent.Main outcome measuresComparing the retinal sensitivity on the MAIA with various measurements on the SD-OCT.ResultsThe retinal sensitivity on the MAIA showed a significant correlation with total retinal thickness and outer retinal thickness on the SD-OCT. There was no association with either the inner retinal thickness or the choroidal thickness. ORT showed a statistically significant correlation with the anatomical classification of ELM (r=−0.76, P<0.001), IS/OS (r=−0.800, P<0.001), and COST (r=−0.733, P<0.001).ConclusionThis study determined that there was a high correlation of the structure and function of the central macula in patients with RP. These studies are important to establish surrogate markers that can be used as end points for various tests in future therapeutic clinical trials.

Brain-inspired algorithms for retinal image analysis

Retinal image analysis is a challenging problem due to the precise quantification required and the huge numbers of images produced in screening programs. This paper describes a series of innovative brain-inspired algorithms for automated retinal image analysis, recently developed for the RetinaCheck project, a large-scale screening program for diabetic retinopathy and other retinal diseases in Northeast China. The paper discusses the theory of orientation scores, inspired by cortical multi-orientation pinwheel structures, and presents applications for automated quality assessment, optic nerve head detection, crossing-preserving enhancement and segmentation of retinal vasculature, arterio-venous ratio, fractal dimension, and vessel tortuosity and bifurcations. Many of these algorithms outperform state-of-the-art techniques. The methods are currently validated in collaborating hospitals, with a rich accompanying base of metadata, to phenotype and validate the quantitative algorithms for optimal classification power.

Differences in biopsychosocial profiles of diabetes patients by level of glycaemic control and health-related quality of life: The Maastricht Study

Aims Tailored, patient-centred innovations are needed in the care for persons with type 2 diabetes mellitus (T2DM), in particular those with insufficient glycaemic control. Therefore, this study sought to assess their biopsychosocial characteristics and explore whether distinct biopsychosocial profiles exist within this subpopulation, which differ in health-related quality of life (HRQoL). Methods Cross-sectional study based on data from The Maastricht Study, a population-based cohort study focused on the aetiology, pathophysiology, complications, and comorbidities of T2DM. We analysed associations and clustering of glycaemic control and HRQoL with 38 independent variables (i.e. biopsychosocial characteristics) in different subgroups and using descriptive analyses, latent class analysis (LCA), and logistic regressions. Results Included were 840 persons with T2DM, mostly men (68.6%) and with a mean age of 62.6 (±7.7) years. Mean HbA1c was 7.1% (±3.2%); 308 patients (36.7%) had insufficient glycaemic control (HbA1c>7.0% [53 mmol/mol]). Compared to those with sufficient control, these patients had a significantly worse-off status on multiple biopsychosocial factors, including self-efficacy, income, education and several health-related characteristics. Two ‘latent classes’ were identified in the insufficient glycaemic control subgroup: with low respectively high HRQoL. Of the two, the low HRQoL class comprised about one-fourth of patients and had a significantly worse biopsychosocial profile. Conclusions Insufficient glycaemic control, particularly in combination with low HRQoL, is associated with a generally worse biopsychosocial profile. Further research is needed into the complex and multidimensional causal pathways explored in this study, so as to increase our understanding of the heterogeneous care needs and preferences of persons with T2DM, and translate this knowledge into tailored care and support arrangements.

Baerveldt drainage tube motility in the anterior chamber.

Purpose To investigate the stability in position of the Baerveldt glaucoma drainage tube over time and to study movement of the drainage tube in the anterior chamber (AC) under varying light conditions. Methods This prospective study included 70 eyes with implantation of a Baerveldt glaucoma drainage tube in the anterior chamber. Anterior segment optical coherence tomography (AS-OCT) images were made preoperatively to quantify AC depth. AS-OCT images were made twice under photopic and twice under scotopic conditions, in the angle parallel to the Baerveldt tube to quantify drainage tube position, at 3, 6, 12, and 24 months postoperatively. Tube-corneal (T-C) and tube-iris (T-I) distances were measured. Additionally, the central AC depth and the peripheral angle opening (AOD 500) were determined. Two subgroups were distinguished according to tube position: free in the AC (group 1, n = 48) and transiridal (group 2, n = 22). Results After 24 months of follow-up, the drainage tube was found to move statistically significantly closer (0.12 mm) to the corneal endothelium in group 1 (p<0.01). There was no statistically significant difference in T-C distance over time in group 2. The T-C distance did not differ under photopic versus scotopic circumstances (p = 0.32). In both groups, the T-I distance was larger under scotopic conditions, a result of pupil dilation. Conclusions The Baerveldt glaucoma drainage tube remained in a stable position when a transiridal implantation was performed, whereas the tube moved closer to the endothelium when placed free into the AC. Transiridal implantation of the Baerveldt tube seems a safe alternative for tube implantation with respect to tube motility.

Distinguishing between Better and Worse Visual Acuity by Studying the Correlation with Quality of Life in Neovascular Age-Related Macular Degeneration

PURPOSE To determine whether there is a level of visual acuity (VA) in neovascular age-related macular degeneration (nAMD) above which the correlation of VA with disease-related quality of life (QoL) is significantly greater than below this level. DESIGN An observational, cross-sectional study. PARTICIPANTS A total of 184 patients with nAMD aged at least 50 years were included in the study. METHODS In face-to-face interviews, we assessed QoL with the Macular Disease-Dependent Quality of Life (MacDQoL) questionnaire. We measured VA with standardized Radner reading charts. We used regression splines analysis with a single hinge point, with the MacDQoL score as the dependent variable and VA as the independent variable. The x-coordinate (VA) of the hinge point was varied and tested with each iteration. A second method of regression splines analysis was also performed, without a preset hinge point. MAIN OUTCOME MEASURES The primary outcome measure is the cutoff point at or below which VA is associated with significantly less change in QoL than above this cutoff. The linear coefficients below and above the cutoff are defined as change in MacDQoL score per logarithm of the minimum angle of resolution (logMAR) unit of change in VA. RESULTS With Snellen equivalent VA 0.05 (1.3 logMAR) or worse, the linear coefficient was 0.15. With VA better than 0.05, the linear coefficient was 2.40 (P value of the difference: 0.009). CONCLUSIONS When VA is above 0.05, there is a stronger and significant relation between VA and QoL. At or below this level, the relation between VA and QoL approaches zero. With better VA, a difference in VA implies a significant difference in QoL. With poorer VA, a difference in VA is unlikely to imply a difference in QoL. Therefore, in treating nAMD, the aim should be to keep Snellen VA above 0.05 to have an impact on QoL. If it is certain that the best-corrected VA below 0.05 is permanent, these findings imply there may be less, if any, benefit to continue further treatment. This is to be evaluated on a case-by-case basis.

Does the World Health Organization criterion adequately define glaucoma blindness

Purpose Blindness in glaucoma is difficult to assess with merely the use of the current World Health Organization (WHO) definition (a visual field restricted to 10° in a radius around central fixation), as this criterion does not cover other types of visual field loss that are encountered in clinical practice and also depict blindness. In this study, a 5-point ordinal scale was developed for the assessment of common visual field defect patterns, with the purpose of comparing blindness as outcome to the findings with the WHO criterion when applied to the same visual fields. The scores with the two methods were compared between two ophthalmologists. In addition, the variability between these assessors in assessing the different visual field types was determined. Methods Two glaucoma specialists randomly assessed a sample of 423 visual fields from 77 glaucoma patients, stripped of all indices and masked for all patient variables. They applied the WHO criterion and a 5-point ordinal scale to all visual fields for the probability of blindness. Results The WHO criterion was mostly found applicable and in good agreement for both assessors to visual fields depicting central island of vision or a temporal crescent. The percentage of blindness scores was higher when using the ordinal scale, 21.7% and 19.6% for assessors A and B, respectively, versus 14.4% and 11.3% for the WHO criterion. However, Kappa was lower, 0.71 versus 0.78 for WHO. Conclusions The WHO criterion is strictly applied and shows good agreement between assessors; however, blindness does not always fit this criterion. More visual fields are labeled as blind when a less stringent criterion is used, but this leads to more interobserver variability. A new criterion that describes the extent, location, and depth of visual field defects together with their consequence for the patient’s quality of life is needed for the classification of glaucoma blindness.

[OP.5A.05] GLUCOSE METABOLISM STATUS IS ASSOCIATED WITH IMPAIRED RETINAL ARTERIOLAR VASODILATATION: THE MAASTRICHT STUDY

Objective: Type 2 diabetes (T2DM) is associated with a ∼2-fold increased risk of cardiovascular disease (CVD). This can be explained, in part, by the finding that large artery dysfunction already occurs before the onset of diabetes (‘ticking clock hypothesis’). Whether a similar phenomenon occurs for microvascular dysfunction is not known. We therefore tested the hypothesis that microvascular dysfunction (MVD) is already present in impaired glucose metabolism (IGM; prediabetes) and worsens further in T2DM by investigating the association between glucose metabolism and MVD using the retinal arteriolar dilator response to flicker light. Design and method: In a population-based cohort study with oversampling of T2DM (n = 2092), we determined flicker-light-induced retinal arteriolar %-dilatation (Dynamic Vessel Analyzer; Imedos, Germany) and glucose metabolism status (OGTT; classified as normal (NGM), IGM or T2DM). Differences were compared with multivariable regression adjusted for age, sex, waist, smoking, systolic-BP, lipid profile, retinopathy, eGFR, (micro)albuminuria, the use of lipid-modifying and/or blood-pressure-lowering medication, and prior CVD. Results: 1192 individuals had NGM (41% men, aged 58 ± 8 years (mean ± SD)), 323 IGM (54% men, aged 61 ± 7 years) and 577 T2DM (69% men, aged 63 ± 8 years). Arteriolar %-dilatation (mean ± SD) was 3.42 ± 2.84 in NGM, 3.01 ± 2.76 in IGM, and 2.34 ± 2.64 in T2DM. Adjusted analyses showed a lower %-dilatation in IGM (&bgr; = −0.20, [CI95% −0.56; 0.15]), which further decreased in T2DM (&bgr; = −0.61, [−0.97; −0.25]) vs NGM, p for trend = 0.001. In addition, higher HbA1c (&bgr; = −0.32, [−0.48; −0.16], p < 0.001) and fasting plasma glucose (FPG) (&bgr; = −0.16, [−0.24; −0.07], p < 0.001) were associated with lower arteriolar %-dilatation in fully adjusted models. Conclusions: Glucose metabolism status, HbA1c, and FPG are associated with reduced flicker-light-induced retinal arteriolar dilatation, independently of major cardiovascular risk factors. These findings support the concept that MVD precedes and thus may contribute to T2DM and T2DM-associated CVD.