Association of anthropometric markers with globe position: A population-based MRI study.

PURPOSE: Exophthalmometry is a common examination in ophthalmology. For example it is relevant for diagnosis or follow-up of thyroid eye disease. However, exophthalmometry is affected by several factors such as ethnicity, sex and age. The purpose of this study was to determine the globe position by magnetic resonance imaging (MRI) and to investigate its correlates among the general Northeast German adult population. METHODS: A total of 3030 subjects aged between 20 and 89 from the population-based Study of Health in Pomerania (SHIP) underwent a standardised whole-body MRI. Axial length and globe position were determined in axial T1-weighted images of the orbit. The image had to include the corneal apex as well as the optic nerve head. Study participants were excluded from imaging analysis if there was no plane available that included both structures. Further exclusion criterion was a lateral deviation of the subject's viewing direction. Images with inadequate quality due to motion artefacts or other technical reasons were excluded as well. Globe position was defined as the perpendicular distance between the interzygomatic line and the posterior surface of the cornea (exophthalmometric value). The distance between the posterior surface of the cornea and the posterior pole of the eyeball, at the boundary with orbital fat, was defined as axial length. We used posterior surface of the cornea for our measurements, because it seemed to be less vulnerable for motion artefacts than the anterior one. Moreover body measurements including body mass index (BMI), waist and hip circumferences were determined. Associations between anthropometric measurements with exophthalmometric outcomes were analysed by linear regressions adjusted for age and stratified by sex. P-values <0.05 were considered as statistically significant. To assess intra-reader variability intra-class correlation coefficients (ICC) were computed for repeated measurements of the MRI scans of 25 subjects. RESULTS: After considering the exclusion criteria 1926 evaluable subjects remained. There was no significant difference between means of right and left eyes. The mean exophthalmometric value was significantly higher in men (16.5 +/- 2.2 mm) than in women (15.3 +/- 2.1 mm). The mean MRI-axial length was 23.4 +/- 0.8 mm for men and 22.8 +/- 0.9 mm for women. BMI, waist and hip circumferences were positively correlated with exophthalmometric value (p<0.001). Difference of mean MRI-based exophthalmometric value for obese subjects (BMI ≥30 kg/m2) and non-overweight (BMI <25 kg/m2) was 2.1 mm for men and 1.6 mm for women. ICC between 0.97 and 0.99 indicate excellent repeatability of our method. CONCLUSION: We conclude that MRI-based exophthalmometric values are positively correlated with BMI, waist- and hip-circumference among the general Northeast German adult population. This association is independent from age and axial length. Consequently bodyweight of patients should be regarded to interpret exophthalmometric values correctly. MRI-exophthalmometry seems to be a suitable method to determine globe position. Considering the large number of study participants, exophthalmometric values of our study could be used as comparative values for exophthalmometry of people of Western European descent in future.

[Static Retinal Vessel Analysis in Population-based Study SHIP-Trend]. / Statische Gefäßanalyse der retinalen Blutgefäße in einer populationsbasierten Kohorte unter Berücksichtigung des Diabetes mellitus.

BACKGROUND: Interdisciplinary investigations of possible connections between general diseases and ophthalmological changes are difficult to perform in the clinical environment. But they are gaining in importance as a result of the age-related increase in chronic diseases. The collection of health-related parameters in the Study of Health in Pomerania (SHIP) project allows to derive conclusions for the general population. METHODS: The population-based SHIP trend study was conducted between 2008 and 2012 in Greifswald. The baseline cohort included 4420 subjects (response 50.1%) at the age of 20 to 84 years. The pre-existence of arterial hypertension, diabetes mellitus and smoking status were questioned in a standardized questionnaire, the blood pressure and the HbA1c were determined by the laboratory. The vascular diameter of retinal arterioles and venules were determined by means of non-mydriatic fundus images and the retinal arterial (CRAE) and venous equivalent (CRVE) were calculated therefrom. The association of diabetes mellitus, HbA1c, smoking status and blood pressure with the retinal vascular parameters was tested for age and sex with linear regression models. RESULTS: In 3218 subjects with evaluable standardized fundus photographs, significant associations of elevated HbA1c (> 6.5%), smoking status and systolic and diastolic blood pressure were found with the retinal vessel widths CRAE and CRVE. Anamnestic diabetes mellitus, on the other hand, was not associated with any of the vascular parameters. CONCLUSION: This research study reveals a relevant correlation between general diseases and the retinal blood flow in the eye. Therefore, general diseases can induce ophthalmological changes and eye examination can provide information for the assessment of general diseases.

[Diabetic retinopathy--Current aspects of therapy]. / Diabetische Netzhauterkrankungen. Aktuelle Aspekte in der Therapie.

Pathological changes of the small blood vessels are the main risk for diabetic retinopathy. A distinction is made between proliferative and non-proliferative processes. The diabetic macular edema can manifest itself at any stage of the diabetic retinopathy and poses a serious threat to vision and quality of life. Evidence based therapy primarily focuses on laser coagulation. Laser coagulation suspends progression of the disease and is used particularly for extrafoveolar edema. Especially a pathological swelling, such as the cystoid edema, in this central part of the retina, can cause a rapid deterioration of vision. The treatment of cystoid macular edema with intravitreal application of drugs is a widespread therapeutical approach. Invasive therapeutical drug application into the vitreous cavity has to be sterile in order to prevent infection. The usage of VEGF (Vascular endothelial growth factor) antagonists is an effective treatment for the diabetic macular edema. Several drugs are now available for intravitreal injection. Nevertheless a small number of medical drugs regularly administered to patients still have to be approved by the authorities (off-label use). One can distinguish mainly between VEGF antagonist (growth factor antagonist) like ranibizumab, aflibercept and bevacizumab and steroid therapy which includes dexamethasone, fluocinolone and triamcinolone.