Myopiekontrolle: aktuelle Strategien

Purpose. The prevalence of myopia is increasing worldwide and its long-term effects can have major impacts on eye health. Paediatric onset of myopia leads to a higher risk for developing high levels of myopia in adulthood. Slowing down or stopping myopia progression is an important task for the future. Material and Methods. Based on a literature review, the latest developments in the field of myopia control for children were summarized. The current study situation for orthokeratology, soft contact lenses, atropine therapy and spectacle lenses for the management of myopia is discussed in detail. Results. Results on the safety and effectiveness of orthokeratology and modified soft contact lenses are exceedingly consistent. Soft multifocal contact lenses, as well as newer spectacle lenses, recently received regulatory approval for myopia control. Studies on the administration of atropine recommend a dosage of 0.01 - 0.05 %. All methods slow down myopia progression and decrease axial length growth of the eye. Side effects, adverse events or discontinuation of treatment only occur in the rarest of cases. Orthokeratology and atropine continue to deliver the best results. Conclusion. From today’s perspective, carrying out myopia control can be recommended with great certainty. The choice of method depends on the individual requirements of each patient, with all methods offering success in reducing myopia progression. In the future, even more advanced contact lens geometries, more precise atropine dosages or improved optics of spectacle lenses will further increase the success of the treatment. Keywords. Progressive myopia, myopia control, children, contact lenses, atropine, spectacle lenses

Prototyp eines Bildschirmfarbtests

Purpose. The purpose of this study is to develop a new digital colour vision test. Material and Methods. Based on the principle of metamerism, a digital testing strategy was developed for efficient measurement of colour vision. Twentyfive subjects participated in the study, 21 of whom had normal colour vision and four of whom had a congenital colour vision disorder. Differences in colour vision were examined by monocular presentation of halfquadrants of different hues and degrees of saturation, and the algorithm calculated the colour vision defects that occurred based on the subjects’ responses. The following colour vision values were assigned from the data: a colour scale range of 2.76 – 7.18 for normal colour vision and greater than 7.18 for colour sense disorders. A second new colour scale assessed the type of colour vision disturbance: in the range of 0 – 0.3 were values for a deuteranomaly, in the range of 0.6 – 1.0 were values for a protanomaly, and a value of 1.0 corresponded to a tritanomaly. Results. The difference in colour vision between subjects with normal colour vision and those with a colour vision defect was confirmed (p < 0.001) by measuring the type and the extent of the colour vision disorder was determined. In the group of subjects with normal colour perception, a mean colour scale value of 3.41 ± 0.52 was determined. The extent of colour sense disturbance for the subjects with colour vision impairment was values of 7.18 – 14.33 according to the colour scale, indicating greater variability. Conclusion. The developed algorithm provided meaningful results regarding the colour perception of the test persons. It was possible to differentiate between normal colour vision and colour vision disorder could be shown. Furthermore, the variation between subjects with normal colour vision could be evaluated. Keywords. Colors, colour vision, colour sense disorders, colour test, software algorithm

Auswirkungen auf den vorderen Augenabschnitt beim Andocken eines Femtosekundenlasers an das Patienteninterface

Purpose. To compare the intraoperative OCT (optical coherence tomographer) of the femtosecond laser LenSx (Alcon Pharma GmbH, Freiburg) with a Scheimpflug-tomographer and an anterior segment OCT and thus to investigate a possible influence on the anterior segment of the eye when docking the patient’s interface. Material and Methods. A prospective cross-sectional study was conducted with 57 subjects who underwent a planned femtosecond laser-assisted cataract surgery or refractive lens exchange. The eye to be operated on was measured prior to the operation in mydriasis with the Visante OCT (Carl Zeiss Meditec AG, Jena) and the Pentacam AXL (Oculus Optikgeräte GmbH, Wetzlar). During the surgery, images of the anterior segment of the eye were taken by the integrated intraoperative OCT of the laser, which were evaluated afterwards and compared to the values of the other devices. The parameters examined were the internal anterior chamber depth (ACD), nasal and temporal chamber angles, central corneal thickness (CCT) and central lens thickness (LT). Results. The comparison of the intraoperative OCT and the two other devices showed clinically relevant differences in all parameters. The intraoperative OCT showed a 9.19 ± 27.55 μm larger CCT, 0.96 mm (median difference) larger LT, 0.05 mm smaller ACD than the Pentacam AXL and a 21.36 ± 25.50 μm larger CCT, 0.10 mm (median difference) smaller ACD than the Visante OCT. Conclusion. The comparison of the intraoperative OCT with the Visante OCT and the Pentacam AXL shows clinically relevant differences. Changes in the anterior segment of the eye may be due to errors in measurement or docking of the patient’s interface. Keywords. femtosecond laser, OCT, anterior segment of the eye, cataract surgery, refractive lens exchange

Veränderung des NPC bei Personen mit Konvergenzinsuffizienz nach I.F.S.-Visualtraining

Purpose. The aim of this study was to evaluate the efficacy of the I.F.S. visual therapy (convergence training) developed by Bruce Evans in a randomized-controlled setting. The analysis of the changes of the near point of convergence (NPC) was the main target of the study. Material and Methods. 20 subjects (39.0 ± 15.32 years) with convergence insufficiency and an NPC > 10 cm underwent 4 weeks of visual therapy in a randomised-controlled singleblind setting. The verum group followed the I.F.S. exercises, while the control group performed a placebo therapy. Before and after the training phase, the NPC and the positive fusional vergence (PFV) were measured in all subjects and the Sheard and Mallett criteria were also assessed. The CISS questionnaire was used to record and quantify subjective symptoms. Results. The statistical analysis (α = 0.05) shows that the NPC of the verum group improved significantly compared to the control group (p = 0.0008) and within the verum group only (p = 0.0002). The positive effect of the I.F.S. exercises is confirmed by the also significant improvement of the PFV. Conclusion. The results as well as the practical experience with the exercises indicate that the I.F.S. visual therapy proves to be effective for individuals with a convergence insufficiency and an NPC > 10 cm in improving the near point of convergence. Keywords. convergence insufficiency, near point of convergence, NPC, visual therapy, convergence training, I.F.S. exercises