No description available.

No description available.

No description available.

Diss. (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 4 uppsatser.

Thesis (Ph. D.)--Ohio State University, 2008. / Title from first page of PDF file. Includes bibliographical references (p. 117-129).

2021 / Background: Radiation retinopathy is a progressive ocular disease that is a common complication following exposure to ionizing radiation. Despite current treatments, some patients continue to lose vision due to retinal ischemia and retinal edema, necessitating further investigation into therapeutical alternatives. Pilot studies of supplemental oxygen and hyperoxia therapy have recently demonstrated improved outcomes in vision and reduction of symptoms in ocular disorders involving diseases of the retinal vasculature such as diabetic retinopathy and retinal vein occlusion. Hyperbaric oxygen therapy (HBOT) has been reported to improve complications associated with radiation retinopathy, but HBOT poses challenges regarding affordability and availability of hyperbaric chambers. Normobaric hyperoxia (NBH) therapy presents a more cost-effective and accessible alternative that has been successfully shown to ameliorate edema and improve visual outcomes in retinopathies with similar clinical presentations as radiation retinopathy and thus may be an effective treatment for complications due to radiation retinopathy. Objective: In this case study, we investigated whether administration of NBH could reduce retinal edema and improve visual acuity in a patient with retinal edema and vision loss associated with radiation retinopathy. Methods: Three patients with radiation retinopathy were initially screened for NBH treatment. Of those, one patient proceeded with treatment and completed two 3-hour NBH sessions and one 3-hour normobaric normoxia (NBN) session which served as a control. Before and after each session, best corrected distance visual acuity (VA) was assessed using Early Treatment Diabetic Retinopathy Study testing, and retinal thickness was imaged using optical coherence tomography. Retinal thickness measurements were taken at five points along the area of edema and average differences and percent changes in thickness were calculated. A student’s one-tailed t-test was used to analyze statistical significance. Results: Retinal thickness in the area of edema was reduced by an average of 27±7.14 µm with an average percent change in thickness of 4.35±1.01%, and VA improved from 20/63-2 (LogMAR=0.54) to 20/63+1 (0.48) after the first NBH trial. After the second NBH trial, retinal thickness in the area of edema was reduced by an average of 20.2±2.59 µm with an average percent change in thickness of 4.42±0.58%, and VA was improved from 20/50 (0.4) to 20/32-1 (0.22). Following the NBN control session, retinal thickness was reduced by an average of 5.8±0.84 µm and had a percent change of 1.71±0.23% with relatively little change in VA. Retinal thickness was found to be significantly reduced following each NBH trial when compared to NBN measurements (p = 0.001 and 0.0002). Conclusion: In a patient with radiation retinopathy, NBH treatment demonstrated improved outcomes in VA and reduction of retinal edema. Addition of NBH therapy to existing disease management plans may expand the treatment repertoire for patients suffering from radiation retinopathy and lend further support for the use of NBH therapy as a treatment option for additional ophthalmic disorders.

The early detection of acquired losses of colour vision can provide the ophthalmologist with a very sensitive indicator of visual dysfunction. As a result we have developed and tested an automated, CRT-based, chromatic discrimination system that allows us to measure acquired colour-vision deficits with great precision. This system, known as the Sussex Gratings Machine, can produce chromatic stimuli in any direction in equal luminance colour space. However, we have found that measurements made along a constant MIL-cone axis (Tritan) or a constant S-cone (Red/Green) confusion axis are most useful. Using this system we have investigated acquired colour vision deficits in diabetes ,. and thyroid eye disease. We have shown that tritan discrimination losses can be used to screen for severe diabetic retinopathy and also to predict those who are likely to develop it within 18 months. We have also confirmed that acquired tritan discrimination losses are a very useful indicator of optic-nerve compression in thyroid eye disease.

published_or_final_version / Molecular Biology / Doctoral / Doctor of Philosophy

Die Frühgeborenenretinopathie (Retinopathia praematurorum (RPM)) ist eine Erkrankung der Netzhaut, die vor allem sehr unreife Frühgeborene betrifft und in ihrem Endstadium zur Erblindung führen kann. Ein gesicherter Risikofaktor für die Entwicklung einer RPM ist die Gabe von hohen Konzentrationen an Sauerstoff nach der Geburt. Gegenstand dieser Arbeit war die Frage, ob nach der Einführung eines Sauerstoffprotokolls 2007 das Auftreten höherer Stadien der RPM reduziert werden konnte. Das Sauerstoffprotokoll hatte zum Ziel die Gabe von inspiratorischem Sauerstoff nach Möglichkeit zu senken und übermäßige Fluktuationen zu vermeiden. Hierfür wurden 268 Frühgeborene mit einem Gestationsalter < 32Wochen bei Geburt, welche in den Jahren von 2005 bis 2006 (pre-Gruppe) und 2008 bis 2009 (post-Gruppe) in der Universitätsklinik Leipzig geboren und einem RPM-Screening unterzogen wurden, verglichen. Es konnte gezeigt werden, dass die Inzidenz der RPM nach 2007 signifikant niedriger war. So erkrankten in der pre-Gruppe 12 von 102 Kinder an einer höhergradigen RPM (>Stadium 3), wohingegen diese Stadien in der post-Gruppe nicht mehr beobachtet wurden. Demzufolge reduzierte sich auch die Notwendigkeit einer Therapie von 7,4 % auf 0 % (jeweils p = 0.0005). In Hinblick auf die Kerndaten wie Gestationsalter, Geburtsgewicht, Körpergröße, sowie dem Auftreten schwerer Begleiterkrankungen wie u.a. der nekrotisierenden Enterokolitis oder der bronchopulmonalen Dysplasie fanden sich keine Unterschiede zwischen den Gruppen. Allerdings wies die post-Gruppe eine höheren Anteil an männlichen Frühgeborenen auf. Die Mortalität zeigte keine signifikante Veränderung nach der Intervention und lag bei 7.8 % in der pre- bzw. 6.6 % in der post-Gruppe (p = 0.81). Die Auswertung der pulsoximetrisch gemessenen Sauerstoffsättigung (SpO2) und der inspiratorischen Sauerstofffraktion (FiO2) zeigte, dass der SpO2 leicht und der FiO2 deutlich reduziert werden konnte. Ein signifikanter Unterschied ergab sich hier jedoch lediglich für den FiO2, insbesondere in den ersten 14 Lebenstagen. Die logistische Regressionsanalyse legt nahe, dass hohe SpO2- und FiO2-Werte sowie das Auftreten von intrakraniellen Blutungen mit schwerwiegenden ROP-Stadien korrelieren. Ein bedachter Umgang in der Sauerstofftherapie Frühgeborenen könnte in der Lage sein das Auftreten der Frühgeborenenretinopathie zu reduzieren ohne eine Erhöhung der Mortalitätsrate zu riskieren.

PURPOSE: Diabetic macular edema (DME) is the most common cause of vision loss in patients with diabetic retinopathy. This study aims to approach diabetic macular edema and diabetic retinopathy as ischemic conditions and explores a potential treatment through hyperoxia. The study measured changes in retinal thickness, visual acuity, and contrast sensitivity in subjects receiving normobaric oxygen. METHODS: Fifty-one patients with diabetic macular edema at Beth Israel Deaconess Medical Center Eye Clinic (Boston, MA) received oxygen via a face mask at 5 liters per minute for 3 hours. Retinal thickness at the central subfield and maximal retinal thickness were measured using optical coherence tomography. Contrast sensitivity, best corrected visual acuity, and intraocular pressure were measured before and after oxygen as well. RESULTS: Macular thickness from diabetic macular edema decreased by an average of 2.09% (p < .05) at the point of maximal thickness, and by 0.88% (p < .05) at the central subfield. Vision also improved by an average of 0.043 LogMAR units (p < .05). Changes in macular thickness and visual acuity were non-significant in healthy control eyes that received oxygen. The results of hyperoxia on contrast sensitivity were indeterminate. CONCLUSIONS: We found that normobaric hyperoxia for 3 hours reduces macular thickness from diabetic macular edema and improves visual acuity. This study offers additional evidence that diabetic macular edema is an ischemic disorder and suggests that oxygen therapy may serve as an alternate or complimentary treatment of DME. / 2020-06-17T00:00:00Z