No

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.

Call number: LD2668 .T4 1948 M67 / Master of Science

Call number: LD2668 .T4 1957 A58 / Master of Science

No description available.

No description available.

No description available.

Purpose: This study asks whether active horizontal angular Vestibulo-Ocular Reflex (VOR) gain is capable of monocular adaptation after 4 hours of wearing 10 dioptres (D) of induced anisometropia in healthy human adults. Method: The participants (average age 28 years) wore a contact lenses/spectacles combination for 4 hours. The power of the spectacle was +5. 00D (magnified images 8. 65%) in front of the right eye and ?5. 00D (minified images 5. 48%) for the left eye, while the power of the contact lenses was equal to the subjects? habitual correction, summed with the opposite power of the spectacle lens. Eye and head position data was collected in complete darkness, in one-minute trials before adaptation and every 30 minutes for 2 hours after adaptation. Eye and head position data obtained using a video-based eye tracking system, was analyzed offline using Fast Fourier Transform in MATHCADTM 11. 1 software to calculate VOR gain. The VOR gain was compared between the right eyes and left eyes for the trials before and after adaptation. Results: In the first post-adaptation trial, a significant decrease in VOR gain (? 6%) occurred in the left eye in response to the miniaturizing lens. The right eye VOR gain did not show a significant change in the first post-adaptation trial (?2% decrease). During the remaining trials in the 2 hour follow-up time, both eyes showed a significant decrease compared to the baseline trial. This might indicate habituation of the VOR from repeated testing, or fatigue. Conclusion: There was monocular adaptation of VOR in response to the combined contact lenses/spectacles, but it was not complete and it was not as we expected. However, trying different amounts of anisometropia in one or two directions, a longer adaptation period (more than 4 hours) or monitoring the gain for more than 2 hours after adaptation with a longer separation between trials, might show different results.

Syfte: Att undersöka läshastigheten på datorskärm och om den kan förbättras med hjälp av färgade overlays, samt om det finns någon skillnad i läshastighet på utskrivet papper och datorskärm. Metod: Deltagarna (n=30) fick läsa ett Wilkins rate of reading test översatt till svenska, där antalet ord som hann läsas upp högt under en minut jämfördes då de läste på papper utan overlay och på datorskärm med och utan overlay. Studien gjordes på studenter mellan 18-31 år. Resultat: Den här studien visar att det inte finns någon signifikant skillnad i läshastighet mellan läsning på utskrivet papper och datorskärm (p=0,508). Deltagarna läste 1,6 ± 13,3 ord mer/min på datorskärm än på papper. En signifikant skillnad kan däremot ses mellan läsning på datorskärm med och utan färgat overlay (p=0,008). Läshastigheten ökade med 4,7 ± 9,1 ord/min med färgat overlay. Slutsats: Läshastigheten på papper och datorskärm är ungefär densamma. Man kan öka läshastigheten på datorskärm genom att placera ett färgat overlay över texten. / Purpose: To investigate reading speed on a computer screen and if it can be improved by using coloured overlays, and also if there is any difference in reading speed on printed paper and computer screen. Methods: The participants (n=30) read a Wilkins rate of reading test translated into Swedish, where the number of words read out loud in one minute was compared when reading on a paper without overlay and on a computer screen with and without an overlay. This study was performed on students aged 18-31 years. Results: This study shows that there is no significant difference in reading speed between reading on a printed paper and on a computer screen (p=0.508). The participants read 1.6 ± 13.3 words/min more on the computer screen than on the paper. A significant difference however was found in reading on a computer screen with and without coloured overlay (p=0.008). The reading speed increased with 4.7 ± 9.1 words/min with a coloured overlay. Conclusions: The reading speed on paper is similar to the reading speed on computer screen. The reading speed on the computer screen can be increased by placing a coloured overlay in front of the text.

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