PURPOSE: Age-related macular degeneration (AMD) is a complex, progressive ocular disorder that results in outer retinal ischemia and severe vision loss. Dry AMD, the most common form of AMD, is characterized by the build-up of extracellular drusen deposits, dysfunction of the outer retinal layers and degeneration of photoreceptors. This study aimed to examine the anatomic and physiologic effects of short-term normobaric hyperoxia in patients at different stages of dry AMD.
METHODS: Twenty-two eyes from 16 patients diagnosed with dry AMD (11 females, 5 males) were used in this study. Eyes were categorized as having either small drusen or drusenoid pigment epithelial detachments (DPEDs) through optical coherence tomography (OCT) imaging. Eyes associated with small drusen received 3-hours of 40% fraction of inspired oxygen (FiO2) normobaric hyperoxia (NBH), whereas eyes associated with DPEDs received either 3-hour NBH or 3-hours of 20% FiO2 normobaric normoxia (NBN). Visual acuity and OCT images of the macula were taken before and after oxygen treatment. Anatomic outcomes consisted of foveal thickness, foveal volume, macular volume and maximum drusen height; visual acuity was the functional outcome. The relationship between maximum drusen height and visual acuity was then examined to determine if these outcomes were associated.
RESULTS: Eyes associated with DPED treated with 3-hour NBH had the largest decreases in foveal thickness, foveal volume, macular volume and maximum drusen height. The macular layers were then divided into inner and outer layers. The outer layers, comprised of Bruch’s membrane, drusen and the retinal pigment epithelium, had significant decreases in anatomic outcomes, whereas the inner layers showed no changes. DPED patients treated with 3-hour NBH also had the largest increase in visual acuity following treatment. There was a significant negative correlation between baseline drusen height and baseline visual acuity. For patients with small drusen treated with 3-hour NBH, there were no significant changes to anatomic or functional outcomes.
CONCLUSION: The current study demonstrates the efficacy of short-term administration of normobaric hyperoxia in high-risk dry AMD patients with associated DPEDs. Normobaric hyperoxia appears to be a novel and promising treatment that requires further investigation.
| Identifer | oai:union.ndltd.org:bu.edu/oai:open.bu.edu:2144/43745 |
| Date | 31 January 2022 |
| Creators | Wang, Justin |
| Contributors | Spencer, Jean L. |
| Source Sets | Boston University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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