High-altitude retinopathy with isolated ellipsoid zone loss: a case report
Johnathan Abraham Bailey1, Maximilian Daechul Kong1,2, Baichun Hou1
1Department of Ophthalmology, Vanderbilt Clinic, Columbia University Irving Medical Center, 622 W 168Th St 3Rd Floor, New York, NY, 10032, USA.
Purpose:
To describe a case of High-altitude retinopathy (HAR) and associated imaging and multimodal assessment.
Methods:
The patient was evaluated at Columbia University Irving Medical Center using a comprehensive multimodal imaging protocol that included color fundus photography, fundus autofluorescence (FAF), and spectral-domain optical coherence tomography (OCT). Functional assessments were conducted using full-field electroretinography (ERG), following the ISCEV standard protocols to ensure consistent and reproducible measurements of photoreceptor activity.
Results:
A 44-year-old woman with stable RP and previously remitted cystoid macular edema presented with acute bilateral blurry and distorted vision after climbing Mt. Kilimanjaro. OCT revealed new bilateral foveal EZ loss with preserved peripheral retina. OCT-A demonstrated intact retinal and choroidal perfusion, excluding ischemic injury. Dilated fundus examination (DFE) and autofluorescence were unchanged from baseline. Methazolamide was discontinued, and N-acetylcysteine (1800 mg BID) was initiated. At 3-month follow-up, visual acuity improved, and OCT showed partial EZ recovery, consistent with a metabolic or hypoxic insult.
Conclusions:
This case highlights a previously undescribed manifestation of HAR: isolated central photoreceptor damage without vascular involvement presenting as EZ line loss. The findings suggest that the high metabolic demand of foveal cones may predispose to hypoxia-induced injury, especially in patients with pre-existing retinal degeneration. Ophthalmologists should consider non-vascular mechanisms of high-altitude retinal injury, particularly in individuals with underlying retinal disease.
