Xu Huizhuo, chief physician of ophthalmology at Xiangya Hospital of Central South University, notes that photographing the eye\u2014without a blood draw or fasting\u2014can screen for eye diseases such as glaucoma and macular degeneration and can also indicate risks of multiple chronic diseases.<\/p>\n
A recent study by the Chinese University of Hong Kong and collaborating institutions, published in Nature Medicine<\/em>, reports that AI analysis of one fundus photograph can assess, in about 30 seconds, the risk of six common chronic diseases: type 2 diabetes, hypertension, hyperlipidemia, gout, osteoporosis, and thyroid disease. The approach also has the potential to predict onset risk over the next 5 to 10 years.<\/p>\n The fundus comprises structures at the back of the eye, including the vitreous, retina, optic disc, and macula. It is the only site where blood vessels and nerve tissue can be observed directly and noninvasively. These vessels are homologous with systemic vessels, are highly metabolically active, and are highly sensitive to blood pressure, blood glucose, blood lipids, and endocrine changes. A fundus camera uses optical imaging and requires no pupil dilation, or only brief dilation, to capture an image. Traces of disease can appear before obvious symptoms.<\/p>\n Long-term high blood glucose can damage fundus microvessels, leaving bleeding points and exudates. Hypertension can narrow and harden small arteries. Hyperlipidemia may form a characteristic \u201clipid ring\u201d or milky-white veins. Urate crystals in gout can harden microvessels, seen as narrowed vessels. Abnormal calcium metabolism in osteoporosis can affect choroidal thickness and the retinal pigment layer. Orbital compression from hyperthyroidism can secondarily cause optic-disc edema and retinal folds. AI can quantify these subtle changes into risk indicators for noninvasive, rapid early assessment.<\/p>\n Besides the six chronic diseases, fundus photography can screen for diabetic retinopathy, hypertensive retinopathy, age-related macular degeneration, glaucoma, optic neuropathy, and retinal detachment, and may supply clues relevant to kidney disease, blood disorders, and intracranial disease.<\/p>\n The test is noninvasive and quick, and images can be archived for comparison. These groups are especially advised to consider screening:<\/p>\n Healthy adults under 40 may be examined once every one to two years.<\/p>\n Fundus photography is unsuitable when severe cataract or corneal opacity blocks the view of the fundus, or during acute eye infection or trauma. Contact lenses and heavy eye makeup should be avoided beforehand, and the head should be kept still during the exam.<\/p>\n Fundus photography is a screening method, not a diagnosis, and does not replace a specialist\u2019s judgment. People with eye discomfort or high-risk factors should see an ophthalmologist for an assessment that combines history with other examinations.<\/p>\n\n