Why is glaucoma called the 'silent thief of sight'?
Glaucoma typically has no early warning symptoms that you would notice in daily life. A 2024 review explains that the condition often has 'mild symptoms that take time to manifest and may not be apparent until considerable harm has already been done' [2]. This means you can lose a significant amount of peripheral vision before realizing anything is wrong. The same review emphasizes that routine eye exams are crucial because early detection and treatment can prevent further vision loss, even though there is no cure [2].
What do the studies say about catching glaucoma early?
The evidence consistently points to the same conclusion: glaucoma is hard to detect early without professional screening. A 2022 systematic review for the US Preventive Services Task Force noted that screening relies on tests like visual field testing, which detects loss of peripheral vision, and imaging of the optic nerve [5]. However, a 2025 study on deep learning for glaucoma classification confirms that 'early detection is quite challenging, since glaucoma is asymptomatic in its nature' [4]. This is why researchers are exploring new biomarkers, such as altered metabolites in the blood or eye fluid, which a 2022 meta-analysis found to be specifically changed in patients with primary open-angle glaucoma [3]. These metabolic changes could serve as future early warning signs, but they are not yet used in routine care.
About These Sources
This answer is built on 5 peer-reviewed studies — published from 2022 to 2025, 3 from 2024 or later, 1 in Q1 journals, collectively cited 100 times — selected as the most relevant from 5 studies that passed quality screening, drawn from 55 papers retrieved from a database of over 500 million.
Sources used in this answer
Association between systemic inflammatory response index and glaucoma incidence from 2005 to 2008
In a cross-sectional study of 4,514 participants, elevated Systemic Inflammatory Response Index (SIRI) levels were significantly associated with glaucoma; those in the highest SIRI quartile had a 62% higher odds of having glaucoma (OR 1.62, 95% CI 1.12-2.34).
A review on glaucoma: causes, symptoms, pathogenesis & treatment
A 2024 review states that glaucoma often has mild, slow-to-appear symptoms and can cause irreparable vision loss if untreated; it emphasizes routine eye exams for early detection, especially for those over 60 or with a family history.
Metabolomics in Primary Open Angle Glaucoma: A Systematic Review and Meta-Analysis
A systematic review and meta-analysis found that several metabolites in the blood and aqueous humor are specifically altered in patients with primary open-angle glaucoma, suggesting they could serve as biomarkers for early detection.
A deep retinal vision network for glaucoma classification
A 2025 study on deep learning for glaucoma classification notes that early detection is challenging because glaucoma is asymptomatic, and proposes a computer-vision approach to reduce misdiagnosis.
Screening for glaucoma in adults: updated evidence report and systematic review for the US Preventive Services Task Force
A 2022 systematic review for the US Preventive Services Task Force describes that screening for glaucoma involves visual field testing (to detect peripheral vision loss) and imaging of the optic nerve, and focuses on first-line medical treatments.