The diagnostic potential of aqueous humor: Unlocking ocular and systemic insights

The anatomy and physiology of aqueous humor (AH) are essential to maintaining ocular health and managing diseases such as glaucoma, diabetic retinopathy, and Fuchs endothelial corneal dystrophy (FECD). This review compiles recent findings on AH dynamics, molecular composition, and clinical applications. AH, produced by the ciliary processes, supports intraocular pressure regulation, nourishes avascular tissues, and preserves immune privilege within the eye. Production occurs through diffusion, ultrafiltration, and active secretion, while drainage relies on trabecular and uveoscleral pathways. Imbalances in these processes can lead to ocular diseases. Elevated levels of cytokines, oxidative stress markers, and growth factors in AH have been associated with conditions such as glaucoma, diabetic retinopathy, and postoperative inflammation. Advanced technologies, including proteomics, metabolomics, and aqueous angiography, have revealed the diagnostic and therapeutic potential of AH analysis. Specific cytokine and metabolic profile changes in diabetic patients correlate with disease severity, while cytokine alterations can influence surgical outcomes in FECD and cataract surgery. Understanding the composition and behaviour of AH is critical for developing precise diagnostic tools and treatments for ocular diseases. Additionally, insights into AH's role in surgical recovery emphasize the importance of customized perioperative care, particularly for patients with conditions such as FECD or diabetes.