From the Guidelines
Corneal edema is primarily caused by dysfunction of the corneal endothelium, which normally maintains corneal clarity by pumping excess fluid out of the cornea. This dysfunction can lead to fluid accumulation within the corneal stroma, resulting in swelling and clouding of the cornea. According to the most recent study 1, inflammatory and pressure-related corneal edema often clears as the underlying problem resolves, but if sufficient endothelial damage occurs, corneal edema may recur years later.
Common Causes of Corneal Edema
- Fuchs' endothelial dystrophy, a genetic condition causing progressive endothelial cell loss
- Trauma from eye surgery, particularly cataract surgery which can damage endothelial cells
- Contact lens overwear, especially with extended wear lenses that reduce oxygen to the cornea
- Elevated intraocular pressure from conditions like glaucoma
- Inflammatory conditions such as uveitis
- Infections like herpes simplex keratitis As stated in the study 1, the primary therapeutic goal is to control the underlying cause of the corneal edema or opacity and enhance the patient’s quality of life by improving visual acuity and maximizing comfort. Treatment depends on the underlying cause and may include hypertonic saline drops, anti-inflammatory medications, pressure-lowering medications, and in severe cases, corneal transplantation procedures. It is crucial to protect remaining endothelial cells, as they cannot regenerate significantly, to maintain corneal clarity long-term 1.
From the Research
Causes of Edema in the Cornea
- Corneal edema is a common sign of acute or protracted corneal disease of various aetiologies 2
- Fuchs endothelial corneal dystrophy (FECD) is a primary cause of corneal edema, characterized by the progressive decline of corneal endothelial cells and the formation of extracellular matrix excrescences in Descemet's membrane 3, 4, 5
- Endothelial dysfunction or damage can result in corneal edema and visual impairment 6
- The clinical course of FECD usually spans 10-20 years, and when the number of endothelial cells becomes critically low, the cornea swells and causes loss of vision 5
Pathophysiological Bases of Corneal Edema
- FECD is a complex and heterogeneous genetic disease where interaction between genetic and environmental factors results in cellular apoptosis and aberrant ECM deposition 3
- Abnormal corneal endothelial cell-Descemet's membrane interactions trigger the vicious cycle of FECD pathogenesis 3
- Corneal endothelial dysfunction can be caused by various factors, including genetic, epigenetic, and exogenous factors that incite oxidative stress, auto(mito)phagy, unfolded protein response, and mitochondrial dysfunction 3, 6