Corneal arcus is a commonly found condition in the front of the eye, particularly among the elderly population. It is characterized by the presence of a lightly colored ring encircling the iris, the colored part of the eye. This ring consists of excess cholesterol and fat compounds. Although not considered a normal finding, corneal arcus itself does not cause any additional complications or symptoms. Usually, it is monitored during yearly eye appointments, except in the case of younger individuals, where it may indicate abnormal cholesterol levels and require further evaluation through blood work.
Exploring the Layers of the Cornea
The cornea, the transparent outer structure of the eye responsible for bending incoming light, is composed of several layers. Starting from the outermost layer, the layers of the cornea include the corneal epithelium, Bowman’s membrane, corneal stroma, Descemet’s membrane, and the corneal endothelium. Each layer serves specific functions crucial for maintaining ocular health. Notably, the corneal stroma, the largest layer, acts as a repository for nutrients and essential vitamins that support optimal eye function.
Cholesterol Accumulation in the Eye
When there is an excess amount of cholesterol or fat in the body, these substances can be deposited in various storage areas. The corneal stroma is one such area where these unnecessary fat compounds are stored long-term. As cholesterol and fat compounds accumulate, the corneal stroma begins to exhibit signs of this buildup, giving rise to the formation of corneal arcus. This ring-like accumulation becomes visible during a comprehensive eye examination.
Symptoms and Impact of Corneal Arcus
The primary symptom of corneal arcus is the presence of discoloration in the form of a ring in front of the iris. This ring represents the visualization of cholesterol buildup within the corneal stroma. It is important to note that while this ring is externally visible, it does not impact vision in any way or alter the shape or function of the cornea. As corneal arcus is merely a passive and non-functional observation, it is typically considered a benign condition that rarely necessitates concern.
It is not uncommon for a patient to notice the ring suddenly as if it appeared overnight, however, it is a gradual progression and build-up. Usually, it is too subtle to notice the incremental changes.
When to Examine Corneal Arcus Closely
Although corneal arcus itself does not pose a direct threat to vision or overall eye health, it can potentially indicate an underlying health issue. Typically, corneal arcus is observed in the elderly population, especially those aged 65 and above. However, if corneal arcus develops in younger individuals, it may be a sign of significantly elevated or unstable cholesterol and fat compound levels. This condition, known as hypercholesterolemia, is relatively common in the United States. However, to the extent that it leads to the formation of corneal arcus, its advancement is required. In such cases, the presence of corneal arcus should prompt a comprehensive blood panel and a referral to a primary care provider for further evaluation and appropriate management.