A caruncle is a small, fleshy growth found in various parts of the body across different species. This term, derived from the Latin word “caruncula” meaning “little piece of flesh,” can refer to structures ranging from outgrowths on bird heads, like a turkey’s wattle, to specialized appendages on certain plant seeds. While the term has broad biological applications, in human anatomy, it most commonly refers to a specific structure located in the corner of the eye. This small, soft tissue plays a role in the eye’s delicate ecosystem.
The Ocular Caruncle: Location and Appearance
The ocular caruncle, specifically known as the lacrimal caruncle, is positioned in the medial canthus, which is the inner corner of the human eye. It sits adjacent to the plica semilunaris. This small structure typically appears as a reddish or pinkish nodule, often measuring only a few millimeters in diameter, with a soft, somewhat irregular texture.
It features fine hairs, which are usually light in color and very short, often barely noticeable. Additionally, it contains sebaceous glands, which are oil-producing glands, and some sweat glands. The caruncle’s appearance can vary slightly among individuals, but its characteristic location and general features remain consistent.
Role of the Ocular Caruncle
The ocular caruncle contributes to the maintenance of eye health through its involvement in tear film dynamics. It aids in the collection and drainage of tears and small debris that accumulate at the inner corner of the eye. This process helps to clear the eye surface of foreign particles and excess fluid.
The sebaceous glands within the caruncle secrete an oily substance that contributes to the tear film. This oil layer helps to reduce the evaporation of the watery component of tears, thereby maintaining the eye’s lubrication and preventing dryness. The caruncle also contains lymphoid tissue, suggesting a minor role in immune surveillance and defense against potential pathogens.
Common Issues and When to Consult a Doctor
The ocular caruncle, like other parts of the body, can sometimes experience minor issues, most of which are generally not serious. Inflammation of the caruncle, known as carunculitis, can occur, leading to redness, mild swelling, or discomfort. Irritation from factors like contact lens wear or environmental allergens can also cause temporary symptoms. Small cysts, such as sebaceous cysts, may occasionally form within the caruncle due to blocked glands, appearing as small, painless bumps.
While many caruncle-related concerns are benign, certain symptoms warrant professional medical evaluation. Persistent pain, significant or rapidly increasing swelling, or any unusual discharge from the caruncle should prompt a visit to an eye care specialist. Changes in vision, the development of new growths, or any changes in the size, shape, or color of an existing caruncle, especially if it becomes darker or irregular, are important signs to have checked. Persistent redness that does not resolve quickly, or any discomfort that interferes with daily activities, indicates a need for medical advice.