Band keratopathy is an eye condition characterized by the deposition of calcium salts across the cornea, which is the clear, dome-shaped front surface of the eye. These deposits accumulate in the superficial layers of the cornea, specifically within the epithelial basement membrane and Bowman’s layer. The condition acquires its name from the distinctive horizontal, band-like appearance that forms across the cornea as these calcium deposits develop.
Symptoms and Visual Appearance
Individuals with band keratopathy often notice a progressive change in their vision and the appearance of their eyes. A whitish-gray, opaque band becomes visible on the corneal surface, typically starting from the periphery and gradually advancing towards the center. This band can have clear areas, sometimes described as a “Swiss cheese” pattern.
As the calcium deposits thicken and extend across the central part of the cornea, known as the visual axis, they interfere with light entering the eye. This interference can lead to decreased visual acuity, blurry or hazy vision, and increased sensitivity to light (photophobia). Many individuals also experience glare, especially in bright conditions, due to the irregular corneal surface. Physical discomfort is also common, manifesting as a foreign body sensation, irritation, or pain. This discomfort can worsen if small pieces of the calcium plaque loosen or become elevated.
Underlying Causes
Band keratopathy can arise from various factors, often categorized into chronic ocular diseases, systemic conditions, and other less common influences. Long-standing eye inflammation, such as chronic uveitis, is a frequent ocular cause, as it can alter the corneal environment and promote calcium precipitation. Other chronic eye conditions like end-stage glaucoma, phthisis bulbi (a shrunken, non-functional eye), or severe dry eye syndrome may also contribute to its development.
Systemic conditions can disrupt calcium metabolism, leading to its deposition in the cornea. Elevated blood calcium levels, known as hypercalcemia, are a significant systemic cause, often resulting from conditions like hyperparathyroidism, sarcoidosis, chronic kidney failure, or excessive vitamin D. Diseases such as multiple myeloma and gout have also been linked to the development of band keratopathy.
Additional factors include long-term exposure to certain chemical irritants, such as mercurial preservatives. Ocular trauma or previous eye surgeries can also create an environment conducive to calcium deposits. In some instances, a specific cause for band keratopathy cannot be identified, and these cases are referred to as idiopathic.
Medical Treatments
Managing band keratopathy typically focuses on removing the calcium deposits and alleviating symptoms. The most common approach is chelation therapy, which involves applying a solution of ethylenediaminetetraacetic acid (EDTA) to the corneal surface. After the corneal epithelium is gently removed, the 3% EDTA solution is applied to bind with and dissolve the calcium deposits.
This procedure is usually minimally invasive and can often be performed in an outpatient setting. Once the calcium is dissolved, the remaining deposits are carefully scraped away. For more extensive or deeper calcium deposits, more advanced options are available.
Phototherapeutic keratectomy (PTK) uses an excimer laser to precisely ablate and smooth the corneal surface. Manual lamellar keratectomy, which involves surgically removing superficial corneal layers containing the deposits, is another option for more challenging cases. An important aspect of treatment involves identifying and addressing any underlying ocular or systemic conditions that contributed to the band keratopathy, as managing these root causes helps prevent recurrence.