A corneal abrasion refers to a scratch or scrape on the cornea, the clear, dome-shaped outer layer at the front of the eye. This transparent tissue plays a significant role in focusing light into the eye and shielding it from external elements like dust and germs. While often uncomfortable, a common concern is whether such an injury can result in permanent vision loss.
Understanding Corneal Abrasions
A corneal abrasion involves damage to the corneal epithelium, the outermost layer of the cornea. This common eye injury can arise from various forms of trauma. Causes include being poked by a fingernail, walking into a tree branch, or getting foreign objects like dust, dirt, or sand in the eye. Improper contact lens use, such as wearing ill-fitting or dirty lenses, or rubbing the eye too forcefully, can also lead to abrasions.
When a corneal abrasion occurs, individuals experience immediate and often severe pain, described as feeling like something is stuck in the eye. This discomfort is due to the high density of nerve fibers in the cornea. Other symptoms include excessive tearing, redness, sensitivity to light (photophobia), blurred or hazy vision, and a gritty feeling in the eye.
Potential for Vision Loss
Most corneal abrasions do not cause permanent vision loss, especially if minor and promptly treated. The cornea heals quickly, often within a few days for smaller abrasions. However, vision can be temporarily affected, particularly if the abrasion is located over the central part of the cornea.
Vision loss can occur if complications arise. A risk is infection, which can lead to bacterial keratitis. If left untreated, bacterial keratitis can progress to a corneal ulcer, an open sore on the cornea, considered a medical emergency. Corneal ulcers can cause permanent damage, including scarring, and may lead to reduced vision or even blindness. Deep or large abrasions can also result in permanent scarring of the corneal surface, which impairs visual acuity.
Medical Care and Healing
Medical care for a corneal abrasion aims to control pain, prevent infection, and promote healing. A healthcare provider may prescribe antibiotic eye drops or ointments to prevent bacterial infections, especially for contact lens wearers, who face a higher risk of certain infections like Pseudomonas. Pain management often involves oral nonsteroidal anti-inflammatory drugs (NSAIDs) or topical NSAID eye drops.
Eye drops that dilate the pupil, known as cycloplegics, may be used to relieve pain and light sensitivity. A bandage contact lens, a special type of soft contact lens, might be placed on the eye to reduce pain and facilitate healing. While eye patching was traditionally used, current evidence suggests it does not necessarily speed healing for smaller abrasions and is generally not recommended for contact lens-related injuries due to infection risk. Most small abrasions heal within 24 to 48 hours, while larger ones can take up to a week. Follow-up appointments are often scheduled to ensure proper healing and to monitor for complications.
Minimizing Risks and Preventing Recurrence
To prevent complications during healing, it is important to follow all prescribed treatments, including antibiotic drops or ointments for the recommended duration. Patients should avoid rubbing their eyes, as this can worsen the abrasion or introduce new contaminants. If contact lenses are worn, they should be removed and not used until the eye is fully healed and a healthcare provider advises it is safe to resume.
Preventive measures can reduce the risk of future abrasions. Wearing protective eyewear, such as goggles or safety glasses, is advisable during activities that pose a risk of eye injury, including working with power tools, gardening, or participating in certain sports. Maintaining proper contact lens hygiene, including cleaning and replacing lenses as instructed, and avoiding extended wear, can also prevent abrasions. Using artificial tears or lubricating eye ointments, especially at bedtime, can help if dry eyes contribute to recurrent erosions.