When a corneal abrasion occurs either from the contact lens itself or another source, the injured cornea is much more susceptible to this type of bacterial infection than a non-contact lens users would be. This is an optical emergency as it is sight- (in some cases eye-) threatening. Contact lens wearers who present with corneal abrasions should never be pressure patched because it has been shown through clinical studies that patching creates a warm, moist dark environment that can cause the cornea to become infected or cause an existing infection to be greatly accelerated on its destructive path.Corneal abrasions are also a common and recurrent feature in people with specific types of corneal dystrophy, such as lattice corneal dystrophy. Lattice dystrophy gets its name from an accumulation of amyloid deposits, or abnormal protein fibers, throughout the middle and anterior stroma. During an eye examination, the doctor sees these deposits in the stroma as clear, comma-shaped overlapping dots and branching filaments, creating a lattice effect. Over time, the lattice lines will grow opaque and involve more of the stroma. They will also gradually converge, giving the cornea a cloudiness that may also reduce vision. In some people, these abnormal protein fibers can accumulate under the corneas outer layer—the epithelium. This can cause erosion of the epithelium. This condition is known as recurrent epithelial erosion. These erosions: (1) Alter the corneas normal curvature, resulting in temporary vision problems; and (2) Expose the nerves that line the cornea, causing severe pain.
This accounts for a more sterile procedure by keeping the eyelashes as far as possible, and reduces the chance of eliciting a blink reflex. If necessary, the eyelids can be kept open using an eyelid speculum, the examiners fingertips, a cotton tip or an assistant. Anaesthetic and pupil dilator: Local anaesthetic is instilled into both eyes in order to reduce blepharospasm. Topical oxybuprocaine 0.4% is the preferred choice as it has an onset of action of 20 seconds and a half-life of 20 minutes. A drop of topical pupil dilator such a cyclopentolate 1%, if available, can be helpful to reduce ciliary spasm after removal of the foreign body. Atropine is generally avoided due to its long-lasting mydriatic effects. Removal techniques: There are mainly two types of techniques, the choice of which will depend on the nature of the foreign body. The first technique is the cotton tip removal, which is indicated in superficial foreign bodies with no surrounding corneal reaction, and the second is the hypodermic needle or nº15 blade removal with which the complete foreign body and any surrounding rust ring can be removed. Irrigation of the ocular surface and upper and lower fornices can be performed after the procedure to wash out any residual loose foreign body material. A 10 mL ampoule of sterile saline is usually sufficient. Medications
Current recommendations stress the need to use topical and/or oral analgesia and topical antibiotics.