Perspective: The normal healthy cornea is usually very resistant to infection. Sometimes the cornea is damaged after a foreign object has penetrated the intact healthy tissue, such as from a poke in the eye. In other instances, bacteria or fungi from a contaminated contact lens can pass into the cornea. Situations like these can cause painful inflammation and corneal infections called Keratitis. These infections can reduce visual clarity, produce corneal discharges, and perhaps even erode the cornea. Corneal infections can also lead to corneal scarring, which can impair vision and may require a corneal transplant. Quick diagnosis and treatment are the best way to avoid the potential for damage and vision loss from a corneal infection.
Description, Signs & Symptoms: The cornea is composed of five individual and optically clear layers of tissue that “refract” or bend light so that it focuses clearly on the retina. From the outermost to the innermost, the corneal layers are the a) Anterior Epithelium b) Bowman’s Membrane c) Corneal Stroma d) Decemet’s Membrane and e) Endothelium. The Epithelium provides a membrane function that is impermeable to virtually all microorganisms and thus it provides a barrier to infection. If the Epithelium is damaged from trauma of any type, such as from getting a poke in the eye from a branch or a finger, a foreign body such as metal or even from a dirty or damaged contact lens, it is possible for bacteria, viruses or fungi to penetrate the cornea and cause an infection. An infection of the cornea is called a Keratitis or Ulcer. The signs and symptoms of a corneal infection or Keratitis may include a) redness b) pain c) watering d) light sensitivity and e) you may develop a white spot that is actually visible where the infection is focused. In addition, Keratitis can cause a painful inflammation with a discharge, which if not treated quickly and appropriately, can lead to corneal erosion, corneal ulceration and corneal scarring. Generally, the deeper the corneal infection, the more severe the symptoms and the greater the potential for loss of vision.
About Herpes Zoster (Shingles) Keratitis Herpes Zoster Keratitis is actually caused by the same virus that causes chicken pox, called Varicella-Zoster virus. It is entirely possible that after having chicken pox as a child, the Varicella-Zoster virus remains in the nerve cells of your body in an inactive state. For a number of possible reasons, the Varicella-Zoster virus can reactivate later in life and travel through the nerves in your body causing a painful blistering rash. If the Varicella-Zoster virus travels to your head or neck it can affect the eye and thus cause a corneal infection.
It is critical to have Herpes Zoster Keratitis diagnosed quickly as the infection can penetrate deeply into the cornea and it can cause scarring. The infection can also result in a loss of corneal sensation, which can be permanent. It may be necessary to prescribe both oral medications and eye drops to try and resolve the infection and prevent serious damage from occurring.
It is possible for anyone who has been exposed to the Varicella-Zoster virus to get shingles. However, it seems to affect those of advanced age and those with weakened or suppressed immune systems many times more often. Further, corneal problems from shingles may occur many months after the facial shingles appear to have resolved so it is important to schedule regular follow up appointments for eye examinations as instructed by your doctor.
About Herpes Simplex Keratitis Ocular Herpes or Herpes of the eye is caused by the Herpes Simplex virus and is the most common causes of corneal blindness in the United States today. Up to 50% of people who have a single Herpes Simplex viral infection of the eye will experience a flare up or recurrence. The virus often leads to irreversible scarring of the cornea.
Ocular Herpes may start as a painful sore on the eyelid or surface of the eye. If left untreated, it may multiply and begin to destroy epithelial cells and progress deeper into the cornea. If the Ocular Herpes penetrates the deeper layers of the cornea and causes a Stromal Keratitis it may cause corneal scarring-so prompt diagnosis and treatment of Ocular Herpes is important.
It is estimated that 400,000 people in the United States have had some type of Ocular Herpes, with more than 50,000 initial and recurring cases being diagnosed each year. Of these, it is believed that 25% are the more severe form of Herpes Stromal Keratitis. The recurrence of Herpes Simplex eye infections is significant in that it appears to recur in about 10% of patients with one year, 23% of patients within two years and 63% of patients within 20 years of their initial infection. Sometimes a recurrence can be prompted by sunlight, stress, fevers or an unrelated eye injury.
Management & Treatment of Corneal Infections: Careful and thorough examination of the cornea using a specialized optical microscope will be used to observe the location, depth and severity of the Keratitis. It may be necessary to culture the infection in order to identify what organism is causing the infection. The best course of treatment for a corneal infection will depend on the type of microorganism that suspected to be causing the infection. Sometimes this might be an antibiotic eye drop, an antifungal eye drop, an antiviral eye drop and sometimes it might even include a steroid eye drop to reduce the inflammation. In addition the treatment may also include oral medications. The goal is to quickly diagnose and treat all corneal infections so that no corneal scarring occurs as this may result in a loss of corneal transparency and can require a corneal transplant in order to restore vision.
4. light sensitivity
Please feel free to contact us regarding information for patients with Fuch’s Dystrophy or any corneal disease or problem. Drs. Altman, Primack, and Shah are Fellowship trained Cornea Specialists at Eye Consultants of Pennsylvania, P.C. and may be reached at 610-378-1344.