Microbial keratitis is a common, potentially sight threatening ocular infection that may be caused by bacteria, fungi, viruses, or parasites. The challenge for the ophthalmologist is to distinguish clinically microbial keratitis from other noninfectious inflammatory conditions of the cornea resulting from trauma, hypersensitivity, and other immune-mediated reactions.
Infectious keratitis is a potentially blinding ocular condition of cornea which can cause severe visual loss if not treated at early stage. If the appropriate antimicrobial treatment is delayed, only 50% of the eyes gain good visual recovery. It can be caused by bacteria, virus, fungus, protozoa, and parasites. The common risk factors for infectious keratitis include ocular trauma, contact lens wear, recent ocular surgery, preexisting ocular surface disease, dry eyes, lid deformity, corneal sensational impairment, chronic use of topical steroids, and systemic immunosuppression.
Infective Keratitis is a commonly encountered sight-threatening ocular emergency. In developing countries, it is a major cause of corneal blindness. Empirical treatment without microbiological work up often leads to treatment failure.
As contact lenses continue to gain popularity (including for recreational purposes) the proportion of the population at increased risk of developing Acanthamoeba keratitis may rise.
Regularly leaving your contact lenses in while taking a shower can increase your risk developing a painful and eyesight-threating infection seven-fold, a study warned.
Researchers from the UK surveyed the habits of 78 contact lens wearers to determine the risk factors for developing contact lens-related microbial keratitis.
This condition causes a painful redness of the eye and ulcers on the surface of the cornea. If left untreated, it can cause blurred vision and permanent corneal scarring.
Herpes in the eye is as bad as it sounds. The virus infects the cornea, forming tree-like branching ulcers across the eye. It can cause irritation, pain, sensitivity to light, and ultimately blindness if untreated. Herpes in the eye is a leading cause of blindness in the world. The cornea, after all, is a transparent layer of tissue at the front of the eye, whose job is essentially to let in as much light as possible. Infection can turn the cornea cloudy—permanently. In most cases, herpes infections in the eye can be treated with antiviral drugs like Zovirax, but the herpes viruses are becoming increasingly resistant to these drugs.
But don’t get too worried: Acanthamoeba keratitis is rare. In the U.S. there are just one to two cases per 1 million contact users annually. And the best news is that we can avoid it. “But a little bit of concern is good,” Raju says. “Contacts are great as long as we take care of them, but we have to remember it’s still plastic. We don’t need them in our eye 24/7, 365.”
People who wear contact lenses say they're diligent about keeping them clean. But press them for details, and it turns out that hardly anyone is doing it the right way.
Photokeratitis, or Ultraviolet Keratitis, is a painful eye condition which can develop after unprotected exposure to Ultraviolet (UV) rays. Ultraviolet rays, from a variety of sources including welding arcs (arc eye, welder's eye) , reflections off snow (snow blindness), and germicidal UV lamps can damage the corneal epithelial cells and cause them to slough off after several hours. This is similar to having a "sunburn" of the eye. This leaves underlying corneal nerves exposed and damaged, causing symptoms of intense pain, photophobia, and foreign body sensation.
Keratitis caused by a virus or bacterium tends to get better relatively quickly. Herpes keratitis and bacterial keratitis are treated with antiviral medication or antibiotics. Keratitis caused by other viruses usually gets better on their own within a few days. If keratitis is related only to contact lenses, the duration tends to be brief. Keratitis caused by autoimmune disease, some parasites or prior injury can be difficult to treat and may be long lasting (chronic). In these cases, permanent damage to the cornea with impaired vision may occur despite intense treatment.