Are you having back pain with any of the following?

  • Severe pain, weakness or tingling in your leg(s).
  • Difficulty stopping urination or loss of control of bladder or bowels.
  • Unexplained fever, nausea or vomiting.
  • A history of cancer or unexplained weight loss.

We understand that you are experiencing one or more of the health issues that might be impacting your back pain.

We recommend that you discuss these health issues with your doctor before proceeding with this program.

Once you are cleared by your doctor to do this program, we hope it helps you find relief from your back pain.

Corneal Scar


The cornea is the clear front dome of the eye that plays an important role in ensuring that you can see clearly. As light enters the eye, the cornea refracts, or bends, it onto the lens. The lens then refocuses that light onto the retina, a thin layer of tissue that lines the inside back wall of your eye. The retina, in turn, converts the light into electrical signals and sends them to the brain to be interpreted as images. The light rays must be refracted and focused on the retina very precisely for you to see clearly. 

The strong outer layer of the cornea, the epithelium, protects the eye from germs, dust, and other foreign bodies. Usually, the cornea is very resilient and able to recover from minor abrasions easily. However, if an injury or infection damages the deeper layers of the cornea, it may not recover completely and scars may form. A scar can distort the way that light is refracted onto the lens, leading to distorted vision. In severe cases, a corneal transplant may be the only way to restore good vision.

Anatomy of the eye showing the cornea, lens, and retina.


A scar on the cornea can cause a variety of mild to severe vision symptoms. These include:

  • Astigmatism. This is blurry vision caused by the distortion of the cornea.
  • Hazy vision. This is caused by a scar that obscures an area of your visual field.


Anything that damages the eye can lead to a corneal scar.

  • Corneal abrasion or eye injury. If an abrasion is deep enough, it can cause a scar. Corneal abrasions are not uncommon but usually damage only the outer layer of the cornea. Tree branches, pens and pencils, sports equipment, and contact lenses can all cause minor abrasions. Contact lens overuse can cause microscopic injury. More serious injuries can be caused by sharp instruments or a ball directly hitting the eye. These injuries are more likely to be deep and generate a scar. 
  • Corneal infection. Corneal infections can be mild and treatable; however, if an infection is left untreated, it can spread to a deeper layer of the cornea known as the stroma. These infections, known as stromal keratitis, are much more difficult to treat and may lead to scar formation. A number of viruses can cause corneal infections. Most can be treated effectively with antiviral medications. However, some viruses, such as herpes simplex, can recur and cause further infections that may be difficult to treat and may cause scarring.
  • Epithelial basement membrane dystrophy. This condition causes abnormal growths of the tissue layer that covers your eye (epithelium). Raised ridges of this tissue layer on your cornea can cause irregular types of astigmatism and visual distortion. In addition, the cornea can sometimes become cloudy, and scar tissue can develop on the epithelium. 
  • Keratoconus (pronounced ker-uh-toh-CONE-uhs). This is a genetic eye condition in which the cornea becomes thinner and weaker. Over time, the weakened cornea starts to bulge outward in a cone shape, due to the natural pressure exerted on it from inside the eye. This coning eventually leads to scarring on the cornea.


We can schedule a general eye exam for you in either our Optometry or Ophthalmology department. However, if you have sudden vision changes or symptoms that concern you, contact us to schedule an urgent appointment in Ophthalmology.

We will ask you about your symptoms and examine your eyes. If we suspect a corneal scar, the examination will include the following tests:

  • Visual acuity test. Just like a regular eye exam, this tests the strength of your central vision by requiring you to read letters on a wall chart some distance away.
  • Slit-lamp exam. During the exam we use a slit-lamp microscope to examine the cornea. The instrument uses a narrow beam of light – like a slit – that helps us see the cornea clearly. 


There are a number of things you can do to keep your eyes healthy and reduce your risk for developing a corneal infection or injury that may lead to the development of a scar.

  • Practice consistent eye hygiene. Always wash your hands before touching your eye or the area around your eye. Keep makeup utensils clean and replace them regularly. If you wear contact lenses, wash your hands thoroughly before inserting or removing your lenses. Use the cleaning solution(s) we recommend for your type of lens and keep your contact lens case clean. Ask us how long to keep the lenses in your eyes. We strongly recommend that you not sleep with your contact lenses in place, even the extended wear type, since most contact lens-related corneal infections are caused by sleeping with your contact lenses in place.
  • Schedule regular eye exams. We recommend that everyone come in for regular eye exams. If you wear contact lenses, you need to come in every year to have your prescription checked. 
  • Protect your eyes. According to the American Academy of Ophthalmology (AAO), 90 percent of eye injuries could be avoided by wearing proper eye protection. Wearing effective goggles or glasses during sports, home do-it-yourself projects, or work can prevent blunt trauma or a sharp object from damaging your cornea. We recommend that you review the American Academy of Ophthalmology guidelines about appropriate eyewear for all activities.


There are a number of treatment options that we wiIl discuss with you. They include the following:

  • Glasses or hard contact lenses. If your vision is significantly reduced by a corneal scar, we may recommend glasses or a hard contact lens to rehabilitate your vision.
  • Laser treatment. We may use a laser to gently remove the scar if it is very shallow. This procedure is called PTK (phototherapeutic keratectomy).
  • Corneal transplant surgery. For the deepest scars, we may recommend a complete or partial transplant of your cornea. The exact type of surgery will depend on the nature and location of the scar. During a standard corneal transplant surgery, we remove the damaged cornea and replace it with a donated human cornea. After a period of time, your vision will usually improve.

Additional References:

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If you have an emergency medical condition, call 911 or go to the nearest hospital. An emergency medical condition is any of the following: (1) a medical condition that manifests itself by acute symptoms of sufficient severity (including severe pain) such that you could reasonably expect the absence of immediate medical attention to result in serious jeopardy to your health or body functions or organs; (2) active labor when there isn't enough time for safe transfer to a Plan hospital (or designated hospital) before delivery, or if transfer poses a threat to your (or your unborn child's) health and safety, or (3) a mental disorder that manifests itself by acute symptoms of sufficient severity such that either you are an immediate danger to yourself or others, or you are not immediately able to provide for, or use, food, shelter, or clothing, due to the mental disorder.

This information is not intended to diagnose health problems or to take the place of specific medical advice or care you receive from your physician or other health care professional. If you have persistent health problems, or if you have additional questions, please consult with your doctor. If you have questions or need more information about your medication, please speak to your pharmacist. Kaiser Permanente does not endorse the medications or products mentioned. Any trade names listed are for easy identification only.