Pseudotumor cerebri is an eye condition that can be confused with a brain tumor due to swelling of the optic nerve. Like a brain tumor, the fluid inside the skull that cushions the brain and flows around the spinal column develops elevated pressure. It is also referred to as Idiopathic Intracranial Hypertension or Benign Intracranial Hypertension. It is more prevalent in women between the ages of 20 and 50. Symptoms of pseudotumor cerebri are usually an undiagnosed chronic headache, and in more severe cases there may be visual symptoms such as double vision. Also nausea and vomiting may occur. There is an unusual effect of pulsating sounds within the head that are synchronous with the heart rate referred to as Pulse-synchronous tinnitus.
A routine eye exam is where the initial diagnosis of mild cases of pseudotumor cerebri is often first made. The optic nerve that enters the back of the eye appears elevated in both eyes, a condition referred to as papilledema. Because the nerve is an extension of the brain and enclosed by the same tissues and fluid that cushion the brain, elevation in the pressure inside the brain also cause the nerve to swell. Since most cases occur in young to middle age overweight females, an elevated nerve with a history of chronic headaches and otherwise healthy is often indicative of pseudotumour cerebri. Other visual symptoms include double vision, brief periods of blurred vision or dim vision, and occasionally patient will have temporary episodes of blindness in one or both eyes. Changes in posture such as suddenly standing up or bending over may elicit symptoms, as may coughing or sneezing.
Double vision may occur when looking to the side. This is caused by a defect in abduction or the ability of an eye to turn out. due to a restriction in the capacity for one or both eyes to turn out. This presents a confusing picture when taken out of context because it is not due to damage to the abducens nerve (6th Cranial Nerve) that controls the eyes outward motion. In this case, the double vision is called a false localizing sign. Pain can occasionally be associated with eye movements.
Rarely, the pressure can become very high and cause severe problems with vision and alterations in levels of awareness. Most of the time truly is benign idiopathic intracranial hypertension and is managed by weight loss and occasionally medications. Sometimes discontinuation of certain medication may resolve the problems. The most severe cases may require a shunt to drain the increased fluid from the ventricles in the brain into the abdominal cavity.
Traumatic Brain Injuries are common causes of undiagnosed vision symptoms. The brain is cushioned in a compartment but sudden changes in velocity can cause it to move slightly and cause axonal shearing (minute tearing of the nerves in the brain). People who have been in accidents, especially car accidents, often find their visual system seems disjointed days to weeks after the accident. They may have double vision, light sensitivity, poor focusing skills, difficulty reading, dry eyes, and a number of other eye problems. Even very low velocity accidents can result in trauma under the right circumstances.
Treatment is available. There are multiple modalities to treat dry eyes, special tints to reduce the photophobia (light sensitivity), special eyeglass corrections with prism to relieve double vision, and vision therapy (eye exercises) that can help alleviate other eye symptoms.
One of the outcomes of the war in Afghanistan and Iraq has been a large increase in eye injuries. Somewhere between 15-20% of evacuations have been due to eye injuries. Improved Body armor has led to survival of wounds that would have been lethal in the past but has left more veterans living with sight loss. There is currently increasing awareness in our military hospitals of traumatic brain injury eye problems.
Seat belts, helmets, and protective eyewear save lives and eyesight. Don’t be remiss in making sure your family is safe.
And this Memorial Day Holiday, consider a donation to the Veteran’s Plaza being planned for Spring Canyon Community in Fort Collins. Captain Diggs Brown is the visionary, planner, and fundraiser-see Veterans Plaza or Ray Martinez’s Commentary for more information on the Veterans Plaza in Sprng Canyon Park.
Be safe and see safe this holiday weekend!
A fun new movie I recently went to see was Monsters vs. Aliens. It started just before a wedding with a bride growing (not glowing) from meteorite exposure, to enormous height and strength. Reese Witherspoon supplies the voice. Not a great movie but it is fun and the technology is fascinating. Monsters vs. Aliens was released on almost every 3-D screen avaible today with a count over 2000 and growing.Projections are for 40 new 3-D films within the next three years. RealD technology utilizes circular polarization, a technique with the polarization varying in a clockwise or counterclockwise direction. In Optometrists offices, polarized lenses and images are utilized in one constant plane tests for lazy eye (amblyopia) or crossed eyes (strabismus). Eye Doctors also use polarized equipment when treating binocular dysfunction for eyestrain, double vision, and convergence insufficiency causing vision related reading problems. Quality sunglasses enhance vision by using a fixed plane polarization to block reflections that occur most frequently from the surface of water. The RealD technology is comes with a high price tag costing theatres $50,000 to $70,000 per screen for the digital projection equipment and additional licensing fees. That’s why there is a nice little surcharge ($2.50 in Fort Collins) for the special eyeglasses needed. The neat thing is the circular polarization helps you maintain binocular vision and lessens eyestrain when you tilt your head, unlike older technologies. Less squinting and your eyes won’t leave the theatre with dry eyes from staring throughout the film trying not to see double. The first 3-D film shown to a paying audience was The Power of Love in Los Angeles in 1922. It was projected with anaglyphs, which involves showing a green image to one eye and a red image to the other which are shown from slightly different view points. Anaglyphs are still used by Optometrist in vision therapy for problems like Computer Vision Syndrome. Looking to the future, Steven Spielberg started work on a 3-D system in 2005 using plasma screens that is supposed to work without any special glasses! Coming to a TV near you some day.
