Quite often I find myself counseling a patient about the flashes of light that they see.  When this occurs for the first time it is a shocking experience and can be freightening.  These flashes can be in the center of the visual field or off to the side.  The location of the flash is highly diagnostic of the cause.  I am going to discuss the centrally located flashes in this blog and we can discuss peripheral flashes in the future.

Central flashes are always on a vascular basis, ie, they are in some way related to the blood circulation in the eye.  The flashes may come in the form of a colored zigzag line or a bright colored blob in the center of the vision.  It may gradually grow in intensity over 10 to 30 minutes.  This visual aura may or may not be followed by a pounding headache, nausea and vomiting and light sensitivity.  Whether there is a headache or not, the cause is the same, a migraine.  When there is no headache but only the aura, it is refered to as an ocular migraine or migraine variant.

In my experience the ocular migraine is very often associated with emotional stress.  There seems to be an ”epidemic” around the Christmas holidays.  While there is no pain, there is a transient loss of vision which can be debilitating especially  if you are driving.  The way traffic flows in Miami the best thing to do is pull off the road as quickly as possible and wait for the vision to return.  I don’t know of any instances where the vision was permanently lost.

The best explanation for the occurence of migraines is that they are due to changes in the seratonin levels in the brain resulting in the constriction of cerebral blood vessels.  The constriction causes reduced oxygen supply to the brain and in some way this causes the headache.

Many people having migraines have a family history of this problem.  Certain foods trigger the headaches, including aged cheese, nitrates, red wine, chocolate, MSG, aspartame from Nutrasweet and alcohol.  Pregnancy, the use of BC pills and the menstrual cycle are associated with migraines. 

The best way to manage the migraine is to try to avoid the triggers.  Once the symptoms have developed the pain may be managed with aspirin, ibuprofen, ergotamines, or prescription drugs such as Imitrex or Amerge.

If the migraine headaches are infrequent it is probably best to “tough it out” seclusion in a dark room and over the counter medications.  When I see folks with symptoms which are incresing in frequency I often make a referral to a neurologist.

Here in Miami and probably elsewhere, about half of my patients having cataract surgery also have dry eyes or eye allergies or various types of inflammation of the eyelids.  It is amazing to me how this problem can reduce the good results of well done cataract surgery (LASIK surgery as well).  In many cases the condition is only slightly bothersome prior to surgery, however, when you have cataract surgery with one of these ocular surface diseases present, there appears to be a surprising diminusion of the visual outcome.  If you have chosen to make a significant “lifestyle enhancement” with a multifocal lens insertion at the time of cataract surgery you want to maximize the result and achieve the ultimate potential of this new technology. 

During the preoperative examination at Miami Eye Center, we look at the tear film using new technology and are able to determine if you have a deficiency in the water component of the tear film or if your tears are evaporating too fast.  When found, patients are treated with artificial tears preoperatively and the surgery itself is performed in a way which protects the surface of the cornea.  If we find an inflammatory problem causing a tear film deficiency we treat that with a course of cortisone eye drops before the surgery.  We might also use Restasis to decrease inflammation. In cases of eyelid inflammation a round of oral antibiotics as well as antibiotic eyedrops over a period of several weeks can improve the tear film.

The take home message here is that there are subtle issues which can impact the outcome of your eye surgery that are beyond just having a good procedure and your surgeon needs to evaluate these factors and discuss them with you.