Eye Doctor Explains Constantly Dilated Pupils From Adie’s Tonic Pupil Syndrome
Occasionally parents or individuals will notice the eye pupils appear to be abnormally large and stay dilated all of the time. Patients may complain of sensitivity to light and occasionally have problems focusing and reading at near distances. This may occur in one or both eyes. About 3/4’s of the time it occurs in one eye only. While many reports indicate the occurrence age as in
the 20-to 40 year age bracket, most of the cases we have seen in our Fort Collins Optometry Clinic tend to be young girls in their early teens. The prevalence is seven to eight times higher in females than in males.
An Eye Exam by Your Ft Collins Optometrist is Essential to Rule Out Serious Vision Conditions
Diagnosis can be somewhat tricky. If only one eye is dilated the determination needs to be made by an eye care professional if one eye is dilated more than normal, or if the other eye is constricted making the other eye have the appearance of an abnormally enlarged eye pupil by comparison. This can occur in Horner’s Syndrome. While usually benign, a number of serious health condition may cause Horner’s Syndrome in the eyes. A tumor near the apex (top) of the lung is one of the problems you would not want to develop to an advanced stage when an eye exam and visit to your optometrist could help detect serious causes of Horner’s Syndrome at an early stage. To help your eye doctor diagnose Adies Pupillary problems, a prescription eye drop called Pilocarpine can be applied to the eye in a very diluted from. The loss of nerve stimulation causes the eye drug receptor sites to become hypersensitive and eyecare patients with Adie’s Tonic Eye Disorder will constrict to a concentration that has little effect on a normal eye.
Adie’s Tonic Pupil is a dysfunction of the parasympathetic nerve fibers. First a short explanation of the nervous system of the body. The central nervous system is composed of the brain and spinal cord. The peripheral nervous system is everything else, and has two parts, the autonomic system and the somatic system. The autonomic nervous system has two branches, the parasympathetic and the sympathetic. Combined, these generally control functions automatically, we don’t will our eyes to dilate (it can however be trained) or our heart to beat. The somatic nervous system is the part of the nervous system under our conscious control, that helps us move arms and legs when we want to go someplace, like to the optometrist office to find out why the eyes pupils are staying dilated all the time.
The parasympathetic nervous system controls functions in a manner usually opposite to the sympathetic system. The parasympathetic system is the opposite of the sympathetic fight or flight response when the body is in a state of arousal. Parasympathetic nerves increase tearing from the eyes, fluid secretions in the mouth, increase bladder and bowel function, move blood out to the surface layers of the body and digestive track. In comparison, the sympathetic nervous system moves blood away from the surface tissues and the digestive track, so the individual in a threatening environment can increase their chances of survival by protecting blood flow to vital organs.
The parasympathetic nerves also connect to the iris, the colored tissue that surrounds the black pupil. The iris determines the size of the pupil. The parasympathetic nerves act to constrict the pupil (by increasing the iris size leaving a smaller opening) when activated by sunlight. The sympathetic nerves act to dilate the eye pupil (decreasing the iris size by bunching it back toward the outer edges which exposes more open space thus enlarging the pupil). Just as a reminder, the pupil is a hole through the colored iris of the eye that allows light into the eye. Smaller pupils allow less light inside the eye which is important on sunny days. Dilated eye pupils allow more light inside the eye to help in dark environments and at night. When the parasympathetic nerves are compromised, the sympathetic nerves are unopposed in activating the iris muscle that draws the iris back and results in a larger pupil. Sometimes this problem extends past it’s base to the attached culinary body where a muscle functions to focus the eye for near vision. When this muscle contracts, it alters the shape of the lens inside the eye creating more curvature to allow focusing at close distances. If the damage to the parasympathetic nerves extends to the ciliary body, the ciliary body can’t contract normally and there will be an eye focusing problem that causes blurred vision when trying to read with symptoms of eyestrain and occasionally headaches. Other symptoms may include sensitivity to light due to the inability of the pupils of the eyes to constrict in bright light.
Your Eye Doctor Can Help You With Treatment
Once it has been determined your eye condition is Adie’s Tonic Pupil (also known as Holmes-Adie’s Syndrome or Ross Syndrome when there is an alteration in sweating), several treatments are recommended. Sunglasses need to be worn outdoors even when photophobia (light sensitivity) is not a symptom. A larger pupil allows more ultraviolet light and blue light to enter the eyes and can increase the risk over a lifetime for developing macular degeneration and cataracts. This is especially important to eye doctors in areas like fort collins and Northern Colorado where the number of sunny days and light reflected off of snow greatly increases UV exposure. Prescription eyeglass lenses may be needed to help with near vision. This is normally not a progressive condition and the pupils may even become smaller with time, even though the lack of response to light will continue. Occasionally, prescription eyedrops have been used to decrease the dilation of the eyes pupil.
How Does Your Optometrist Determine The Cause of the Constantly Dilated Pupils?
Well that’s why they call Eye Doctors Offices Practices. Like a lot of other eye diseases and conditions we just don’t know yet. The very definition of Adie’s Tonic Pupil is an idiopathic tonic pupil (idiopathic is a nice word diverting the attention away from the fact that we have no idea). Rightfully so, idiopathic sounds like the Eye Doctor has an idiot disorder themselves! Even after numerous years as a Ft Collins Optometrist, the rapid expansion of knowledge serves more and more to show me how little we really know about eye diseases and disorders.
There is a significant incidence of Adie’s Tonic Pupils that occur shortly after a viral or bacterial infection of the body. Most colloquial eyecare provider reports indicate a viral infection. Somehow an infection is causing inflammation that damages the parasympathetic nerves connecting to the iris muscle. Since migraine headaches occur at a much higher frequency in females than males, and also after puberty, one can only speculate there could be some kind of correlation with changes in hormonal levels. Migraine headaches also frequently damage neurons and cause small losses of peripheral vision that are not noticed by the eyecare patient. Migraine headaches may create a disruption of blood flow or some other mechanism that acts in conjunction with an infection in the body to damage the Pupillary eye response. Twenty percent of Adies Eye Syndrome occur in both eyes. Other symptoms that can occur are increased and decreased areas of sweating and the loss of deep tendon reflexes (When your Doctor whacks your knee and the involuntary kick is lost). It may be found to have multiple different causes in the future.
Some known cases are of Adie’s eye disorder include complications of retinal detachment surgery involving a sclera buckle, other types of eye surgery, eye trauma, diabetes, Herpes Zoster infections (the chicken pox virus), syphilis, some dental, surgery, Guillain–Barré syndrome which rarely is caused by vaccinations, and some internal organ problems. While I have not seen any documented cases, I suspect that viral infections like West Nile Virus which has been so prevalent in Northern Colorado probably result in an occasional case of Adie’s eye disorder. Most viral infections remain latent in the body after they are resolved, and viral infections like Herpes Simplex sit dormant in the ciliary ganglion (where the parasympathetic nerves for the eye aggregate together) until some form of stress causes the virus to follow the nerves back to the lips causing cold sores or to the herpes eye ulcers. Any virus laying dormant in the ciliary ganglion could possibly be reactivated by stressors like infections in the body and damage the parasympathetic nerves. Most of the time, we just don’t know what causes the Pupillary disorder and can only speculate.
Glaucoma and Adie’s Tonic Dilated Pupils
Little research is available on Adie’s Tonic Pupil and Glaucoma. Because the iris tissue is typically bunched up by Adie’s pupil eye disease it could result in blocking the drainage of eye fluid leading to a rapid increase in the eye pressure. This could result in an uncommon form of the eye disease called angle closure glaucoma. Theoretically, the effect of the parasympathetic nerve dysfunction on the ciliary body should result in an increase in eye pressure. I am not aware of any studies that substantiate this. In past years the drug Pilocarpine was frequently used to treat glaucoma by stimulating the parasympathetic system and increasing the outflow of the fluid inside the eye (resulting in intraocular eye pressure reduction). The effect of the Adie’s Tonic Pupil on glaucoma remains unknown, but probably is significant only in rare cases.
Perhaps the most important thing to learn about this eye condition is that it does not progress or cause blindness and vision loss. You can lead a normal, healthy life after appropriate diagnosis and treatment by your optometrist.