SARCOIDOSIS OF THE EYE
by Steven Hamilton, M.D.,
Summary of a presentation given October 5, 1996.
Many people have sarcoidosis with ophthalmic involvement. Studies of patients show involvement ranges from 25 to 50%. Those on the high end of the series have mild involvement. These patients have been biopsy-proven to have sarcoid. They may have originally gone to an ophthalmologist for an eye evaluation even though there were no symptoms. Others had eye complaints and were ultimately diagnosed with sarcoidosis. Those studies indicated that twice as many blacks had eye involvement as did whites.
The most common problem is an inflammation called Uveitis . Involvement is 1) Anterior Uveitis- front of the orbit, 2) Posterior Uveitis – back of eye and 3) conjunctivitis (inflammation of the conjunctiva).
The outside of the eye consists of the pupil, iris (colored portion), sclera (white part), conjunctiva (pink fold under the eye lid). The cornea is a kind of dust cover for the eye and is very hard. It refracts light, somewhat changes the shape of light and images.
The pupil is formed by the opening of the iris directly in front of the lens, and focuses the image on back of the eye, the retina.
The front part or the anterior portion of the eye has a fluid, aqueous humor, between the cornea and iris. When there is an inflammation here it is called Anterior Uveitis.
Behind the lens of the eye is a clear jelly, the vitreous fluid. Floaters are pieces of this jelly that have hardened or dried. These can get in the way of vision. This area behind the lens is referred to as the back of the eye (Posterior). The retina is like a piece of film on which a picture is projected and is then sent through a “cable” (optic nerve) to the brain.
In the middle of the brain the nerves from each eye crosses in front of the brain stem. This crossing is called the Chiasm. Then the nerves begin to radiate into the back of the brain where visual memories are stored. The eye works like a camera and the optic nerve is like a VCR cable to the TV.
The lachrymal glands which provide moisture/tears can be involved with granulomas. They lie to the side of the side of the eye orbit and can be seen on Gallium scans. Dry eyes are the most common symptom presented. When the eyelids have granulomas, these are easily biopsied. This scan will “light up” the area in 60 to 70% of cases. People with enlargement of the lachrymal glands can actually have a bulging of the eye, pushing the eye out or down causing double vision. This is usually painless. Bulging of the eye is rare if it is caused by pressure from within.
With Conjunctiva involvement, the inner part of the lid can have fine granulomas, like sand, on the surface or there can be large granulomas seen. Dry eyes and/or burning, sore eyes with blurred vision late in the day can be symptoms of conjunctivitis.
The cornea, the outside coverings of the eye sometimes become cloudy from infiltrate materials. This is what seems to happen with sarcoidosis and with chronic uveitis. Anterior Uveitis is what most people have when they have eye involvement. About half of these are acute, the rest are recurrent or chronic and present with red eyes, painful eyes, blurred vision, light sensitivity and can easily be treated with topical steroids. Systemic steroids are used in rarer cases.
When an ophthalmologists sees granulomatous infiltrates in front of the iris, he sees “mutton fat” particulates that look like cloudy rain drops on the inside surface of the cornea, or nodules on the surface of the pupil which are called Koeppe and Busaca when on the iris. Debris on top of the iris can look like “mutton fat” or “soap suds” and can be seen with the slit lamp.
Herefords Syndrome is a combination of symptoms besides uveitis. Facial nerves can be involved with the swelling of the parotid gland, which is located in front of the ears. When swollen the patient can appear to have “chipmunk cheeks.” Sometimes Bell’s Palsy is the presenting symptom. Problems occur with recurrent or chronic cases and can be difficult to manage. Glaucoma and cataracts are associated with this.
Posterior Uveitis is inflammation behind the lens. Think of the Christmas glass ball with snowflakes that swirl about when you shake it. Inflammatory cells are like the snowflakes, vision becomes very cloudy. Debris floats in the vitreous jelly making it difficult to see the retina clearly. “String of pearls”, grape-like clusters of material, may be seen on the retina and there can be chorioretinal granulomas on the retina as well. In Posterior Uveitis other things are seen. “Candle wax drippings” are seen along the veins, rarely are arteries involved. This is referred to as retinal periphlebitis.
Posterior Uveitis increases the chance of central nervous system involvement at the rate of 35% of ocular cases Vs 2-5% of all other sarcoid case involvement. It goes to say there is an increased chance of brain involvement because the optic nerve serves as a direct pathway from the eye into the brain.
Vasculitis is when vessels are numerous and become inflamed and can spasm. The formation of tiny new vessels to help nourish the retina is often very weak and can leak fluid into the macula and can also hemorrhage. These are treated by laser therapy, photogulation, to prevent further leakage. Fluorescing angiogram shows the leaks and helps determine where to use laser treatment.
In children, especially those under 5 years of age, anterior uveitis is usually asymptomatic and regular eye examinations are recommended. It is not understood why these cases rarely have lachrymal involvement.
Swelling of both optic nerves can occur when spinal fluid pressure is high and can cause other symptoms. Peripheral vision fields may be limited. After the facial nerve, optic nerve involvement is the most common. Inflammation and neuritis-like symptoms are caused by surface granulomas. Enough scarring can cause atrophy and starving of the nerve. This does not necessarily disrupt vision and often, with response to treatment, the patient sees better than expected.
When a practitioner notices the crossing fibers (Chiasm) of the optic nerve there is involvement of both eyes and other glandular symptoms: like temperature regulation, thirst and drinking, and possible menses problems, including amenorrhea (no periods). Vision loss in this area of inflammation tends to be at the outside edges of the vision field.
Loss of half of the vision in one or both eyes is due to compression and is seen in visual field test results.
Double vision can be related to one or several things: inflammation in the eye, inflammation in the muscles of the eye, or in the nerves of the eye. The 6th nerve is used to pull the eyes so you can see to the side and is the most common nerve involved. When compromised, it keeps the muscle from functioning.
Problems with the pupils themselves are rarely seen. Hormen’s Syndrome is involvement of the sympathetic pathway that controls the size of the pupil. The muscles in the border of the pupil do not work. Or the pupil may remain large, unable to close down in bright light.
The mainstay treatment for ocular sarcoidosis is usually topical steroids and cycloplagics, especially in anterior and mild uveitis. Systemic steroids are prescribed for resistant and recurring uveitis, posterior uveitis, neurovascularization to quiet the inflammation as well as lessen CNS involvement. Sometimes injections with long-acting steroids are used. But here complications of glaucoma or the rare incidents of artery damage dictate caution with this therapy. Chemotherapy drugs are used when neurological complications are present.
Individuals with acute eye involvement usually do very well, as opposed to persons with chronic involvement. Those who develop glaucoma tend to do poorly. Visual acuity that decreases to 20/200 may be caused by glaucoma, cataracts or fluid build-up. Visual symptoms do not usually parallel other organ system involvement. Symptoms may be quiet, or there can be high ocular activity.
Dr. Hamilton is a Neuro-Ophthalmologist and Clinical Professor at the University of Washington School of Medicine and also has a private practice in Seattle, WA.
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