Medical Emergency of Eye
Eyeball consists of 3 coats. From the outside to inward:
B) Uvea and
Cornea-sclera: Anterior part of the eyeball appears as black known as cornea, which helps to transmit light in to the eyeball. Sclera appears as white next to cornea protect the eyeball also preserve the shape of the eyeball.
Uvea: Uvea- is the middle coat, which is also called vascular coat of the eye. Main bulk of the vasculature of the eyeball resides in this coat. It serves as the main nutrient supplier to the eye. It has 3 parts. Most anterior part is iris; next is ciliary body and posterior most is choroids.
Retina: Retina- is the innermost layer of the eye. It is the neural layer which is designed to receive the light rays; convert it in to electrical signal and transmit it to the brain where it transformed in to image for visual perception by the brain.
Uveitis: Uveitis inflammation of the uvea or uveal reaction due to insult by the infective agents (bacteria, virus, fungus, parasites etc.) or immunological / hypersensitivity reaction, trauma or chemical substances.
Etiology of Uveitis: In our country Tuberculosis, Rubelle virus, Candida & Aspergillus, Toxoplasma are the common infective causes of uveitis. There are some systemic diseases like Ankylosing Spondylitis, Juvenile Rheumatoid Arthritis, Psoriatic Arthritis, Chrones disease, Ulcerative Colitis, Reiter’s Syndrome etc are autoimmune nature means tissue reaction caused by the insult of the body’s own tissue bearing structural error. These systemic conditions are sometime associated with uveitis means uveal tissue reaction of autoimmune nature. Ocular trauma may cause uveitis. Chemicals are also potent agents for uveitis.
What happens to uveal tissue in case of uveitis: Caliber of vessels are increased in diameter resulting more blood to rash in the tissue at the same time blood cells are engaged in the battle resulting release of many chemical mediators which derange the internal microenvironment of the uvea. It causes red eye and pain. Excessive protein leakage in the clear internal fluid is causing internal fluid (aqueous & vitreous) turbid which impair light transmission resulting visual impairment.
Presentation of Uveitis: Acute presentation- redness of eye; pain in affected eye; watering from the eye; photophobia or intolerance to light; blurring of vision. These presentations are mainly found in involvement of the anterior part of the uvea (iris & ciliary body) called anterior uveitis. There are presentations, which are less acute mainly found in posterior uveitis. These features are floater (black spot before eye), photopia (flashes of light), metamorphopsia (object seen larger or smaller or different shape). These features sometimes pass unnoticed to the patient.
How to approach a case of Uveitis:
1st step (history):
Uveitis may be the presenting feature of some systemic diseases like ankylosing Spondylitis, Psoriasis, Chrohn’s disease, Cealiac disease, Juvenile Rheumatoid Arthritis, Tibulo-interstitial Nephritis etc. These are diseases of autoimmune nature. Tissue reaction occurs spontaneously due to some derangement of the immune system of the body. So it is very important to take history of the patient about the mentioned systemic diseases. Medical records may help. Ophthalmologist should keep it in mind so that systemic diseases might be explored. These patients have the history of low back pain or joint pain like knee, ankle etc associated with redness of different degree with or without pain in eye as well as blurring vision of different degree. In case of rheumatoid arthritis in children there may not be any pain or redness in eye at all. At some stage blurring of vision in the effected eye is the only presentation. If affection occurs in one eye it may go unnoticed to the child. So it is wise to have a routine eye examination by the eye specialist for those who has the systemic diseases mentioned above.
2nd step (Clinical examination):
With slitlamp microscope an ophthalmologist can easily be able to diagnose a case of uveitis revealing the features of uveitis- conjunctival congestion, keratic precipitate (clumping of inflammatory cells on the posterior surface of the cornea), cell flare in the anterior chamber, hypopyon (protein rich fluid in anterior chamber that is within eyeball), synechiae as well as other signs in the eye.
3rd step (diagnostic tool):
Help of diagnostic tools
- B-scan ultrasonography of affected eye
- Flouroscein angiogram of eye.
1. Steroid preparations for short term use only for weeks.
Topical (eye drop) – routinely use, the frequency & duration of which should be exactly judged by an ophthalmologist.
Periocular (injectable form to be given around eye – subtenon, subconjunctival or intravitreal)
Oral – is to augment the topical steroid when steroid drop is not enough to control the episode of uveitis. Oral steroid should be given in a dose schedule properly judged by the ophthalmologist. Usually severe uveitis reaction or autoimmune diseases association needs oral steroid preparation.
Intravenous- steroid injection is used for a loading dose to accelerate the initial concentration of steroid in the affected eye.
2. In case of uveitis with associated systemic autoimmune diseases sometime requires a long term use of systemic/ oral steroid for months together.
When to use steroid for long term?
- Uveitis is chronic in nature.
- Uveitis has chances of recur as in case of autoimmune diseases association.
Precautions in long term use of steroid:
It may cause rise of intraocular pressure (IOP) – so it require regular measurement of IOP and in rise of it should be addressed properly.
Aggravate the hypertension & diabetes. So before starting the steroid it is mandatory to exclude hypertension and diabetes.
Growth retardation & congenital anomalies of fetus would be in pregnant women so it is better to avoid systemic steroid in pregnant women.
Steroid may concentrate in mother’s milk resulting growth retardation of the breast feeder baby. It is better to avoid in lactating mother.
Osteoporosis aggravation-Older age group usually suffers from osteoporosis without disease. Osteoporosis means withdrawn of calcium from the bone. So in case of older people or persons are suffering from osteoporosis should be prescribed calcium & vita- D supplement along long terms steroid use.
Weight gain & generalized weakness.
What to do when steroid is not sufficient or contra-indicated?
Immunosuppressive agent: Alternate option is immunosuppressive agent like- methotraxate, immuran, salfasalagin etc. Immunosuppressive agents are also not hazards free. It may cause bone marrow suppression and also cause toxicity to liver. In case of immunosuppressive use it is mandatory to do regular blood count as well as liver function test from starting of immunosuppressive medication till discontinuation.
Fate of Uveitis:
- Complete cure without any residual effect.
- Cataract formation
- CME- It means Chronic Cystoids Macular Edema (collection of fluid in the macula, the most sensitive part of the retinal nerve fiber layer.
- Retinal detachment- It is a separation or splitting of retinal nerve fiber layer.
- Gross visual impairment
- Phthysical eye- shrinkage of eyeball.
- Person suffering from red eye with/without pain & blurring as well as scotoma should attend an eye specialist.
- Pregnant women & lactating mother with red eye deserves special attention in case of long term steroid medication.
- Person having diseases like Ankylosing Spondylitis, Juvenile Rheumatoid Arthritis, Psoriasis, etc. facing red eye should think of uveitis.
- On attending an eye specialist with red eye patient should inform about pregnancy, lactation, low back pain or medication for related diseases mentioned above.
- Be sincere about the long term medication when it required along other laboratory investigations.
- Don’t forget- Uveitis is a blinding disease and an ocular emergency.
Dr. Md. Sayedul HoqueMBBS, FCPS, MS (ophth) National Eye Care Centre Ring Road, Shyamoli, Dhaka. Ex-Associate Professor National Institute of Ophthalmology & Hospital