Wednesday, June 18, 2008

Anterior Uveitis

Anterior uveitis is the inflammation of the uvea, and as we all know the uvea consists of the choroid, iris and the CB. A uveitis can be brought on by physical ocular trauma, a systemic underlying disease, or simply be idiopathic. It can present itself unilaterally or bilaterally. If you see a bilateral presentation and a recurrent one think systemic disease as underlying cause. Furthermore, anterior uveitis can present itself in an acute or a chronic form. Signs and symptoms that patients typically experience include photophobia, hyperlacrimation and pain. Entering tests such as VA can be reduced, the pupil may not constrict or dilate upon exposure to light due to the formation of the synechiae. A synechiae can be of 2 forms posterior and anterior. Anterior synechiae is when the iris attached to the cornea, this can cause many problems such as zippering of the iris 360 degrees all around. Once the angle closes it can only be opened surgically no prophylactic treatment is helpful hence one must break the angle immediately. Anterior synechiae can also induce a pupillary block which can induce secondary angle closure glaucoma. Posterior synechiae is the attachment of the iris to the lens. Synechiae is caused by the stickeness of the cells and flare that are produced, basically the white cells that are released in response to the inflammatory reaction are sticky and they are what cause the adhesion. Upon gross examination of the eye structure you can see prominent red eye due to inflamed dilated blood vessels which can vary from a very mild to a severe presentation. Upon examining of the angle you will observe cells and flare. Upon tonometry via GAT IOP can either be very low or very high. Low because the inflammation can stop the CB from producing aqueous hence decreasing IOP or it can be high due to closure of the angle via synechiae or via clogging of the TM with white blood cells. Treating an anterior uveitis can be simple if you keep in mind that ultimately this is inflammation reaction. The very first thing you want to do is provide some sort of pain relief for the patient. Prescribe 1% atropine bid or scopolomine 0.25% tid or 5% homatropine. Hamatropine is usually more effective with patients of lighter pigmentation. In addition to reliving the pain the cycloplegics will also help with breaking the synechiae. If this does not work consider adding a sympathomimetic such as 10% phenylephrine. Moreover, prescribe a potent steroid for 2 reasons one to brake the fibrotic membrane and inhibit inflammation. Use 1% Pred Forte (prednisolone acetate) initially q15m for first 6 hours followed by q1h or q2h. Do not use an ointment at night there is no need for it, one can advise the patient to instill the steroid prior 5 minutes before bedtime qm. Also, use and NSAID in addition to the steroid. Taper the steroid over a 4 week period slowly only once the cells and flare resolve. Remember be patient and be aggressive, the typical resolvent time of anterior uveitis is 6 to 8 weeks. If nothing seems to be working and you feel uncomfortable with prescribing steroids for a long periods of time remember your friends and refer. Also remember to differentiate and anterior uveitis with other disease such as scleritis, conjuctivitis, episcleritis, etc. Keep in mind if its a recurrent case and is bilateral recommend a systemic work up to screen for any underlying systemic diseases.