The red eye: diagnostics and treatment (Proceedings)
The "red eye" may present for many different reasons. Periocular trauma, conjunctival hyperemia, corneal vascularization, intraocular hemorrhage, and detached subalbinotic retinas may all lead to the complaint of a "red eye". Examination of the eye should lead to localization of the abnormality and standard ophthalmic testing should be performed, including schirmer tear tests, fluorescein staining, and intraocular pressures. If cytology and/or culture and sensitivity need to be submitted this should be done prior to instillation of topical fluorescein.
Most red eyes are associated with uveitis and intraocular hemorrhage. This involves deterioration of the blood:ocular barrier resulting in leaky blood vessels and extravasation of red blood cells, white blood cells, and proteins. The cause of the uveitis may be systemic or ocular only. Chronic ocular conditions such as glaucoma, cataract formation, retinal detachment, neoplasia, or post-surgical uveitis may lead to the development of pre-iridal fibrovascular membranes (PIFM's); PIFM formation is associated with chronic intraocular hypoxia and may predispose to hemorrhage. Trauma leading to uveitis may be blunt and compressive in nature or involve entry into the eye by puncture or laceration. Additionally, there are many inherited and congenital ocular syndromes that may lead to hemorrhage, such as persistent hyperplastic primary vitreous in Doberman Pinschers and Collie Eye Anomaly in Collies and Australian Shepherds. Determining the etiology will allow the best and most specific treatment. In addition to the above standard diagnostic testing blood pressures, complete physical examination, submission of bloodwork and urinalysis, ocular ultrasound, electroretinogram, MRI or CT, centesis, retrobulbar aspirates, and biopsies may be part of the diagnostic plan. When I evaluate a case, consultation with other specialists may ensue if the diagnosis is considered to be an ocular manifestation of systemic disease.
When chronic uveitis and hemorrhage secondary to an ocular condition are present therapy may involve both medical and surgical treatment. If chronic glaucoma is the issue, performing an enucleation or intrascleral prosthesis placement will relieve the pain for the patient as well the hemorrhage. Similarly, retinal detachments may respond to treatment for uveitis but surgery may be an option as well. If the retinal detachment is rhegmatogenous and recent, retinal reattachment surgery may also be performed to address the hemorrhage. Hemorrhage secondary to cataract formation may require aggressive treatment with anti-inflammatories, cataract surgery as soon as possible if the eye is visual, or enucleation or intrascleral prosthesis placement if the eye is nonvisual and painful. Neoplasia associated with hemorrhage usually leads to the recommendation for enucleation. An exception to this would be lymphoma; some of these cases respond to aggressive treatment with anti-inflammatories and immunosuppressive chemotherapeutics. Post-surgical inflammation and bleeding usually necessitates an increased schedule of anti-inflammatories, possible irrigation of the anterior chamber, injection of triamcinolone or betamethasone subconjunctivally or intravitreally. Tissue plasminogen activator (TPA) may also be injected intracamerally to address uveitis once active bleeding is controlled.