Assessment of vision loss

Many patients present in primary care settings, often outside normal surgery hours.[1]Rossi T, Boccassini B, Iossa M, et al. Triaging and coding ophthalmic emergency: the Rome Eye Scoring System for Urgency and Emergency (RESCUE): a pilot study of 1,000 eye-dedicated emergency room patients. Eur J Ophthalmol. 2007 May-Jun;17(3):413-7. http://www.ncbi.nlm.nih.gov/pubmed/17534826?tool=bestpractice.com [2]Fea A, Bosone A, Rolle T, et al. Eye injuries in an Italian urban population: report of 10,620 cases admitted to an eye emergency department in Torino. Graefes Arch Clin Exp Ophthalmol. 2008 Feb;246(2):175-9. http://www.ncbi.nlm.nih.gov/pubmed/18183412?tool=bestpractice.com

Vision loss may occur from an abnormality in the visual system from the tear film to the occipital cortex. The most important factor to determine initially is the rapidity of symptom onset. Early assessment of the presence or absence of associated symptoms such as pain, double vision, and flashes and/or floaters is also important. This helps to identify patients with potentially life-threatening disease, and highlights those requiring prompt ophthalmology opinion[1]Rossi T, Boccassini B, Iossa M, et al. Triaging and coding ophthalmic emergency: the Rome Eye Scoring System for Urgency and Emergency (RESCUE): a pilot study of 1,000 eye-dedicated emergency room patients. Eur J Ophthalmol. 2007 May-Jun;17(3):413-7. http://www.ncbi.nlm.nih.gov/pubmed/17534826?tool=bestpractice.com or surgical intervention.[3]Ramos M, Kruger EF, Lashkari K. Biostatistical analysis of pseudophakic and aphakic retinal detachments. Semin Ophthalmol. 2002 Sep-Dec;17(3-4):206-13. http://www.ncbi.nlm.nih.gov/pubmed/12759852?tool=bestpractice.com

Acute vision loss that occurs suddenly or over the course of several minutes to hours usually requires urgent ophthalmic opinion. People with sub-acute or chronic vision loss (where vision loss has developed over weeks, months, or years) may still need specialist input but usually on a non-urgent basis.

Any significant vision loss justifies a call to the ophthalmologist for advice on referral timing.

Vision loss may also be the initial manifestation of a number of systemic diseases for which separate work-up is required.[4]Klig JE. Ophthalmologic complications of systemic disease. Emerg Med Clin North Am. 2008 Feb;26(1):217-31. http://www.ncbi.nlm.nih.gov/pubmed/18249264?tool=bestpractice.com

Acute vision loss

Retinal or optic nerve disease usually presents acutely. Other acute causes of vision loss include acute angle-closure glaucoma, retinal vascular occlusion, and trauma.

The patient's age and determination of the medical history assists in diagnosis.

Chronic vision loss

Patients may recognise symptoms of chronic deterioration 'acutely', meaning chronic vision loss may present in the accident and emergency department, making diagnosis difficult.

Associated symptom review makes it possible to differentiate between urgent and non-urgent cases and arrange for appropriate ophthalmic consultation.

Systemic considerations

It is essential to take thorough histories, focusing on vascular and neurological processes as well as visual processes.

Diabetic retinopathies may develop before systemic diabetes is diagnosed, making it important to measure blood glucose levels in all patients presenting with acute vision loss and to perform ophthalmological examination of all newly diagnosed adults with diabetes.

Other serious systemic diseases (including granulomatosis with polyangiitis [Wegener's granulomatosis], bacterial meningitis, or disseminated malignancies) may need to be addressed in the A&E department or by hospital admission.[5]Mitra A, Chavan R, Gunda M. Occult giant cell arteritis and steroid therapy: how urgent is urgent? Ann Ophthalmol (Skokie). 2006 Winter;38(4):343-5. http://www.ncbi.nlm.nih.gov/pubmed/17726223?tool=bestpractice.com