[Differential diagnostic strategies in uncertain vision disorders].

The differential diagnosis of visual disturbances of unclear origin can cause major problems in ophthalmology, especially if there are no functional defects or if functional defects cannot be explained by morphological findings after an extensive regular ophthalmological investigation. The aim of this paper is to present strategies that allow subtle visual disturbances to be related to certain groups of functional defects. Especially simple investigations are emphasized that lead quickly to a well-founded possible diagnosis that helps both the ophthalmologist and patient save time and cost-consuming deviations. The key investigations are: (1) a symptom-oriented case history; (2) exclusion of refractive problems by pin-hole test, retinoscopy and ophthalmometry; (3) the swinging flashlight test; (4) ophthalmoscopy of the macula and optic disc; (5) visual field. A flow chart is presented that explains the strategy of additional special investigations based on the results of the key findings in order to approach quickly the cause of a visual disturbance. Some of the more common causes of visual disturbances of unclear origin are discussed, including some major therapeutic principles.