8th December 2023

Diagnostic algorithm

The limited exposure to Ophthalmology in the undergraduate medical curriculum means the diversity of possible diagnoses with a red eye can feel staggering4. Algorithms are useful diagnostic aids and can act as a guide towards having an appropriate list of differential diagnoses and recognising salient features. They also reduce bias, errors and increase efficiency.

The Edinburgh Red Eye Diagnostic Algorithm is a validated tool in referral groups that has been shown to have a diagnostic accuracy of 72% overall, 100% in acute angle closure, 82% in iritis and up to 70% in epithelial keratitis. The sensitivity of this algorithm increases with the severity of the condition, which makes it particularly suited to non-ophthalmologists. Once an appropriate list of differential diagnoses is made, further investigations and management is subject to the most probable diagnosis. Below is a traffic light system illustrating the recommended management system from NICE according to the most likely differential diagnosis.

Image Source: https://cks.nice.org.uk/topics/red-eye/diagnosis/diagnosis/(accessed 5 May 2022).

References 

• Scantling-Birch Y, Naveed H, Tollemache N, et al. Is undergraduate ophthalmology teaching in the United Kingdom still fit for purpose? Eye 2021 362 2021; 36: 343–345.
• Timlin H, Butler L, Wright M. The accuracy of the Edinburgh Red Eye Diagnostic Algorithm. Eye 2015; 29: 619.
• Bhattacharyya A, Patel N. Pocket Tutor Ophthalmology. JP Medical Limited, 2012. Epub ahead of print 2012. DOI: 10.5005/jp/books/11542.