“My baby’s got a red eye, Doctor!”

Introduction

Although most of the time the cause of a red eye in infancy is easily identified, uncomplicated and treatable, occasionally the underlying problem is serious, with potential risks for visual development or even the patient’s life. Clinical suspicion and skills are therefore required for each presentation; all infants with a red eye must have a complete ocular examination. Although ideally slit-lamp biomicroscopy should be a part of this evaluation, assessment with simple magnification may be all that is possible and is often sufficient to make a diagnosis. Red-free illumination is very useful to differentiate the type of conjunctival congestion and fluorescein staining helps to reveal conjunctival and corneal epithelial defects or foreign bodies.

The following are the most relevant questions to be solved by the expert for getting to the right diagnosis in an infant with a red eye.

Is conjunctival congestionsuperficial or deep?

Dilation of the superficial posterior conjunctival vessels is more intense at the fornix; the vessels branch irregularly, appearing bright red. This type of congestion indicates a purely conjunctival problem. Deep, pericorneal, limbal, or ciliary injection is more intense at the limbus, where the ciliary vessels radiate in a regular pattern. Deep congestion is present when a pathological process involves the eyeball itself, particularly when anterior segment structures are affected. The vessels may be more purple/rose than bright red. Deep or limbal congestion may be present in a 360 degree distribution pattern, meaning a diffuse or serious involvement of any structure of the anterior segment, while sectorial pericorneal congestion usually indicates a localized corneal process. Superficial and deep congestion may coexist and the ophthalmologist must determine which is more prominent to make the correct diagnosis.

Superficial conjunctivalcongestion with discharge?

The most common cause of red eye in infancy is conjunctivitis. The presence of superficial congestion and purulent discharge suggests a diagnosis of bacterial conjunctivitis including ophthalmia neonatorum. Fornix conjunctival injection with watery discharge is a sign of viral conjunctivitis. Neonates with this clinical picture could have herpes simplex-2 conjunctivitis acquired through the birth canal. In an older infant with bilateral conjunctival congestion and watery discharge, follicular adenoviral conjunctivitis is a probable diagnosis, especially if there is a clear history of close contact with another infected person.