The Yellow Purkinje Sign: A Clinical Clue To Identify Blue-Filtering Intraocular Lenses

Recognition of the type of IOL implanted (blue filtering vs non-blue filtering) can be helpful in certain scenarios to ensure that the same IOL type is implanted in both eyes as it was shown that some patients did not tolerate the difference in colour vision between both eyes. We herein describe a simple clinical sign that allows differentiation between blue-light filtering (yellow-tinted) and non-blue-filtering intraocular lenses (IOLs) using Purkinje–Sanson images during slit-lamp examination. 

This is an observational study conducted at the Department of Ophthalmology, Cambridge University Hospitals, Cambridge, United Kingdom

Observation of Purkinje–Sanson reflections during slit-lamp biomicroscopy was used to differentiate between blue-filtering and non-blue-filtering IOLs. Diffuse and slit illumination were applied to eyes implanted with different IOL types, including yellow-tinted blue-filtering lenses and clear non-blue-filtering lenses. The colours of Purkinje–Sanson reflections were evaluated. The findings were compared with the patients' records. 

Under diffuse illumination, non-blue-filtering IOLs (e.g. Eye Cee One IOL) demonstrated that all Purkinje–Sanson images were white. In contrast, blue-filtering IOLs (e.g. Acrysof IQ SN60 WF) showed a characteristic yellow posterior Purkinje–Sanson image. Similarly, slit illumination produced a white reflection from clear IOLs and a yellow reflection from blue-filtering IOLs. In all examined cases, the findings were consistent with patients’ records. 

A simple slit-lamp observation of Purkinje–Sanson reflections can assist in identifying whether an implanted IOL is blue-filtering or non-blue-filtering. This technique may be particularly useful when surgical records are unavailable and may help guide clinical decision-making in situations where IOL type influences management such as second-eye IOL selection and retinal laser treatment planning.