Ironically, those who have vitamin A deficiency may have an OCT finding that resembles a double carrot. Photo: Gabriel Gurrola on Unsplash.
Carrots have long been linked to eye health, and this was never truer than now. In what sounds like an April Fools’ Day joke, a recent study found that some patients with vitamin A deficiency actually had carrot-shaped retinal signs. They improved with vitamin A supplementation.
The study characterized this novel finding by retrospectively reviewing patients with vitamin A deficiency and assessing the condition using spectral-domain OCT and full-field electroretinography (ERG). These patients had become vitamin A-deficient following bariatric or colon surgery. The researchers reported in their paper that all patients had nyctalopia, a common early sign of vitamin A deficiency, extinguished scotopic rod-specific function with ERG and decreased serum vitamin A. None of the patients had surface abnormalities, and all received intramuscular vitamin A with subjective symptom resolution.
Four of six eyes had homogenous foveal hyperreflectivity anterior to the retinal pigment epithelium-Bruch’s complex on OCT. The researchers described this finding as “reminiscent of a ‘double carrot’” in their paper for the journal Eye. They explained in their publication that the double carrot improved with vitamin A supplementation. The ERG findings showed improved scotopic rod-specific function for all patients, but two cases still had diminished photopic function.
Vitamin A deficiency is a growing concern due to the increased frequency of bariatric surgery, the researchers pointed out in their paper. “Many patients exhibit visual impairment from retinal dysfunction with vitamin A deficiency before any signs of corneal or conjunctival abnormalities like Bitot spots or xerophthalmia,” they wrote. “It’s critical that clinicians involved in caring for [patients who have had bariatric surgery or who have other complicated gastrointestinal histories] are aware of the early manifestations of vitamin A deficiency such as nyctalopia and the mainstays of treatment including intramuscular vitamin A supplementation.”
The researchers noted that not all eyes in their study or in previous studies have “overtly demonstrated the proposed ‘double carrot’ sign” so clinicians shouldn’t rely too heavily on this finding for establishing a vitamin A deficiency diagnosis. “However, the proposed ‘double carrot’ sign shows promise as a robust imaging feature for vitamin A deficiency identification within the proper clinical context.”
Breazzano MP, Oh J, Batson SA, et al. Vitamin A deficiency and the retinal “double carrot” sign with optical coherence tomography. Eye (Lond). July 15, 2022. [Epub ahead of print].