Purpose: To report the case of a 28-year-old patient with persistent bilateral burning pain and foreign body sensation in both eyes for the past 1 year. The patient showed a poor response to 0.05% cyclosporine eye drops and frequent instillations of artificial tears. Ocular examination showed few superficial punctate epithelial defects, well-positioned laser in situ keratomileusis (performed 5 years ago with symptomless recovery) flaps, and clear interfaces bilaterally, with a tear film breakup time of 7 and 8 seconds in the right and left eyes, respectively. The results of Schirmer tests, confocal microscopy, corneal esthesiometry, and meibography were normal for both eyes. The patient was incidentally diagnosed with vitamin B12 deficiency, with a serum vitamin B12 value of 90 pg/mL (reference range, 236-911 pg/mL), during routine laboratory tests. In view of weak correlation between signs and symptoms, a putative diagnosis of ocular neuropathic pain secondary to vitamin B12 deficiency was made.
Methods: Case report.
Results: The patient was treated with parenteral vitamin B12, and topical therapy was continued without any changes. The patient experienced dramatic improvement with a decrease in symptoms within 3 weeks of administering vitamin B12 supplements and was symptom-free in the absence of any topical medication 6 months after treatment.
Conclusions: Vitamin B12 deficiency, although common in India, has not been reported to be associated with ocular symptoms, including pain and mimicking those seen in severe dry eye. Vitamin B12 deficiency should be considered in the differential diagnosis of ocular neuropathic pain and dry eye in patients presenting with recalcitrant ocular neuropathic pain.