Case study: Nyctalopia points to gastric bypass complication

DENVER – In a case study presented as a poster here at the American Academy of Optometry meeting, nyctalopia was determined to be secondary to a severe vitamin deficiency caused by a gastric bypass procedure.

Study authors Bradley Lane, BS, BA, and John Dovie, OD, FAAO, evaluated a case in which nyctalopia – a condition characterized by an impairment of night vision – was the presenting sign of a severe vitamin A deficiency caused by gastric bypass surgery.

In the study, a 59-year-old white male complained of difficulty driving at night, as well as difficulty in seeing objects in darkened rooms. These difficulties had been present for the past year, according to the patient.

The subject's systemic history included hypertension, arthritis, hypothyroid disorder and a recent pneumonia. Also noteworthy in the patient's systemic history was an uncomplicated gastric bypass surgery approximately 20 years prior.

The patient's systemic medications included furosemide 20 mg, atenolol 25 mg and levothyroxine sodium 125 mcg. The patient's ocular history included dry eye, for which he was using cyclosporine 0.05% in each eye twice daily. Entrance testing on the patient was normal, and anterior segment evaluation showed only lenticular changes.

A complete laboratory test showed hypovitaminosis with absence or deficiencies in vitamins A, D, E and K. The patient was then referred to his primary care doctor for an appropriate vitamin regimen.

The researchers concluded that, based on a laboratory workup, this patient's nyctalopia was secondary to a vitamin deficiency related to poor nutrition caused by gastric bypass surgery. After this problem was identified and the patient's primary care physician notified, action was taken to correct his vitamin levels.