Woman's weight-loss surgery leads to vision loss

A woman's vision loss and lesions on her eyes turned out to have an unexpected cause: a vitamin deficiency stemming from weight-loss surgery, according to a recent report of her case.

The woman, in her early 40s, visited an ophthalmology clinic in Texas because she was having vision problems and eye pain, and had developed lesions on her eyes, according to the report published March 31 in the journal JAMA Ophthalmology.

These symptoms are the effects of a severe vitamin A deficiency, said Kyle Kirkland, a medical student at the Texas College of Osteopathic Medicine and the lead author of the case report. [16 Oddest Medical Cases]

Vitamin A plays an important role in eye health, and deficiency can lead to severe dryness of the eye, night blindness and lesions called "Bitot spots" that form on the surface of the eye, Kirkland told Live Science. These raised bumpy lesions form on the white part of a person's eye, called the sclera, he said. While the lesions don't affect a person's vision, the process that causes the lesions to form can also cause severe dryness, which can alter vision, he said.

But it's rare for people in the U.S. to have a vitamin A deficiency that's severe enough to cause eye problems, because it's easy to get enough of the vitamin from our diets, Kirkland said. (In developing countries, however, vitamin A deficiency is much more common — in fact, it’s a leading cause of preventable blindness, he added.)

Indeed, the woman's vitamin A deficiency was actually the result of weight-loss surgery (also called bariatric surgery) that she had had a year before, according to the report.

In the particular type of weight-loss surgery the woman had — known as a "duodenal switch" — the surgeon not only makes the stomach smaller, but also creates a bypass around a section of the small intestine. This is done by taking the beginning of the small intestine (called the duodenum) and connecting it to a lower-down part of the small intestine.

The small intestine is where the nutrients in food are absorbed into the body, so by shortening the length of small intestine that the food travels through, the surgery lowers the amount of calories and nutrients the body can absorb from food, Kirkland said.

Although the surgery has been shown to help with weight loss, it may also significantly lower a person's level of certain vitamins, including vitamin A, according to the report. [The Best Way to Keep Weight Off]

The woman was told at the time of her surgery that vitamin deficiencies were a common side effect of the surgery, and she had been taking a multivitamin in order to prevent this from happening, Kirkland said. But the multivitamin "was not enough to keep her from getting severe vitamin A deficiency," he said.

The woman's case is the second report of this specific type of weight-loss surgery led to eye-related symptoms, to the authors' knowledge, Kirkland said.

Other types of weight-loss surgery have been reported to lead to vision problems, and as weight-loss surgeries become more common, it's possible that eye problems such as these may also become more common, Kirkland said.

To treat the vitamin A deficiency, the woman was given intravenous (IV) vitamin A, according to the report. She did not return for a follow-up visit, but reported that her symptoms and vision problems had gone away. However, the authors noted that in order to prevent the symptoms from returning, she would need to keep receiving infusions of vitamin A until she could have another surgery, to alter her intestines to fix the problem permanently.

In addition, while an IV dose of vitamin A alleviated this woman's symptoms, the damage that can occur from a vitamin A deficiency is not always reversible, "which is why it is critical to receive proper nutrition after such a procedure," Kirkland said.

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