Acessibilidade / Reportar erro

Serum levels of vitamin A, visual function and ocular surface after bariatric surgery

Níveis séricos de vitamina A, função visual e superfície ocular após cirurgia bariátrica

ABSTRACT

BACKGROUND

Bariatric surgery is the most effective treatment for severe obesity, but the surgery increases the risk of developing nutritional deficiencies, such as vitamin A deficiency. In human metabolism, vitamin A plays a role in vision.

OBJECTIVE

To evaluate serum vitamin A, visual function and ocular surface of patients undergoing bariatric surgery.

METHODS

A cross-sectional and analytical study was conduced with 28 patients undergoing bariatric surgery for at least 6 months. Ophthalmologic evaluation was done through color vision test, contrast sensitivity test, ocular surface tests and confocal microscopy, as well as vitamin A serum measurement.

RESULTS

Vertical sleeve gastrectomy was performed in seven (25.0%) patients and Roux -en-Y gastric by-pass in 21 (75.0%). Mean serum vitamin A level was 1.7±0.5 µmoL/L. Most patients (60.7%) had symptoms of dry eye. Five (17.9%) patients had contrast sensitivity impairment and 18 (64.3%) color vision changes. In the group of patients undergoing Roux -en-Y gastric by-pass , mean vitamin A levels were 1.8±0.6 µmoL/L, whereas they were 1.7±0.5 µmoL/L in patients submitted to the restrictive technique vertical sleeve gastrectomy . The analysis of the influence of serum levels of vitamin A in the visual function and ocular surface was performed by Pearson correlation test and there was no significant correlation between any of the variables and vitamin A.

CONCLUSION

There was no influence of the bariatric surgery technique used on serum vitamin A levels, on the visual function or on the ocular surface. Moreover, there was no correlation between serum levels of vitamin A and the visual function or the ocular surface changes.

Headings:
Bariatric surgery; Vitamin A deficiency; Night blindness; Xerophthalmia

Instituto Brasileiro de Estudos e Pesquisas de Gastroenterologia e Outras Especialidades - IBEPEGE. Rua Dr. Seng, 320, 01331-020 São Paulo - SP Brasil, Tel./Fax: +55 11 3147-6227 - São Paulo - SP - Brazil
E-mail: secretariaarqgastr@hospitaligesp.com.br