title: Serum levels of vitamin A, visual function and ocular surface after bariatric surgery.
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.
  
  
  CONCLUSIONS
  - 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.
authors.affiliation: Hospital de Olhos de Pernambuco (HOPE), Recife, PE, Brasil.
authors.forename: Luana Paula Nogueira de Araújo
authors.initials: LP
authors.lastname: Brandão
authors.affiliation: Hospital de Olhos de Pernambuco (HOPE), Recife, PE, Brasil.
authors.forename: Lucio
authors.initials: L
authors.lastname: Vilar
authors.affiliation: Hospital de Olhos de Pernambuco (HOPE), Recife, PE, Brasil.
authors.forename: Bernardo Menelau
authors.initials: BM
authors.lastname: Cavalcanti
authors.affiliation: Hospital de Olhos de Pernambuco (HOPE), Recife, PE, Brasil.
authors.forename: Pedro Henrique Amorim
authors.initials: PH
authors.lastname: Brandão
authors.affiliation: Hospital de Olhos de Pernambuco (HOPE), Recife, PE, Brasil.
authors.forename: Tiago Eugênio Faria E
authors.initials: TE
authors.lastname: Arantes
authors.affiliation: Hospital de Olhos de Pernambuco (HOPE), Recife, PE, Brasil.
authors.forename: Josemberg Marins
authors.initials: JM
authors.lastname: Campos
mesh_terms: D000328:Adult; D050110:Bariatric Surgery / Q000009:adverse effects*; D003430:Cross-Sectional Studies; D004728:Endothelium, Corneal; D005260:Female; D006801:Humans; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D009767:Obesity, Morbid / Q000601:surgery; D016896:Treatment Outcome; D014786:Vision Disorders / Q000209:etiology / Q000503:physiopathology; D014792:Visual Acuity / Q000502:physiology*; D014801:Vitamin A / Q000097:blood*
chemical_list: D014801:Vitamin A