title: Electrolyte composition of retro-oil fluid and silicone oil-related visual loss.
abstract: OBJECTIVE
  Up to one-third of patients with intra-ocular silicone oil (SO) tamponade for complex macula-on retinal detachment may experience an unexplained visual loss during or after SO tamponade. Although the underlying mechanism is unknown, previous studies suggested that accumulation of retinal potassium could be involved. Hence, this study tested the hypothesis that intra-ocular potassium levels are elevated during SO tamponade.
  
  
  METHODS
  A prospective cohort study was carried out from 13 October 2013 through 5 March 2015. Potassium, sodium, magnesium, chloride, calcium, lactate dehydrogenase (LDH) and glucose levels were measured in retro-oil fluid and paired serum from 16 patients undergoing oil removal, including two patients with SO-related visual loss (SORVL). Vitreous humour and paired serum from 27 patients with macular hole (n = 19) or floaters (n = 8) served as controls.
  
  
  RESULTS
  Median potassium levels in retro-oil fluid and vitreous humour were similar. Magnesium and chloride levels were lower in retro-oil fluid compared with vitreous humour (p < 0.01) and LDH levels were elevated in retro-oil fluid (p < 0.0001). One of the two patients with SORVL revealed abnormal high potassium and magnesium levels. The other patient had normal levels.
  
  
  CONCLUSIONS
  Potassium levels are not increased in retro-oil fluid during SO tamponade, making the 'potassium accumulation' hypothesis unlikely. The disturbance in magnesium concentration during SO tamponade warrants further investigation.
authors.affiliation: Department of Ophthalmology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: Laura M E
authors.initials: LM
authors.lastname: Scheerlinck
authors.affiliation: Department of Ophthalmology, University Medical Center Utrecht, Utrecht, the Netherlands.|Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: Jonas J W
authors.initials: JJ
authors.lastname: Kuiper
authors.affiliation: Department of Ophthalmology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: Albert T A
authors.initials: AT
authors.lastname: Liem
authors.affiliation: Department of Ophthalmology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: Peter A W J F
authors.initials: PA
authors.lastname: Schellekens
authors.affiliation: Department of Ophthalmology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: Redmer
authors.initials: R
authors.lastname: van Leeuwen
mesh_terms: D000368:Aged; D002118:Calcium / Q000378:metabolism; D015331:Cohort Studies; D004573:Electrolytes / Q000378:metabolism*; D058450:Endotamponade / Q000379:methods*; D005260:Female; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008274:Magnesium / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000378:metabolism*; D011446:Prospective Studies; D012163:Retinal Detachment / Q000378:metabolism / Q000601:surgery*; D012827:Silicone Oils / Q000009:adverse effects*; D012964:Sodium / Q000378:metabolism; D014786:Vision Disorders / Q000209:etiology* / Q000378:metabolism; D058609:Visual Field Tests; D014821:Vitrectomy; D014822:Vitreous Body / Q000378:metabolism*
chemical_list: D004573:Electrolytes; D012827:Silicone Oils; D012964:Sodium; D007770:L-Lactate Dehydrogenase; D008274:Magnesium; D011188:Potassium; D002118:Calcium
keywords: potassium; retina; silicone oil; visual loss; vitreous