title: Blood components and OCT reflectivity evaluated in animal model.
abstract: OBJECTIVE
  To see the relationship between blood components and optical coherence tomography (OCT) reflectivity using an animal model in which the aqueous humor was substituted by different experimental solutions without changing the integrity of the retina.
  
  
  METHODS
  The aqueous humor of an enucleated swine eye was replaced with plasma obtained from healthy volunteers. The OCT reflectivity of the anterior chamber filled with each plasma was calculated from individual OCT images, and was expressed by an arbitrary unit (AU). The concentration of blood components such as cholesterol, hemoglobin (Hb) and bilirubin of each individual was measured, and the correlation between each of them and the OCT reflectivity of aqueous humor in an enucleated swine eye was analyzed. Using the same model, the effects of the single plasma component on OCT reflectivity were examined.
  
  
  RESULTS
  Blood samples were obtained from 24 individuals. OCT reflectivity was 30.68 ± 14.8 AU (average ± SD), ranging from 11.11 to 60.31 AU. OCT reflectivity correlated significantly with the concentration of triglycerides (R = 0.634, p = 0.001) and total cholesterol (R = 0.488, p = 0.015) using Spearman's rank correlation coefficient. While a partial correlation analysis showed that it correlated significantly with triglyceride (R = 0.60, p = 0.003), but not total cholesterol. OCT reflectivity was highest in a balanced salt solution (BSS) with Hb (average 42.05 AU), followed by fibrinogen (8.08 AU), bilirubin (6.12 AU) and γ-globulin (2.85 AU). Albumin did not increase the reflectivity of the BSS with a normal concentration (1.11 AU) compared to the control BSS alone (0.73 AU).
  
  
  CONCLUSIONS
  OCT reflectivity was most strongly affected by the presence of triglycerides among the blood components. Some molecules such as Hb and fibrinogen significantly increase the OCT reflectivity. This information should be helpful for interpreting the OCT findings correctly.
authors.affiliation: Department of Ophthalmology, Kagoshima University Graduate School of Medical and Dental Sciences , Sakuragaoka, Kagoshima , Japan.
authors.forename: Shozo
authors.initials: S
authors.lastname: Sonoda
authors.forename: Taiji
authors.initials: T
authors.lastname: Sakamoto
authors.forename: Makoto
authors.initials: M
authors.lastname: Shirasawa
authors.forename: Takehiro
authors.initials: T
authors.lastname: Yamashita
authors.forename: Eisuke
authors.initials: E
authors.lastname: Uchino
authors.forename: Hiroto
authors.initials: H
authors.lastname: Terasaki
mesh_terms: D000085:Acetates; D000328:Adult; D000818:Animals; D000867:Anterior Chamber / Q000473:pathology*; D001082:Aqueous Humor; D001663:Bilirubin / Q000378:metabolism; D001772:Blood Cell Count; D001798:Blood Proteins / Q000378:metabolism*; D004195:Disease Models, Animal; D004338:Drug Combinations; D005260:Female; D005340:Fibrinogen / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D008903:Minerals; D010949:Plasma; D012965:Sodium Chloride; D058471:Subretinal Fluid; D013552:Swine; D041623:Tomography, Optical Coherence / Q000379:methods*; D014280:Triglycerides / Q000378:metabolism
chemical_list: D000085:Acetates; C030660:BSS solution; D001798:Blood Proteins; D004338:Drug Combinations; D008903:Minerals; D014280:Triglycerides; D012965:Sodium Chloride; D005340:Fibrinogen; D001663:Bilirubin
keywords: Cyst: subretinal fluid; diabetic retinopathy; optical coherence tomography; serous retinal detachment