title: Effects of GH/IGF-I Axis on Retinal Vascular Morphology: Retinal Vascular Characteristics in a Clinical Setting with Severe IGF-I Deficiency.
abstract: BACKGROUND
  The purpose of this study was to assess retinal vascular characteristics of patients with Laron syndrome (LS) as a genetic model of IGF-I deficiency before and after rhIGF1/IGFBP3 treatment and to compare them with healthy controls.
  
  
  METHODS
  A total of 28 subjects (11 LS, and 17 controls) were enrolled. Patients with LS received combined rhIGF1/rhIGFBP3 1-2 mg/kg/d in a single dose and digital fundus imaging was performed. The number of branching points and tortuosity of retinal vessels were studied. Pre- and post-treatment findings were compared with each other and with controls.
  
  
  RESULTS
  The number of branching points was significantly lower in patients with LS in comparison to controls (12.73 ± 3.41, and 17.47 ± 5.82 respectively, p = 0.012). This difference persisted after treatment (12.09 ± 2.66 post-treatment LS versus controls, p = 0.017). Tortuosity indices of nasal arteries (NA) were significantly less in LS than that of controls (upper NA 1.07 ± 0.04 and 1.12 ± 0.06 respectively p = 0.022; lower NA 1.07 ± 0.03 and 1.13 ± 0.07 respectively, p = 0.004). This difference also persisted following treatment (p < 0.05). Remaining vessels did not differ in tortuosity index. There was no significant difference of tortuosity index and number of branching points before and after treatment in patients with LS.
  
  
  CONCLUSIONS
  Retinal vascular development may be adversely affected in the setting of severe IGF-I deficiency confirming a major role for GH/IGF-I axis during retinal vascular development in humans antenatally. Resolution of IGF-I deficiency following birth using rhIGF1, however, may not reverse these changes, suggesting that IGF-I may be necessary but insufficient by itself for postnatal angiogenesis.
authors: a Departments of Ophthalmology .
authors: Hande Taylan
authors: HT
authors: Sekeroglu
authors: a Departments of Ophthalmology .
authors: Sibel
authors: S
authors: Kadayıfcılar
authors: a Departments of Ophthalmology .
authors: Burcu
authors: B
authors: Kasım
authors: b Biostatistics , and.
authors: Umut
authors: U
authors: Arslan
authors: c Pediatric Endocrinology, Faculty of Medicine, Hacettepe University , Ankara , Turkey.
authors: Alev
authors: A
authors: Ozon
mesh_terms: D002648:Child; D004338:Drug Combinations; D005260:Female; D006130:Growth Disorders / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology*; D013006:Growth Hormone / Q000502:physiology*; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology*; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000627:therapeutic use; D007334:Insulin-Like Growth Factor I / Q000172:deficiency* / Q000502:physiology* / Q000627:therapeutic use; D046150:Laron Syndrome / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology*; D008297:Male; D012164:Retinal Diseases / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology*; D012171:Retinal Vessels / Q000473:pathology*; D014792:Visual Acuity / Q000502:physiology
chemical_list: D004338:Drug Combinations; C543394:IGF-I-IGFBP-3 complex; D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone
keywords: Growth hormone; Laron; insulin like growth factor; insulin like growth factor binding protein; retinal vascularization