title: Electrophysiological assessment for early detection of retinal dysfunction in β-thalassemia major patients.
abstract: OBJECTIVE
  The purpose of this study was to assess the role of various diagnostic tests in early detection of retinal changes in β-thalassemia major patients.
  
  
  METHODS
  Thirty-eight visually asymptomatic β-thalassemia major patients receiving regular blood transfusions and iron-chelation therapy with deferoxamine (group A, n = 13), deferasirox (group B, n = 11) or deferoxamine with deferiprone (group C, n = 14) and fourteen age- and sex- matched healthy individuals were included in the study. All participants underwent ophthalmoscopy, full-field electroretinography (ERG), visual evoked potentials (VEP), multifocal electroretinography (mfERG), fundus autofluorescence (FAF) imaging and optical coherence tomography (OCT) scans.
  
  
  RESULTS
  Retinal pigment epithelium changes were present in two cases. Scotopic ERG demonstrated decreased a-wave amplitude in groups A, B and C (p = 0.03, p = 0.002 and p = 0.002, respectively) and decreased b-wave amplitude in groups B and C (p = 0.002 and p = 0.01, respectively) compared to controls. Photopic ERG showed delayed b-wave latency in groups A and C (p = 0.03 and p = 0.03, respectively) ERG maximal combined response and VEP response did not differ between groups. MfERG showed reduced retinal response density in ring 1 in groups A, B, C (p < 0.001, p < 0.001, p = 0.001, respectively) and ring 2 in group B (p = 0.02) and delayed latency in ring 5 in groups A and B (p = 0.04 and p = 0.04, respectively). Abnormal FAF images appeared in three cases and OCT abnormalities in one case, whereas no changes were observed in controls (p = 0.55 and p = 1.00, respectively).
  
  
  CONCLUSIONS
  Full-field ERG and mfERG are more sensitive tools for detecting early retinal changes in β-thalassemia patients compared with ophthalmoscopy, VEP, FAF imaging and OCT scans.
authors.affiliation: First Department of Ophthalmology, "G. Gennimatas" General Hospital, Medical School, National and Kapodistrian University of Athens, 154 Mesogion Avenue, Athens, 11527, Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Dettoraki
authors.affiliation: Thalassemia Unit, First Department of Pediatrics, Aghia Sofia Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Antonis
authors.initials: A
authors.lastname: Kattamis
authors.affiliation: First Department of Ophthalmology, "G. Gennimatas" General Hospital, Medical School, National and Kapodistrian University of Athens, 154 Mesogion Avenue, Athens, 11527, Greece.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Ladas
authors.affiliation: Thalassemia Unit, "Hippocratio" General Hospital, Athens, Greece.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Maragkos
authors.affiliation: First Department of Ophthalmology, "G. Gennimatas" General Hospital, Medical School, National and Kapodistrian University of Athens, 154 Mesogion Avenue, Athens, 11527, Greece.
authors.forename: Chryssanthi
authors.initials: C
authors.lastname: Koutsandrea
authors.affiliation: First Department of Ophthalmology, "G. Gennimatas" General Hospital, Medical School, National and Kapodistrian University of Athens, 154 Mesogion Avenue, Athens, 11527, Greece.
authors.forename: Klio
authors.initials: K
authors.lastname: Chatzistefanou
authors.affiliation: Department of History of Medicine, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Laios
authors.affiliation: First Department of Ophthalmology, "G. Gennimatas" General Hospital, Medical School, National and Kapodistrian University of Athens, 154 Mesogion Avenue, Athens, 11527, Greece.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Brouzas
authors.affiliation: First Department of Ophthalmology, "G. Gennimatas" General Hospital, Medical School, National and Kapodistrian University of Athens, 154 Mesogion Avenue, Athens, 11527, Greece. moschosmarilita@yahoo.fr.
authors.forename: Marilita M
authors.initials: MM
authors.lastname: Moschos
mesh_terms: D000328:Adult; D042241:Early Diagnosis; D004596:Electroretinography / Q000379:methods*; D005074:Evoked Potentials, Visual; D005260:Female; D005451:Fluorescein Angiography; D005654:Fundus Oculi; D006801:Humans; D008297:Male; D008875:Middle Aged; D009887:Ophthalmoscopy; D012160:Retina / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012164:Retinal Diseases / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D041623:Tomography, Optical Coherence; D014792:Visual Acuity; D017086:beta-Thalassemia / Q000150:complications*
keywords: Beta thalassemia major; Chelation therapy; Electroretinography; Retinal toxicity