title: Ophthalmic Evaluation in Beta-Thalassemia.
abstract: OBJECTIVE
  To determine the association of ocular manifestations in beta-thalassemia with the patient's age, blood transfusion requirements, average serum ferritin and dose and duration of iron chelation therapy.
  
  
  METHODS
  Sixty multi-transfused beta thalassemia patients of 12 to 18 y of age on chelation therapy were included in this cross-sectional analysis. Structural and functional evaluation of the retina was done using Optical coherence tomography (OCT) and Electroretinography (ERG), including flash ERG and Pattern ERG (PERG). Routine ophthalmic examination and B scan of the eye was also done. Flash ERG a-waves and b-waves were recorded, however only a-wave amplitude was evaluated. Pattern ERG n35, n95 and p50 waves were recorded and p50 wave amplitude was evaluated. The a-wave on flash and p50 on pattern waves represent retinal photoreceptor epithelium (RPE) photoreceptor response, which is mainly affected in beta-thalassemia.
  
  
  RESULTS
  Ocular changes were detected in 38.3% and a significant correlation was noted with increase in age (p = 0.045) but not with serum ferritin, transfusion requirements or chelation therapy. Refractive errors were found in 14 cases (23%), such as myopia with astigmatism in 13 (21.7%) and only myopia in 6 subjects (10%). OCT abnormality was noted in 1 patient (1.7%) who had thinning of central retina; right eye 132 μm and left eye 146 μm (n > 200 μm). Abnormalities were noted in a-wave amplitude on flash ERG in 20% of cases, while reduced p50 amplitude on PERG was noted in 15%.
  
  
  CONCLUSIONS
  A significant correlation was noted between ocular findings and increase in age, but not with serum ferritin, transfusion requirements or chelation therapy. ERG appears to be a promising tool for screening patients with beta-thalassemia and can serve as a follow-up test for evaluating retinal function.
authors.affiliation: Department of Pediatrics, Nanavati Super-Speciality Hospital, Vile Parle (West), Mumbai, Maharashtra, 400056, India. deandoc2000@hotmail.com.
authors.forename: Rashid H
authors.initials: RH
authors.lastname: Merchant
authors.affiliation: Department of Pediatrics, Nanavati Super-Speciality Hospital, Vile Parle (West), Mumbai, Maharashtra, 400056, India.
authors.forename: Hrishikesh
authors.initials: H
authors.lastname: Punde
authors.affiliation: Department of Ophthalmology, Nanavati Super-Speciality Hospital, Mumbai, Maharashtra, India.
authors.forename: Neepa
authors.initials: N
authors.lastname: Thacker
authors.affiliation: U B M Institute, Mumbai, Maharashtra, India.
authors.forename: Deepak
authors.initials: D
authors.lastname: Bhatt
mesh_terms: D000293:Adolescent; D002648:Child; D004596:Electroretinography; D005260:Female; D006801:Humans; D008297:Male; D012164:Retinal Diseases / Q000209:etiology*; D041623:Tomography, Optical Coherence; D017086:beta-Thalassemia / Q000150:complications*
keywords: Beta-thalassemia; Electroretinography; Optical coherence tomography