title: Potential of handheld optical coherence tomography to determine cause of infantile nystagmus in children by using foveal morphology.
abstract: OBJECTIVE
  To investigate the feasibility of handheld (HH) ultra-high-resolution spectral-domain optical coherence tomography (SD-OCT) in young children with nystagmus, to determine its sensitivity and specificity in classifying foveal abnormalities, and to investigate its potential to determine the cause of infantile nystagmus with the use of foveal morphology.
  
  
  METHODS
  Prospective, case-control study.
  
  
  METHODS
  A total of 50 patients with nystagmus and 50 healthy control subjects (mean age, 3.2 years; range, 0-8 years).
  
  
  METHODS
  Each patient was scanned using HH SD-OCT (Bioptigen Inc., Research Triangle Park, NC) without sedation, and foveal morphology was classified into 1 of 4 categories: (1) typical foveal hypoplasia (predicting clinical diagnosis of albinism, PAX6 mutations, or isolated foveal hypoplasia); (2) atypical foveal hypoplasia (predicting achromatopsia); (3) other foveal changes (corresponding to retinal dystrophies); and (4) normal fovea (predicting idiopathic or manifest latent nystagmus). An independent interpretation of the HH SD-OCT scans by masked examiners was performed, and the sensitivity and specificity of the predicted diagnosis were calculated.
  
  
  METHODS
  The success rate of image acquisition and sensitivity and specificity of the HH SD-OCT in classifying foveal abnormalities.
  
  
  RESULTS
  In 94% of examinations, HH SD-OCT was successful. Twenty-three patients had typical foveal hypoplasia (category 1). Of these patients, 21 were diagnosed with albinism and 2 were diagnosed with PAX6 mutations. Five patients were classified as atypical (category 2) and diagnosed with achromatopsia. Six patients had other abnormal foveal morphology (category 3) and were diagnosed with retinal dystrophy. Sixteen patients had normal foveal morphology (category 4). Of these patients, 12 were diagnosed with idiopathic nystagmus and 4 were diagnosed with manifest latent nystagmus. Sensitivities of HH SD-OCT for classifying typical or atypical foveal hypoplasia, other abnormal foveal morphology, and normal morphology were 92.8%, 86.7%, 41.1%, and 88.4%, respectively, with specificities of 91.4%, 94.8%, 97.7% and 95.1%, respectively.
  
  
  CONCLUSIONS
  We demonstrate excellent feasibility of HH SD-OCT in the diagnosis of conditions associated with infantile nystagmus. The HH SD-OCT classification of foveal abnormalities was highly sensitive and specific. This classification was used to determine the underlying cause of infantile nystagmus. Handheld SD-OCT in early childhood can facilitate focused investigations and earlier diagnosis. This is important in an era when potentially time-sensitive treatment, such as gene therapy, is imminent.
authors.affiliation: Ophthalmology Group, University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom.
authors.forename: Helena
authors.initials: H
authors.lastname: Lee
authors.affiliation: Ophthalmology Group, University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom.
authors.forename: Viral
authors.initials: V
authors.lastname: Sheth
authors.affiliation: Ophthalmology Group, University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom.
authors.forename: Mashal
authors.initials: M
authors.lastname: Bibi
authors.affiliation: Ophthalmology Group, University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom.
authors.forename: Gail
authors.initials: G
authors.lastname: Maconachie
authors.affiliation: Ophthalmology Group, University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom.
authors.forename: Aarti
authors.initials: A
authors.lastname: Patel
authors.affiliation: Ophthalmology Group, University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom.
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: McLean
authors.affiliation: The UCL Institute of Ophthalmology and Moorfields Eye Hospital, London, United Kingdom.
authors.forename: Michel
authors.initials: M
authors.lastname: Michaelides
authors.affiliation: Ophthalmology Group, University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom.
authors.forename: Mervyn G
authors.initials: MG
authors.lastname: Thomas
authors.affiliation: Ophthalmology Group, University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom.
authors.forename: Frank A
authors.initials: FA
authors.lastname: Proudlock
authors.affiliation: Ophthalmology Group, University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom. Electronic address: ig15@leicester.ac.uk.
authors.forename: Irene
authors.initials: I
authors.lastname: Gottlob
mesh_terms: D016117:Albinism, Ocular / Q000175:diagnosis; D015783:Aniridia / Q000175:diagnosis / Q000235:genetics; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003117:Color Vision Defects / Q000175:diagnosis; D005124:Eye Abnormalities / Q000145:classification* / Q000175:diagnosis; D005136:Eye Proteins / Q000235:genetics; D005240:Feasibility Studies; D005584:Fovea Centralis / Q000002:abnormalities*; D018398:Homeodomain Proteins / Q000235:genetics; D006801:Humans; D007223:Infant; D020417:Nystagmus, Congenital / Q000175:diagnosis / Q000209:etiology*; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors / Q000235:genetics; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012097:Repressor Proteins / Q000235:genetics; D012680:Sensitivity and Specificity; D041623:Tomography, Optical Coherence / Q000295:instrumentation*
chemical_list: D005136:Eye Proteins; D018398:Homeodomain Proteins; D000071841:PAX6 Transcription Factor; C000605730:PAX6 protein, human; D051761:Paired Box Transcription Factors; D012097:Repressor Proteins