Journal of Postgraduate Medicine
 Open access journal indexed with Index Medicus & ISI's SCI  
Users online: 373  
Home | Subscribe | Feedback | Login 
About Latest Articles Back-Issues Article Submission Resources Sections Etcetera Contact
 
  NAVIGATE Here 
  Search
 
 :: Next article
 :: Previous article 
 :: Table of Contents
  
 RESOURCE Links
 ::  Similar in PUBMED
 ::  Search Pubmed for
 ::  Search in Google Scholar for
 ::  Article in PDF (158 KB)
 ::  Citation Manager
 ::  Access Statistics
 ::  Reader Comments
 ::  Email Alert *
 ::  Add to My List *
* Registration required (free) 

  IN THIS Article
   Discussion
   References
   Article Figures

 Article Access Statistics
    Viewed7033    
    Printed167    
    Emailed5    
    PDF Downloaded221    
    Comments [Add]    

Recommend this journal


 


 
IMAGES IN MEDICINE
Year : 2006  |  Volume : 52  |  Issue : 2  |  Page : 143-144

Oguchi disease


Department of Ophthalmology, Sri Ramachandra Medical College and Research Institute, (A Harvard Medical International affiliated institution), Chennai - 600 089, India

Correspondence Address:
Priyanka P Doctor
Department of Ophthalmology, Sri Ramachandra Medical College and Research Institute, (A Harvard Medical International affiliated institution), Chennai - 600 089
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


PMID: 16679684

Rights and PermissionsRights and Permissions




How to cite this article:
Kalpana S, Muthayya M, Doctor PP. Oguchi disease. J Postgrad Med 2006;52:143-4

How to cite this URL:
Kalpana S, Muthayya M, Doctor PP. Oguchi disease. J Postgrad Med [serial online] 2006 [cited 2019 Jun 16];52:143-4. Available from: http://www.jpgmonline.com/text.asp?2006/52/2/143/25165


A 9-year-old healthy boy was brought by his mother for non-progressive defective vision in the evenings in both eyes of four years duration. His day-time vision was normal. He did not give history of trauma, previous ocular or systemic disease. His father has similar history of defective night vision. He was born of second-degree consanguinity and other two siblings were normal. In both eyes, uncorrected visual acuity was 6/6, N6. Slit lamp examination of anterior segment was normal. Color vision & field of vision (Octopus static white on white perimetry) were normal in both eyes. Fundus examination of both eyes revealed a patchy grayish metallic phosphorescent sheen. Optic disc, macula, retinal vessels were normal. When the boy was subjected to dark adaptation for 3 hours, the fundus background colour changed from gray to red. (Mizuo Nakamura phenomenon) [Figure - 1][Figure - 2][Figure - 3][Figure - 4].

The ERG response, schematically illustrated in [Figure - 5], consists of an initial negative wave, the a-wave, followed by a second positive wave, the b-wave. The a-wave is derived from the retinal photoreceptors: the rods and cones. It was originally thought that the Müller cells produced the b-wave, but more recent findings suggest that the b-wave is actually a result of bipolar cell activity. Since the nucleus of the Müller cell resides within the bipolar cell layer, this response is therefore indicative of changes occurring in that particular layer. There is no contribution to the ERG from the retinal ganglion cells. ERG of our patient showed a rod/ max combined/ Oscillatory Potentials (OPs) response, in which the b wave amplitude was diminished in both eyes [Figure - 6]. The Cone ERG was normal in both eyes [Figure - 7].

Examination of the patient's mother & other two siblings were unremarkable. His father could not be examined as he was a convict under custody.


  Discussion Top


Oguchi's disease, first described by Chuta Oguchi in 1907, is a rare autosomal recessive disorder characterized by congenital stationary night blindness and a unique morphological and functional abnormality of the retina. Patients have non-progressive night blindness since young childhood with normal day vision, but often report improvement of light sensitivities when they remain long in the dark environment; dark-adaptation study demonstrates that highly elevated rod thresholds decrease several hours later and eventually result in a recovery to the normal or nearly normal level. The fundus has a diffuse or patchy appearance, silver-gray or golden-yellow metallic sheen and the retinal vessels stand out in relief against the radiant background. A prolonged dark adaptation of three hours or more, leads to disappearance of the unusual discoloration of the normal reddish appearance, called Mizuo-Nakamura phenomenon.[1] Oguchi's disease is also unique in the electroretinographic responses in the light- and dark-adapted condition. B wave amplitude is reduced in rod response and cone response is normal.[2] Recent identification of the arrestin gene mutation[3],[4] in chromosome 2q[5] in patients with Oguchi's disease may account for the characteristic fundus and functional abnormality. As rhodopsin kinase works with arrestin in shutting off rhodopsin after it has been activated by a photon of light, it has been proposed that some cases of Oguchi disease are due to defects in rhodopsin kinase.[6]

In our patient, the classical Mizuo phenomenon was present and the fundus discolouration returned to normal with dark adaptation. The differential diagnosis includes Stargardts disease, female carrier of retinitis pigmentosa, juvenile retinoschisis, progressive cone dystrophy. All these conditions may have fundus changes but without the classical Mizuo phenomenon. In ERG both rod and cone abnormalities are found.

This rare disease is more commonly encountered in Japan and is presented in view of its novelty.

 
  References Top

1.Usui T, Ichibe M, Ueki S, Takagi M, Hasegawa S, Abe H, et al . Mizuo phenomenon observed by scanning laser ophthalmoscopy in a patient with Oguchi disease. Am J Ophthalmol 2000;130:359-61.  Back to cited text no. 1    
2.Yamamoto S, Hayashi M, Takeuchi S, Shirao Y, Kita K, Kawasaki K. Normal S cone electroretinogram b-wave in Oguchi's disease. Br J Ophthalmol 1997;81:1043-5.   Back to cited text no. 2  [PUBMED]  [FULLTEXT]
3.Palczewski K, Rispoli G, Detwiler PB. The influence of arrestin (48K protein) and rhodopsin kinase on visual transduction. Neuron 1992;8:117-26.  Back to cited text no. 3    
4.Maw M, Kumaramanickavel G, Kar B, John S, Bridges R, Denton M. Two Indian siblings with Oguchi disease are homozygous for an arrestin mutation encoding premature termination. Hum Mutat 1998;1:S317-9.  Back to cited text no. 4    
5.Maw MA, John S, Jablonka S, Muller B, Kumaramanickavel G, Oehlmann R, et al . Oguchi disease: suggestion of linkage to markers on chromosome 2q. J Med Genet 1995;32:396-8.  Back to cited text no. 5    
6.Yamamoto S, Sippel KC, Berson EL, Dryja TP. Defects in the rhodopsin kinase gene in the Oguchi form of stationary night blindness. Nat Genet 1997;15:175-8.  Back to cited text no. 6    


    Figures

[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4], [Figure - 5], [Figure - 6], [Figure - 7]



 

Top
Print this article  Email this article
Previous article Next article
Online since 12th February '04
© 2004 - Journal of Postgraduate Medicine
Official Publication of the Staff Society of the Seth GS Medical College and KEM Hospital, Mumbai, India
Published by Wolters Kluwer - Medknow