Indian Journal of Ophthalmology

ARTICLES
Year
: 1977  |  Volume : 25  |  Issue : 2  |  Page : 5-

Oguchi's disease and night blindness


B Manohar Rao 
 Kasturba Medical College, Mangalore, India

Correspondence Address:
B Manohar Rao
Department of Ophthalmology, Kasturba Medical College, Mangalore
India




How to cite this article:
Rao B M. Oguchi's disease and night blindness.Indian J Ophthalmol 1977;25:5-5


How to cite this URL:
Rao B M. Oguchi's disease and night blindness. Indian J Ophthalmol [serial online] 1977 [cited 2021 Jun 21 ];25:5-5
Available from: https://www.ijo.in/text.asp?1977/25/2/5/31248


Full Text

Oguchi's disease is a very rare condition in India. A case of this disease is presented in this paper.

 Case Report



Miss M. a resident of Derebail, Mangalore, aged 20 years visited the Eye Department of Government Wenlok Hospital, Mangalore, complaining of night blindness of two years duration. No history of consanguinity of marriages or night blindness in the family. Past history does not reveal anything significant excepting for not being sure of noticing night blindness since birth, Her mother stresses that she used to `bump' into objects at night during her childhood.

On Examination: Systemic and ophthalmic (external) did not reveal any abnormality. Vision was normal (6/6) in both eyes. Fields were within normal limits.

Fundus Examination: On ophthalmoscopic examina­tion of fundi after dilating the pupils with Drosyn (Phenylephrine) 10% eye drops, revealed: Optic discs were normal. There was greyish-white discolouration of the fundus in which the vessels stand out sharply. There was little distinction between arteries and veins­both being absolutely dark in contrast to the greyish­white fundus colour. The patient was made to sit in the dark room. In an hour's duration it was noted that the fundus colour was entirely replaced by the normal red colour (Mizuo's phenomenon).

This case was diagnosed as a case of Oguchi's disease on two cardinal features--Fundus picture of greyish-white colour and positive Mitzuo's pheno­menon.

 Discussion



Majority of cases occur in Japan and are usually the result of consanguinous marriages.

Only 35 cases have been reported from outside Japan. About 20 cases have been reported in the literature as occurring among non-Japanese Four cases have been reported in our country[2] although many might have been seen. A case seen in Mangalore is presented.

This disease, a recessive hereditary form of night blindness with ophthalmoscopic and microscopic abnormality of the retina, was described by Oguchi[1] in 1921 The retina shows an anomalous distribution of the cones and an interposed layer between the pigment epithelium and the rods and cones (which may be responsible for the greyish fund us appearan­ce)[3] It is interesting to note Mizuo's pheno­menon mentioned above, is usually accompanied by an increase in the visual acuity so that there is not so much night blindness as an excessi­vely slow dark adaptation-atavistic in nature, similar to that obtained in certain species be­low the mammals.

(I thank Prof. P. Narayana Rao, Head of the Ophthalmology Department and Dr. C. R. Kamath, Asst. Prof. for their kind co-operation and help in prepairing this paper)

References

1A. J. Ballantyne and Issac C. Michaelson, 1970, The fundus of the Eye.
2Dhanwant Singh and Daljit Singh 1969, Jour. Of All India Ophthal. Soc. 17, 222-5.
3Patrick D. and Trevor Roper 1974, The eye and its disorders.