|Year : 1988 | Volume
| Issue : 1 | Page : 44-45
Situs inversus of the optic disc
Saurendra Chandra Sen, Partha Bhattacharya, Pradyot Narayan Biswas
Regional Institute of Ophthalmology, Medical College, Calcutta-700 073, India
Saurendra Chandra Sen
Regional Institute of Ophthalmology, Medical College, Calcutta-700 073
Source of Support: None, Conflict of Interest: None
A case of bilateral sites inversus of the optic disc, presenting with marked impairment of vision due to associated optic neuritis in one eve has been reported.
|How to cite this article:|
Sen SC, Bhattacharya P, Biswas PN. Situs inversus of the optic disc. Indian J Ophthalmol 1988;36:44-5
| Introduction|| |
Situs inversus or inversion of optic disc is a rare developmental anomaly, where the central retinal blood vessels emerge and go towards the nasal side, instead of the temporal side. It was first reported by Fuchs  in 1882. Since then only a few cases have been reported ,,,. A case of bilateral situs inversus of the optic disc with an episode of optic neuritis in one eye is being reported.
| Case report|| |
Mrs. U. B., 40 years old, resident of a remote village of West Bengal, attended the out patient department of our institute on 11.3.85 with a complaint of marked impairment of vision in the right eye of about two weeks, which was associated with headache and vertigo. The patient was afebrile and there was no history of injury or any significant past illness.
On examination, the pupil of the right eye was slightly dilated, there was lack of sustained constriction of pupil to light but consensual light reflex in that eye was normal Ocular tenderness, a characteristic feature in the initial stage of optic neuritis, was not present Vision was counting fingers at 2 feet not improving with glasses. Retinoscopy showed compound hypermetropic astigmatism. Ocular media were clear. Ophthalmoscopical examination revealed blurring of the optic disc margin with engorgement of retinal veins. Retinal vessels emerged on the nasal side of the optic disc The temporal branches first passed towards the nasal side and then arched towards the temporal side. Macula was pigmented, with a somewhat 'salt and pepper' appearance [Figure - 1]a. Foveal reflex was absent There was nothing abnormal externally in the left eye. Maximum corrected vision was 6/9 part Compound hypermetropic astigmatism (+0.50 Dsph with +1.00 D. CyL-165°). Optic disc was healthy. Retinal vessels emerged and coursed similarly like those of right eye [Figure - 1]b. Field of vision (tested with 5 mm white object) showed concentric contraction of field in the right eye. Field of vision was normal in the left eye. Colour vision tested with Ishihara Chart showed no abnormality in either eye.
Systemic examination did not reveal any abnormality.
Blood: Hb - 62%, W.B.C. - 11,500/cmm, Neutrophils42% Lymphocytes - 31 %, Eosinophils - 27%, R S. R - 34 mm/ 1 st hour.
Mantoux test 1 in 10,000 dil - positive (Induration 21 mm).
As there was clinical evidence of optic neuritis on the right side, the patient was treated with a course of Tab. Prednisolone in tapering doses for a period of 3 weeks, along with injection Vit BI '+B12 + B6 LM. on alternate days.
After3 weeks vision corrected with glasses (+0.50 Dsph with + 1.50 D. Cyl-15°) in the right eye was 6/36. There was no improvement in the field of vision. The patient was followed up for about one year, but there was no further improvement in visual acuity in right eye.
| Discussion|| |
This was a case a bilateral situs inversus of the optic disc, associated with optic neuritis on the right side. This inflammatory episode, which was not related to the developmental anomaly, improved to some extent probably due to a course of oral cortiosteroids. Increased eosinophil count and raised sedimentation rate of blood were probably due to some co-incidental chronic systemic infection. As the condition of the right eye improved with a course of oral corticosteroid, no further investigations were done.
A tilting of the insertion of the primitive optic stalk to the secondary optic vesicle generally results in congenital crescents or conus usually on the inferior side, but in some cases, this phenomenon of tilting of the primitive optic stalk gives rise to situs inversus of the optic disc This condition has also been named as dysversion of the optic nerve head by Rucker .
In our case, there was no cresent Defective vision with various types of field defects are usually present due to atrophic changes in the retina. 'Salt and Pepper' appearance was noted in the retina in right eye.
The defective vision may also be due to the associated refractive error, commonly myopic astigmatism due to anomalous curvature of the posterior segment . In our case refractive error was compound hypermetropic astigmatism of moderate degree in both eyes.
Sometimes situs inversus of optic disc maybe associated with other anomalies. Fishman et a1  reported familial incidence of situs inversus of the optic disc associated with divergent strabismus and dextrocardia Gupta et a1  reported presence of cilioretinal arteries along with situs inversus of the optic disc. In our case no other abnormality except 'Salt and Pepper' appearance in the fundus oculus of the right eye was detected.
| References|| |
Fuchs, 882 - Duke Elder, S. System of Ophthalmology., Vol III, Part 2, 677, Henry Kimpton, London, 1964.
Rucker, 1946 - Duke Elder, S. System of Ophthalmology, Vol III, Part 2, 678, Henry Kimpton, London, 1964.
G.P. Gupta & Hamida Saiduzzafar, - Proc All India Ophthalmol. Soc Vol XXIII, 198, 1966.
Fishman et al- Am. J. Medical Science, 271, 225-232, 1976.
Quevillon, A; Bronillette, G & Aube, M- Canadian J. Ophthalmol,, Vol 12, 261-264, 1977.
[Figure - 1]