|Year : 1969 | Volume
| Issue : 3 | Page : 117-119
Bilateral multiple congenital pits in the optic disc with opaque nervefibres and maculopathy
S.R.K Malik, AK Gupta, G Singh
Department of Ophthalmology, Maulana Azad Medical College, New Delhi, India
Department of Ophthalmology, Maulana Azad Medical College, New Delhi
|How to cite this article:|
Malik S, Gupta A K, Singh G. Bilateral multiple congenital pits in the optic disc with opaque nervefibres and maculopathy. Indian J Ophthalmol 1969;17:117-9
|How to cite this URL:|
Malik S, Gupta A K, Singh G. Bilateral multiple congenital pits in the optic disc with opaque nervefibres and maculopathy. Indian J Ophthalmol [serial online] 1969 [cited 2013 May 24];17:117-9. Available from: http://www.ijo.in/text.asp?1969/17/3/117/38526
Congenital pits of the optic disc were first described by Weithe in 1882. Greear  reviewed from the literature 70 such cases and added three cases of his own. Kranenburg  reported 24 cases, 30 per cent of which showed an associated picture of central serous retinopathy; 20 per cent of the cases showed evidence of old central serous retinopathy. Sugar  reported central sercus retinopathy in two cases out of a total of six cases of congenital pits of the optic disc. Majority of the cases reported in the literature are unilateral.
The present case reported in this paper is of interest as the condition was bilateral associated with maculopathy and opaque nerve fibres-an association not so far reported in the literature
| Case Report|| |
Mrs. D. aged 30 years attended the eye cut patient department of Irwin Hospital, New Delhi for routine refraction check up. On examination no significant abnormality was observed in general examination. Ophthalmic examination of the anterior segment did not reveal any abnormality. Visual acuity of the patient in both eyes was O.D. 6/12 and O.S. 6, 9 with a correction of + 0.50 D/+0.50 D cyl. 180°. Examination of the right fundus revealed three pits on the optic disc one on the temporal side and two on the nasal side The size of the pits varied from 1/8th to 1/5th diameter of the disc. The macular area showed shiny deposits along with moderate pigment mottling. Opaque nerve fibres were present all round the disc. [Figure - 1].
Examination of the left eye fundus revealed two pits on the disc--one on the temporal and the other on the nasal side. Macular changes were similar to those in the right eve though less pronounced. There was a small patch of opaque nerve fibres along the inferior margin of the disc [Figure - 2]. Central field examination revealed enlargement of the blind spot in both the eyes.
| Discussion|| |
The characteristic pits of the disc are usually single and located within the margin of the disc in the inferior temporal quadrant Greear,  Kranenburg,  and Sugar,  Rarely, however, more than one pit upto a maximum of four have been described. Van der Hoeve  described three separate pits while Vauthier and Zanen  noted four separate pits on the optic disc of one case. Pits of the optic disc are usually unilateral. Pathologically, it is believed that the disc optic pits are formed by dipping down of rudimentary retinal tissue into the intermediary tissue of the optic disc near the point of junction of the lamina cribrosa with the scleral promontory. This rudimentary retinal tissue extends towards the vaginal space and comes to lie into the neural aspect. What factors promote the ingrowth of the retinal tissue in the area of the optic disc is not clear. We feel that the primary defect may be in the lamina cribrosa. The weakness or the absence of lamina cribrosa allows the migration of retinal tissue into the optic disc. This hypothesis is supported by the fact that defects in the lamina cribrosa have been demonstrated on histopathological examination of optic disc pits.
Presence of opaque nerve fibres in both the eyes is of great significance if we try to correlate the pathogenesis of optic disc pits and opaque nerve fibres. In human beings, medullation of the nerve fibres stops short at the level of the lamina cribrosa. In certain animals e.g. rabbits, where lamina cribrosa is normally absent, opaque nerve fibres are also seen as a normal feature. Everbusch  (hypothesized that even in human-beings the presence of medullated nerve fibres could be the result of a defect in the lamina cribrosa. We have already pointed out that the essential pathogenetic factor even for optic nerve pits is the defect in the lamina cribrosa. The presence of opaque nerve fibres in our case is, therefore, not merely a coincidence but a manifestation of a common pathogenetic factor i.e. the defect in the lamina cribrosa.
Presence of macular pathology was another interesting feature of our case. Different workers have reported varied types of macular pathology in association with the pits of the optic disc - oedema. haemorrhages, cyst or macular hole. The cause of these degenerative lesions of the macula is disputed. Kranenburg  explained it as a defensive tissue response in the macular area which, due to the papillomacular bundle involvement, has lowered resistance to seemingly slight noxious agent. Sugar  however, considered the lesion to be mechanical in nature due to the actual seepage of the intraocular fluid into the pit and then transmitted to the papillomacular bundle. In our opinion the macular pathology is due to the congestion of the papillomacular fibres, into a comparatively smaller available area which results in disturbance of circulation in small blood vessels leading to anoxia and macular degeneration. The same pathogenesis can explain the occurrence of sector shaped field defects sometimes reported in these cases.
Analysis of the whole case, therefore, reveals that the most significant pathological factor is the defect in the lamina cribrosa This defect is responsible for the crater as well as the medullation of the nerve fibres. The macular pathology has been explained on the basis of disturbance of blood circulation due to mechanical reasons.
| Summary|| |
A case of bilateral multiple pits of the optic disc with opaque nerve fibres and macular degeneration has been reported. Association of opaque nerve fibres with optic disc pits has been explained on the basis of a common pathological feature i.e. the defect in the lamina cribrosa. Macular pathology is the result of embarrassed blood circulation of vessels supplying the papillomacular bundle due to mechanical factors.
| References|| |
|1.||Duke Elder, W. S. (19(34) System of ophthalmology. Pub. Henry Kirnpton, London. Vol. III, 648, 678. |
|2.||Everbusch (1885) Klin MBL Augenheilk, 21, 1. as cited by Duke-Elder in. 1. |
|3.||Greear, J. N. (1942) Arch. Ophthal. (Chicago) 28, 467. |
|4.||Kranenburg, E. W. (1960) Arch, Ophthal. (Chicago) 64, 912. |
|5.||Sugar, S. H (1962) Amer. J. Ophthal. 53, 307. |
|6.||Van der Hoeve (1906) Arch. Augenheilk, 57, 13 as cited by Duke-Elder in 1. |
|7.||Vauthier and Zanen J. (1955) Bull Soc. Beige Ophthal. 110, 162. |
[Figure - 1], [Figure - 2]