Indian Journal of Ophthalmology

ORIGINAL ARTICLE
Year
: 1983  |  Volume : 31  |  Issue : 4  |  Page : 317--319

Orbital ultrasonography-a diagnostic tool


Y Dayal, N Verma, IM Bhatia 
 Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India

Correspondence Address:
Y Dayal
Dr. Rajendra Prasad Centre for ophthalmic Sciences, A.I.I.M.S., New Delhi-110029
India




How to cite this article:
Dayal Y, Verma N, Bhatia I M. Orbital ultrasonography-a diagnostic tool.Indian J Ophthalmol 1983;31:317-319


How to cite this URL:
Dayal Y, Verma N, Bhatia I M. Orbital ultrasonography-a diagnostic tool. Indian J Ophthalmol [serial online] 1983 [cited 2024 Mar 29 ];31:317-319
Available from: https://journals.lww.com/ijo/pages/default.aspx/text.asp?1983/31/4/317/27542


Full Text

Orbital pseudotumors are an important cause of unilateral exophthalmos and a signi�ficant cause of bilateral proptosis (16% Reese, 1969).

In this study, the ultrasonographic fea�tures of orbital inflammatory disease, their follow up on therapy and the differential diagnosis are presented.

 MATERIALS AND METHODS



Twenty six patients were chosen from a series of seventy patients with orbital disease who were examined by ultrasonography.

All patients underwent a routine proptosis work up with appropriate laboratory investi�gations and radiology (both conventional and CT scanning) and a presumptive diagnosis was made. Ultrasonography was performed using the Kretztechnik 7200 MA and Oph�thalmoscan 200 scanning units. Compound, arc, linear and sector scanning was done. Five of these patients were subjected to sur�gery and the rest put on appropriate medical therapy.

 OBSERVATIONS AND DISCUSSION



These patients formed 37.1 �o of all exa�mined and were in the first to fourth decades of life.

There were certain common features observed in all patients:

(A) Myositis : The rectus muscles are normally visualized as clear spaces on very high sensitivity settings. Enlargement due to oedema or infiltration causes a rearrangement of connective tissue septae and renders these muscles echogenic at lower sensitivity settings (58 db). Myositis as evidenced by focal, nodular or generalized muscle enlargement was seen in all patients with orbital inflamma�tory disease [Figure 1].

The average muscle thickness was 5.72 mm and a decrease in their size on therapy was demonstrated which correlated well with muscle function improvement on repeated Hess charting. In cases of thyroid orbito�pathy:

(B) Optic nerve changes : (i) accentuation of the optic nerve sheath (linear), (ii) widen�ing of the optic nerve shadow (angular) (never more than 60� ), (iii) elevation of the optic nerve head (Papilloedema).

The optic nerve is normally an echo free space, however, inflammation of its sheath renders it echogenic. The normal four spike pattern on A scanning which is characteristic of the optic nerve was never lost-which helped differentiate infiltration of the optic nerve by inflammatory products from that by a tumor. The average optic nerve thickness was 6.07 mm and a decrease in size was demonstrable with appropriate therapy

[Figure 6].

(C) Sclerotenonitis : (i) widening of the normal potential episcleral space into a cresent shaped area (posteriorly) (ii) presence of an echo free interval in the retrobulbar fat complex. (A scan)

In two patients an enormous dilatation of this space to form a serous cyst was observed. This dilatation disappeared on therapy.

(D) Changes in Orbital fat : This is by far the most important set of changes in orbital inflammatory disease and helps differentiate the various causes of this condition. They consist of : (i) widening of the normal retro�bulbar fat complex from 150-200% of its nor�mal value, (ii) a decrease in the normal transmitted pulsation (on A & M scanning), (iii) reduced compressibility of the retrobul�bar fat complex-a feature more marked in thyroid orbitopathy, (iv) presence of tall spikes with a less echogenic interval seen in micro abscess formation (orbital cellulitis). Angle K=10�sub -30�. (v) areas of increased sound attenuation-with fairly well defined borders- granulomas (seen in 72.7%). Angle K=50� -60� [Figure 3]. (vi) coarsening of the fat pattern (which normally has a fairly regu�lar structure). (B Scan.) [Figure 1]

All the above changes correlate well with the histology of these tumors. The orbital fat is separated by inflammatory cells and oedema fluid which creates reflecting inter�faces and increases the width of the retrobul�bar spike complex. When the infiltration is by mucopolysaccharides (thyroid orbitopathy) or fungal hyphae, the attenuation is more rapid. The granuloma represents an area of focal lymphocytic infiltration and this accounts for the greater sound attenuation. With surgery the following observations were made:

[INLINE:1]

Evidently CT scanning and conventional orbital radiology are of limited value in the diagnosis and management of orbital inflam�matory disease, the changes being beyond the resolving capacity of instruments available today. Moreover, involvement of the optic nerve is often difficult to decide.

It is often difficult to differentiate lympho�mas and lymphosarcomas from orbital inflam�matory disease and therefore if a granuloma does not regress with therapy surgical inter�vention is indicated.

It is to be noted that the regression of changes with therapy are detected first by echography-before clinical changes become evident.

Ultrasonography is thus an important tool in the diagnosis and management of orbital inflammatory lesions. Correct diagnosis in these patients obviates the need for surgery or alternatively helps direct its route.

 SUMMARY



The value of ultrasonography in the dia�gnosis and management of orbital inflam�matory disease is presented.