|Year : 1982 | Volume
| Issue : 4 | Page : 375-378
Role of A-can ultrasonography in ocular media opacities
VB Pratap Agarwal, SKJ Agarwal, MK Mehra
Department of Ophthalmology, K. G. Medical College, Lucknow, India
V B Pratap Agarwal
Department of Ophthalmology, K.G's. Medical College Lucknow 226 003
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Pratap Agarwal V B, Agarwal S, Mehra M K. Role of A-can ultrasonography in ocular media opacities. Indian J Ophthalmol 1982;30:375-8
|How to cite this URL:|
Pratap Agarwal V B, Agarwal S, Mehra M K. Role of A-can ultrasonography in ocular media opacities. Indian J Ophthalmol [serial online] 1982 [cited 2020 Aug 15];30:375-8. Available from: http://www.ijo.in/text.asp?1982/30/4/375/29476
Since the first application of ultrasound to ophthalmology in 1956 by Mundt and Hughes, ultrasonography has a special diagnostic place in cases of media opacities i.e., opacities of the cornea, anterior chamber, lens and vitreous where internal examination of the eyes is not possible by other methods.
A normal A-Scan ultrasonogram consists of 3 clearly demonstrated vertical deflections anteriorly from the cornea and from the anterior and posterior surfaces of the lens then the wave returns to the zero line indicating a sound homogenous vitreous cavity, posteriorly coats of eye ball and the orbital fat. Any abnormal deflection from the zero lines indicates some interference in the media which may be due to haemorrhage, exudates, detachment of retina, foreign body and tumour etc.
In this series of 44 eyes with opacities in the media, 5 eyes had corneal opacities, 5 had opacities of the anterior chamber, 18 had lenticular opacities and 16 had vitreous opacities.
| Cornea|| |
Out of 5 cases of corneal opacities which were studied. The echograms were normal in 3 cases (in a case of Sturge-Weber syndrome the axial length was increased, the echograni being otherwise normal). In another patient in whom the echogram was normal, a rotating keratoplasty was done and subsequently the child had an appreciable improvement in vision. Thus ultrasonography assumes significance in patients going in for keratoplasty. In a patient in multiple myeloma with proptosis and exposure keratitis right eye fundus examination was not possible. Ultrasonography was done to detect any intraocular Deposits. The echograms showed very small reflections - from the vitreous cavity at high sensitivity settings indicating the presence of fine vitreous opacities due to the associated uveities. In a case having a conjunctival growth which was completely covering the cornea, the initial reflection was followed by several irregular reflections indicating a possible intra-ocular extension of the growth.
| Anterior chamber|| |
Ultrasonography was done in 5 cases of hyphaema and exudates in the anterior chamber. Out of these, the echograms were abnormal in only one case who had traumatic hyphaema following a gun shot injury. Ultrasonography indicated the presence of an intraocular foreign body in the nasal quadrant [Figure - 1]. Axial echograms were normal but in diascleral echograms when the probe was applied at a specific point in the temporal quadrant a large echo peak was obtained just before the posterior reflections. This peak persisted even when the sensivtiity was reduced. The foreign body in this case was radio-opaque and the diagnosis was confirmed radiologically. Thus ultrasonography is of importance in detecting and localizing intraocular foreign bodies.
In this study Oksala (1964) had found that intra-ocular foreign bodies reflect echoes from a very limited area. Ossoinig 3 also found that a single high amplitude echo spike is obtained when the sound beam is directed through the centre of the lesion.
| Lens|| |
Ultrasonography was done in 18 cases of cataract of several types. The echograms in II cases did not show any abnormal echo peaks from the vitreous cavity. In 4 cases (one had traumatic cataract while the other 3 had Eales's disease with complicated cataract) the echographic pattern of retinal detachment was found. The anterior reflections were followed by a zero-line indicating a clear vitreous, from somewhere in the middle of the vitreous cavity (depending on the position of the detached retina) a single high amplitude echospike was reflected behind which was the zero-line followed by reflections from the posterior coats of the eye. This echo was reflected from a large area in contrast to the echo from a foreign body which was reflected from a very limited area. Goldberg and Sarin found that a single echospike obtained in the vitreous cavity, followed by a clearance back to the posterior pole is typical of serous retinal detachment.
Ossoinig demonstrated that if the reflectivity of the echo from the detached retina is compared with that of the sclera a difference of 6-18 db is obtained. Values within this range were obtained in the present study [Figure - 2].
In 3 cases (one had traumatic cataract while the other 2 had old iridocyclitis with complicated cataract) low amplitude, irregular echoes were obtained from the vitreous cavity.
These echoes tend to disappear at low settings (60.65 dh.) indicating a source of low reflectivity either vitreous opacities due to exudative uveitis or haemorrhage [Figure - 3].
| Vitreous|| |
(A) Ultrasonography was done in 10 cases who had a normal pupillary reflex but no fundus glow was visible. Clinically these cases were diagnosed as having vitreous haemorrhage. In 8 of these cases echographic pattern of vitreous haemorrhage was obtained. In the other 2 cases the low irregular echoes of either haemorrhage or opacities in the vitreous due to exudative uveitis were followed by a large echopeak characteristic of a detached retina. The wave returned to the zeroline between the echo from the detached retina and the echoes from the posterior eye wall. Thus in cases of vitreous haemorrhage especially those who have a defective light projection ultrasonography should be done to exclude the presence of retinal detechment as well. Similar results have been reported by Gitter, Meyer and Sarin.
(B) Ultrasonography was done in 6 children who had a whitish pupillary reflex (Leukocoria). In 5 of these cases there were large irregular high amplitude echoes in the vitreous extending back upto the reflections from the posterior wall of the eye [Figure - 4]. These echoes persist even at low sensitivity settings of 60 db. Goldberg and Sarin have shown that this pattern is due to intra-ocular tumours. A diagnosis of retinoblastoma was made by histopathological examination in one of these cases after enucleation.
In one case a similar pattern of echoes was obtained but were lower in amplitude and had a tendency to disappear when the sensitivity setting was reduced to 70 db. The axial length of the eye ball was also smaller in this case. These findings suggest a diagnosis of endophthalmitis in this case-the dense exudates in the vitreous giving rise to the irregular echoes as well as the whitish reflex of the pupil.
| Summary|| |
In this study of 44 eyes with media opacities, A-Scan ultrasonography was found to be of much diagnostic help.
| References|| |
Mundt, G.M. and Hughes, W.F., 1956, Amer. J Ophthalmol. 41 : 488.
Oksala, A., 1964,- Amer. J 57 : 453.
Ossoig, K.C. 11972 - Clinical Echo-ophthalmography in Current concepts in ophthalmology Vol. III ed by Blodi, F.C.. Mosby, St. Louis.
Goldberg, R.E. and Sarin, L.K., 1966 Amer J Ophthalmol. 61 : 1497
Gitter, K.A., Meyer, D. and Sarin, L.K., 1977, Amer J. Ophthalmol. 64: 100.
[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4]