Experimental and Clinical Observations on the Echograms in Vitreous Haemorrhages

Oksala, Arvo

doi:10.1136/bjo.47.2.65

Cited by 13 publications

(7 citation statements)

References 2 publications

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“…On the other hand, we know from numerous previous clinical investigations (Oksala 1959(Oksala , 1960(Oksala , 1962) that the retina alone reflects an almost equally high echo peak as the choroid alone. On the other hand, we know from numerous previous clinical investigations (Oksala 1959(Oksala , 1960(Oksala , 1962) that the retina alone reflects an almost equally high echo peak as the choroid alone.…”

Section: Discussionmentioning

confidence: 94%

“…By studying the echo from the rear wall with the help of the gelatin injection we could visualise from the vitreous space the echo of the retina + the choroid, and when we studied the echoes from the calotte formed of the choroid + the sclera, the echo from the sclera was joined by the echo from the choroid. On the other hand, we know from numerous previous clinical investigations (Oksala 1959(Oksala , 1960(Oksala , 1962) that the retina alone reflects an almost equally high echo peak as the choroid alone. W e therefore feel that the results of the investigation show that the first echo when examining the rear wall past the lens is reflected by the retina.…”

Section: Discussionmentioning

confidence: 94%

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Analysis of Echoes From the Rear Eye Wall With the Aid of Experimental Research

Oksala

Varonen

1964

Acta Ophthalmologica

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Diagnosis of the eye by ultrasound has been successfully applied since 1956 in various eye diseases. The circumstance that ultrasonic diagnosis was easy to apply to the examination of eye diseases is due to the fairly clear-cut macroscopic structure of the eye. From the point of view of ultrasonic diagnosis the eye can be interpreted as a ball filled with fluid, inside of which there are some parts separated from each other by marked border surfaces. If we place the crystal in the middle of the cornea and guide the sonic waves axially in the direction of the rear wall of the eye, we shall get an echogram on which there is at first an initial echo, followed by the zero-line representing the anterior chamber. The anterior and posterior surfaces of the lens reflect clear echoes, in between of which there is a zero-line. The longest zero-line represents the vitreous and one or several echoes are obtained from the rear wall of the eye. If the sonic waves are guided past the lens, only the initial echo and the echo or echoes from the rear wall are obtained, there being only a zero-line between them.A closer analysis of the echoes from the rear wall of the eye was not easy, because the resolving power of the present-day ultrasonic equipment is only about 0,3-0,5 mm, because the continuous direction of the sound beam perpendicularly against the rear wall of the eye produces considerable difficulties in practice, and because it is difficult to clarify the exact direction of the sound beam in regard to the rear wall. E. g. we have had up to the present no exact knowledge from what point of the rear eye wall the first echo is reflected and *) This study was supported by Sigrid JusClius Stiftelse. **) Received Nov. 14th 1963.

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Section: Discussionmentioning

confidence: 94%

Section: Discussionmentioning

confidence: 94%

Analysis of Echoes From the Rear Eye Wall With the Aid of Experimental Research

Oksala

Varonen

1964

Acta Ophthalmologica

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“…Several patterns of haemorrhagic invasion of the vitreous cavity are illustrated, together with detachment, collapse, and retraction of the vitreous gel. Diagnostic ultrasound has been used for many years for the investigation of ocular and orbital diseases (Oksala, 1963;Baum, 1964;Purnell, 1966;Ossoinig, 1972;Coleman, 1972;Bronson, 1972). Examination methods currently available include A-, B-, C-, and M-scanning and ultrasonic holography.…”

mentioning

confidence: 99%

Rapid B-scanning of the vitreous.

McLeod¹,

Restori²,

Wright³

1977

British Journal of Ophthalmology

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SUMMARY Ultrasonic examination is an essential investigation in most patients awaiting vitrectomy. Rapid B-scanning of the vitreous is described utilising a new system capable of high resolution and good tonal quality. Several patterns of haemorrhagic invasion of the vitreous cavity are illustrated, together with detachment, collapse, and retraction of the vitreous gel.Diagnostic ultrasound has been used for many years for the investigation of ocular and orbital diseases (Oksala, 1963;Baum, 1964;Purnell, 1966;Ossoinig, 1972;Coleman, 1972;Bronson, 1972). Examination methods currently available include A-, B-, C-, and M-scanning and ultrasonic holography. Apparatus capable of ophthalmic A-, B-, and C-scanning and holography was designed by Aldridge et al. (1974) and has been on clinical trial at Moorfields Eye Hospital for the past three years. A report of its use in the investigation of orbital lesions is to be published shortly (Restori and Wright, 1977). This paper presents our experience of real-time Bscanning of the vitreous cavity, particularly in patients being considered for vitrectomy. controls include gain, transmission pulse duration, scanning speed, and a swept gain facility to compensate for sound attenuation in the globe and orbit.The system is capable of good resolution and is remarkably free of artefacts. The scanning mechanism has been built to a high standard of rigidity and precision, and the instantaneous position of the transducer is transferred to the display tube with minimum error. These are design criteria for holographic imaging and undoubtedly contribute to the quality of the B-scan display.Adequate sensitivity and accurate echo registration allow weak echoes to be detected and displayed. The dynamic range of the system is 40 dB, and an amplifier to compress this 40 dB into the 20 dB dynamic range of an oscilloscope would improve the grey scale appearance of the B-scan display.A time-gate has proved useful in selecting echoes for amplitude quantitation from any B-scan section.

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“…Neurosonography is implemented regularly in the care of patients with SAH for monitoring of cerebral vasospasms. The sonographic evaluation of vitreoretinal diseases with VH has become a well‐established tool over the past five decades . Recently, one study described its usefulness in acute SAH for the first time …”

Section: Introductionmentioning

confidence: 99%

“…The sonographic evaluation of vitreoretinal diseases with VH has become a well-established tool over the past five decades. [20][21][22][23] Recently, one study described its usefulness in acute SAH for the first time. 24 This prospective study investigates the diagnostic accuracy of ocular sonography in comparison with standard head CT for diagnosing OH in acute SAH.…”

Section: Introductionmentioning

confidence: 99%