Documenta Ophthalmologica 43,1 : 137-146, 1977 A NEW ULTRASONIC APPARATUS FOR OPHTHALMOLOGY USING MANUAL COMPOUND SCANNING AKIHIRO KANEKO, SADAWO SHIGEYAMA & ROKURO UCHIDA

(Tokyo, Japan) ABSTRACT A new ultrasonic equipment for ophthalmological diagnosis has been developed. Manual compound scanning using water immersion made acurate representation of cross-section of the orbital structure possible. A large, focused transducer brought resolution and sensitivity. Gray scale display of the ultrasonogram increased information concerning intensity of echoes. Ultrasonograms of retinoblastoma, vitreous hemorrhage, melanocytoma, optic disc coloboma and unilateral exophthalmos are presented. There are many reports (PurneU, 1967; Coleman, 1972) concerning application of B-scan ultrasonography in ophthalmology. However, complexity and high cost have prevented wide clinical use in many clinics. Recently Bronson (1972) developed a simple and portable B-scan equipment, but the quality of the ultrasonogram is not sufficient for clinical use of high level. We are therefore developing a new B-scan ultrasonograph which is less expensive than the Coleman Ophthalmoscan, although the quality is not inferior. METHOD Our idea involves an adaptation of a compound contact scanner normally used for abdominal gynecological purposes (Aloka SSD-60C). Water immersion was preferred as smooth compound, contact scanning of the eye is impossible owing to unevenness of the surface of the ocular region. The water bath was made of a surgical drape. The depth of physiological saline was about 5 cm to avoid multiple echoes which disturb the ocular ultrasonogram. The probe was manually moved in the bath over one or both eyes (Fig. 1). The arm of the original scanner was shortened to 10 cm to facilitate bilateral orbital scanning. Shifting of the scanning plane was displayed digitally in one millimeter units. The scanning plane was illuminated by a narrow band of light on the surface of lids. The transducer is made of ceramics, 5 MHz, 14 mm diameter, 60 mm radius of curvature. A, B and M-modes are available. A logarithmic amplifier is not used, but dynamic range is about 40 dB. General anesthesia was necessary for the examination of infants.

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Fig. I. (A. Kaneko). Focused transducer in the water bath is scanning a child with leukokoria, under general anesthesia.

Fig. 2. (A. Kaneko). Ultrasonogram of a test object.

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RESULTS 1. Ultrasonogram of a test object: A test object was made of 16 nylon threads of 0.05 mm diameter, which were set at equal intervals along a circle of 25 mm diameter. Cross section of this test piece was excellent (Fig. 2). 2. A skull was immersed in the water bath to test the accuracy of representation on compound scanning. Figs. 3A and 3B show that the orbital walls were accurately represented. 3. Ultrasonogram of a normal infant orbit (Fig. 4) revealed the upper lid, zygomatic bone, cornea, iris, anterior and posterior surface of the lens, posterior eye wall, retrobulbar tissue, posterior orbital wall and lateral rectus muscle. 4. A retinoblastoma was revealed as a solid mass of bright spots in the antero-nasal part of the retina (Fig. 5). A funnel shaped total retinal detachment was also revealed. Tumor and detached retina were clearly differentiated. 5. Ultrasonogram of vitreous hemorrhage (Fig. 6): This aphakic eye was enucleated because of absolute glaucoma and irradiation retinopathy. Before the operation ultrasonography revealed vitreous hemorrhage in the middle of the vitreous and right side of the ciliary body which was confirmed by pathological examination. 6. Ultrasonogram of melanocytoma: This tumor was a typical melanocytoma overlying the optic disc. The thickness was 7 diopter (about 2 ram). The diameter was about 3 mm. Ultrasonography clearly revealed this small t u m o r and the border between the t u m o r and the eye wall (Figs. 7A and 7-

B). 7. A case of optic disc coloboma was photographed with a wide angle fundus camera (Fig. 8A). The deep eXcavation of the optic disc and the surrounding chorioretinal atrophy may be recognized. Ultrasonography revealed the posterior protrusion of the eye ball (Fig. 8B). 8. Ultrasonogram of unilateral exophthalmos (Fig. 9). This ultrasonogram clearly disclosed abnormality of the right orbit which showed exophthalmos. A defect of normal retrobulbar echoes and the presence of abnormal internal echoes were found. The location and extent of this cystic t u m o r was clearly demonstrated in horizontal and vertical sections (Figs. 9A, 9B). 139

Fig. 3. (A. Kaneko). Ultrasonograms of orbits in two different horizontal sections.

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Fig. 4. (A. Kaneko). Ultrasonogram of the normal eye of an infant. Horizontal section.

Fi~ 5. (A. Kaneko). Retinoblastoma. A solid mass with brighter spots is the retinoblastoma, which causes a defect of retrobulbar echoes due to intense attenuation by this tumor. A funnel shaped retinal detachment is also present.

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Fig. 6. (A. Kaneko). Vitreous hemorrhage due to radiation retinopathy~

DISCUSSION Comparison of ultrasonograms produced by different instruments is difficult. Accurate representation of anatomy and precise information concerning intensity of echoes are indispensable for adequate diagnosis using intensity modulated ultrasonography. Our equipment has excellent qualities for these two factors. Manipulation of this equipment is not difficult. Light illumination on the scanned object is convenient for confirming which part is being scanned. Simultaneous scanning of both eyes makes comparison of the two sides easier. This equipment costs about $25.00 in Japan which is half the price of the Coleman Ophthalmoscan. ACKNOWLEDGEMENT This work was supported in part by a Grant-in-Aid for Cancer Research from the Ministry of Health and Welfare of Japan. 142

Fig. 7A. (A. Kaneko). Melanocytoma overlying the optic disc. Fig. 7B., Ultrasonogram.

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Fig. 8A. (A. Kaneko). Coloboma of the optic disc. Fig. 8B. Ultrasonogram.

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Fig. 9~ (A. Kaneko). Right sided unilateral exophthalmos. 9A: horizontal section; 9B: vertical section of the right orbit.

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REFERENCES Bronson, N.R. Development of a simple B-scan Ultrasonoscopeo Tr. Amer. Ophthal. Soc. 70:365-408 (1972). Coleman, J. Reliability of ocular and orbital diagnosis with B-scan ultrasonography. Am. J. Ophthal. 73:501-516 (1972) PurneU, E.W. Intensity Modulated (B-Scan) Ultrasonography. In: Goldberg & Sarin (Eds), Ultrasonics in Ophthalmology, W.B. Saunders Co. pp. 102-123 (1967). Authors' addresses: Department of Ophthalmology National Cancer Center Hospital Tokyo Japan Aloka Company Ltd Tokyo Japan

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