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2. Thomas, R., Mulligan, N., Aylward, G. W., and Billson, F. A.: Angle closure glaucoma due to iris and ciliary body cysts. Aust. N.Z. J. Ophthalmol. 17:317, 1989. 3. Vela, A., Rieser, J. C , and Campbell, D. G.: The heredity and treatment of angle-closure glaucoma secondary to iris and ciliary body cysts. Ophthalmol­ ogy 91:332, 1984. 4. Layden, W. E., Torczynski, E., and Font, R. L.: Mucogenic glaucoma and goblet cell cyst of the anterior chamber. Arch. Ophthalmol. 96:2259, 1978.

Central Retinal Artery Occlusion After Neck Irradiation Lawrence S. Evans, M.D., William B. Van de Graaff, M.D., William H. Baker, M.D., and Susan N. Trimble, M.D. Departments of Ophthalmology, Internal Medicine, and Surgery, Stritch School of Medicine, Loyola University of Chicago. Inquiries to Lawrence S. Evans, M.D., Department of Ophthalmology, Loyola University of Chicago, 2160 S. First Ave., Maywood, IL 60153. A 38-year-old woman complained to her in­ ternist of blurred vision in the right eye of one-day duration. She was a nonsmoker with a normal blood pressure and normal cholesterol level, and she did not use birth control pills. Her medical history was extensive. At 12 years of age, she had undergone a left parotidectomy with bilateral radical neck dissection for mucoepidermoid carcinoma. She then received 70 Gy of radiotherapy by linear accelerator to the left side of the face and the neck. Many facial reconstructive procedures were performed for several years. She was being treated with erythromycin by her internist for a fever and cough of one-week duration. Thoracic radiography showed a right middle lobe infiltrate, and com­ puted tomography of the chest, brain, basilar skull, and neck was ordered. The same day, an eye examination disclosed a best-corrected vis­ ual acuity of 20/20 in each eye, and the left eyelids could not be closed because the facial nerve had been resected during her original surgical procedure and the left cornea showed exposure keratitis. Results of ophthalmoscopy were normal. Goldmann visual fields showed minimal depression in the peripheral isopters 20 degrees above fixation in both eyes. It was decided to observe the patient.

August, 1992

Nine days later, she was seen because of further episodes of vision loss in the right eye described as loss of the entire visual field or either the upper or lower hemifield separately. Visual acuity of the right eye was counting fingers at 2 feet. On ophthalmoscopy, a large white embolus was seen at the first bifurcation of the central retinal artery (Fig. 1). Treatment consisted of digital massage of the eye, rebreathing air into a paper bag to increase her P C 0 2 to dilate the retinal arteries, and oral administration of 60 ml of 50% glycerol and 500 mg of acetazolamide. She was admitted to the hospital, administered heparin, and admin­ istered betaxolol 0.5%, twice a day, to the right eye; 125 mg of acetazolamide, four times a day; and 5% CO.,, with 95% 0 2 to breathe for ten minutes every hour. Episodes of both the upper and lower hemifield loss continued, so a paracentesis of the anterior chamber was performed with removal of 0.1 ml of aqueous humor. After three days, fundus photography showed a small area of retinal edema superior to the fovea of the right eye with a cotton-wool spot along the superior vascular arcade. The embolus on the disk appeared unchanged. Fluorescein angiography showed no abnormal filling of major retinal vessels. Computed tomography of the head did not disclose cerebral infarcts and com­ puted tomography of the neck showed calcium plaquing in both internal carotid arteries. Carotid Doppler studies showed less than 75% stenosis in both arteries and carotid angiography showed stenosis at the origin of the

Fig. 1 (Evans and associates). Fundus of the right eye with embolus at the bifurcation of the central retinal artery.

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they recommended carotid vascular studies for all five-year survivors of malignancies who re­ ceived radiotherapy to the neck. Our case illustrated another origin of central retinal artery occlusion and emphasized the need for awareness of the risk of carotid occlu­ sive disease long after therapeutic irradiation to the neck.

References Fig. 2 (Evans and associates). B-mode ultrasonogram of right eye showing density on the optic nerve corresponding to the location of the embolus.

great vessels and a small filling defect that possibly represented a thrombus at the bifurca­ tion of the right common carotid artery and that extended up the internal carotid artery. Echocardiography disclosed no valvular vegetations or thrombi in the cardiac chambers. Titers of rheumatoid factor, antinuclear antibody, antinative DNA, C3, C4, and CH50 were normal as were the hemoglobin level, hematocrit, platelet count, prothrombin time, partial thromboplastin time, and the erythrocyte sedimentation rate. Warfarin was administered as an anticoag­ ulant, and the patient was discharged. Acetylsalicylic acid was given as an anticoagulant after four months. B-mode ultrasonography showed a reflective density on the right optic nerve that was consistent with the size and position of the embolus (Fig. 2). The association between radiotherapy and the delayed onset of atherosclerosis has been known for decades. 14 Carotid artery occlusion after cervical irradiation has been described frequently, but central retinal artery occlusion is uncommon. We believe calcified plaque in the carotid artery was the source of the embolus because it appeared between examinations while the patient had vision symptoms compat­ ible with embolie disease. Drusen of the optic nerve head and calcified phleboliths of the central retinal vein may have an appearance similar to that of our patient on B-scan echography. 6 Eldering and associates 4 reviewed 910 cases of patients who survived at least five years after irradiation to at least one side of the neck for neoplasia and found that 63 patients had strokes for a mean observation period of nine years. This was markedly higher than the incidence for a matched normal population, so

1. Glick, B.: Bilateral carotid occlusive disease fol­ lowing irradiation for carcinoma of the vocal cords. Arch. Pathol. 92:352, 1972. 2. Levinson, S. A., Close, M. B., Ehrenfeld, W. K., and Stoney, R. J.: Carotid artery occlusive disease following external cervical irradiation. Arch. Surg. 107:395, 1973. 3. Conomy, J. P., and Kellermeyer, R. W.: Delayed cerebrovascular consequences of therapeutic radia­ tion. Cancer 36:1702, 1975. 4. Eldering, S. C , Fernandez, R. N., Grotta, J. C, Lindberg, R. D., Causay, L. C , and McCurtrey, M. J.: Carotid artery disease following external cervical irradiation. Ann. Surg. 194:609, 1981. 5. Boldt, H. C, Byrne, S. F., and DiBernardo, C: Echographic evaluation of optic nerve drusen. J. Clin. Neuro-ophthalmol. 11:85, 1991.

Traumatic Rupture of a Persistent Hyaloid Artery Eng-Yiat Yap, M.D., and Helmut Buettner, M.D. Department of Ophthalmology, Mayo Clinic and Mayo Foundation. Supported in part by the Higher Manpower Development Plan of the Ministry of Health, Singapore, Singapore (Dr. Yap); an unre­ stricted grant from Research to Prevent Blindness, Inc., New York, New York; and by the Mayo Founda­ tion, Rochester, Minnesota. Inquiries to Helmut Buettner, Μ.Ό., Mayo Clinic, E-7, Rochester, MN 55905. Complete or partial persistence of the central hyaloid artery is a frequent abnormality in the human eye. 1 In its most severe form, persistent hyperplastic primary vitreous, it is often associ­ ated with microphthalmia, cataract, ciliary body, and traction retinal detachment, which result in dismal visual function. 2 Milder forms of persistence of the central hyaloid artery,

Central retinal artery occlusion after neck irradiation.

224 AMERICAN JOURNAL OF OPHTHALMOLOGY 2. Thomas, R., Mulligan, N., Aylward, G. W., and Billson, F. A.: Angle closure glaucoma due to iris and ciliar...
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