150 February, 1989 AMERICAN JOURNAL OF OPHTHALMOLOGY concerning heredity could be drawn. However, taken as a whole, within this genetically isolated population, it is not surprising to have found optic disk sizes and cup/disk ratios that are different from our usual white reference population. Faced with a pale disk accompanied by a large cup/disk ratio, other signs and symptoms indicative of an optic disk abnormality are usually searched for. It is reasonable from this study to conclude that in addition to signs and symptoms such as decreasing visual acuity, visual field defects, pupil abnormalities, in- 5. Kuzma, J. W.: Basic Statistics for the Health Sciences. Mountain View, California, Mayfield Pub- creased intraocular pressure, poor color vision, and defects in the peripapillary nerve fiber layer and the neural rim, one should also take into account the racial or ethnic background of the patient before determining that the disk is abnormal. Furthermore, given the variability in optic disk size, measurements of rim area may prove more useful when assessing neuronal loss than measurements of the cup/disk ratio. References lishing Co., 1984, p. 67. 6. Kahn, H. A., Leibowitz, H. M., Ganley, J. P., Kini, M.M., Colton, T., Nickerson, R.S., and Dawber, T. R.: The Framingham eye study, Am. J. Epidemiol. 106:17, 1977. 7. Syndacker, D.: The normal optic disc. Am. J. Ophthalmol. 58:958, 1964. 8. Armaly, M. F.: Genetic determination of cup/ disc ratio of the optic nerve. Arch. Ophthalmol. 78:35, 1967. 9. Miller, N. R.: Walsh and Hoyt’s Clinical NeuroOphthalmology, ed. 4. Baltimore, Williams and Wilkins, 1982, vol. 1, p. 343, 10. Adams, W. H., Harper, J. A., Heotis, P. M., and Jamner, A. H.: Hyperuricemia in the inhabitants of the Marshall Islands. Arthritis Rheum. 27:6, 1984, 11. Britton, R.J., Drance, S.M., Schulzer, M,, Douglas, G. R., and Mawson, D. K.: The area of the neuroretinal rim of the optic nerve in normal eyes. Am. J. Ophthalmol. 103:497, 1987. 12. Airaksinen, P. J., Drance, S. M., and Schulzer, M.: Neuroretinal rim area in early glaucoma. Am. J. Ophthalmol. 99:1, 1985. 13. Pickard, R.: The alteration in size of the normal optic disc and cup. Br. J. Ophthalmol. 32:355, 1948. 14. Carpel, E. P., and Engstrom, P. F.: The normal cup/dise ratio. Am. J. Ophthalmol. 91:588, 1981. 1. Brown, G., and Tasman, W.: Congenital Anom- alies of the Optic Disc. New York, Grune and Stratton, 1983, pp. 207-212. 2. Conrad, R. A.: Late radiation effects in Marshall Islanders exposed to fallout 28 years ago. In Boice, J. D., Jr., and Fraumeni, J. F., Jr. (eds.): Radiation Carcinogenesis. Epidemiologyand Biological Signifi- cance. New York, Raven Press, 1984, p. 57. 3. Collins, J. F.: Handbook of Clinical Ophthalmology. New York, Masson Publishing USA, Inc., 1982, p. 714. 4. Franceschetti, A., and Bock, R. H.: Megalopa- pilla. A new congenital anomaly. Am. J. Ophthal- 15. Teal, P. K., Marin, J. D., and McCulloch, C.: Assessment of the normal disc. Trans. Am. Ophthal!mol. Soc. 52:165, 1972. 16. Caprioli, J., and Miller, J. M.: Optic disc rim area is related to disc size in normal subjects. Arch. Ophthalmol. 105:1683, 1987. 17. Beck, R. W., Messner, D. K., Musch, D. C., Maronyi, C. L., and Lichter, P. R.: Is there a racial difference in physiologic cup size? Ophthalmology 92:873, 1985. 18. Bengtsson, B.: The inheritance and development of cup and disc diameters. Acta Ophthalmol. 58:733, 1980. mol. 33:227, 1950. REPOSITORY BNL RECORDS COLLECTION LVARSHALL Boxne. S40ICAL ISCANDS PYBLIC A TIONS DEPT ARR Fo.pen —WUAVLABELED The Medical Research Center Brookhaven National Labora Uptou, L. L, New York ok