Intra-ocular Metallic Foreign Bodies.

THE purpose of this paper is to study the mass of an intra-ocular metallic foreign body and the problem of infection in a series of patients seen at the Glasgow Eye Infirmary. Although there is much work on the problem of sepsis, there are few references in the literature to the mass of the fragment. The fibrous macromolecules of collagen in the outer coat of the eye are so arranged in compact bundles and layers as to resist with ease the stresses produced by the pull of the six extra-ocular muscles. The depth to which a flying fragment will penetrate into or through this tough tissue will depend on resistance, the configuration of the leading part of the fragment, the mass, and the velocity. Of these the mass is the most readily available for measurement. In the literature I found two references discussing the mass of the intra-ocular fragment. Morax and Moreau (1917) classified their fragments into less than 250 mg., 250 mg. to 5 g., and greater than 5g.; their cases were all war injuries. Gronvall and Hultgren (1959) reviewed 131 cases in which the mass of the fragments ranged from 0 01 mg. to 12 3 g.; they were mainly concerned with the metallurgy of the fragments. Other authors have classified the intra-ocular fragments by volume (Roper-Hall, 1954; Stevens, 1956), and by shape, as " spicules ", " scales ", or " chunks " (Brownlie, 1915). During the quinquennium January, 1956, to December, 1960, at the Glasgow Eye Infirmary, 81 patients with intra-ocular foreign body were admitted to the wards, and these accounted for one in 200 ophthalmic in-patients from all causes and one in 2,000 of all ophthalmic accident patients. The mass of 73 fragments was found and the results are shown in Fig. 1.