380 KING: The Heterochromia of Fuchs 2. Benedict, W. L.: Retinitis of Cardiovascular and of Renal Disease, Am. J. Ophth., 1921, iv, p. 495. 3. Benedict, W. L.: Retinitis Associated with Disease of the Cardiovascular System, N. Y. M. J., 19293, cxvii, p. 741. 4. Cushing, Harvey, and Bordley, James: Subtemporal Decompression in a Case of Chronic Nephritis with Uremia; with Especial Consideration of the Neuroretinal Lesion, Am. J. M. Sc., 1908, cxxxvi, p. 484. 5. Ellis, A. W. M., and Marrack, J. R.: An Investigation of Renal Function in Patients with Retinitis and High Blood-Pressure, Lancet, 1923, i, p. 891. 6. Morax, V.: Pathologic Oculaire, Felix Alcan, Paris, 1921, p. 278. 7. Schieck, F., and Volhard, Franz: Netzhautveranderungen und Nieren- leiden, Zentralbl. f. d. ges. Ophth. u. i. Grenzgeb., 1921, v, p. 465. 8. Volhard, Franz: Die doppelseitigen hamotogenen Nierenerkrankungen, Berlin. Julius Springer, 1918, p. 576. 9. Wagener, H. P.: Retinitis and Renal Function in Cardiovascular Renal Disease, Am. J. Ophth., 1924, vii, p. 272. 10. Wagener, H. P., and Keith, N. M.: Cases of Marked Hypertension, Adequate Renal Function and Neuroretinitis, Arch. Int. Med., 1924, xxxiv, p. 374. TUBERCULOUS IRIDOCYCLITIS AS A CAUSE OF THE HETEROCHROMIA OF FUCHS* CLARENCE KING, M.D. Cincinnati (From the I. University Eye Clinic, Vienna, Professor Meller) Heterochromia, in its literal meaning, signifies different coloring. As commonly used in ophthalmology, the term indicates a different coloring of the irides of an individual. The term as used in this paper does not include changes of color of the iris due to acute inflammation, or those changes following intra-ocular hemorrhage, or changes due to stain- ing by metal salts, or changes which are secondary to glau- coma. This condition early attracted the attention of ophthalmologists, and the numerous articles dealing with it in the literature of recent years indicate the wide-spread interest which attaches to it. Despite the work which has * Candidate's thesis for membership accepted by the Committee on Theses. The author forwarded with this thesis sixteen excellent water colors, but owing to the cost of color reproduction it was impossible to include these in the manu- script.-Editor. KING: The Heterochromia of Fuchs 381 been done upon the subject, no explanation of the problems connected with it received general recognition as being entirely adequate, and no classification of the various types of heterochromia obtained general acceptance. Hetero- chromia is commented upon early in the literature in articles by Wilde (1848), Lawrence54 (1853), and Hutchinson38 (1869). The first detailed study of this condition upon which subse- quent work was based was made by E. Fuchs before 1902. Reference was made to this work in his textbook, which was published in that year. Extensive articles appeared in 190625 and 1917.26 In connection with the following statements it may be useful to refer to some observations of Salzmann on the color and structure of the normal iris. Salzmann80 distinguished between two types of irides-the brown iris and the iris which was lighter in color. The two types differed not only in color but also in the character of the relief of the anterior surface. In the light-colored iris it was possible to observe many more details of the deeper layers than was the case with the brown iris. The radial arrangements of the trabec- ulae could be observed more readily; the crypts were larger and more definitely marked; the contraction furrows, on the contrary, were clearly discernible only in lateral illumina- tion. The brown iris showed a coarse relief; the ciliary zone was flatter; the crypts were few and smaller; the contrac- tion furrows were clearly seen even when the pupil was contracted. The anterior limiting membrane determined the color of the iris not only by its pigment content but by its thickness. According to Salzmann, the blue iris had a delicate limiting membrane and the cells contained just a few color particles. According to Munch (discussion of Bistis's7 paper), the cells of the anterior layer of the blue iris contained pigment, but this pigment was not ordinarily apparent and could be demonstrated only by special staining methods. The heterochromia of Fuchs represented a distinct type of 382 KING: The Heterochromia of Fuchs this condition with certain well-known characteristics. The observations of Fuchs have been generally confirmed by subsequent writers on the subject. The clinical picture which was established in the literature of the subject will first be described. Departures from this typical appearance which have been noted in the personal material will be com- mented upon subsequently. Fuchs's description is as follows: "On examination, the iris of one eye appears lighter in color than the other. The iris tissue in the lighter eye presents a peculiar appearance. The difference in the two eyes is especially apparent when one eye is blue and the other a lighter blue. In the normal blue eye, the pigment layer can be discerned in the inter- stices of the trabeculae of the overlying tissue. The trabec- ule are sharply outlined. In the lighter heterochromic iris, the retinal pigment layer is sometimes dinily apparent or not visible at all. The whole iris has a dull, blurred, less transparent appearance. The difference in the irides of the two eyes may be so slight as to escape attention except with the loupe. The relief of the anterior surface is not so apparent as in the sound eye. The fine, radial markings of the pupillary zone are not so prominent or may be entirely absent. There is an absence of any evidence of pronounced inflammation or its sequele. No marked exudative changes are seen; posterior synechie are absent; defects in the ret- inal pigment layer are frequently found; the pupillary pig- ment border may be partially or entirely absent. It may appear sharp in contour and may be replaced by a fine, grayish line with a gnawed-out appearance. The pupil in the lighter eye, with a normal reaction, may be wider than the other." In this type of heterochromia, precipitates on the posterior surface of the cornea are nearly always seen, and catarac- tous changes are frequently present. The precipitates are fine and few in number; they are sharply circumscribed KING: The Heterochromia of Fuchs 383 and located usually in the lower half of the cornea. They show no tendency to become confluent. The cataract, which is so frequently a feature of the clinical picture, usually begins in the posterior cortex. When complete, the cataract has a bluish-white appearance, with pronounced sector markings and a decided tendency to swelling. Despite the fact that the cataract is complicated, its extraction ordinarily causes no difficulty and the result is usually good. The precipitates may be absent and the cataract alone be present, or vice versa. It may be well to note that as the result of the disclosures made by the slit-lamp, it may be necessary entirely to revise our impression as to the presence or absence of minute changes in the cornea, iris, or lens in heterochromia. Early studies of this condition were made without the aid of even the loupe. It is to be presumed that observations with the slit-lamp in future cases will afford valuable data for more accurate classification. The hetero- chromia of Fuchs may be accompanied by opacities of the vitreous, also by choroidal inflammatory changes. A sym- pathetic nerve paralysis or a paresis may be present. Opin- ions of its significance differ. The lighter eye in heterochromia is inclined to increase in pressure. In some of Fuchs's cases, congenital defects were found in other parts of the eye. Clinical history: The patients with Fuchs's heterochromia usually seek the advice of the ophthalmologist because of defects or difficulties in vision. No complaint is made of pain or redness of the eyes. The history sometimes dis- closes that the difference in the color of the two eyes has ex- isted from birth or from the early years of life. Other patients state that they have accidentally noticed the color difference later in life, or that one eye has gradually become lighter. One rarely encounters cases like those reported in this paper, in which a positive statement is made that the color of the eye has become lighter within a definite period. The patients often have dark hair but the condition is seen also in 384 KING: The Heterochromia of Fuchs blond races. With the exception of two cases, the disease in all of the reported cases is confined to one eye. In a report in 1906, Fuchs discussed a case of heterochromia in which similar pathologic changes were observed in both eyes removed from a cadaver. Other references in the literature indicate that there is a possibility of a double heterochromia. The family history as to the color of the eyes frequently discloses the fact that one parent has brown eyes and the other light eyes; or that there were variations in this respect in the ancestral line on either side. In the cases reported, the disease has not been connected with any general dis- turbance; and the history has not been considered signifi- cant. Heine discussed in a paper, to which reference will subsequently be made, the possibility of tuberculosis as a factor in complicated heterochromia. In the cases of Fuchs, there was a predominance of women. However, taking the average of reported cases, the distribution of sexes was about equal. The time of the onset of the color difference is obviously uncertain, as already indicated. The symptoms of the cyclitis seem to occur from the twentieth to the thirtieth year.