Essential progressive iris atrophy.

Unilateral progressive iris atrophy is uncommon and only a few cases have been reported, although the clinical picture has been recognized since Harms (I903) gave the first description of this interesting atrophy, and reviewed other cases previously reported by Johnson (i886) and Hess (I892). Duke-Elder (i 966) mentions ninety authors who have reported cases. The condition occurs much more frequently in women than in men; it usually begins in the third decade, and is commonly unilateral. The bilateral cases have been seen mainly in males, but some have also been seen in females. Other diseases have been reported in association with it, and other organic changes have been described, but are probably coincidental (hypogonadism, myotonia atrophica, Gazala; I960). The clinical course of a typical case has an insidious onset with slight displacement of the pupil. The atrophy is visible in the "stretched" area of the iris, opposite the side of the displacement. Large holes appear, which tend to become larger, leaving only a few fine strands of tissue attached to the rather conspicuous sphincter pupillae (Fig. i), which is unaffected by the atrophy. It seems that stromal atrophy is most pronounced, while the atrophic changes of the ectodermal pigment give rise to a clear red reflex on transillumination. The atrophic changes in essential iris atrophy do not difler from iris atrophy caused by other diseases, but the absence of other changes (such as posterior synechiae, keratitic precipitates, pigment deposits, flare, and other signs of inflammation) aids the diagnosis. Gonioscopy is most important in clinical examination and in following the development of the condition. Troncoso first presented a gonioscopic description (see McKeown, I937) followed by Sugar (1945), Lohlein (I95I), and Daily and Daily (1957). The arterior stromal layer of the iris is drawn towards the angle of the anterior chamber, where tissue of a compact fibrous yellowish appearance is formed fixing the iris to the limbus with peripheral anterior synechiae. When the atrophy has advanced, the tension may rise and this glaucoma offers the most serious threat to the function of the eye. NMedical treatment of the glaucoma seems to have very little effect, and surgery should be attempted before sight is impaired (Duke-Elder, I966). A sclerectomy controlled the tension for 4 years (Waite, 1928), Preziosi's filtering operation was successful for Ii years (Papierbuch and Kurz, 1960), cyclodialysis has helped (von Grosz, 1936; Thorne-Thorne, I949; Vancea, 1960), repeated trephinings and radiation controlled the tension for I I years (Friedenwald, I 950), and cyclodiathermy for some years (Castroviejo, I953); a total removal of the atrophic iris was suggested by Clarke (I960).