The blinding mechanisms of incontinentia pigmenti.

Five case histories illustrate the disabling visual diseases caused by retinal and cerebral infarction in incontinentia pigmenti. Cortical blindness was definitely present in one baby, who had bilateral absence of light perception, and was probably present in a second infant also. Retinal detachment occurred in three eyes of three patients, one of whom had spontaneous reattachment. In a second patient, a partial tractional retinal detachment progressed within 4 months during infancy to a total, inoperable, retrolental, white fibrovascular mass mimicking stage 5 retinopathy of prematurity. Phthisis bulbi resulted. In a third patient, a localized tractional retinal detachment originated at the nonperfused macula and extended over a 7-month period to the ora serrata. Preretinal neovascularization waxed and waned in these and other patients. Abnormalities of the macula were pronounced but were sometimes difficult to detect. Their severity and relative frequency have not been previously described in detail. Abnormalities included blunting or absence of the foveal pit and absence of the normal foveal avascular zone. One patient at 12 days of age had an infarcted macula with a cherry-red spot. Similar episodes may have occurred in other children and would be sufficient to explain the appearance of macular abnormalities and otherwise unexplainable poor visual acuity in older individuals. Well-focused macular angiography appears to be highly useful in explaining visual disability due to abnormal foveal anatomy and function. Optic atrophy occurred in several eyes. Its pathogenesis may be multifactorial. Further research is necessary to elucidate the mechanisms of vascular closure in the retina as well as the pathogenesis of destructive encephalopathy in this exceptionally severe disease. Valid therapeutic possibilities may then become more obvious than they are at present. It is possible that the retina and brain undergo similar disease processes in incontinentia pigmenti.