Severe color change in corneal tattoos: Report of 3 cases

Corneal tattooing is a noninvasive technique which appears relatively well-tolerated in the medium term. We report the cases of 3 patients with a significant change in the color of their tattoos performed over 5 years previously. Three patients with a history of intracorneal tattooing several years previously were studied because of a significant change from their initial color. Each patient's file was reviewed with analysis of slit lamp photographs, OCT and specular microscopy. All three patients experienced a significant color change in their tattoos between 5 and 6 years after surgery. The color had changed to golden-brown. Retrospective analysis of the components of the tattoo ink found the presence of iron in the black pigment. We believe that pigments composed of iron oxide are transformed into golden-brown ferric iron oxide in the presence of oxygen in the aqueous environment. The presence of moderate corneal edema in these three cases of multioperated patients could explain, in these specific cases, the occurrence of oxidation typically not described. Corneal tattooing remains a simple and very interesting technique when partial or total absence of iris causes significant photophobia. However, the significant changes in color that we report more than 5 years later suggest removing iron from the dyes used for the cornea and limiting its use in cases of limited endothelial prognosis. A long-term evaluation of corneal tattoos appears necessary.