1313 The blood-aqueous barrier after corneal excimer laser surgery

Pm-pose: T&o&g is employed to provide unsightly oxseas with a central srtificial pupil or to reduce glare from a parscentral leucoms. The technique is to apply platinum (or gold) chloride to the designated area sfter an epitbelial debridement and subsequently to apply a reducing agent. This procedure is nowadays tmcmnmon in tbe western world, but is still popular in some countries. According to the literature of the last half of the century metallic salt granules are exclusively seen witbin tbe comeal stmma However, as early as 1929 B&d reported deposition of these grsnula also in tbe regenerated epitbelium’. The aim of this study was to clarify tbis controversy usmg modem techniques M&o&: The comeal button of 59 year-old male who received a comeal tattoo in Iran 20 years ago was examined by conventional light and electron microscopy. Immuncchistcchemistry was performed using CD 68 macropbage marker. Resulrs: L&t microscopy revealed clumps of black granules in the kerstocytes of tbe anterior and mid stroma and to a less extend behveen stromal lamellae Deposition of these granules was also suspected in basal epitbelial cells. Trsnsmission electron microscopy confirmed a predominating intracytoplssmstic localisation of tbe salt granules in keratocytes, but also showed the deposition of identical electron dense particles in tbe cytoplasm oftbe epitbelisl basal cells. Unlike inflammatory cells adherent to the posterior surface of tbe comes, neltber keratocytes nor epitbelial cells containing metsllic salt granules were positive for CD68. Conclusions: There IS ultrastructural evidence of metallic salt granules deposition in basal epitbelial cells. Apparently, there is retrograde movement of these granules to tbe comeal surface with subsequent phagocytosis by tbe epitbelium.