Cone damage in patients receiving high-dose irofulven treatment.

OBJECTIVES To describe the clinical, perimetric, and electroretinographic (ERG) results of 4 patients with cone dysfunction following irofulven treatment including the histopathologic and immunocytochemical features of one patient's retinas. DESIGN Observational case series. METHODS The patients were examined clinically, including perimetric and ERG evaluations. Eyes from patient 1 and healthy postmortem eyes were processed for histopathologic and immunocytochemistry studies with antibodies specific for cones, rods, and reactive Müller cells. MAIN OUTCOME MEASURES Clinical signs and symptoms, perimetry, ERG, retinal histopathologic and immunocytochemistry study results. RESULTS All 4 patients had ERG changes consistent with abnormal cone responses and relatively normal rod responses. Compared with control eyes, the retina of patient 1 had approximately half the normal numbers of macular cones and fewer peripheral cones. The number of rods were normal but all rod and cone outer segments were shortened. CONCLUSION High-dose irofulven treatment causes cone-specific damage with relative sparing of rods.