ObjectiveTo observe the clinical features of late-onset cone dystrophy (LOCD). MethodsEleven patients (15 eyes) of LOCD were enrolled in this study. The patients included 7 males and 4 females. The age was ranged from 50 to 79 years, with a mean age of 60.2 years. There was no obvious photophobia and hemeralopia. The visual acuity was less than or equal to 0.05 in 4 eyes, 0.06-0.2 in 5 eyes, 0.3-1.0 in 6 eyes. Visual acuity, slit lamp microscope, indirect ophthalmoscopy, flash electroretinogram (FERG) and multifocal electroretinograms (mfERG) were examined for all patients, fundus fluorescein angiography (FFA) for 11 eyes, optical coherence tomography (OCT) and chromoptometry for 6 eyes. ResultsThere were 6 eyes with red/green color blindness, 2 eyes with color weakness. Normal fundus was found in 11 eyes, while derangement of macular pigment epithelial in 4 eyes. FFA results showed that there were 5 eyes with normal fundus, 4 eyes with blocked fluorescent spots, 2 eyes with oval macular atrophy. FERG results showed that in cone response, the amplitude was lower in 6 eyes (including mild decrease in 4 eyes, moderate decrease in 1 eye and severe decrease in 1 eye); both in cone and rod response, the amplitude were lower in 9 eyes. mfERG results showed that central part of the cone (less than 7 degree from the center) was damaged in 5 eyes, both central and peripheral part (outside of 7 degree) of the cone were damaged in 10 eyes. OCT results showed that pigment derangement in 3 eyes, fovea was normal in 8 eyes, thinned in 5 eyes (foveal thickness was 83-111 μm). ConclusionsThe fundus manifestations of LOCD patients are variable, from normal fundus to oval macular atrophy. FERG is abnormal, which mainly in cone response at early stage and both in cone and rod response at late stage. Central part and (or) peripheral part of the cone are abnormal by mfERG.