Objective. To present the results of successful treatment of a patient with corneal lesions caused by Acanthamoeba spp. receiving long-term conservative treatment.Methods. A child with corneal ulcer of mixed etiology with a history of wearing orthokeratology lenses and long-term ineffective treatment in Moscow hospitals was referred to Moscow in S.N. Fyodorov Eye Microsurgery Federal State Institution. The patient underwent a complete ophthalmological examination, including confocal microscopy.Results. The condition of the child’s eye was extremely severe, live and dead cysts of Acantamoeba spp were found in the central zone of the cornea at the depth of 113–149 μm, Along with intensive conservative treatment with catheterisation of the retrobulbar space and introduction of drugs into the irrigation system, UV corneal crosslinking was performed twice.Conclusion. Treatment according to the proposed method allowed to achieve excellent results: there was no corneal syndrome, complete epithelialisation of the corneal defect, disappearance of corneal edema and remission of uveitis manifestations. According to the data of confocal microscopy there is no growth of microflora and acanthamoeba cysts.