Intraocular lymphoma (IOL) is a rare lymphocytic malignancy. The gold standard for the definite diagnosis remains histopathologic examination of the ocular specimen. But cytologic confirmation of malignant lymphoma cells in vitreous or chorioretinal specimens is challenging and dependending on highly skilled cytopathologist, due to the sparse cellularity and specimen degeneration. Consequently, false-negative rates arecommon, which delays diagnosis and treatment seriously. Because of the limited diagnostic capacity of cytology, other adjunct diagnostic tools have been developed. Additional procedures that may support IOL diagnosis include flow cytometry, immunocytochemistry, cytokines study with identification of interleukin (IL)-10 and IL-6 level, and polymerase chain reaction amplification. And more recently, new techniques of mutational analysis have been validated for the diagnosis of vitreoretinal lymphoma (VRL) and may represent a helpful diagnostic tool for the detection of early cases. Metagenomic deep sequencing technology may provide an important basis for VRL diagnosis and personalized treatment. In the future, it is expected to deepen the understanding of IOL disease phenotypes at the molecular level, discover new target therapies, monitor response to treatment, and detect intraocular recurrences. These may offer insights into how we might create a tailored therapeutic approach for each patient's VRL in the future.