I wonder whether infectious agents including oncogenic viruses, bacteria and possibly parasites play any role in the genesis or might acts as a factor or co-factor in the development and prognosis of the ocular tumors
Some cestodes, especially Echinococcus hydatids cause ocular tumors or cysts. Dirofilaria repens, a nematode, can as well. See the references below from our work on the latter.
Bruce
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Undoubtedly, as already mentioned above, different infectious agents can lead to tumor lesions in eyes. However, some of these agents, especially viruses, may be the genesis of some kinds of cancer and "not merely tumors". The differentiation between these concepts is necessary. On ocular neoplasias induced by viruses, I suggest you the reading, for example, of the reviews:
Carreira et al. HIV and HPV infections and ocular surface squamous neoplasia: systematic review and meta-analysis. Br J Cancer. 2013 Oct 1;109(7):1981-8. doi: 10.1038/bjc.2013.539.
Gichuhi et al. Epidemiology of ocular surface squamous neoplasia in Africa. Trop Med Int Health. 2013 Dec;18(12):1424-43. doi: 10.1111/tmi.12203.