[Dr Alan]

Intraocular tumors, sometimes melanomas, sometimes other tumors, can occur in many species. If it is a melanoma, the potential for it to be an aggressive and malignant (cancerous) tumor is high. Unfortunately, the only way to establish a diagnosis is by biopsy, and in larger animals, that often means enucleation (surgically amputating the eyeball). How that would play out with a crested gecko is questionable, since there's not a great deal of skin to work with, and the surgeon would be dealing with the eyelid crests. In mammals other than humans, enucleation usually entails removing the globe and closing skin over the socket. This would present some difficulties with a crested gecko, and replacing the globe with an artificial eye is very problematic and costly. Your veterinarian might be able to obtain a diagnostic biopsy via fine-needle aspiration of the suspected tumor but even if that was successful in establishing the diagnosis, you still would likely be looking at further surgery (enucleation).

It might be possible to enucleate the eyeball and just leave the "socket" empty (get her a patch!) but then you'd be dealing with the cosmetic issue - and I'm unsure how that would ultimately look, as well as having an open wound and a possible infection problem, given crested geckos' habit of eyeball licking.