William H Wildgoose MRCVS
Pet fish vet
Intraocular tumours in goldfish
Tumours that develop inside the eye are exceptionally rare in fish although they appear more commonly in black moors (telescope eye goldfish varieties). They cause noticeable enlargement of the eyeball which is easily seen by comparing to the opposite unaffected eye. They are often at an advanced stage when first presented for treatment and ultrasound scanning is the most effective means of diagnosis. Identifying the exact tissue type is challenging and requires specialised staining of histological samples. Enucleation is often unsuccessful, and this may be related to collateral damage to the brain. Click here for a scientific report.
This 11+year old telescope eye goldfish had lived on its own before developing a rapidly growing swelling of the left eye. A solid mass had developed under the eye together with a fluid-filled cyst that bulged outwards. The corneal surface was densely pigmented and opaque making it impossible to see into the eyeball.
A large, black-pigmented mass situated behind the eyeball was protruding through the white surface at the back of the eye and appeared to surround the optic nerve. The fish was euthanised due to the rapid growth of the tumour and poor prognosis.
The skin tumour regrew over 3 months and invaded the gill space. The fish was euthanised because of poor health. The eye was sent for pathological examination and considered to be a neurofibroma originating from the optic nerve sheath. It occupied most of the eye and had destroyed much of the retina.
This 11+year old telescope eye goldfish had lived on its own before developing a rapidly growing swelling of the left eye. A solid mass had developed under the eye together with a fluid-filled cyst that bulged outwards. The corneal surface was densely pigmented and opaque making it impossible to see into the eyeball.