| Eye proptosis | |
|---|---|
| Classification and external resources | |
| DiseasesDB | 18612 |
| MeSH | D005094 |
Eye proptosis is a condition resulting in forward displacement and entrapment of the eye from behind by the eyelids. The condition is also known as eye dislocation and eye luxation. It is a common result of head trauma and pressure exerted on the front of the neck too hard in dogs. Most commonly it occurs in brachycephalic (short nosed) breeds. In cats, eye proptosis is uncommon and is often accompanied by facial fractures.[1]
About 40 percent of proptosed eyes retain vision after being replaced in the orbit, but in cats very few retain vision.[2] Replacement of the eye requires general anesthesia. The eyelids are pulled outward, and the eye is gently pushed back into place. The eyelids are sewn together in a procedure known as tarsorrhaphy for about five days to keep the eye in place.[3] Replaced eyes have a higher rate keratoconjunctivitis sicca and keratitis and often require lifelong treatment. If there is severe damage, the eye is removed in a relatively simple surgery known as enucleation of the eye.
The prognosis for a replaced eye is determined by the extent of damage to the cornea and sclera, the presence or absence of a pupillary light reflex, and the presence of ruptured rectus muscles. The rectus muscles normally help hold the eye in place and direct eye movement. Rupture of more than two rectus muscles usually requires that the eye be removed, because there is usually also significant blood vessel and nerve damage.[3] Compared to brachycephalic breeds, dochilocephalic (long nosed) breeds usually have more trauma to the eye and its surrounding structures, so there is a worse prognosis.[4]
Although human eye proptosis or luxation is uncommon, both women and men have attempted the Guinness World Record for "eye-popping". Eye luxation is therefore not unique to dogs and can be acquired from natural causes at birth, rather than from head trauma. Proptosis is also seen in association with Graves' Disease, a form of hyperthyroidism.
Although Cláudio Paulo Pinto, who is the Brazilian record holder for eye-popping, can "pop" his out 7 millimetres (0.28 in), the current world record holder is Kim Goodman of Chicago who can extend her globes 11 millimetres (0.43 in) out of her sockets.[5]