Dacryoadenitis can be diagnosed by examination of the eyes and lids. Special tests such as a CT scan may be required to search for the cause. Sometimes biopsy will be needed to be sure that a tumor of the lacrimal gland is not present.

Mumps can be prevented by immunization. Gonococcus, bacteria can be avoided by the use of condoms. Most other causes cannot be prevented.

The best imaging modality for idiopathic orbital inflammatory disease is contrast-enhanced thin section magnetic resonance with fat suppression. The best diagnostic clue is a poorly marginated, mass-like enhancing soft tissue involving any area of the orbit.

Overall, radiographic features for idiopathic orbital inflammatory syndrome vary widely. They include inflammation of the extraocular muscles (myositis) with tendinous involvement, orbital fat stranding, lacrimal gland inflammation and enlargement (dacryoadenitis), involvement of the optic sheath complex, uvea, and sclera, a focal intraorbital mass or even diffuse orbital involvement. Bone destruction and intracranial extension is rare, but has been reported. Depending on the area of involvement, IOI may be categorized as:

- Myositic

- Lacrimal

- Anterior – Involvement of the globe, retrobulbar orbit

- Diffuse – Multifocal intraconal involvement with or without an extraconal component

- Apical – Involving the orbital apex and with intracranial involvement

Tolosa–Hunt syndrome is a variant of orbital pseudotumor in which there is extension into the cavernous sinus through the superior orbital fissure. Another disease variant is Sclerosing pseudotumor, which more often presents bilaterally and may extend into the sinuses.

CT findings

In non-enhanced CT one may observe a lacrimal, extra-ocular muscle, or other orbital mass. It may be focal or infiltrative and will have poorly circumscribed soft tissue. In contrast-enhanced CT there is moderate diffuse irregularity and enhancement of the involved structures. A dynamic CT will show an attenuation increase in the late phase, contrary to lymphoma where there is an attenuation decrease. Bone CT will rarely show bone remodeling or erosion, as mentioned above.

MR findings

On MR examination there is hypointensity in T1 weighted imaging (WI), particularly in sclerosing disease. T1WI with contrast will show moderate to marked diffuse irregularity and enhancement of involved structures. T2 weighted imaging with fat suppression will show iso- or slight hyperintensity compared to muscle. There is also decreased signal intensity compared to most orbital lesions due to cellular infiltrate and fibrosis. In chronic disease or sclerosing variant, T2WI with FS will show hypointensity (due to fibrosis). Findings on STIR (Short T1 Inversion Recovery) are similar to those on T2WI FS. In Tolosa–Hunt syndrome, findings include enhancement and fullness of the anterior cavernous sinus and superior orbital fissure in T1WI with contrast, while MRA may show narrowing of cavernous sinus internal carotid artery (ICA).

Ultrasonographic findings

On grayscale ultrasound there is reduced reflectivity, regular internal echoes, and weak attenuation, in a way, similar to lymphoproliferative lesions.

IOI or orbital pseudotumor is the second most common cause of exophthalmos following Grave’s orbitopathy and the third most common orbital disorder following thyroid orbitopathy and lymphoproliferative disease accounting for 5–17.6% of orbital disorders, There is no age, sex, or race predilection, but it is most frequently seen in middle-aged individuals. Pediatric cases account for about 17% of all cases of IOI.

The extent of inflammation that can occur in IgG4-ROD is well demonstrated on magnetic resonance imaging (MRI).

Infraorbital nerve enlargement (IONE) is considered to be a particularly suspicious sign of IgG4-ROD, but seems to occur only when inflammation is in direct contact with the infraorbital canal. IONE is defined as the infraorbital nerve diameter being greater than the optic nerve diameter in the coronal plane.

Symptoms, if any, can be mild even in the presence of significant swelling or masses.

Lacrimal gland involvement may cause swelling of the upper eyelid, or proptosis if there is severe swelling. Other orbital masses or inflammation can result in visual disturbance (blurred vision, double vision, visual field impairment), restricted eye movements, pain or discomfort, numbness in the distribution of the supraorbital and/or infraorbital nerves, or proptosis.

IgG4-related ophthalmic disease has been estimated to account for approximately 25% of all cases of proptosis, eyelid swelling and other features of orbital swelling.

Measurement of the degree of exophthalmos is performed using an exophthalmometer.

Most sources define exophthalmos/proptosis as a protrusion of the globe greater than 18 mm.

The term exophthalmos is often used when describing proptosis associated with Graves' disease.

Exophthalmos is commonly found in dogs. It is seen in brachycephalic (short-nosed) dog breeds because of the shallow orbit. However, it can lead to keratitis secondary to exposure of the cornea. Exophthalmos is commonly seen in the Pug, Boston Terrier, Pekingese, and Shih Tzu.

It is a common result of head trauma and pressure exerted on the front of the neck too hard in dogs. In cats, eye proptosis is uncommon and is often accompanied by facial fractures.

About 40% of proptosed eyes retain vision after being replaced in the orbit, but in cats very few retain vision. 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. Replaced eyes have a higher rate of keratoconjunctivitis sicca and keratitis and often require lifelong treatment. If the damage is severe, 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 the eye to be removed, because significant blood vessel and nerve damage also usually occurs. Compared to brachycephalic breeds, dochilocephalic (long-nosed) breeds usually have more trauma to the eye and its surrounding structures, so the prognosis is worse .

Hypereosinophilia may occur in the setting of damage to a single specific organ due to a massive infiltration by eosinophils. This disorder is sub-classified based on the organ involved and is not considered to be a form of primary hypereosinophila, secondary hypereosinophila, or the idiopathic hypereosinophilic syndrome because: a) the eosinophils associated with the disorder have not been shown to be clonal in nature; b) a reason for the increase in blood eosinophils has not been determined; c) organ damage has not been shown to be do to eosinophils; and d) the disorder in each individual case typically is limited to the afflicted organ. Examples of organ-restricted hypereosinopilia include eosinophilic myocarditis, eosinophilic esophagitis, eosinophilic gastroenteritis, eosinophilic cystitis, eosinophilic pneumonia, eosinophilic fasciitis, eosinophilic folliculitis, eosinophilic cellulitis, eosinophilic vasculitis, and eosinophilic ulcer of the oral mucosa. Other examples of organ-restricted hepereosinophilia include those involving the heart, kidney, liver, colon, pulmonary pleurae, peritoneum, fat tissue, myometrium, and synovia.

A class of steroid hormones secreted by the adrenal gland, glucocorticoids, inhibit eosinophil proliferation and survival. In adrenal insufficiency, low levels of these hormones allow increased eosinophil proliferation and survival. This leads to increases in blood eosinophil levels, typically eosinophilia and, less commonly, hypereosinophilia.