Primary Acquired Nasolacrimal Duct Obstruction (PANDO)
PANDO is a condition in which chronic inflammation and scarring block the tear drainage system without another identifiable cause for the obstruction, such as trauma, tumor, etc. Patients with PANDO usually seek help when tears overflow. Patients with obstructions are also at risk for infection of the nasolacrimal system.
Orbital Inflammatory Syndrome (OIS)
OIS refers to noninfectious inflammation of the orbital tissues—the lacrimal gland (dacryoadenitis), extraocular muscles (myositis), and sclera (scleritis)—or diffuse inflammation and/or a combination of any of these tissues. The inflammation may be idiopathic or may be secondary to a bona fide inflammatory condition, such as sarcoidosis, granulomatosis with polyangiitis, IgG4-related disease, and others.
Patients with OIS often seek help because their eyelids and the area around their eyes are red, swollen, and painful. The eye may be protruding. Vision problems, including double vision and a decrease of vision, can occur.