May Be Caused by

 Common

Craniometaphyseal dysplasia

Enucleation

Fibrous dysplasia

Hypercalcemia

Meningioma

Optic nerve atrophy

Osteopetrosis

Osteosarcoma

Paget disease of bone

Radiation therapy

Thalassemia

 Uncommon

Anophthalmos

Antral cyst

Antral neoplasm

Congenital orbital hypoplasia

Coronal suture craniosynostosis

Forebrain hypoplasia

Frontal sinus mucocele

Frontal sinus neoplasm

Microphthalmia

Neurofibromatosis

Orbital dysplasia

Sphenoid sinusitis