 
Choroidal or retinal detachment, masses or leukocaria are the different ways of presentation of globe lesions.
Etiologies vary according to age of onset.
In childhood, retinoblastoma is the
most common intraocular malignancy and occurs before 2 years old.
Sporadic forms are unilateral whereas inherited diseases (10 %) are
bilateral in 33 % of tumors (2 to 8 %) and can be associated with
intracranial midline neuroectodermal tumors, specially pineal lesions
(trilateral retinoblastomas), as well as soft tissue sarcomas (ref 1).
If imaging is better to demonstrate extension to the optic nerve (fig.
1), subarachnoid seeding and intracranial involvement (fig. 2), CT scan
can found in 95 % of cases, calcifications, a very important
radiological sign in the differential diagnosis of the following
pathologies associated with leukocaria (fig. 3). Coats disease is a
rare congenital non familial primary anomaly of the retina with leaking
telangiectasic vessels and exudative retinal detachment (fig. 4).
Unilateral, it effects predominantly male children between 6-8 years
and simulate toxocariosis (ref. 2). Persistent hyperplastic primary
vitreous results from failure of involution of the fetal hyaloid
vasculature (ref. 2). Detected at birth, the globe appears hypoplasic
(fig. 5). Retinopathy of prematurity is usually a bilateral avascular
proliferative disorder affecting newborns with low birth weights,
probably associated with oxygene administration (ref. 3).
In adulthood, uveal melanoma is the
most common intraocular tumor with a white/black ratio of 15/1 (ref.
4). US is extremely helpful for detecting small (less than 3 mm) and
flat lesions. Because of the paramagnetic properties of melanin MR
imaging is the method of choice for accurate diagnosis in melanomas and
demonstrate orbital invasion and intracranial extension (fig. 6). Often
confused with melanomas, choroidal hemangiomas are congenital
hamartomas seen in middle aged people (ref. 4). They are solitary,
located in the macular area whereas hemangiomas seen in children with
Sturge Weber syndrome are diffuse processes (fig. 7).
Radiologically and clinically uveal
melanomas can be confused with uveal metastases. The tumorous embolies
reach the orbit via the short ciliary arteries and affect the posterior
half of the globe. The tumors that metastasize most frequently are
breast (more than 50 %) and lung carcinomas. Unilateral in 90 % of
cases, they are often small and difficult to recognize underneath
subretinal fluid. Lymphomas and leukemias may infiltrate the globe
(fig. 34). Inflammatory lesions affecting the globe include
granulomatous diseases such as sarcoidosis with uveal tract
involvement, Wegener’s granulomatosis and pseudo-tumors with scleritis
or Tenon fasciitis (fig. 8). Otherwise, posterior scleritis may be
observed in bacterial, fungal, viral or auto-immune disorders.
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