It is a rare congenital tumor derived from the nonpigmented ciliary epithelium
, and usually occur between 5 and 20 years of age.
Intraocular medulloepithelioma is a congenital tumor of the nonpigmented ciliary epithelium
, usually diagnosed in childhood.
The vascular layer of the ciliary body is located between its muscle layer and the 2 layers of ciliary epithelium
. The choroid, the largest and most posterior portion of the uvea, is located between the retinal pigment epithelium and the sclera and extends from the ora serrata to the optic nerve.
Free tumor cells express TGF-[beta] and VEGF, are spread via the aqueous humor between the vitreous base and ciliary epithelium
for 360[degrees], migrate through the pupil where they become implanted into the iris, and cause neo vascularization of the iris.
Beta blockers reduce Intraocular Pressure (IOP) by blockade of sympathetic nerve endings in the ciliary epithelium
causing a fall in aqueous humour production.
As there are no nicotinic receptors in the ciliary epithelium
, nicotine from tobacco has no effect on the site of production of aqueous humor.
(1,2,3) Transscleral cyclophotocoagulation (TS-CPC) is currently a widely employed method of ciliary body ablation that reduces aqueous humor formation by destroying the ciliary body and ciliary epithelium
using a continuous diode laser energy source.
The rate of production is also influenced by adrenergic receptors in the ciliary epithelium
. [beta]-antagonists, for example, Timolol, and [alpha]-2 agonists, such as brimonidine, both suppress aqueous production.