Ciliary processes
Processus ciliares
- Related terms: Ciliary process
Definition
The ciliary processes are radial, fold like projections arising from the pars plicata (corona ciliaris) of the ciliary body, located just posterior to the iris. They are arranged in a circular pattern around the lens and typically consist of approximately 70 major processes, with smaller intermediate ridges between them.
Aqueous humour production
Each ciliary process has a central vascular core containing fenestrated capillaries, surrounded by a thin stroma and covered by a double layer of epithelium. This epithelium includes an outer pigmented layer and an inner non-pigmented layer. The non-pigmented layer being highly specialised for active secretion of aqueous humour. The extensive folding of these processes significantly increases the surface area, making them the primary site of aqueous humour production.
Accommodation for near vision
In addition to their secretory role, the ciliary processes serve as attachment points for the zonular fibres (suspensory ligaments of the lens), which transmit forces from the ciliary muscle to the lens during accommodation.
Through these functions, the ciliary processes are essential for both intraocular fluid dynamics and visual focusing.
References
Standring, S. (Ed.). (2015). Eye (Chapter 42). In Gray's anatomy: The anatomical basis of clinical practice (41st ed., pp. 686-706). Churchill Livingstone.
