Ora serrata
Ora serrata
Definition
The ora serrata is the anterior limit of the photosensitive retina and marks the transition between the neural (light sensitive) retina and the nonneural, non-photosensitive ciliary epithelium. In simple terms, it represents the point inside the eye where the seeing part of the retina ends and the non-seeing part begins.
Posterior to the ora serrata, the retina contains all its specialised ten layers, including photoreceptors responsible for detecting light and forming images. As one moves anteriorly toward this boundary, these layers gradually thin and disappear, and beyond it, the tissue becomes a simpler double-layered epithelium continuous with the ciliary body, consisting of an outer pigmented and an inner nonpigmented layer.
Structurally, the ora serrata appears as a serrated line located circumferentially near the anterior margin of the retina, just posterior to the pars plana region of the ciliary body. Functionally, it demarcates the limit of visual field and maintains continuity between the retina and anterior uveal tract.
Clinical Relevance
1. Retinal detachment
The ora serrata is a relatively firm attachment site, but tractional forces near this region may contribute to peripheral retinal tears.
2. Vitreoretinal interface
Strong vitreous base attachment spans the ora serrata → important in vitreoretinal surgery.
References
Standring, S. (Ed.). (2015). Eye (Chapter 42). In Gray's anatomy: The anatomical basis of clinical practice (41st ed., pp. 686-696). Churchill Livingstone.
