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Bowman's layer
Vertical section of human cornea from near the margin. Magnified. Epithelium Anterior elastic lamina substantia propria Posterior elastic lamina Endothelium of the anterior chamber Oblique fibers in the anterior layer of the substantia propria Lamellae, the fibers of which are cut across, producing a dotted appearance Corneal corpuscles appearing fusiform in section Lamellae, the fibers of which are cut longitudinally Transition to the sclera, with more distinct fibrillation, and surmounted by a thicker epithelium Small bloodvessels cut across near the margin of the cornea
Details
Identifiers
Latin	lamina limitans anterior corneae
MeSH	D050541
TA98	A15.2.02.019
FMA	58273
Anatomical terminology[edit on Wikidata]

The Bowman's layer (Bowman's membrane, anterior limiting lamina, anterior elastic lamina) is a smooth, acellular, nonregenerating layer, located between the superficial epithelium and the stroma in the cornea of the eye. It is composed of strong, randomly oriented collagen fibrils in which the smooth anterior surface faces the epithelial basement membrane and the posterior surface merges with the collagen lamellae of the corneal stroma proper.

In adult humans, Bowman's layer is 8-12 μm thick. With ageing, this layer becomes thinner.

The function of the Bowman's layer remains unclear and it appears to have no critical function in corneal physiology. Recently, it is postulated that the layer may act as a physical barrier to protect the subepithelial nerve plexus and thereby hastens epithelial innervation and sensory recovery. Moreover, it may also serve as a barrier that prevents direct traumatic contact with the corneal stroma and hence it is highly involved in stromal wound healing and the associated restoration of anterior corneal transparency at the morphological level.

Part of the Bowman's layer is ablated by the photorefractive keratectomy refractive surgery (commonly known as PRK). As the layer is non-generative, the section of the layer ablated in the procedure is lost forever.

History

The Bowman's layer is named after Sir William Bowman (1816–1892), an English physician, anatomist and ophthalmologist, who discovered this structure. Bowman's layer is not a true basement membrane, despite being originally referred to as such.

See also

• Refractive surgery
• Descemet's membrane

References

1. Kenyon, KR. Morphology and pathologic responses of the cornea to disease. In: Smolin G, Thoft RA, eds. The Cornea. Scientific Foundations and Clinical Practice. Boston: Little, Brown & Co.; 1983:45.
2. Hogan MJ, Alvarado JA, Weddell E: Histology of the Human Eye. Philadelphia: WB Saunders, 1971
3. Wilson, SE; Hong, JW (Jul 2000). "Bowman's layer structure and function: critical or dispensable to corneal function? A hypothesis". Cornea. 19 (4): 417–20. doi:10.1097/00003226-200007000-00001. PMID 10928749. S2CID 10793246.
4. Lagali, N; Germundsson, J; Fagerholm, P (Sep 2009). "The role of Bowman layer in corneal regeneration after phototherapeutic keratectomy: a prospective study using in vivo confocal microscopy". Invest Ophthalmol Vis Sci. 50 (9): 4192–8. doi:10.1167/iovs.09-3781. PMID 19407024.
5. Mills, Stacey, ed. (2020). Histology for Pathologists (5th ed.). Wolters Kluwer. p. 337. ISBN 978-1496398949.
6. Wilson, S. E. (2020). "Bowman's layer in the cornea– structure and function and regeneration". Experimental Eye Research. 195: 108033. doi:10.1016/j.exer.2020.108033. PMC 7283008. PMID 32339517.

External links

• Histology image: 08002loa – Histology Learning System at Boston University
• Diagram at sheinman.com
• Diagram at cornea_crosssection_en.jpg

v t e Anatomy of the globe of the human eye
Fibrous tunic (outer)	Sclera Episcleral layer Schlemm's canal Trabecular meshwork Cornea Limbus layers Epithelium Bowman's Stroma Dua's layer Descemet's Endothelium
Uvea / vascular tunic (middle)	Choroid Capillary lamina of choroid Bruch's membrane Sattler's layer Ciliary body Ciliary processes Ciliary muscle Pars plicata Pars plana Iris Stroma Pupil Iris dilator muscle Iris sphincter muscle
Retina (inner)	Layers Inner limiting membrane Nerve fiber layer Ganglion cell layer Inner plexiform layer Inner nuclear layer Outer plexiform layer Outer nuclear layer External limiting membrane Layer of rods and cones Retinal pigment epithelium Cells Photoreceptor cells (Cone cell, Rod cell) → (Horizontal cell) → Bipolar cell → (Amacrine cell) → Retina ganglion cell (Midget cell, Parasol cell, Bistratified cell, Giant retina ganglion cells, Photosensitive ganglion cell) → Diencephalon: P cell, M cell, K cell, Muller glia Other Macula Perifoveal area Parafoveal area Fovea Foveal avascular zone Foveola Optic disc Optic cup Ora serrata
Anatomical regions of the eye	Anterior segment Adnexa (Eyebrow, Eyelid, Conjunctiva, Lacrimal system, Orbit) Fibrous tunic Anterior chamber Aqueous humour Iris Posterior chamber Ciliary body Lens Capsule of lens Zonule of Zinn Posterior segment Vitreous chamber Vitreous body Retina Choroid
Other	Keratocytes Ocular immune system Optical coherence tomography Eye care professional Eye disease Refractive error Accommodation Physiological Optics Visual perception

• Human eye anatomy
• Anatomy named for one who described it