The Cornea: No Difference in the Wound Healing Response to Injury Related to Whether, or Not, There’s a Bowman’s Layer
Bowman’s layer is an acellular layer in the anterior stroma found in the corneas of humans, most other primates, chickens, and some other species. Many other species, however, including the rabbit, dog, wolf, cat, tiger, and lion, do not have a Bowman’s layer. Millions of humans who have had photore...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-04-01
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| Series: | Biomolecules |
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| Online Access: | https://www.mdpi.com/2218-273X/13/5/771 |
| _version_ | 1827741903622242304 |
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| author | Steven E. Wilson |
| author_facet | Steven E. Wilson |
| author_sort | Steven E. Wilson |
| collection | DOAJ |
| description | Bowman’s layer is an acellular layer in the anterior stroma found in the corneas of humans, most other primates, chickens, and some other species. Many other species, however, including the rabbit, dog, wolf, cat, tiger, and lion, do not have a Bowman’s layer. Millions of humans who have had photorefractive keratectomy over the past thirty plus years have had Bowman’s layer removed by excimer laser ablation over their central cornea without apparent sequelae. A prior study showed that Bowman’s layer does not contribute significantly to mechanical stability within the cornea. Bowman’s layer does not have a barrier function, as many cytokines and growth factors, as well as other molecules, such as EBM component perlecan, pass bidirectionally through Bowman’s layer in normal corneal functions, and during the response to epithelial scrape injury. We hypothesized that Bowman’s layer represents a visible indicator of ongoing cytokine and growth factor-mediated interactions that occur between corneal epithelial cells (and corneal endothelial cells) and stromal keratocytes that maintain the normal corneal tissue organization via negative chemotactic and apoptotic effects of modulators produced by the epithelium on stromal keratocytes. Interleukin-1 alpha, produced constitutively by corneal epithelial cells and endothelial cells, is thought to be one of these cytokines. Bowman’s layer is destroyed in corneas with advanced Fuchs’ dystrophy or pseudophakic bullous keratopathy when the epithelium becomes edematous and dysfunctional, and fibrovascular tissue commonly develops beneath and/or within the epithelium in these corneas. Bowman’s-like layers have been noted to develop surrounding epithelial plugs within the stromal incisions years after radial keratotomy. Although there are species-related differences in corneal wound healing, and even between strains within a species, these differences are not related to the presence or absence of Bowman’s layer. |
| first_indexed | 2024-03-11T03:54:43Z |
| format | Article |
| id | doaj.art-5e6f7183557a4d01a0afdced01c0529f |
| institution | Directory Open Access Journal |
| issn | 2218-273X |
| language | English |
| last_indexed | 2024-03-11T03:54:43Z |
| publishDate | 2023-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Biomolecules |
| spelling | doaj.art-5e6f7183557a4d01a0afdced01c0529f2023-11-18T00:38:57ZengMDPI AGBiomolecules2218-273X2023-04-0113577110.3390/biom13050771The Cornea: No Difference in the Wound Healing Response to Injury Related to Whether, or Not, There’s a Bowman’s LayerSteven E. Wilson0The Cole Eye Institute, I-32, Cleveland Clinic, 9500 Euclid Ave, Cleveland, OH 44195, USABowman’s layer is an acellular layer in the anterior stroma found in the corneas of humans, most other primates, chickens, and some other species. Many other species, however, including the rabbit, dog, wolf, cat, tiger, and lion, do not have a Bowman’s layer. Millions of humans who have had photorefractive keratectomy over the past thirty plus years have had Bowman’s layer removed by excimer laser ablation over their central cornea without apparent sequelae. A prior study showed that Bowman’s layer does not contribute significantly to mechanical stability within the cornea. Bowman’s layer does not have a barrier function, as many cytokines and growth factors, as well as other molecules, such as EBM component perlecan, pass bidirectionally through Bowman’s layer in normal corneal functions, and during the response to epithelial scrape injury. We hypothesized that Bowman’s layer represents a visible indicator of ongoing cytokine and growth factor-mediated interactions that occur between corneal epithelial cells (and corneal endothelial cells) and stromal keratocytes that maintain the normal corneal tissue organization via negative chemotactic and apoptotic effects of modulators produced by the epithelium on stromal keratocytes. Interleukin-1 alpha, produced constitutively by corneal epithelial cells and endothelial cells, is thought to be one of these cytokines. Bowman’s layer is destroyed in corneas with advanced Fuchs’ dystrophy or pseudophakic bullous keratopathy when the epithelium becomes edematous and dysfunctional, and fibrovascular tissue commonly develops beneath and/or within the epithelium in these corneas. Bowman’s-like layers have been noted to develop surrounding epithelial plugs within the stromal incisions years after radial keratotomy. Although there are species-related differences in corneal wound healing, and even between strains within a species, these differences are not related to the presence or absence of Bowman’s layer.https://www.mdpi.com/2218-273X/13/5/771Bowman’s layercorneal wound healingfibrosismyofibroblastskeratocytescorneal fibroblasts |
| spellingShingle | Steven E. Wilson The Cornea: No Difference in the Wound Healing Response to Injury Related to Whether, or Not, There’s a Bowman’s Layer Biomolecules Bowman’s layer corneal wound healing fibrosis myofibroblasts keratocytes corneal fibroblasts |
| title | The Cornea: No Difference in the Wound Healing Response to Injury Related to Whether, or Not, There’s a Bowman’s Layer |
| title_full | The Cornea: No Difference in the Wound Healing Response to Injury Related to Whether, or Not, There’s a Bowman’s Layer |
| title_fullStr | The Cornea: No Difference in the Wound Healing Response to Injury Related to Whether, or Not, There’s a Bowman’s Layer |
| title_full_unstemmed | The Cornea: No Difference in the Wound Healing Response to Injury Related to Whether, or Not, There’s a Bowman’s Layer |
| title_short | The Cornea: No Difference in the Wound Healing Response to Injury Related to Whether, or Not, There’s a Bowman’s Layer |
| title_sort | cornea no difference in the wound healing response to injury related to whether or not there s a bowman s layer |
| topic | Bowman’s layer corneal wound healing fibrosis myofibroblasts keratocytes corneal fibroblasts |
| url | https://www.mdpi.com/2218-273X/13/5/771 |
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