Histopathologic and Immunohistochemical Studies of Keratoglobus

Association of Variants in TMEM45A With Keratoglobus

“…In keratoglobus, several aspects suggest a pathophysiologic association with extracellular matrix components in the corneal stroma. These include the characteristic ectatic clinical nature of thinning and protrusion, the association of keratoglobus with connective tissue disorders, and the typical histopathologic findings, which include stromal thinning and disruption of the collagen-rich Bowman layer, the anterior part of the corneal stroma . Taken together, the preliminary evidence on the functions of TMEM45A appear to coincide with the current evidence on keratoglobus pathophysiology.…”

Association of Variants in TMEM45A With Keratoglobus

“…In keratoglobus, several aspects suggest a pathophysiologic association with extracellular matrix components in the corneal stroma. These include the characteristic ectatic clinical nature of thinning and protrusion, the association of keratoglobus with connective tissue disorders, and the typical histopathologic findings, which include stromal thinning and disruption of the collagen-rich Bowman layer, the anterior part of the corneal stroma . Taken together, the preliminary evidence on the functions of TMEM45A appear to coincide with the current evidence on keratoglobus pathophysiology.…”

Presumptive keratoglobus in a great horned owl(Bubo virginianus)

“…These degradation enzymes were present diffusely throughout the cornea (as opposed to centrally as in keratoconus), although a higher concentration was noted in the basal epithelium near breaks in Bowman's layer . IHC studies also showed a decrease in the concentration of α1‐proteinase inhibitor in corneal epithelial cells, thus leading to an increase in protease activity . These findings suggest that an imbalance of degradation enzymes and proteinase inhibitors plays a role in the stromal thinning of keratoglobus corneas.…”

“…The three most commonly described histopathologic characteristics of keratoglobus in people include frequent disruptions or complete absence of Bowman's layer, stromal thinning most evident in the periphery, and breaks or thickening of Descemet's membrane . However, there are other definitions of keratoglobus that do not include corneal thinning .…”

“…The pathogenesis of keratoglobus is not clearly understood; however, immunohistochemistry (IHC) studies in humans have identified a significant increase in degradation enzymes such as matrix metalloproteinases (MMP‐1, MMP‐2, and MMP‐3) in keratoglobus corneas as compared to controls . These degradation enzymes were present diffusely throughout the cornea (as opposed to centrally as in keratoconus), although a higher concentration was noted in the basal epithelium near breaks in Bowman's layer . IHC studies also showed a decrease in the concentration of α1‐proteinase inhibitor in corneal epithelial cells, thus leading to an increase in protease activity .…”

Tuck-in Lamellar keratoplasty with an lenticule obtained by small incision lenticule extraction for treatment of Post- LASIK Ectasia

“…Discrepant histopathological, ultrastructural, and biochemical evidence suggests that the pathogenesis of post-LASIK ectasia and keratoconus could be different 12 . Post-LASIK ectasia might be considered the biologic equivalent of an interfiber disruption of composite materials.…”

Association of Variants in TMEM45A With Keratoglobus

“…In keratoglobus, several aspects suggest a pathophysiologic association with extracellular matrix components in the corneal stroma. These include the characteristic ectatic clinical nature of thinning and protrusion, the association of keratoglobus with connective tissue disorders, and the typical histopathologic findings, which include stromal thinning and disruption of the collagen-rich Bowman layer, the anterior part of the corneal stroma . Taken together, the preliminary evidence on the functions of TMEM45A appear to coincide with the current evidence on keratoglobus pathophysiology.…”

Presumptive keratoglobus in a great horned owl(Bubo virginianus)

“…These degradation enzymes were present diffusely throughout the cornea (as opposed to centrally as in keratoconus), although a higher concentration was noted in the basal epithelium near breaks in Bowman's layer . IHC studies also showed a decrease in the concentration of α1‐proteinase inhibitor in corneal epithelial cells, thus leading to an increase in protease activity . These findings suggest that an imbalance of degradation enzymes and proteinase inhibitors plays a role in the stromal thinning of keratoglobus corneas.…”

“…The three most commonly described histopathologic characteristics of keratoglobus in people include frequent disruptions or complete absence of Bowman's layer, stromal thinning most evident in the periphery, and breaks or thickening of Descemet's membrane . However, there are other definitions of keratoglobus that do not include corneal thinning .…”

“…The pathogenesis of keratoglobus is not clearly understood; however, immunohistochemistry (IHC) studies in humans have identified a significant increase in degradation enzymes such as matrix metalloproteinases (MMP‐1, MMP‐2, and MMP‐3) in keratoglobus corneas as compared to controls . These degradation enzymes were present diffusely throughout the cornea (as opposed to centrally as in keratoconus), although a higher concentration was noted in the basal epithelium near breaks in Bowman's layer . IHC studies also showed a decrease in the concentration of α1‐proteinase inhibitor in corneal epithelial cells, thus leading to an increase in protease activity .…”

Tuck-in Lamellar keratoplasty with an lenticule obtained by small incision lenticule extraction for treatment of Post- LASIK Ectasia

“…Discrepant histopathological, ultrastructural, and biochemical evidence suggests that the pathogenesis of post-LASIK ectasia and keratoconus could be different 12 . Post-LASIK ectasia might be considered the biologic equivalent of an interfiber disruption of composite materials.…”

Association of Variants in TMEM45A With Keratoglobus

“…In keratoglobus, several aspects suggest a pathophysiologic association with extracellular matrix components in the corneal stroma. These include the characteristic ectatic clinical nature of thinning and protrusion, the association of keratoglobus with connective tissue disorders, and the typical histopathologic findings, which include stromal thinning and disruption of the collagen-rich Bowman layer, the anterior part of the corneal stroma . Taken together, the preliminary evidence on the functions of TMEM45A appear to coincide with the current evidence on keratoglobus pathophysiology.…”

Presumptive keratoglobus in a great horned owl(Bubo virginianus)

“…These degradation enzymes were present diffusely throughout the cornea (as opposed to centrally as in keratoconus), although a higher concentration was noted in the basal epithelium near breaks in Bowman's layer . IHC studies also showed a decrease in the concentration of α1‐proteinase inhibitor in corneal epithelial cells, thus leading to an increase in protease activity . These findings suggest that an imbalance of degradation enzymes and proteinase inhibitors plays a role in the stromal thinning of keratoglobus corneas.…”

“…The three most commonly described histopathologic characteristics of keratoglobus in people include frequent disruptions or complete absence of Bowman's layer, stromal thinning most evident in the periphery, and breaks or thickening of Descemet's membrane . However, there are other definitions of keratoglobus that do not include corneal thinning .…”

“…The pathogenesis of keratoglobus is not clearly understood; however, immunohistochemistry (IHC) studies in humans have identified a significant increase in degradation enzymes such as matrix metalloproteinases (MMP‐1, MMP‐2, and MMP‐3) in keratoglobus corneas as compared to controls . These degradation enzymes were present diffusely throughout the cornea (as opposed to centrally as in keratoconus), although a higher concentration was noted in the basal epithelium near breaks in Bowman's layer . IHC studies also showed a decrease in the concentration of α1‐proteinase inhibitor in corneal epithelial cells, thus leading to an increase in protease activity .…”

Tuck-in Lamellar keratoplasty with an lenticule obtained by small incision lenticule extraction for treatment of Post- LASIK Ectasia

“…Discrepant histopathological, ultrastructural, and biochemical evidence suggests that the pathogenesis of post-LASIK ectasia and keratoconus could be different 12 . Post-LASIK ectasia might be considered the biologic equivalent of an interfiber disruption of composite materials.…”