Topological–histological investigation of the pterygium

Seifert, Péter; Eckert, Jens; Spitznas, Manfred

doi:10.1007/s004170100262

Cited by 13 publications

(14 citation statements)

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“…In the current study, we confirmed the presence of the lobes of pterygium stromal tissue that projected sideways from the continuous base of the pterygium, a pattern that was described also by Seifert et al 2001(Seifert et al 2001.…”

Section: Discussionsupporting

confidence: 86%

“…Asterisks indicate the creeping conjunctival stroma of the pterygium. Seifert et al 2001 who studied the topological and histological patterns of the pterygium. In their study, they proved histologically the presence a narrow strip of newly formed layer of pathological pterygium stroma lying between the corneal epithelium and the Bowman's membrane beyond the end of the pterygium boundaries, and this finding was also clearly demonstrated in our study.…”

Section: Discussionmentioning

confidence: 99%

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Spectral domain anterior segment optical coherence tomography assessment of pterygium and pinguecula

Soliman

Mohamed

2010

Acta Ophthalmologica

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ABSTRACT.Purpose: To study the morphological patterns of pterygia and pingueculae using high-resolution anterior segment spectral domain optical coherence tomography (SD-OCT). Methods: Prospective cross-sectional study of 25 eyes presented with pterygia and pingueculae was conducted, and the eyes were examined by anterior segment SD-OCT. Results: We examined 25 eyes, including 13 eyes with primary pterygia, six eyes with recurrent pterygia, one case with a pseudopterygium and five eyes with pingueculae. Primary pterygia revealed elevation of the corneal epithelium by a wedge-shaped mass of tissue separating the corneal epithelium from the underlying Bowman's membrane, which became wavy and interrupted. We found satellite masses of pterygium tissue advanced under the epithelium beyond the clinically seen pterygium margins. In recurrent pterygia, we detected that the central tip of the pterygium was more advanced and creeping beneath the basal corneal epithelium than the primary pterygium. In pseudopterygium, the SD-OCT images showed that the overgrowing membrane was not really attached to the underlying cornea. In cases of pingueculae, SD-OCT revealed a wedge-shaped mass that was nearly similar in pattern to that of the pterygia but stopped at the limbal region. Immediately after removal of pterygia, we noticed many remnants of the pterygia masses over the corneal stroma in spite of the clinically clear appearance of cornea. Conclusions: SD-OCT provided us with high-resolution images of the pterygium and the pinguecula and showed clearly the anatomical relationship between the corneal tissues and these lesions. The use of this new modality of imaging may help to decrease the current recurrence rates after pterygium excision through using the anterior segment SD-OCT in the evaluation of these lesions.

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Section: Discussionsupporting

confidence: 86%

Section: Discussionmentioning

confidence: 99%

Spectral domain anterior segment optical coherence tomography assessment of pterygium and pinguecula

Soliman

Mohamed

2010

Acta Ophthalmologica

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“…This activation may cause 1) phenotypic alterations in a distinct population of epithelial cells, 2) production of proinflammatory and angiogenic cytokines 7 and growth factors, 8 and 3) increased invasiveness due to enhanced production of matrix metalloproteinases (MMPs) over and above their natural tissue inhibitors (TIMPs). 6,9 -12 To date, we 6,9 -12 and others [13][14][15][16][17] have accumulated data from in vitro culture and in vivo tissue-based studies that resemble investigations performed in human UVexposed skin. These studies have demonstrated increased MMPs in human skin and skin-derived cells in response to UV radiation.…”

mentioning

confidence: 99%

Epidermal Growth Factor Receptor Signaling Is Partially Responsible for the Increased Matrix Metalloproteinase-1 Expression in Ocular Epithelial Cells after UVB Radiation

Girolamo

Coroneo

Wakefield

2005

The American Journal of Pathology

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Pterygia are inflammatory, invasive, and proliferative lesions of the human ocular surface in which the matrix metalloproteinase (MMP) collagenase-1 (MMP-1) is highly expressed. Pterygia development may involve MMP-1 activity against interstitial fibrillar collagen, an abundant extracellular matrix component of the cornea, and its induction by ultraviolet light (UVB). We examined the pathways responsible for enhanced expression of MMP-1 in pterygium epithelial cells after UVB exposure and/or treatment with chemical inhibitors of mitogen-activated protein kinases or epidermal growth factor receptor. The induction of MMP-1 by UVB was comparable to that mediated by heparin-binding epidermal growth factor-like growth factor and epidermal growth factor. The epidermal growth factor receptor inhibitor PD153035 partially blocked the UVB-mediated induction of MMP-1 and totally abrogated its production after stimulation with either heparin-binding epidermal growth factor-like growth factor or epidermal growth factor. UVB exposure enhanced the phosphorylated form of ERK1/2 in a time-dependent manner whereas the ERK1/2 inhibitor PD98059 decreased this induction by at least fivefold. Transcripts for c-jun and c-fos were detected as early as 2 hours after UVB exposure and were suppressed by PD98059. The identification of a specific intracellular signaling pathway responsible for the enhanced production of a key enzyme that denatures intact fibrillar collagen has important implications for understanding the pathophysiology and future therapy for pterygia. Pterygium is a condition of the ocular surface characterized by squamous cell metaplasia and goblet cell hyperplasia. The lesion consists of a wing-shaped mass of fibrovascular conjunctival tissue that invades the normal cornea. Other obvious pathological changes include activation of stromal fibroblasts, a persistent inflammatory component, elastotic degeneration, and destruction of collagenous barriers such as Bowman's layer. Pterygia are particularly prevalent in heavily sun-exposed individuals in whom extensive epidemiological studies link this disease to excessive ultraviolet (UV) radiation. 1-5 Despite this evidence, there is still controversy regarding the actual trigger for the development of pterygia and whether or not there is a genetic predisposition to this disease. 6 Recently, we have identified UVB as an environmental agent likely to be responsible for initiating molecular events that lead to the formation of pterygia. 7,8 From our hypothesis, 9 we postulate that UVB radiation activates cells at or near the limbus. This activation may cause 1) phenotypic alterations in a distinct population of epithelial cells, 2) production of proinflammatory and angiogenic cytokines 7 and growth factors, 8 and 3) increased invasiveness due to enhanced production of matrix metalloproteinases (MMPs) over and above their natural tissue inhibitors (TIMPs). 6,9 -12 To date, we 6,9 -12 and others [13][14][15][16][17] have accumulated data from in vitro culture and in vivo tissue-b...

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“…Seifert et al (24) by using conventional staining procedure (hematoxylin-eosin, alcian blue and toluidine blue) demonstrated the presence of many large-diameter lymphatic vessels in a markedly edematous human pterygium and more recently Pérez-Rico et al (6) showed the expression of fibulin-2 and fibulin-3 in the subepithelial connective tissue of human pterygium distributed along blood and lymphatic vessels.…”

Section: Discussionmentioning

confidence: 99%

“…Few data are available concerning lymphangiogenesis in the cornea and the presence of lymphatic vessels in pterygium (24). The aim of this study was to evaluate by immunohistochemistry, by using antibodies against D2-40 and Prox-1, the presence of lymphatic vessels in human pterygium.…”

Section: Introductionmentioning

confidence: 99%

Preliminary evidence of the presence of lymphatic vessels immunoreactive for D2-40 and Prox-1 in human pterygium

et al. 2011

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Abstract. Human pterygium is a benign fibrovascular outgrowth of the corneo-conjunctival junction, characterized by tissue remodeling, cellular proliferation, angiogenesis and inflammation. No data are available concerning the presence of lymphatic vessels in this pathological condition. The aim of this study was to evaluate by immunohistochemistry, using antibodies against D2-40, Prox-1 and Ki-67, the presence and the proliferative activity of lymphatic vessels in human pterygium. An increased lymphatic microvessel density was observed in the human pterygium compared to the normal conjunctiva. Moreover, D2-40-positive lymphatic endothelial cells were also actively proliferating, as assessed by Ki-67 immunostaining, while in normal conjunctiva proliferating lymphatic endothelial cells were not detectable. Overall, these data clearly indicate the presence of active proliferating lymphatic vessels in human pterygium, suggesting that active lymphangiogenesis occurs in this pathological condition. IntroductionPterygium is a disease characterized by surface ocular lesions associated with chronic ultraviolet exposure in which the primary effect is a solar actinic elastosis within the stroma and all other changes are secondary to the primary effect (1-7). Pterygium is characterized by cellular proliferation, inflammatory infiltration, fibrosis, angiogenesis, and extracellular matrix breakdown; the lesion begins to grow from limbal epithelium and invades the cornea centripetally followed by conjuntival epithelium, exhibiting degenerative and hyperplastic changes (1-7).Seifert and Sekundo identified intraepithelial capillaries in the optical half of 42.3% pterygia, providing the first evidence of neovascularization in this pathological condition (8). Other reports followed (9,10) and several angiogenic cytokines, such as fibroblast growth factor-2 (FGF-2), vascular endothelial growth factor (VEGF) platelet-derived growth factor (PDGF), transforming growth factor β (TGF-β), tumor necrosis factor α (TNF-α), interleukin-6 and -8 (IL-6 and IL-8) and nerve growth factor (NGF) (11-14) have been implicated as mediators of angiogenesis. Furthermore, the presence of mast cells has been correlated with the degree of angiogenesis in pterygium (15,16).Several antiangiogenic approaches have been proposed for the treatment of petrygium. One case report documented the successful treatment of an early recurrent pterygium using interferon α2β (17) and more recently, bevacizumab, a human monoclonal antibody anti-VEGF, has been proposed in the treatment of pterygium (18)(19)(20)(21)(22)(23).Few data are available concerning lymphangiogenesis in the cornea and the presence of lymphatic vessels in pterygium (24). The aim of this study was to evaluate by immunohistochemistry, by using antibodies against D2-40 and Prox-1, the presence of lymphatic vessels in human pterygium. Materials and methodsThe study group included 20 bioptic specimens of surgical excised primary or recurrent pterygium. Ten nasal epibulbar conjunctival segments, excised d...

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Topological–histological investigation of the pterygium

Cited by 13 publications

References 34 publications

Spectral domain anterior segment optical coherence tomography assessment of pterygium and pinguecula

Spectral domain anterior segment optical coherence tomography assessment of pterygium and pinguecula

Epidermal Growth Factor Receptor Signaling Is Partially Responsible for the Increased Matrix Metalloproteinase-1 Expression in Ocular Epithelial Cells after UVB Radiation

Preliminary evidence of the presence of lymphatic vessels immunoreactive for D2-40 and Prox-1 in human pterygium

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