Immunocytochemical localisation of collagens (I–V) in the human iris

Konstas, Anastasios G. P.; Marshall, G. E.; Lee, W. R.

doi:10.1007/bf02764315

Cited by 21 publications

(7 citation statements)

References 13 publications

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“…Actually, though occasionally, association of Col I with BMs has been previously reported in the nasal mucosa of allergic subjects, 27 in retinal arterioles and venules, 28 in the trabecular beams of human trabecular meshwork, 29 in aged human ciliary body, 30 and in human iris. 31 Curiously, with the exception of the allergic nasal mucosa, all other reports deal with the human eye.…”

Section: Discussionmentioning

confidence: 99%

The Peculiar Pattern of Type IV Collagen Deposition in Epiretinal Membranes

Regoli

Tosi

Neri

et al. 2019

J Histochem Cytochem.

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Idiopathic epiretinal membranes are sheets of tissue that develop in the vitreoretinal interface. They are formed by cells and extracellular matrix, and they are considered the expression of a fibrotic disorder of the eye. Confocal and immunoelectron microscopy of the extracellular matrix of excised membranes, revealed high contents of type IV collagen. It was distributed within epiretinal membranes in basement membrane-like structures associated with cells and in interstitial deposits. In both cases, type IV collagen was always associated with type I collagen. Col IV was also coupled with Col VI and laminin. At high magnification, type IV collagen immunolabelling was associated with interstitial deposits and showed a reticular appearance due to the intersection of beaded microfilaments. The microfilaments are about 12 nm in diameter with interbead distance of 30–40 nm. Cells of the epiretinal membranes showed intracellular lysosome-like bodies heavily labeled for type IV collagen suggesting an active role in membrane remodeling. Hence, type IV collagen is not necessarily always associated with basement membranes; the molecular interactions that it may develop when not incorporated in basement membranes are still unknown. It is conceivable, however, that they might have implications in the progression of epiretinal membranes and other fibrotic disorders.

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Section: Discussionmentioning

confidence: 99%

The Peculiar Pattern of Type IV Collagen Deposition in Epiretinal Membranes

Regoli

Tosi

Neri

et al. 2019

J Histochem Cytochem.

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“…The elasticity of the iris is determined by the distribution and quantity of types I and III collagen in the stroma. Type I collagen decreases elasticity, while type III collagen increases elasticity . It has been shown that the total amount of collagen and the proportion of type I collagen are considerably greater in angle‐closure eyes than in normal eyes .…”

Section: Discussionmentioning

confidence: 99%

Comparison of anterior segment morphology following prophylactic laser peripheral iridotomy in Caucasian and Chinese eyes

Lee

Kasuga

Cui

et al. 2013

Clinical Exper Ophthalmology

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Background To compare anterior segment biometric parameters between Caucasians and Chinese before and after laser peripheral iridotomy (LPI). Design Prospective clinical cohort study Participants Caucasian and Chinese primary angle closure suspects. Methods Anterior segment optical coherence tomography images captured before and after LPI were analyzed to measure anterior segment biometric parameters. Paired Student’s t-tests were used for within-ethnic group comparisons. Univariate and linear mixed-effects regression models were used for between-ethnic group comparisons. Main Outcome Measures angle opening distance (AOD500, AOD750); angle recess area (ARA750); iris thickness (IT750, IT2000, ITM); iris curvature (ICURV); anterior chamber area (ACA); anterior chamber volume (ACV); and anterior chamber width (ACW). Results Caucasians had significantly greater preoperative ARA750, ACW, and ICURV and lower preoperative IT2000 compared to Chinese (P<0.05). Ethnic differences in preoperative AOD500, AOD750, IT750, ITCM, ACA, and ACV were insignificant (P>0.05). Significant postoperative increases in AOD500, AOD750, ARA750, ACA, ACV, and ACW along with significant postoperative decrease in ICURV were observed within both ethnic groups (P<0.05). However, the amount of LPI-induced changes in AOD500, AOD750, ARA750, ACA, ACV, ACW, and ICURV did not differ between the two ethnic groups (P>0.05). Conclusion Both Caucasian and Chinese demonstrated opening of anterior chamber angle width (AOD500, AOD750, ARA750), expansion of anterior chamber dimensions (ACA, ACV, ACW), and flattening of iris convexity (ICURV) after LPI. Although certain aspects of anterior segment anatomy differed between Caucasians and Chinese preoperatively, they did not translate into significant ethnic differences in the amount of LPI-induced changes in the anterior segment biometric parameters.

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“…For instance, fibrovascular scarring at the anterior chamber angle was a notable feature of IOP‐induced ocular damage . This scarring effect may have its origins in the organization of collagen as intimately interwoven fibres with blood vessels in the iris, and its synthesis being intimately associated with the activation of these vessels . Indeed, VEGFB has been shown to upregulate collagen genes in vascular cells .…”

Section: Discussionmentioning

confidence: 99%

Distinct iris gene expression profiles of primary angle closure glaucoma and primary open angle glaucoma and their interaction with ocular biometric parameters

Seet

Narayanaswamy

Finger

et al. 2016

Clinical Exper Ophthalmology

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BackgroundThis study aimed to evaluate differences in iris gene expression profiles between primary angle closure glaucoma (PACG) and primary open angle glaucoma (POAG) and their interaction with biometric characteristics.DesignProspective study.ParticipantsThirty‐five subjects with PACG and thirty‐three subjects with POAG who required trabeculectomy were enrolled at the Singapore National Eye Centre, Singapore.MethodsIris specimens, obtained by iridectomy, were analysed by real‐time polymerase chain reaction for expression of type I collagen, vascular endothelial growth factor (VEGF)‐A, ‐B and ‐C, as well as VEGF receptors (VEGFRs) 1 and 2. Anterior segment optical coherence tomography (ASOCT) imaging for biometric parameters, including anterior chamber depth (ACD), anterior chamber volume (ACV) and lens vault (LV), was also performed pre‐operatively.Main Outcome MeasuresRelative mRNA levels between PACG and POAG irises, biometric measurements, discriminant analyses using genes and biometric parameters.Results COL1A1, VEGFB, VEGFC and VEGFR2 mRNA expression was higher in PACG compared to POAG irises. LV, ACD and ACV were significantly different between the two subgroups. Discriminant analyses based on gene expression, biometric parameters or a combination of both gene expression and biometrics (LV and ACV), correctly classified 94.1%, 85.3% and 94.1% of the original PACG and POAG cases, respectively. The discriminant function combining genes and biometrics demonstrated the highest accuracy in cross‐validated classification of the two glaucoma subtypes.ConclusionsDistinct iris gene expression supports the pathophysiological differences that exist between PACG and POAG. Biometric parameters can combine with iris gene expression to more accurately define PACG from POAG.

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Immunocytochemical localisation of collagens (I–V) in the human iris

Cited by 21 publications

References 13 publications

The Peculiar Pattern of Type IV Collagen Deposition in Epiretinal Membranes

The Peculiar Pattern of Type IV Collagen Deposition in Epiretinal Membranes

Comparison of anterior segment morphology following prophylactic laser peripheral iridotomy in Caucasian and Chinese eyes

Distinct iris gene expression profiles of primary angle closure glaucoma and primary open angle glaucoma and their interaction with ocular biometric parameters

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