Transmission Electron Microscopy Analysis of Epithelial Basement Membrane Repair in Rabbit Corneas With Haze

Torricelli, André A. M.; Singh, Vivek; Agrawal, Vandana; Santhiago, Marcony R.; Wilson, Steven E.

doi:10.1167/iovs.13-12106

Cited by 69 publications

(85 citation statements)

References 30 publications

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“…During corneal wound healing, most patients experience transient changes in corneal transparency (9) . Injury to the epithelium and removal of the central epithelial basement membrane, which also occur in PRK, initiate a complex sequence of events mediated by Intraocular straylight before and after low myopic photorefractive keratectomy with and without mitomycin C epithelial-stromal interactions (10,11) . Corneal fibroblast and myofibroblast generation, in addition to changes in the quality and quantity of extracellular matrix, are the main alterations contributing to stromal opacity following PRK surgery (9,12) .…”

Section: Introductionmentioning

confidence: 99%

Intraocular straylight before and after low myopic photorefractive keratectomy with and without mitomycin C

Torricelli¹,

Parede²,

Netto³

et al. 2016

Arquivos Brasileiros De Oftalmologia

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Purpose: To evaluate ocular straylight before and after photorefractive keratectomy (PRK) for low myopia with and without topical mitomycin (MMC) treatment. Methods: Patients who underwent PRK for low myopia were enrolled into the study. PRK without MMC was performed in 21 eyes (12 patients), whereas PRK with topical 0.02% MMC was performed in 25 eyes (14 patients). Both groups were treated using the NIDEK EC5000 excimer laser. Measurements were performed using the C-Quant straylight meter preoperatively and at two and four months postoperatively. Results: The mean patient age was 30 ± 4 years, and the mean spherical equivalent refractive error was -2.2 ± 0.75 D. The mean preoperative intraocular straylight values were 1.07 ± 0.10 in the PRK without MMC group and 1.07 ± 0.11 log(s) in the PRK with topical MMC group. At two months after surgery, there was a decrease in mean intraocular straylight values in both groups. However, a significant difference was only reached in the PRK with MMC group [0.98 ± 0.09 log(s), p=0.002] compared with preoperative values, which was likely due to a greater scatter of measurements in the PRK without MMC group [1.03 ± 0.13 log(s), p=0.082]. At four months postoperatively, ocular straylight values were not significantly different compared with those at baseline in either the PRK without MMC group [1.02 ± 0.14 log(s), p=0.26] or in the PRK with topical MMC group [1.02 ± 0.11 log(s), p=0.13]. Conclusion: PRK for low myopia decreases ocular straylight, and MMC application further reduces straylight in the early postoperative period. However, ocular straylight values do not significantly differ at four months after surgery compared with those at baseline. (1,02 ± 0,14 log(s), p=0,26) quanto no grupo com MMC tópica (1,02 ± 0,11 log(s), p=0,13). Keywords meses da cirurgia houve uma diminuição na média da dispersão de luz intraocular em ambos os grupos. Entretanto uma diferença estatisticamente significante, comparado com os valores préoperatórios, foi observada apenas no grupo PRK com MMC (0,98 ± 0,09 log(s), p=0,002), provavelmente devido as medidas com maior espalhamento de luz no grupo sem MMC (1,03 ± 0,13 log(s), p=0,082). Após 4 meses de pósoperatório, os valores de dispersão de luz não apresentavam diferença estatisticamente significantes quando comparados com os valores iniciais, tanto no grupo sem MMC Conclusão: PRK para baixa miopia diminui a dispersão de luz ocular e a aplicação de MMC contribui para uma ainda menor dispersão de luz no período pósoperatório inicial. Entretanto, quatro meses após a cirurgia a dispersão de luz intraocular não é significantemente diferente das medidas préoperatórias.Descritores: Ceratectomia fotorrefrativa; Miopia/cirurgia; Mitomicina; Cicatrização this as a troubling symptom, at least in the early postoperative period, following procedures such as photorefractive keratectomy (PRK).Disability glare is the veiling of vision due to the forward scattering of light in the eye (5,6) . Straylight is a known source of disability glare (7) . Th...

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Section: Introductionmentioning

confidence: 99%

Intraocular straylight before and after low myopic photorefractive keratectomy with and without mitomycin C

Torricelli¹,

Parede²,

Netto³

et al. 2016

Arquivos Brasileiros De Oftalmologia

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“…Myofibroblast development occurs when structural and functional defects in the regenerated epithelial basement membrane (BM) allows penetration of transforming growth factor beta (TGF-β) and platelet-derived growth factor (PDGF) from the epithelium into the stroma at sufficient levels to drive precursor development (Singh et al, 2014a; Kaur et al, 2009a; Netto et al, 2006a; Torricelli et al, 2013a). …”

Section: Introductionmentioning

confidence: 99%

Cellular and extracellular matrix modulation of corneal stromal opacity

Torricelli

Wilson

2014

Experimental Eye Research

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101

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Stromal transparency is a critical factor contributing to normal function of the visual system. Corneal injury, surgery, disease and infection elicit complex wound healing responses that serve to protect against insults and maintain the integrity of the cornea, and subsequently to restore corneal structure and transparency. However, in some cases these processes result in prolonged loss of corneal transparency and resulting diminished vision. Corneal opacity is mediated by the complex actions of many cytokines, growth factors, and chemokines produced by the epithelial cells, stromal cells, bone marrow-derived cells, lacrimal tissues, and nerves. Myofibroblasts, and the disorganized extracellular matrix produced by these cells, are critical determinants of the level and persistence of stromal opacity after corneal injury. Decreases in corneal crystallins in myofibroblasts and corneal fibroblasts contribute to cellular opacity in the stroma. Regeneration of a fully functional epithelial basement membrane (BM) appears to have a critical role in the maintenance of corneal stromal transparency after mild injuries and recovery of transparency when opacity is generated after severe injuries. The epithelial BM likely has a regulatory function whereby it modulates epithelium-derived growth factors such as transforming growth factor (TGF) β and platelet-derived growth factor (PDGF) that drive the development and persistence of myofibroblasts from precursor cells. The purpose of this article is to review the factors involved in the maintenance of corneal transparency and to highlight the mechanisms involved in the appearance, persistency and regression of corneal opacity after stromal injury.

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“…For instance, the area of damaged epithelium and basement membrane are smaller than for other surgeries, leading to less release of cytokines [30,31]. Additionally, the extended duration of the implant compared to other corneal surgeries probably caused prolonged biological stress to the surrounding cells.…”

Section: Discussionmentioning

confidence: 99%

“…According to these studies, the disruption of the epithelial basement membrane correlates with the differentiation of myofibroblasts due to the release of transforming growth factor beta-1 [31] followed by myofibroblast-expressed SMA. Although the damage caused to the basement membrane in the incision for ICRS implantation is small, we also found ∝−SMA-positive cells around the segment, although there were fewer than after other procedures, such as phototherapeutic keratectomy [32] and PRK [39].…”

Section: Discussionmentioning

confidence: 99%

Tissue reaction after intrastromal corneal ring implantation in an experimental animal model

Ibares‐Frías

Gallego

Cantalapiedra-Rodríguez

et al. 2015

Graefes Arch Clin Exp Ophthalmol

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Purpose To evaluate corneal wound healing in the hen animal model after additive surgery with an intracorneal ring segment (ICRS). Methods We implanted one ICRS in each eye of 76 hens. In control group 1 (n=22 hens), the stromal channel was prepared but no ICRS was inserted. In control group 2 (n=2 hens), no surgery was performed. Animals were randomly separated into groups and euthanized after clinical follow-up of 4 and 12 hours, 1, 2, 3, and 7 days, and 1, 2, 3, 4, and 6 months. Corneas were stained with hematoxylin-eosin. Apoptosis was measured by terminal uridine nick end-labeling assays. Cell proliferation and myofibroblast-like differentiation were assayed by BrdU and α-smooth muscle actin immunofluorescence microscopy. Stromal matrix changes were documented by electron microscopy.Results Epithelial and stromal cell apoptosis around the ICRS-implanted and control group 1 eyes peaked at 12 hours, but continued for 72 hours. In ICRSimplanted eyes, epithelial and stromal proliferation was present at 12 and 24 hours, respectively, and peaked at 7 days and 72 hours, respectively. Some proliferation in the ICRS-implanted group continued through the 6-month follow-up, and myofibroblast-like cells differentiated one to three months after ICRS implantation. The segments rotated within the stroma as the limbal inferior angle approached the epithelium. Conclusions Wound healing after ICRS implantation in hen corneas was similar to that of other corneal surgical wounds in stages. However, there were some specific features related to the small size of the epithelial wound and the device permanently implanted inside the cornea.

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Transmission Electron Microscopy Analysis of Epithelial Basement Membrane Repair in Rabbit Corneas With Haze

Cited by 69 publications

References 30 publications

Intraocular straylight before and after low myopic photorefractive keratectomy with and without mitomycin C

Intraocular straylight before and after low myopic photorefractive keratectomy with and without mitomycin C

Cellular and extracellular matrix modulation of corneal stromal opacity

Tissue reaction after intrastromal corneal ring implantation in an experimental animal model

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