Prediction of Mean Corneal Power Change After Pterygium Excision

Kim, Sun Woong; Park, Saemi; Im, Chan Young; Seo, Kyoung Yul; Kim, Eung Kweon

doi:10.1097/ico.0000000000000036

Cited by 23 publications

(26 citation statements)

References 18 publications

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“…These contractile features mimic the clinical presentation of pterygium, which leads to significant astigmatism with an elastic nature. 48 In the current study, mTOR inhibition with Torin2 substantially blocked the TGF-b-induced contractile phenotype in pterygium myofibroblasts. However, it did not affect phosphorylation of SMAD proteins, which is a canonical downstream phenomenon of signaling through TGF-b receptors.…”

Section: Discussionsupporting

confidence: 53%

Critical Role of mTORC2-Akt Signaling in TGF-β1-Induced Myofibroblast Differentiation of Human Pterygium Fibroblasts

Kim

Thapa

et al. 2019

Invest. Ophthalmol. Vis. Sci.

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Citation: Kim SW, Kim H-I, Thapa B, Nuwromegbe S, Lee K. Critical role of mTORC2-Akt signaling in TGF-b1-induced myofibroblast differentiation of human pterygium fibroblasts. Invest Ophthalmol Vis Sci. 2019;60:82-92. https://doi.org/10.1167/iovs.18-25376PURPOSE. Profibrotic activation is essential for pterygium development. In this study, we investigated the role of the mechanistic target of rapamycin (mTOR) in regulating TGF-b1induced myofibroblastic responses in human pterygium fibroblasts (HPFs) and elucidated the relative contributions of mTOR signaling components. METHODS.HPFs were pretreated with the mTOR inhibitors rapamycin and Torin2, and TGF-b1induced expression of profibrotic markers, including a-smooth muscle actin (a-SMA) and fibronectin, was evaluated. RNA interference-based approaches targeting raptor and rictor, regulatory subunits of mTOR complex 1 (mTORC1) and 2 (mTORC2), respectively, were used to determine the impact of each mTOR complex on HPFs. The contractile phenotype of HPFs was assessed by a collagen gel contraction assay. RESULTS.The mTOR active-site inhibitor Torin2, which suppresses both mTORC1 and mTORC2 activity in HPFs, inhibited TGF-b1-induced expression of a-SMA and fibronectin. The allosteric inhibitor rapamycin only partially suppressed mTORC1 activity and exhibited a minimal effect on the induction of profibrotic markers. The induction of a-SMA and fibronectin in HPFs was abrogated by RNA interference-mediated knockdown of rictor but was only moderately affected by raptor knockdown. Akt inhibition mimicked the effect of Torin2 and rictor knockdown on myofibroblast differentiation of HPFs. mTOR inhibition potently reduced the contractile ability of HPFs in collagen gel contraction assays.CONCLUSIONS. This study found that mTOR signaling promoted profibrotic activation of HPFs and confirmed the importance of the mTORC2-Akt axis in TGF-b1-induced myofibroblast differentiation. Therefore, our study may open up new avenues for the development of novel therapeutic strategies involving targeting of mTOR signaling to treat pterygium.

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Section: Discussionsupporting

confidence: 53%

Critical Role of mTORC2-Akt Signaling in TGF-β1-Induced Myofibroblast Differentiation of Human Pterygium Fibroblasts

Kim

Thapa

et al. 2019

Invest. Ophthalmol. Vis. Sci.

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“…17 Induced astigmatism is generally characterized as with-the-rule astigmatism that is hemimeridional on the side of the pterygium resulting from localized flattening of the cornea. 3,4,[6][7][8]10,13,17,25 It is postulated that contractile elements within the pterygium exert tractional force and mechanically distort and flatten the cornea. 26 Therefore, it can be inferred that the pterygium with a greater tractional force or larger amount of contractile tissues can induce more severe PIA.…”

Section: Discussionmentioning

confidence: 99%

“…It is also important for making decisions regarding pterygium surgery and patient selection, as this is often difficult because of the high rate of recurrence after pterygium surgery. 11,12 Although several studies showed significant correlation between the length, width, or area of pterygium and PIA, [4][5][6]9,[13][14][15][16][17][18] there are still controversies between the results of these studies. Moreover, influence of factors other than these factors, such as, density of vascularity or fibrous tissue that reflect tractional force exerted from pterygium, has never been investigated.…”

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confidence: 99%

Quantification of Astigmatism Induced by Pterygium Using Automated Image Analysis

Han

Jeon

Kim

et al. 2016

Cornea

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“…Tomidokoro et al 5 found a correlation between the percentage of pterygium extension onto the cornea (%) and induced corneal astigmatism. Mohammad-Salih et al 7 , Kim et al 10 and Han et al 13 paid attention to the pterygium length, width and area and found that PIA was associated with these parameters. Our study found out that the pterygium surface area was an independent predictor of PIA (P < 0.001), which was in consistency with these previous studies.…”

Section: Discussionmentioning

confidence: 99%

“…Thus, cataract surgeons must understand the influences of pterygium on corneal astigmatism and the IOL power calculation before deciding on appropriate surgical strategies. Previous studies have indicated a significant correlation between pterygium-induced astigmatism (PIA) and its size, and the predicted IOL power would increase in eyes with a pterygium 5,[7][8][9][10][11] .…”

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confidence: 99%

Influences of the three-dimensional parameters of pterygium on corneal astigmatism and the intraocular lens power calculation

Tang

Qian

Wei

et al. 2020

Sci Rep

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Pterygium morphology had great effect on corneal astigmatism and intraocular lens (IOL) power calculation in cataract patients. However, previous studies all focused on the pterygium surface parameters, the invasion degree or cross-sectional area of the pterygia into the corneal stroma were neglected. We studied the effect of three-dimensional parameters of pterygium on corneal astigmatism and IOL power prediction. We enrolled 81 eyes of 81 patients with primary nasal pterygium, measured the corneal astigmatism (Pentacam HR) and predicted IOL power change (IOLmaster500) before and after pterygium surgery. The three-dimensional parameters of pterygium (length, width, area, height and invasion cross-sectional area) were measured by slit lamp photography and Scheimpflug images. After pterygium surgery, corneal astigmatism decreased from 4.35 ± 4.24 to 1.07 ± 0.95 D and total corneal refractive power increased from 43.02 ± 1.96 to 43.95 ± 0.95 D (both P < 0.001). The predicted IOL power decreased from 22.87 ± 2.82 to 21.71 ± 2.85 D (P < 0.001) after surgery. Notably, 34 eyes (41.98%) had ≥3.0 D of pterygium induced astigmatism (PIA), and 33 eyes (40.74%) had ≥1.0 D of predicted IOL power change. PIA was independently influenced by the pterygium surface area (r = 0.43, P < 0.001) and cross-sectional area (r = 1.25, P = 0.018), while the predicted IOL power change was independently affected by the pterygium width (r = 0.70, P < 0.001). Cataract surgeons could evaluate the effects of a pterygium according to its three-dimensional parameters and prepare an optimal surgical strategy for cataract combined pterygium patients.

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Prediction of Mean Corneal Power Change After Pterygium Excision

Abstract: Pterygium exceeding a length of 2.0 mm induced a significant corneal power change after surgery. The mean K predicted from the regression analysis could be used as an approximation for a simultaneous pterygium and cataract surgery.

Cited by 23 publications

References 18 publications

Critical Role of mTORC2-Akt Signaling in TGF-β1-Induced Myofibroblast Differentiation of Human Pterygium Fibroblasts

Critical Role of mTORC2-Akt Signaling in TGF-β1-Induced Myofibroblast Differentiation of Human Pterygium Fibroblasts

Quantification of Astigmatism Induced by Pterygium Using Automated Image Analysis

Influences of the three-dimensional parameters of pterygium on corneal astigmatism and the intraocular lens power calculation

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