Abnormal Rubbing and Keratectasia

McMonnies, Charles W.

doi:10.1097/icl.0b013e31814fb64b

Cited by 115 publications

(85 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Eye rubbing is a proven factor that triggers the onset and progression of the disease, through several effects including stimulation of inflammation. 112,113,119,120 Increasing evidence supports the fact that thinning and ectasia of the cornea are related to a degraded extracellular matrix involving inflammatory events (mainly increased levels of MMP-9, IL-6, and TNF-α) 10,[12][13][14]67,91 and increased oxidative stress. [143][144][145][146] However, the precise role of each of the identified molecular factors still needs to be defined in further studies.…”

Section: Resultsmentioning

confidence: 99%

“…72,111-118 Bawazeer et al 11 published the results of a case-control study, which showed, using multivariate analysis, that eye rubbing was a significant predictor of keratoconus. The mechanical factor may have a role, causing an increase in both corneal temperature (secondary to friction with the conjunctiva) and intraocular pressure as McMonnies et al 112,119 has pointed out. In addition, effects of the rubbing at molecular level have been identified as well.…”

Section: Corneal Stroma Compositionmentioning

confidence: 99%

See 1 more Smart Citation

Keratoconus: an inflammatory disorder?

Galvis

Sherwin

Tello

et al. 2015

Eye

302

199

View full text Add to dashboard Cite

Keratoconus has been classically defined as a progressive, non-inflammatory condition, which produces a thinning and steepening of the cornea. Its pathophysiological mechanisms have been investigated for a long time. Both genetic and environmental factors have been associated with the disease. Recent studies have shown a significant role of proteolytic enzymes, cytokines, and free radicals; therefore, although keratoconus does not meet all the classic criteria for an inflammatory disease, the lack of inflammation has been questioned. The majority of studies in the tears of patients with keratoconus have found increased levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and matrix metalloproteinase (MMP)-9. Eye rubbing, a proven risk factor for keratoconus, has been also shown recently to increase the tear levels of MMP-13, IL-6, and TNF-α. In the tear fluid of patients with ocular rosacea, IL-1α and MMP-9 have been reported to be significantly elevated, and cases of inferior corneal thinning, resembling keratoconus, have been reported. We performed a literature review of published biochemical changes in keratoconus that would support that this could be, at least in part, an inflammatory condition.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Corneal Stroma Compositionmentioning

confidence: 99%

Keratoconus: an inflammatory disorder?

Galvis

Sherwin

Tello

et al. 2015

Eye

302

199

View full text Add to dashboard Cite

show abstract

“…2 Although keratoconus is defined as a non-inflammatory corneal disease and the molecular pathophysiology of keratoconus continues to be elucidated, recent studies suggest that a combination of genetic and environmental risk factors, such as eye rubbing, atopy, inflammation, and oxidative stress, play a role in the pathogenesis. [1][2][3] Cornea as a transparent tissue absorbs most of the ultraviolet (UV) light entering the eye and UV is an important environmental stress factor that creates cytotoxic free radicals. 4 It could be suggested that the cornea is exposed to free radicals that lead to cellular damage by reacting with proteins, DNA, and membrane phospholipids.…”

Section: Introductionmentioning

confidence: 99%

Increased systemic oxidative stress in patients with keratoconus

Toprak

Küçükatay

Yıldırım

et al. 2013

Eye

View full text Add to dashboard Cite

Purpose To establish the effect of systemic oxidative stress on the pathogenesis of keratoconus by measuring serum total oxidant status (TOS) and total antioxidant status (TAS) in patients with keratoconus. Methods Twenty-five patients with keratoconus (keratoconus group) and 25 age-sex-matched healthy subjects (control group) were enrolled in the study. Exclusion criteria were smoking habit, history of any other corneal pathology, systemic disease or inflammation, and current antioxidant or anti-inflammatory therapies. All participants underwent a detailed ophthalmological examination and corneal topography. Serum samples were obtained from all participants. Oxidative stress markers (TAS and TOS) were measured using a commercial kit and oxidative stress index (OSI) was calculated. Results The study comprised 25 patients with keratoconus (mean age of 26.4 ± 1.7 years) and 25 healthy control subjects (mean age of 26.6 ± 1.7 years) (P40.05). The serum TOS and OSI values were significantly higher in patients with keratoconus compared with those of the controls (P ¼ 0.036 and 0.037, respectively). However, serum TAS did not show significant difference between the keratoconus and control groups (P ¼ 0.497). Conclusions The higher levels of serum oxidant status and OSI in patients with keratoconus suggest that systemic oxidative stress might be involved in the pathogenesis of keratoconus.

show abstract

“…Vigorous eye-rubbing in keratoconus has been shown to be up to 10 times more forceful than normal eye-rubbing (12,13). Previous studies have found that the values of corneal biomechanical measurements are significantly lower in keratoconic eyes than in normal eyes (14,15).…”

Section: Introductionmentioning

confidence: 97%

Induction of MMP-1 and −3 by cyclical mechanical stretch is mediated by IL-6 in cultured fibroblasts of keratoconus

Du¹,

Chen²,

Li³

et al. 2017

Molecular Medicine Reports

View full text Add to dashboard Cite

Abstract. In order to understand the effect of mechanical stretch on corneal extracellular matrix remodeling, human keratoconus fibroblasts (HKCFBs) were subjected to cyclic stretch in vitro and the expression of matrix metalloproteinases (MMPs), tissue inhibitor of metalloproteinases (TIMPs), and inflammatory cytokines were evaluated. HKCFBs were seeded into a flexible membrane base and subjected to a cyclic stretch regimen of 10% equibiaxial stretch at a stretching frequency of 1 Hz for 6 h using a Flexcell tension unit. An antibody directed against interleukin-6 (IL-6 Ab) was used to investigate the roles of IL-6 on mechanical stretch mediated regulation of MMP in HKCFBs. Culture supernatants were assayed using an enzyme-linked immunosorbent assay for MMP-1 and -3, TIMP-1 and -2, and IL-6. Total RNA from the cells was extracted, and quantitative polymerase chain reaction was used to determine mRNA for MMP-1 and -3, TIMP-1 and -2, and IL-6. In stretched cells, levels of MMP-1 and -3 demonstrated an increase compared with unstretched cells, but levels of TIMP-1, and -2 revealed a decrease. Mechanical stretch significantly increased the mRNA expression and protein synthesis of IL-6 compared with unstretched cells. IL-6 induced MMP-1 and -3 expression, whereas no significant effects were observed in levels of TIMP-1 and -2 compared with the untreated control groups. Additionally, the IL-6 Ab markedly inhibited the stretch-induced increase in MMP-1 and -3 in culture supernatants in a dose-dependent manner. No significant differences in TIMP-1 and -2 protein levels were detected between stretched cells treated with IL-6 Ab and stretched cells without IL-6 Ab treatment. These results indicate that cyclical mechanical stretch augments IL-6 production and MMP expression, and reduces levels of TIMP in HKCFBs. Thus, it is suggested that IL-6 mediates the stretch-induced MMP expression.

show abstract

Abnormal Rubbing and Keratectasia

Cited by 115 publications

References 53 publications

Keratoconus: an inflammatory disorder?

Keratoconus: an inflammatory disorder?

Increased systemic oxidative stress in patients with keratoconus

Induction of MMP-1 and −3 by cyclical mechanical stretch is mediated by IL-6 in cultured fibroblasts of keratoconus

Contact Info

Product

Resources

About