Evidence map›Paper›PMID 42267781›Full record

ArticleInvestigative ophthalmology & visual science2026

Sex Hormone Imbalance in Keratoconus: Estrogen-Mediated Collagen Remodeling and Biomechanical Weakening.

Mengyu Zhang, Yan Liu, Ning Gao, Yulin Ma, Fei Li, Xin Li, Mengchen Cui, Shaozhen Zhao, Ruibo Yang

Abstract read
In one paragraph

Article in Investigative ophthalmology & visual science, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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3 · Its place in the literature

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4 · The record

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PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors.

Mengyu ZhangTianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China.
Yan LiuTianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China.
Ning GaoTianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China.
Yulin MaTianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China.
Fei LiTianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China.
Xin LiTianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China.
Mengchen CuiTianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China.
Shaozhen ZhaoTianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China.
Ruibo YangTianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Purpose: To investigate the role of sex hormone imbalance in keratoconus (KC) pathogenesis and its effects on corneal collagen metabolism and biomechanics. Methods: Fifteen newly diagnosed, treatment-naïve KC patients and 12 age- and sex-matched controls were enrolled. Plasma and tear estradiol (E2), testosterone (T), and matrix metalloproteinase-2 (MMP2) concentrations were measured by ELISA. Associations between sex hormone and clinical parameters were analyzed using Pearson correlation. Human corneal stromal cells (HCSCs) were exposed to physiological or supraphysiological E2/T to evaluate cell viability, matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), type I collagen (COL1), and hydroxyproline (HYP). Estrogen receptor-β (ERβ) involvement was assessed using the ERβ selective antagonist PHTPP. A high-estrogen rat model was established to evaluate central corneal thickness (CCT), stromal collagen ultrastructure, and biomechanical properties. Results: KC patients exhibited significantly elevated plasma and tear E2 but unchanged T levels. Tear E2 concentrations positively correlated with mean keratometry, diopter, and MMP2 levels and negatively correlated with minimum corneal thickness and best-corrected visual acuity (BCVA). Plasma and tear E2, as well as tear MMP2, were significantly increased in male KC patients and showed significant correlations with KC-related parameters. In contrast, no significant differences or associations were observed in female KC patients in this cohort. Hormone treatments showed no cytotoxicity in HCSCs. High estrogen exposure increased MMP2 and decreased TIMP2 mRNA expression, increasing the MMP2/TIMP2 ratio, reducing COL1 protein, and enhancing collagen degradation. Estrogen receptor-β (ERβ) expression was upregulated, and pharmacologic inhibition with PHTPP partially restored MMP/TIMP balance and collagen homeostasis. In vivo, estrogen-treated rats demonstrated reduced CCT, disrupted stromal collagen organization, and decreased Young's modulus. Conclusions: Elevated estrogen disrupts corneal collagen homeostasis and biomechanical integrity via an E2-ERβ-MMP2 axis, establishing a mechanistic link between sex hormone imbalance and KC pathogenesis.

Indexed as

CollagenEstradiolEstrogensKeratoconusAdultAnimalsBiomechanical PhenomenaCells, CulturedCorneal StromaDisease Models, AnimalEnzyme-Linked Immunosorbent AssayFemaleHumansMaleMatrix Metalloproteinase 2RatsCollagenEstradiolEstrogensMatrix Metalloproteinase 2Testosterone

Identifiers

PMID42267781
PMCPMC13284921

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.