Eye Diseases Commons^™

Corneal Sensory Nerve Regulation Of Tear Production Through Stimulation Of Transient Receptor Potential Melastatin 8 (Trpm8) Channel: A Potential New Approach For Treating Dry Eye Disease, Juana Gallar, Stephen Pflugfelder, Anat Galor, Preeya K Gupta, Pedram Hamrah

Faculty, Staff and Students Publications

The lacrimal functional unit (LFU) tightly controls the secretion of all tear components, thus playing a critical role in maintaining ocular surface homeostasis. Forming an exquisitely sensitive neural network across the ocular surface, corneal sensory nerves detect environmental stimuli (e.g., temperature, chemicals, and mechanical pressure) through transient receptor potential (TRP) ion channels. Among these, TRP melastatin 8 (TRPM8) is a key regulator of basal tear production. Stimulated by the small temperature reductions and tear film osmolarity increases that arise due to evaporative cooling, TRPM8 activates the LFU, leading to increased basal tear production. Here, we focus on reviewing the topical …

The Microenvironment Of Ocular Surface In Keratoconus: A Systematic Review, Sana Niazi, Farideh Doroodgar, Stephen Pflugfelder, Kia Bayat, Seyed-Farzad Mohammadi, Maedeh Mazloomi, Jorge L Alió Del Barrio, Majid Moshirfar, Jorge L Alió

Faculty, Staff and Students Publications

Purpose: Keratoconus is a progressive corneal ectatic disorder characterized by thinning and irregularity of the cornea, significantly impairing visual acuity. Recent studies have explored how non-ectatic conditions, such as dry eye and tear film instability and alteration of the ocular surface microenvironment, contribute to the development and progression of keratoconus. This comprehensive review aims to investigate the complex relationship between keratoconus and ocular surface diseases by examining the microenvironmental changes that occur on the ocular surface throughout the course of keratoconus, as well as the related clinical implications.

Methods: In this PROSPERO-registered study (ID: CRD42025643808), PubMed, Scopus, Cochrane, Embase, Web …

Comparative Efficacy Of Current Topical Treatments For Dry Eye Disease: A Review Of Pivotal Clinical Trials Evaluating Corneal Staining Outcomes, Ahmad Fahmy, Masih Ahmed, Stephen Pflugfelder, Anara Serikbaeva, Fang-Wei Tsao

Faculty, Staff and Students Publications

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Safety And Efficacy Of A Mesenchymal Stem Cell Secretome Therapy (Kpi-012) For Persistent Corneal Epithelial Defects: A Phase 1b Trial, Valeria Sánchez Huerta, Hugo Quiroz-Mercado, Enrique O Graue-Hernández, Alejandro Navas, Spencer Alford, Darius Kharabi, Stephen Pflugfelder

Faculty, Staff and Students Publications

Background: Persistent corneal epithelial defect (PCED) is a condition often refractory to conventional treatments. KPI-012 is a topical mesenchymal stem cell secretome therapy under investigation for PCED management.

Objective: To assess the safety, tolerability, and corneal wound healing efficacy of KPI-012 in a phase 1b, proof-of-concept, open-label, single-arm clinical trial.

Methods: The safety profile and tolerability of topical self-administered KPI-012 therapy (twice daily, 1-week duration) were first evaluated in an initial safety cohort of participants with pre-existing permanent vision loss and no active corneal disease (n = 3). The safety profile and efficacy of KPI-012 were then assessed in participants …

Hyperglycemia Causes Differential Change In Macrophage Population In The Lacrimal Gland, Conjunctiva And Cornea, Saleh Alfuraih, Amy Tran, Lois Kim, Rais Ansari, Ajay Sharma

Pharmacy Faculty Articles and Research

Background: Due to its location, the ocular surface is exposed to environmental microbes. Innate immune cells including macrophages are first line defense against infections. In vitro exposure to high glucose as well as diabetes-associated hyperglycemia has been shown to affect innate immune cell function and population. The present study was designed to examine the effect of diabetes-associated hyperglycemia on the lacrimal gland, conjunctiva and cornea macrophage population, phenotypic changes and cytokines/chemokines.

Methods: Mouse model of Streptozotocin-induced diabetes was used to induce hyperglycemia. Immunostaining for CD11b and F4/80 was performed to stain macrophages in whole mount cornea, conjunctiva and 50 µm …

Cd4+ T Cells Drive Corneal Nerve Damage But Not Epitheliopathy In An Acute Aqueous-Deficient Dry Eye Model, Alexia Vereertbrugghen, Manuela Pizzano, Agostina Cernutto, Florencia Sabbione, Irene A Keitelman, Douglas Vera Aguilar, Ariel Podhorzer, Federico Fuentes, Celia Corral-Vázquez, Mauricio Guzmán, Mirta N Giordano, Analía Trevani, Cintia S De Paiva, Jeremías G Galletti

Faculty, Staff and Students Publications

Dry eye disease (DED) is characterized by a dysfunctional tear film in which the corneal epithelium and its abundant nerves are affected by ocular desiccation and inflammation. Although adaptive immunity and specifically CD4+ T cells play a role in DED pathogenesis, the exact contribution of these cells to corneal epithelial and neural damage remains undetermined. To address this, we explored the progression of a surgical DED model in wild-type (WT) and T cell-deficient mice. We observed that adaptive immune-deficient mice developed all aspects of DED comparably to WT mice except for the absence of functional and morphological corneal nerve changes, …

Mouse Corneal Immune Cell Heterogeneity Revealed By Single-Cell Rna Sequencing, Ebru Yaman, Nicole Heyer, Cintia S De Paiva, Mary Ann Stepp, Stephen C Pflugfelder, Jehan Alam

Faculty, Staff and Students Publications

PURPOSE: This study aimed to define the heterogeneity, spatial localization, and functional roles of immune cells in the mouse cornea using single-cell RNA sequencing (scRNA-seq) and immunofluorescent staining.

METHODS: Enriched mouse corneal immune cells (C57BL/6 strain, age 16-20 weeks) underwent single-cell RNA sequencing library preparation, sequencing, and analysis with Seurat, Monocle 3, and CellChat packages in R. Pathway analysis used Qiagen Ingenuity Pathway Analysis software. Immunostaining confirmed cell distribution.

RESULTS: We identified 14 distinct immune cell clusters (56% myeloid and 44% lymphoid). Myeloid populations included resident macrophages, conventional dendritic cells (cDC2s), Langerhans cells, neutrophils, monocytes, and mast cells. Additionally, lymphocyte …

The Latest Ic3d Classification Of Corneal Dystrophies—Overview And Changes Of The 3rd Edition, Tim Berger, Jayne S. Weiss, Walter Lisch, Berthold Seitz

School of Medicine Faculty Publications

The International Committee on Classification of Corneal Dystrophies (IC3D) was founded in 2005 to address difficulties arising from the outdated nomenclature for corneal dystrophies (CD) and to correct misconceptions in the literature. For each of the 22 CDs, a separate template was created to represent the current clinical, pathological and genetic knowledge of the disease. In addition, each template contains representative clinical photographs as well as light and electron microscopic images and, if available, confocal microscopic and coherence tomographic images of the respective CD. After the first edition was published in 2008, the revised version followed in 2015. The third …

Impact Of Obesity And Age On Mouse Corneal Innervation At The Epithelial-Stromal Interface, Justin A Courson, Rolando E Rumbaut, Alan R Burns

Faculty, Staff and Students Publications

PURPOSE: The corneal epithelium is the most highly innervated structure in the body. Previously, we reported a novel event whereby stromal axons fuse with basal epithelial cells, limiting nerve penetration into the epithelium. Although corneal-epithelial nerves undergo changes in sensitivity and distribution throughout life and in response to an obesogenic diet, it is unknown if neuronal-epithelial cell fusion is altered. Here, we sought to determine if neuronal-epithelial cell fusion frequency correlates with obesogenic diet consumption and age.

METHODS: Corneas were collected from C57BL/6 mice and evaluated for neuronal-epithelial cell fusion frequency using serial block-face scanning electron microscopy. To assess the …

Age-Related Differences In The Mouse Corneal Epithelial Transcriptome And Their Impact On Corneal Wound Healing, Anmar Abu-Romman, Kaitlin K Scholand, Gowthaman Govindarajan, Zhiyuan Yu, Sonali Pal-Ghosh, Mary A Stepp, Cintia S De Paiva

Faculty, Staff and Students Publications

PURPOSE: Aging is a risk factor for dry eye. We sought to identify changes in the aged mouse corneal epithelial transcriptome and determine how age affects corneal sensitivity, re-epithelialization, and barrier reformation after corneal debridement.

METHODS: Corneal epithelium of female C57BL/6J (B6) mice of different ages (2, 12, 18, and 24 months) was collected, RNA extracted, and bulk RNA sequencing performed. Cornea sensitivity was measured with an esthesiometer in 2- to 3-month-old, 12- to 13-month-old, 18- to 19-month-old, and 22- to 25-month-old female and male mice. The 2-month-old and 18-month-old female and male mice underwent unilateral corneal debridement using a …

Collagen Type Xii Is Undetectable In Keratoconus Bowman’S Layer, Mohammed Rigi, Hyeck-Soo Son, Loren Moon, Mario Matthaei, Divya Srikumaran, Albert S Jun, Charles G Eberhart, Uri S Soiberman

Faculty, Staff and Student Publications

PURPOSE: Corneal biomechanical failure is the hallmark of keratoconus (KC); however, the cause of this failure remains elusive. Collagen type XII (

METHODS: TaqMan quantitative PCR was performed on 31 corneal epithelium samples of progressive KC and myopic control eyes. Tissue microarrays were constructed using full-thickness corneas from 61 KC cases during keratoplasty and 18 non-KC autopsy eyes and stained with an antibody specific to COL12A1. Additionally,

RESULTS: COL12A1 expression was reduced at transcript levels in KC epithelium compared to controls (ratio: 0.58, p<0.03). Immunohistochemical studies demonstrated that COL12A1 protein expression in BL was undetectable, with reduced expression in KC epithelium, basement membrane, and stroma.

CONCLUSIONS: The apparent absence of COL12A1 in KC BL, together with the functional importance that

Ectoine, From A Natural Bacteria Protectant To A New Treatment Of Dry Eye Disease, Xin Chen, Na Lin, Jin-Miao Li, Haixia Liu, Anmar Abu-Romman, Ebru Yaman, Fang Bian, Cintia S De Paiva, Stephen C Pflugfelder, De-Quan Li

Faculty, Staff and Students Publications

Ectoine, a novel natural osmoprotectant, protects bacteria living in extreme environments. This study aimed to explore the therapeutic effect of ectoine for dry eye disease. An experimental dry eye model was created in C57BL/6 mice exposed to desiccating stress (DS) with untreated mice as controls (UT). DS mice were dosed topically with 0.5-2.0% of ectoine or a vehicle control. Corneal epithelial defects were detected via corneal smoothness and Oregon Green dextran (OGD) fluorescent staining. Pro-inflammatory cytokines and chemokines were evaluated using RT-qPCR and immunofluorescent staining. Compared with UT mice, corneal epithelial defects were observed as corneal smoothness irregularities and strong …

Optical Coherence Elastography Measures The Biomechanical Properties Of The Ex Vivo Porcine Cornea After Lasik, Achuth Nair, Fernando Zvietcovich, Manmohan Singh, Mitchell P Weikert, Salavat R Aglyamov, Kirill V Larin

Faculty, Staff and Students Publications

SIGNIFICANCE: The biomechanical impact of refractive surgery has long been an area of investigation. Changes to the cornea structure cause alterations to its mechanical integrity, but few studies have examined its specific mechanical impact.

AIM To quantify how the biomechanical properties of the cornea are altered by laser assisted in situ keratomileusis (LASIK) using optical coherence elastography (OCE) in ex vivo porcine corneas.

APPROACH: Three OCE techniques, wave-based air-coupled ultrasound (ACUS) OCE, heartbeat (Hb) OCE, and compression OCE were used to measure the mechanical properties of paired porcine corneas, where one eye of the pair was left untreated, and the …

Diabetes-Associated Hyperglycemia Causes Rapid-Onset Ocular Surface Damage, Judy Weng, Christopher Ross, Jacob Baker, Saleh Alfuraih, Kiumars Shamloo, Ajay Sharma

Pharmacy Faculty Articles and Research

Purpose: The metabolic alterations due to chronic hyperglycemia are well-known to cause diabetes-associated complications. Short-term hyperglycemia has also been shown to cause many acute changes, including hemodynamic alterations and osmotic, oxidative, and inflammatory stress. The present study was designed to investigate whether diabetes-associated hyperglycemia can cause rapid-onset detrimental effects on the tear film, goblet cells, and glycocalyx and can lead to activation of an inflammatory cascade or cellular stress response in the cornea.

Methods: Mouse models of type 1 and type 2 diabetes were used. Tear film volume, goblet cell number, and corneal glycocalyx area were measured on …

Conditional Deletion Of Cd25 In The Corneal Epithelium Reveals Sex Differences In Barrier Disruption, Anmar Abu-Romman, Kaitlin K Scholand, Sonali Pal-Ghosh, Zhiyuan Yu, Yashaswini Kelagere, Ghasem Yazdanpanah, Winston W-Y Kao, Vivien J Coulson-Thomas, Mary Ann Stepp, Cintia S De Paiva

Faculty, Staff and Students Publications

PURPOSE: IL-2 promotes activation, clonal expansion, and deletion of T cells. IL-2 signals through its heterotrimeric receptor (IL-2R) consisting of the CD25, CD122 and CD132 chains. CD25 knockout (KO) mice develop Sjögren Syndrome-like disease. This study investigates whether corneal CD25/IL-2 signaling is critical for ocular health.

METHODS: Eyes from C57BL/6 mice were collected and prepared for immunostaining or in-situ hybridization. Bulk RNA sequencing was performed on the corneal epithelium from wild-type and CD25KO mice. We generated a conditional corneal-specific deletion of CD25 in the corneal epithelium (CD25

RESULTS: In C57BL/6 mice, CD25 mRNA was expressed in ocular tissues. Protein expression …

Non-Canonical Wnt Signaling In The Eye, Ruchi Shah, Cynthia Amador, Steven T Chun, Sean Ghiam, Mehrnoosh Saghizadeh, Andrei A Kramerov, Alexander V Ljubimov

Faculty, Staff and Student Publications

Wnt signaling comprises a group of complex signal transduction pathways that play critical roles in cell proliferation, differentiation, and apoptosis during development, as well as in stem cell maintenance and adult tissue homeostasis. Wnt pathways are classified into two major groups, canonical (β-catenin-dependent) or non-canonical (β-catenin-independent). Most previous studies in the eye have focused on canonical Wnt signaling, and the role of non-canonical signaling remains poorly understood. Additionally, the crosstalk between canonical and non-canonical Wnt signaling in the eye has hardly been explored. In this review, we present an overview of available data on ocular non-canonical Wnt signaling, including developmental …

Abcb5+ Limbal Epithelial Stem Cells Inhibit Developmental But Promote Inflammatory (Lymph) Angiogenesis While Preventing Corneal Inflammation, Berbang Meshko, Thomas L. A. Volatier, Karina Hadrian, Shuya Deng, Yanhong Hou, Mark A. Kluth, Christoph Ganss, Markus H. Frank, Natasha Y. Frank, Bruce Ksander, Claus Cursiefen, Maria Notara

Research outputs 2022 to 2026

The limbus, the vascularized junction between the cornea and conjunctiva, is thought to function as a barrier against corneal neovascularization. However, the exact mechanisms regulating this remain unknown. In this study, the limbal epithelial stem cell (LESC) marker ABCB5 was used to investigate the role of LESCs in corneal neovascularization. In an ABCB5KO model, a mild but significant increase of limbal lymphatic and blood vascular network complexity was observed in developing mice (4 weeks) but not in adult mice. Conversely, when using a cornea suture model, the WT animals exhibited a mild but significant increase in the number of lymphatic …

An Ocular Th1 Immune Response Promotes Corneal Nerve Damage Independently Of The Development Of Corneal Epitheliopathy, Alexia Vereertbrugghen, Manuela Pizzano, Florencia Sabbione, Irene Angelica Keitelman, Carolina Maiumi Shiromizu, Douglas Vera Aguilar, Federico Fuentes, Cintia S De Paiva, Mirta Giordano, Analía Trevani, Jeremías G Galletti

Faculty, Staff and Students Publications

Proper sight is not possible without a smooth, transparent cornea, which is highly exposed to environmental threats. The abundant corneal nerves are interspersed with epithelial cells in the anterior corneal surface and are instrumental to corneal integrity and immunoregulation. Conversely, corneal neuropathy is commonly observed in some immune-mediated corneal disorders but not in others, and its pathogenesis is poorly understood. Here we hypothesized that the type of adaptive immune response may influence the development of corneal neuropathy. To test this, we first immunized OT-II mice with different adjuvants that favor T helper (Th)1 or Th2 responses. Both Th1-skewed mice (measured …

Comparison Between The Casia Ss-1000 And Pentacam In Measuring Corneal Curvatures And Corneal Thickness Maps, Robert M Feldman, Gene Kim, Alice Z Chuang, Atsushi Shiraishi, Keiichiro Okamoto, Makoto Tsukamoto

Faculty, Staff and Student Publications

PURPOSE: To compare the intra-device repeatability and inter-device reproducibility between two anterior segment imaging instruments, the CASIA SS-1000 (Tomey Corp., Nagoya, Japan) and Pentacam (OCULUS, Arlington, WA) in measuring anterior segment parameters.

METHODS: Single-center, prospective clinical trial. Participants ≥20 years of age were included. One eye was randomly selected, each imaged by three CASIA SS-1000 devices and three Pentacam devices by three different examiners. Each photographer operated a pair of devices, one CASIA SS-1000 and one Pentacam. The image order for each participant was determined by a random permutation table. Three images were taken from each device. A total of …

A Low-Fat/Sucrose Diet Rich In Complex Carbohydrates Reverses High-Fat/Sucrose Diet-Induced Corneal Dysregulation, Prince K Akowuah, Carolina Lema, Rolando E Rumbaut, Alan R Burns

Faculty, Staff and Students Publications

High-fat/sucrose diet feeding in mice causes loss of corneal nerve function and impairs corneal wound healing. While changing to a diet with a low fat/sugar composition and enrichments in complex carbohydrates mitigates the reduction in nerve function, it remains to be determined if it has an effect on corneal wound healing. In this study, 6-week-old C57BL/6 male mice were fed either a normal diet or a high-fat/sucrose diet for 20 weeks. A third group (diet reversal) was placed on a high-fat/sucrose diet for 10 weeks followed by a normal diet for an additional 10 weeks. A central corneal epithelial abrasion …

Non-Invasive Tear Break-Up Detection With The Kowa Dr-1Α And Its Relationship To Dry Eye Clinical Severity, Stephen Pflugfelder, Lauren Nakhleh, Yasushi Kikukawa, Shin Tanaka, Takuya Kosugi

Faculty, Staff and Students Publications

The purpose of this study is to compare visual versus software detection of non-invasive tear break-up with the KOWA DR-1α tear interferometer and investigate the relationship between non-invasive tear break-up time (NIBUT) and dry eye clinical severity. Tear interferometry with the KOWA DR-1α, together with a standardized comprehensive ocular surface/tear evaluation, was performed on 348 consecutive eyes. Investigator visually detected or software detected non-invasive tear break-up and NIBUT were measured and compared on a subset of these examinations. The relationship between software-detected NIBUT and categorical dry eye severity based on irritation symptoms and corneal and conjunctival dye staining scores was …

Gut Microbiota From Sjögren Syndrome Patients Causes Decreased T Regulatory Cells In The Lymphoid Organs And Desiccation-Induced Corneal Barrier Disruption In Mice, Laura Schaefer, Claudia M Trujillo-Vargas, Firas S Midani, Stephen C Pflugfelder, Robert A Britton, Cintia S De Paiva

Faculty, Staff and Students Publications

Sjögren syndrome (SS) is an autoimmune inflammatory disorder characterized by secretory dysfunction in the eye and mouth; in the eye, this results in tear film instability, reduced tear production, and corneal barrier disruption. A growing number of studies show that homeostasis of the ocular surface is impacted by the intestinal microbiome, and several 16S sequencing studies have demonstrated dysbiosis of the intestinal microbiota in SS patients. In this study, we utilized metagenomic sequencing to perform a deeper analysis of the intestinal microbiome using stools collected from sex- and age-matched healthy (n = 20), dry eye (n = 4) …

Platelet And Erythrocyte Extravasation Across Inflamed Corneal Venules Depend On Cd18, Neutrophils, And Mast Cell Degranulation, Angie De La Cruz, Aubrey Hargrave, Sri Magadi, Justin A Courson, Paul T Landry, Wanyu Zhang, Fong W Lam, Monica A Bray, C Wayne Smith, Alan R Burns, Rolando E Rumbaut

Faculty, Staff and Student Publications

Platelet extravasation during inflammation is under-appreciated. In wild-type (WT) mice, a central corneal epithelial abrasion initiates neutrophil (PMN) and platelet extravasation from peripheral limbal venules. The same injury in mice expressing low levels of the β2-integrin, CD18 (CD18hypo mice) shows reduced platelet extravasation with PMN extravasation apparently unaffected. To better define the role of CD18 on platelet extravasation, we focused on two relevant cell types expressing CD18: PMNs and mast cells. Following corneal abrasion in WT mice, we observed not only extravasated PMNs and platelets but also extravasated erythrocytes (RBCs). Ultrastructural observations of engorged limbal venules showed platelets and RBCs …

Single-Cell Transcriptomics Identifies Limbal Stem Cell Population And Cell Types Mapping Its Differentiation Trajectory In Limbal Basal Epithelium Of Human Cornea, De-Quan Li, Sangbae Kim, Jin-Miao Li, Qianmiao Gao, Jongsu Choi, Fang Bian, Jiaoyue Hu, Yun Zhang, Jin Li, Rong Lu, Yumei Li, Stephen C Pflugfelder, Hongyu Miao, Rui Chen

Faculty, Staff and Students Publications

PURPOSE: This study aimed to uncover novel cell types in heterogenous basal limbus of human cornea for identifying LSC at single cell resolution.

METHODS: Single cells of human limbal basal epithelium were isolated from young donor corneas. Single-cell RNA-Sequencing was performed using 10x Genomics platform, followed by clustering cell types through the graph-based visualization method UMAP and unbiased computational informatic analysis. Tissue RNA in situ hybridization with RNAscope, immunofluorescent staining and multiple functional assays were performed using human corneas and limbal epithelial culture models.

RESULTS: Single-cell transcriptomics of 16,360 limbal basal cells revealed 12 cell clusters belonging to three lineages. …

Analysis Of Ocular Changes In A Cyp1b1-/- Mouse, Kylie Barto

Williams Honors College, Honors Research Projects

The goal of the research is to investigate the structural changes seen in Primary Congenital Glaucoma using a mouse model. Eye sections of a Cyp1b1-/- mouse were compared to eye sections of a healthy normal mouse (wild type, WT). Initial examination of the cornea, iris, and irodocorneal angle showed structural changes in Cyp1b1-/-. These changes were similar to those described in the literature using other animal models. This suggests that a mutation in Cyp1b1-/- in a mouse results in a phenotype similar to that seen in PCG human patients and this model could be used to investigate the pathophysiology of …