bluuebunny/crossref_metadata_2025 huggingface dataset:
Reducing disconfort in contact lens wearers: Refitting symptomatic users to Kalifilcon A
Authors: Ruiz Jose Miguel Sanchez , Di Pierdomenico Johnny , Ayuso Diego Garcia
Published: January 2025

Aims/Purpose: The prevalence of discomfort associated with contact lens (CL) wear is estimated to affect up to half of the wearers, often resulting in the discontinuation of CL wear. This study aimed to determine whether refitting symptomatic wearers with a daily disposable CL (Kalifilcon A) reduces symptoms and improves the wearer experience.

Methods: 47 symptomatic CL wearers (CLDEQ‐8 > 12) were randomly assigned in a masked fashion to receive either Kalifilcon A or their usual CL (placebo). Following one month of CL wear, participants were switched to Kalifilcon A or placebo, which they wore for another month. Non‐invasive tear break‐up time measurements were performed using a Medmont E300USB topographer. Furthermore, the participants completed the CLDEQ‐8 and NEI VQF‐25 questionnaires to assess symptomatology and vision‐related quality of life while wearing CLs. Finally, the participants were asked to subjectively rate the ease of handling, manipulation and comfort of both CLs.

Results: After a one‐month period of wearing both CLs, the results of theCLDEQ‐8 revealed a statistically and clinically significant reduction in symptomatology with Kalifilcon A CL (10.95 ± 8.82) in comparison to the placebo CL (14.65 ± 7.83; p = 0.02). The NEI VFQ‐25 questionnaire outcomes indicate that Kalifilcon A CL exhibits a substantial improvement in the subscales of eye pain, with a score of 59.4 ± 9.9, compared to the score of 47.3 ± 8.2 (p < 0.0001), and in the subscales of role difficulties, with a score of 10.1 ± 13.9, compared to the score of 38.6 ± 8.2 (p < 0.0001).In terms of subjective rate, Kalifilcon A CL demonstrated superior performance in terms of overall satisfaction with comfort (7.78 ± 1.88vs8.5 ± 1.86; p = 0.01) and overall satisfaction with the CL (7.8 ± 1.89vs8.44 ± 1.61; p = 0.04). The results of the tear quality study revealed no statistically significant differences between the two CLs.

Conclusions: Refitting individuals who exhibit symptoms while wearing CLs with Kalifilcon A daily disposable contact lenses resulted in a significant reduction in the incidence of symptoms and a noticeable enhancement in the user's overall experience. This presents a valuable solution for those who may otherwise be at risk of discontinuing CL wear.
The physiochemical properties of artificial tears and their impact on human cultured conjunctival goblet cells
Authors: Alnoor Umalbaninn , Ahrensberg Simone , Heegaard Steffen , Kolko Miriam
Published: January 2025

Aims/Purpose: To investigate the cell survival and mucin release (Muc5AC) of human conjunctival goblet cells (GCs) when incubated with preserved and preservative‐free (PF) artificial tears (AT), and to compare the physicochemical properties of these ATs. Ten different ATs were examined, five containing preservatives (benzalkonium chloride (BAK), PolyQuad, and cetrimide) and five preservative‐free.

Methods: Primary cultures of human conjunctival GCs were cultivated from donor conjunctiva. After incubation with ATs diluted 1: 7 or 1: 3.5 in culture media for 2 hours, GC survival was analysed using a lactate dehydrogenase assay and compared to a negative control. Mucin release was evaluated after incubation with ATs (1: 7) for 4 hours using an ELISA assay. The pH values, osmolarity, and surface tension of the ATs were also measured.

Results: AT (1: 7) preserved with 0.001% BAK and 0.01% cetrimide reduced cell survival by 26% (p < 0.0001) and 19% (p = 0.0304), respectively, compared to a negative control. When diluted 1: 3.5, ATs preserved with 0.005% and 0.006% BAK also significantly decreased cell survival (p = 0.0014 and p < 0.0001, respectively). Preservative‐free ATs did not significantly alter cell survival. Muc5AC release was increased by 0.01% BAK preserved AT (p = 0.0497). The pH values of all ATs varied significantly between different products and were all significantly different from the physiological pH of the tear film (pH = 7.4). None of the ATs were hyperosmolar. PF ATs had a higher surface tension compared to preserved ATs.

Conclusions: BAK‐ and cetrimide‐preserved artificial tears induce goblet cell death in a concentration‐dependent manner, potentially exacerbating dry eye disease (DED). Additionally, BAK appears to increase Muc5AC release. Therefore, preservative‐free or PolyQuad‐preserved artificial tears may be more suitable for DED management. The physicochemical properties of these artificial tears vary which can influence their effectiveness.
Identification of clinical protein markers correlated to the impairment of the lacrimal and meibomian glands in the progression of dry eye syndrome
Authors: Perumal Natarajan , Lindner Anna , Glassmacher Adina , Multani Bettina , Lin Hao , Manicam Caroline
Published: January 2025

Aims/Purpose: Dry eye syndrome (DES) is a multifactorial pathology of the ocular surface, characterized by disruption of tear film homeostasis. Although prevalent, distinct clinical biomarkers associated with the impairment of the lacrimal (LG) and meibomian glands (MG) that exacerbate the progression of DES are still largely lacking. This study was conducted to identify potential DES markers for precise clinical diagnosis.

Methods: Subjects underwent a battery of clinical examinations including the basic secretory test via Schirmer I to evaluate the functional impairment of the LG that leads to aqueous‐deficient DES (DRYaq). Meanwhile, tear break‐up time (TBUT) test was used to evaluate the impairment status of the MG, which leads to evaporative DES (DRYlip). Next, the tear samples (N = 307) were analyzed individually employing mass spectrometry‐based proteomics, followed by in‐depth statistical and bioinformatics analyses.

Results: A total of 47 proteins, largely secreted by the LG and annotated to antibacterial response (p = 5.0 × 10‐9) were found to be significantly (p < 0.01) decreased in abundance with the progression of DRYaq, namely LTF (r = ‐0.79), PROL1 (r = ‐0.64) and AZGP1 (r = ‐0.58). On the contrary, as many as 360 proteins were found to be significantly increased in abundance with the progression of DRYaq, namely SFN (r = +0.68), ORM2 (r = +0.67) and TXN (r = +0.66). These proteins are annotated to various biological functions, especially inflammatory response (p = 3.0 × 10‐17), apoptosis (p = 2.1 × 10‐29) and synthesis of reactive oxygen species (p = 3.7 × 10‐29). Only 26 proteins were found to be significantly expressed with the progression of DRYlip, namely ACTN2 (r = ‐0.33) and ARG1 (r = +0.48). These proteins are exclusively annotated to anti‐inflammatory response (p = 8.1 × 10‐5), citrulline biosynthesis (p = 4.5 × 10‐3) and IL‐15 signaling (p = 2.5 × 10‐4).

Conclusions: For the first time, our study analyzed the proteome of the largest number of individual tear samples in a clinical setting. Importantly, we identified progressive changes in the expression of specific protein markers correlated to the functionality of the LG and MG that could be potentially leveraged for future development of improved clinical diagnosis and targeted therapeutic interventions to ameliorate DES in a personalized manner.
Optimizing keratoconus treatment with AI‐driven lenticule matching using pentacam indices
Authors: Doroodgar Farideh , Niazi Sana , Nematy Hamidreza
Published: January 2025

Aims/Purpose: The aim of this study is to develop an advanced artificial intelligence (AI) methodology to optimize the matching of donor and recipient lenticules for the treatment of keratoconus. This approach leverages Pentacam indices related to corneal thickness and topography to minimize the preparatory modifications required for stromal lenticule implantation.

Methods: We will construct a comprehensive database of donor and recipient lenticules by systematically collecting Pentacam‐derived indices, including central corneal thickness (CCT), anterior and posterior corneal elevation, and corneal curvature, at preoperative, intraoperative, and postoperative stages. Using these datasets, an AI algorithm capable of identifying the most compatible lenticule pairs will be trained and validated. The algorithm's performance will be assessed based on its accuracy in predicting optimal matches and the practical effectiveness of the process.

Results: As this project is in its preliminary phase, no results are currently available. However, we hypothesize that the AI‐assisted matching system will significantly enhance the compatibility of donor and recipient lenticules. Expected outcomes include increased postoperative central corneal thickness, improved corrected distance visual acuity (CDVA), and reduced corneal irregularity.

Conclusions: This study aims to validate the potential of AI‐assisted matching of donor and recipient lenticules using Pentacam indices as a transformative approach in the treatment of keratoconus. By refining the customization process, we anticipate improvements in surgical efficiency and patient outcomes.
Quantitative assessment of chitin synthase gene of demodex mite on eyelashes and correlation to symptomatology of blepharitis
Authors: Andriopoulos Georgios , Kalogeropoulos Chris , Katsanos Andreas , Kozobolis Vasileios , Terzidou Chryssa , Dalianis Georgios , Trivli Alexandra
Published: January 2025

Aims/Purpose: to quantify the presence and activity of Demodex mites and correlate it with patient symptoms, using quantitative determination of gene copy number for the chitin synthase gene.

Methods: 61 patients meeting the inclusion criteria were enrolled in the study. 8 eyelashes from each patient were aseptically placed in sterile microtubes. After DNA isolation, quantitative real‐time PCR reactions were performed with specific primers for the chitin synthase gene (DEM) (for Demodex) and beta‐actin (ACTNB) and Factor V (FV) (for human), to amplify the corresponding genes. The quantitative differences for Demodex DNA copies were relative to the simultaneous amplification of the reference human genes (CtDEM‐CtFV/ΔCt1 or CtDEM‐CtACTNB/ΔCt2).

Results: 51 subjects completed the protocol. Mean age was 57.08 ± 17.35 years. Mean Ocular Surface Disease Index (OSDI) was 41.79 ± 20.05, while mean Total Ocular Symptom Score (TOSS) was 42.25 ± 23.90. Mean conjunctival hyperemia was 1.43 ± 0.48 (0‐3). Subjects had a mean Non‐Invasive Tear Break‐up Time (NIBUT) of 6.86 ± 4.32 sec. Meibography showed a mean of 1.66 ± 0.51 (0‐3), while Marx Line values were 1.56 ± 0.825 (0‐3). Pearson's correlation coefficient indicated a positive correlation of age and TOSS score (p = 0.035) as well as conjunctival hyperemia (p < 0.001) values. Higher OSDI scores were correlated to higher TOSS scores (p < 0.001), lower NIBUT values (p = 0.001) and worse meibography grade (p = 0.038). Conjunctival hyperemia showed a linear relationship with age (p < 0.001). ΔCt1 (CtDEM‐CtFV) showed a positive correlation with ΔCt2 (CtDEM‐CtACTNB) (p < 0.001).

Conclusions: The present study is the first to test the number of Demodex‐severity of symptoms hypothesis, using specific genes and Real‐time PCR. Although no statistically significant correlation was revealed for the specific genes, the clinical data analysis confirmed a correct methodology and sampling, creating a frame for future research on the hypothesis.
Co‐polymer based delivery system for the treatment of ocular surface and cornea diseases
Authors: Astolfi Gloria , Guidotti Giulia , Soccio Michelina , Lotti Nadia , Ponzini Erika , Fontana Luigi , Moramarco Antonio , Versura Piera
Published: January 2025

Aims/Purpose: The treatment of ocular surface diseases (OSD) requires the administration of therapeutic agents in sufficient quantities for the proper time to reach therapeutic efficacy and relieve from subjective symptoms. Delivery systems avoid systemic routes which may require undesirable concentrations of the agents to reach appropriate levels at the target site. The aim of this work was to standardize two polyester‐based co‐polymers for ophthalmic application.

Methods: The cytotoxicity, the morphological changes, and the adhesion behaviour of the copolymers in study were assessed by Human Conjunctival Fibroblasts (HConF) and Epithelial (HCjECs) cell‐culture‐based tests (ISO 10993.5). The controlled release of two model proteins presents in tear fluid, (Human Lactoferrin–LF, and Lysozyme C‐LYS‐C, Sigma) was estimated by uploading both proteins for 24h in a solution with a physiological concentration, and the released kinetic was monitored over time with the Bioanalyzer 2100 (Agilent). The structure of the proteins was monitored by circular dichroism analysis on pure and released proteins.

Results: Both copolymers were demonstrated to be non‐cytotoxic, cell viability was preserved after the contact with both materials or their extracts, growth and proliferation of HConF and HCjECs on the wells were also supported, cells failed to adhere to both materials. The release analysis showed a gradual time dependance, reaching a plateau at 180 minutes for LF and 75 min for LYS‐C. The native structures of released LF and LYS were unchanged as compared to their pre‐loaded structure.

Conclusions: Data from this study suggest that the copolymers under study might represent a versatile, safe and effective treatment option for chronic OSD, to ensure patient's compliance, and effective treatment.
Residence time and ultrastructural effects of a new formulation of multiple‐action tear substitute: Preliminary results at scanning electron microscopy (SEM) examination
Authors: Troisi Mario , Del Prete Salvatore , Troisi Salvatore , Marasco Daniela , Costagliola Ciro
Published: January 2025

Aims/Purpose: The aim of the study is to evaluate with SEM the residence time and ultrastructural effects on the ocular surface cells in patients suffering from dry eye disease (DED) treated with a multiple‐acting tear substitute based on 0.15% cross‐linked HA, cationic liposomes and 3% trehalose (Trimix®, Offhealth SpA, Firenze, Italy).

Methods: We examined 10 eyes of 10 patients with previous clininal diagnosis of DED (Schirmer test 1 < 10 mm, TBUT < 10 s, OSDI > 13). Exclusion criteria: topical or systemic therapies in the previous 30 days; allergic conjunctivitis; infections and other ocular surface diseases in the last 3 months; previous herpetic keratitis; corneal opacities and ulcers; pregnancy and breastfeeding, age < 18 years.

All patients were treated for 30 days BID with Trimix®. At the baseline (T0) and 1h (T1), 6h (T2) and 12h (T3) after the end of the treatment, a cytological sampling of the bulbar conjunctiva with an impression procedure was performed. The cytological smear was examined with SEM for the evaluation of the microvilli, using a preset scale (Del Prete, 2017), and of the persistence of Trimix®, preliminarily identified by SEM on a slide. The results were compared with a control group (CTR) of 10 patients with the same grades of inflammation of DED group, treated with BID balanced salt solution.

Results: At T0 6 DED patients presented mild/moderate inflammation (grade 1‐2 of microvillar alteration); 4 medium/severe inflammation, with grade 3‐4 on the microvillar evaluation. At T1 8/10 eyes (80%) showed a complete restoration of the microvillar surface (p < 0.001), 2/10 (20%) an improvement at stage 1 (p < 0.001). The persistence of the Trimix® molecules was detected at T1 and T2 in all cases; in 9 of them (90%) Trimix® partially enveloped the microvilli at T3. No significant microvillar changes were found in CTR group (p > 0.05). The tear substitute resulted well tolerated as no patient reported any significant side effects.

Conclusions: Microvilli express the vitality of epithelial cells. Their significant improvement or complete recovery after treatment with Trimix® indicates strong trophic and protective properties of the product, that could continue even 12 hours after the instillation, as confirmed by the high residence time. This could suggest a high effectiveness even when administered twice daily.
Transmigration of neutrophils across the avascular corneal endothelium
Authors: van der Krogt Jeffrey , Dallinga Marchien , Murphy Conor , van der Meulen Ivanka , van Buul Jaap
Published: January 2025

Aims/Purpose: The corneal endothelium (CE) functions as a tight barrier to regulate nutrient and fluid influx into the corneal stroma. During corneal infections, leukocytes infiltrate the cornea through the conjunctival lymphoid reservoir or via angiogenesis directed by the limbus. In a previous study, neutrophils were found to migrate across the corneal endothelium (CE) upon stimulation with IFN‐γ, mediated by ICAM‐1 [1]. We aim to further elucidate the transmigration of neutrophils across the CE as a possible third route for corneal infiltration.

Methods: CE tissue samples were obtained from patients with corneal disease that underwent posterior lamellar corneal transplantation or penetrating keratoplasty. Confocal immunofluorescence microscopy was used to study the expression and distribution of adhesion molecule ligands for leukocyte adhesion and the spatial distribution of neutrophils within the CE.

Results: Multiple events of infiltrating neutrophils across the CE monolayer were identified, with the paracellular route being the preferred mode of migration. The expression of the leukocyte ligand ICAM‐1 appeared diffuse but heterogeneous across the CE.

Conclusions: Using high‐end microscopy, we found neutrophil infiltration through the CE monolayer and confirmed the presence of ICAM‐1 on the apical surface of CE cells. These data imply that there is a third pathway of corneal immunity. This has implications for anti‐inflammatory therapies instilled systemically or topically and warrants further investigation.

References

Elner VM, et al., Intercellular adhesion molecule‐1 in human corneal endothelium. Modulation and function. Am J Pathol. 1991.
Ocular lichen planus: An unusual occurence
Authors: Ferrando Sergio Obiol , Ortega Aranzazu Caro , García Amparo Lanuza , de Lara Sánchez Sofía Sánchez , Nadal Andrea Català , Duch‐Samper Antonio , Bouchoutrouch Sarra , Serrano Diego
Published: January 2025

Aims/Purpose: Lichen planus (LP) is an inflammatory disease of autoimmune etiology that primarily affects skin and mucous membranes. Its prevalence varies between 0.07% and 0.84%. The most frequently affected area is the oral mucosa, followed by the genital area. Ocular involvement is extremely rare in the scientific literature. Most cases of ocular LP manifest as chronic cicatrizing conjunctivitis. Chronic inflammation leads to subepithelial fibrosis, shortening of the fornix and symblepharon with irreversible fibrotic changes. Compared to conjunctival LP, corneal involvement is much less frequent.

Methods: A 79‐year‐old male consulted with loss of visual acuity in both eyes in the last two months, with greater loss in the right eye. At the initial visit, a maximum corrected visual acuity of 0.2 in the right eye and counting fingers at 2 meters in the left eye was observed. Biomicroscopic examination of both eyes showed a 360° corneal pannus, a very short tear breakup time, erythema of upper portion and lower portion of the eyelids, severe conjunctival hyperemia, subepithelial fibrosis with shortening of the fornix and presence of inferior symblepharon in both eyes. A scheduled conjunctival biopsy was performed two days after the first visit on the nasal and temporal side of both eyes. Direct immunofluorescence (DIF) results showed linear fibrinogen deposition along the basement membrane consistent with the diagnosis of ocular LP.

Results: After the diagnosis the patient was prescribed tacrolimus 0.03% eye drops every 12 hours and intense lubrication of the ocular surface with daily topical artificial tears and nightly ointment.

Conclusions: Ocular LP is an extremely rare disease, with few cases described in the literature. The most common form of ocular clinical presentation is conjunctival, with corneal involvement being extremely infrequent. Treatment is based on topical and/or systemic immunomodulatory drugs.

References

Mohebbi M, Mirghorbani M, Banafshe Afshan A, Towfighi M. Lichen planus in ocular surface: Major presentations and treatments. Ocul Immunol Inflamm. 2019; 27(6): 987–94.

Safadi M, Viglione M, Zahner S. Ocular lichen planus: An unusual presentation, its treatment, and review of the literature. JAAD Case Rep. 2021; 14: 4–6.
Possible necrotizing scleritis and non‐infectious vitritis following intravitreal injection of bevacizumab
Authors: Outeiriño Patricia Roig , del Mar Esteban Ortega Maria , Martín Sergio Pernas , de Lázaro Alejandra Antón Guzmán , Hernández Eduardo Conesa , Carretero Manuel Moriche
Published: January 2025

Aims/Purpose: This case report describes possible necrotizing scleritis and non‐infectious vitritis in the right eye following intravitreal injections of bevacizumab for the treatment of postsurgical cystic macular edema, highlighting the potential immune‐mediated adverse reactions associated with the intravitreal treatment.

Methods: An ophthalmological examination was performed along with laboratory and imaging tests to diagnose the patient.

Results: After the first injection, the patient developed intense ocular redness, scleral thinning, and pancorneal punctate keratitis, with possible necrotizing scleritis suspected. Treatment was iniciated with a positive progress, however, after resuming the treatment with bevacizumab due to persistence of macular edema, the patient experienced blurred vision and photophobia, and mild vitritis was observed during the examination. Topical treatment produced rapid improvement, but due to suspicion of an immune‐mediated reaction, bevacizumab was discontinued. Alternative treatments were considered, including other anti‐VEGF agents and topical anti‐inflammatory medications.

Conclusions: Although necrotizing scleritis is not described as a possible adverse reaction to treatment with intravitreal bevacizumab, its association with another immune‐mediated reaction that also coincides in time with the treatment suggests a possible causal relationship. This case highlights the importance of recognizing and managing rare immune‐related adverse reactions to intravitreal treatments, emphasizing the need for alternative therapies that minimize risks to the patient.
The relationship between corneal nerve density and corneal dendritic cells in patients with type 2 diabetes macular edema
Authors: Filipek Ania Cikowska , Lagali Neil , Viberg Andreas , Johannesson Gauti , Byström Berit
Published: January 2025

Aims/Purpose: The purpose of this study is to examine a possible correlation of diabetic macular edema (DME) with changes in the anterior segment, focusing on corneal subbasal nerve fibers and the density of corneal inflammatory cells in diabetes type 2.

Methods: Cross‐sectional examination of 30 subjects with type 2 diabetes and DME, and 30 volunteers without diabetes using corneal confocal microscope the same morning as their retinal status were checked. Quantitative measurements of corneal subbasal nerve fibers were made using semi‐automated tracing software. An average corneal nerve fiber length, defined as total length of nerve fibers and nerve branches within a frame (mm/mm2), from every image was quantified. The density of activated and non‐activated dendritic cells in the same corneal layer and same images were additionally identified and quantified.

Results: Preliminary results from 15 subjects with DME and 15 controls showed a trend towards reduced nerve fiber density especially in the whorl region of the corneas, in the DME group. On the contrary, preliminary results did not show a clear difference in the amount of dendritic cells when comparing the groups.

Conclusions: Preliminary results suggest a novel connection between the diabetic status of the eye with DME and the corneal subbasal nerve fiber layer especially in the whorl region of the cornea. A reduced density of nerves was apparent in the DME group. More cases will be analyzed to study the relationships in more detail, which might provide a means to monitor the inflammatory status of DME.
Microbial keratitis in a tertiary hospital in Ireland
Authors: Hegazy Esraa , Fauzi Muhammad Yusuf Bin Mohd , Houlihan Elaine , Gallagher David , Quill Barry , Power William , Knowles Susan , Murphy Conor
Published: January 2025

Aims/Purpose: The aim of this study is to describe trends in the pathogens and antimicrobial resistance isolated from corneal scrapings in a Tertiary Eye Care Centre in Ireland over 10 years.

Methods: Electronic health records of corneal scrapings sent over the period 01.1.2014 until the 31.12.2023 were retrieved. These included positive and negative scrapes, the pathogens isolated as well as antimicrobial sensitivity and resistance.

Results: Overall, 1,291 patients underwent corneal scrapings during this time period. Negative corneal scrapings were found in 52.7% (n = 681) of eyes and 47.3% (n = 610) of eyes yielded positive results. Out of the positive corneal scrapings, 56 had 2 organisms isolated and 6 had 3 organisms isolated. A total of 672 organisms were isolated. Bacteria were isolated in 91.8% (n = 617) of scrapings and fungi were isolated in 8.2% (n = 55) of scrapings. The most common bacterial organisms isolated were coagulase‐negative Staphylococcus (21.8%). Staphylococcus aureus was found in 123 eyes (19.9%), 7 of these were methicillin‐resistant Staphylococcus aureus. This was followed by Moraxella (15.7%), Pseudomonas aeruginosa (15.6%), Streptococcus pneumoniae (6.6%), Corynebacterium (3.8%) and Serratia (3.7%). Of the positive scrapings for fungal infection, Fusarium was the most common fungi isolated (38.2%). Candida was second (25.5%) and Aspergillus (9%) was third. Trends in antimicrobial resistance remained stable over the 10 years. Chloramphenicol drops were sensitive in Staphylococcus aureus (95%), Moraxella (98%) and Streptococcus pneumoniae (100%). Topical ofloxacin was sensitive in Pseudomonas aeruginosa (100%) and in Moraxella (88%). Moxifloxacin was sensitive in Streptococcus pneumoniae (100%), Staphylococcus aureus (92%) and Corynebacterium (87.5%).

Fusarium species were sensitive to Natamycin (90%) and Amphotericin B (66%). Candida species were sensitive to Amphotericin B (100%) and Fluconazole (100%). Aspergillus was sensitive to Amphotericin B (100%).

Conclusions: Bacterial microorganisms accounted for the majority of isolates from corneal scrapings. It is important to be aware of the most common pathogens associated with microbial keratitis including corresponding antibiotic sensitivity. Rates of microbial keratitis infections did not change over time.
The role of substance P in maintaining corneal innervation and ocular surface homeostasis
Authors: Suanno Giuseppe , Fonteyne Philippe , Bartolomeo Nicolò , De Micheli Massimo , Bandello Francesco , Ferrari Giulio
Published: January 2025

Aims/Purpose: To assess the role of Substance P (SP) in maintaining corneal nerve homeostasis. Specifically, we aimed to study how SP impacts sensory nerve regeneration and, in turn, ocular surface physiology.

Methods: This study included eight‐week‐old mice C57BL6/N (WT mice) and Tac1‐deficient B6.Cg‐Tac1tm1Bbm/J (SP‐KO mice). Corneal denervation was achieved by means of central trephination. Mice were followed up to six weeks after denervation, corneal sensitivity, nociception, corneal fluorescein staining were measured at different time points. After sacrifice, corneas were collected and immuno‐stained for beta‐III tubulin, as a marker of corneal nerve density.

Results: SP‐KO mice showed lower beta‐III tubulin staining than WT mice at the baseline (p < 0.01). After trephination, beta‐III tubulin‐positive fibers were significantly reduced in both groups (p < 0.0001) and they were restored in WT mice six weeks after trephination. Similarly, corneal sensitivity was significantly reduced after trephination in both groups (p < 0.0001), and returned to normal levels after 6 weeks in WT mice. Nociception was significantly lower in SP‐KO versus WT mice up to 5 weeks after trephination. Interestingly, punctate keratopathy scores following trephination were higher in SP‐KO mice versus controls (p < 0.0001).

Conclusions: Our findings show that trephination significantly affects ocular surface integrity, pain response/sensitivity and corneal nerve regeneration. SP may have an impact on corneal nerve regeneration following trephination.
4 mm Descemetorhexis and anterior lens capsule graft versus descemet striping only: A preclinical study
Authors: Goin Paul , Louise Parveau , Poinard Sylvain , Oliver Dorado Cortez , He Zhiguo , Philippe Gain , Thuret Gilles
Published: January 2025

Aims/Purpose: Fuchs endothelial corneal dystrophy is currently the main indication for keratoplasty. Alternatively, a localized 4mm Descemet Stripping Only (DSO) has been proposed to treat selected patients with a sufficient peripheral endothelial reserve (1,2). Visual recovery is generally longer than after keratoplasty but no immunosuppressive treatment is needed (3). The anterior lens capsule (ALC) can be used as a support for the culture of corneal endothelial cells (CECs)(4). Their migration is facilitated by the presence of a basal membrane. Aim: to assess the migration capacity of CECs with and without the addition of an ACL disc after a 4mm Descemetorhexis in an ex vivo model

Methods: Pairs of human corneas procured for scientific purposes were used. The ACL were procured during femtosecond laser assisted cataract surgery and decellularized in water. Corneas were deswelled for 72h in our Active Storage Machine (ASM)(5). A central 4mm Descemetorhexis was performed. For each pair, one cornea received a 4mm ALC disc. The corneas were then placed back in the ASM with air tamponade for 72h. All corneas were then stored for 14 days in CorneaMax (Eurobio) and monitored by OCT. The endothelium was finally assessed using: 1/Hoechst 33342, Calcein‐AM and trypan blue staining for cell viability; 2/alizarin red staining for cell morphology; 3/immunostaining targeted CEC membrane proteins, mesenchymal transition markers and keratocytes.

Results: Migration of CEC on the surface of the ALC was more extensive than on the bare stroma. Migrating cells were usually polynucleated and polygonal in both groups. Peripheral viable CECs (Calcein +) were comparable in both groups. Central corneal thicknesses were not statistically different.

Conclusions: The presence of a ALC allows more extensive migration of CECs after 14 days in ASM compared with the DSO. The use of a decellularized ALC disc could therefore allow faster visual recovery for selected FECD patients eligible for DSO, particularly during combined cataract surgery.

References

Borkar et al. Cornea. 2016 Oct; 35(10): 1267–73.

Iovieno et al. Can J Ophthalmol. 2022 Dec; 57(6): 402–7.

Huang et al. Cornea. 2018 Dec; 37(12): 1479–83.

Yoeruek et al. Cornea. 2009 May; 28(4): 416.

Garcin T et al. Am J Transplant. 2019 Jun; 19(6): 1641–51.
Genetically modified mesenchymal stem cells with CXCR4 and TSG‐6 as future cell therapy for the ocular surface: In vitro study of the cell migration and the regenerative capacity in an inflammation model
Authors: Figueroa‐Haro Jessica Nataly , de la Parte Esther González , Marceñido Beatriz , Vázquez Carmen García , de la Rosa Sara Galindo , Paniagua Marina López , Calonge Margarita , López‐Miguel Alberto , Miguel Teresa Nieto , de la Mata Sampedro Ana
Published: January 2025

Aims/Purpose: Regeneration of the corneal epithelium, mediated by limbal epithelial stem cells, is essential for the maintenance of corneal transparency. Loss or dysfunction of these cells or their niche, known as limbal stem cell deficiency (LSCD), causes corneal inflammation, ulceration, neovascularization, chronic pain, and conjunctivalization, leading to corneal blindness. Mesenchymal stem cells (MSCs) are a safe and effective treatment for LSCD, however, there is controversy regarding their migration potential. The aim of this work is to enhance the migration and regenerative capacity of adipose tissue‐derived MSCs (AT‐MSCs) by overexpressing the TNF‐stimulated gene 6 (TSG‐6) and the chemokine receptor CXCR4, while maintaining their phenotype.

Methods: AT‐MSCs were transduced with TSG‐6 and CXCR4 using lentiviral vectors. The immunophenotype of the transduced AT‐MSCs was analyzed evaluating the expression of CD14, CD19, CD34, CD45, HLA‐DR, CD73, CD90 and CD105. Moreover, the migration capacity and the regenerative potential of the modified AT‐MSCs were analyzed using a Transwell cell migration assay in the presence or absence of the pro‐inflammatory cytokine TNFα, and a wound healing assay in human corneal epithelial cells (HCE).

Results: TSG‐6 and CXCR4‐modified AT‐MSCs expressed the MSCs surface markers, maintaining the immunophenotype. Both cells, CXCR4 or TSG‐6‐modified, showed significantly higher migration than control AT‐MSCs in standar conditions. Under inflammatory conditions, a significant increase in the migratory capacity of TSG‐6‐modified AT‐MSCs was observed compared to the control and the CXCR4‐modified ones. The HCE wound healing was faster in the presence of TSG‐6‐modified AT‐MSCs.

Conclusions: TSG‐6 and CXCR4‐modified AT‐MSCs maintain the MSCs immunophenotype and improve their migration capacity under standar conditions. Transduction of AT‐MSCs with TSG‐6 enhances both migratory and regenerative capacity of AT‐MSCs under inflammatory conditions.
Quality control in corneal eye banking: Impact of preservation time on graft endothelium
Authors: Cabanas João Castro , Cardoso Daniel Ferreira , Martins Pedro Moreira , Soares Ricardo Machado , Ribeiro Ana Clara , Arêde Carlos , Sequeira Joaquim
Published: January 2025

Aims/Purpose: To evaluate the impact of preservation duration on the endothelial quality of corneal grafts and to identify the most effective parameters for quality control of these grafts.

Methods: Retrospective analysis of specular microscopy data from corneal grafts collected by the Cornea and Amniotic Membrane Department of Unidade Local de Saúde Gaia e Espinho between 2021 and 2024. According to department protocol, corneal grafts were stored at 4°C in Optisol‐GS (Bausch and Lomb, Rochester, USA) solution, and specular microscopy was performed at 24 hours (D0), day 5 (D5), and day 10 (D10) post‐harvest. Only grafts with at least two specular microscopy exams (D0‐D5) before transplantation were considered. Data collected included donor age, endothelial cell density (ECD), hexagonality (HEX), and coefficient of variation (VC) at all time points. Data was compared across all time points using repeated‐measures ANOVA adjusted for confounders, with a significance level set at 0.05.

Results: Of 93 corneal grafts, 58 met the inclusion criteria, with 12 having specular microscopy analysis at D10. The mean donor age was 61.7 ± 12.9 years. Mean ECD was 2846 ± 434 cells/mm2 at D0, 3025 ± 535 cells/mm2 at D5, and 2880 ± 440 cells/mm2 at D10. Mean HEX was 58.7 ± 11.7% at D0, 51.1 ± 10.5% at D5, and 49.6 ± 12.3% at D10. Mean VC was 34.0 ± 6.7% at D0, 37.9 ± 6.2% at D5, and 38.5 ± 8.7% at D10. Variations in HEX and VC between D0 and D5 were statistically significant (p< 0.001), while no significant difference was found between D5 and D10 (p = 0.915 and p = 0.274, respectively). These differences were independent of graft donor age (p > 0.05).

Conclusions: In this study, preservation time affects the endothelial quality as represented by the decrease of cell HEX and increased VC, especially in the first days of preservation (D0‐D5) while this effect is more attenuated between D5 and D10. Moreover, these two parameters might be more reliable markers of endothelial cell quality in corneal grafts during preservation compared to ECD as this measure is more prone to exam variation as seen in our results.
Designing and testing anti‐scarring and anti‐inflammatory biomaterials for corneal implants: A promising alternative to human donors
Authors: Abu‐Dieh Anas , Om Boda , Thathapudi Neethi , Kiyaseh Mozhgan , Roudbaraki Mostafa , Robert Marie‐Claude , Hébert Mélanie , Jabbour Samir , Harissi‐Dagher Mona , Griffith May
Published: January 2025

Purpose: Corneal blindness is mainly treated by cornea transplantation. However, there is a shortage of cornea donors for surgeries in many countries. Even with accessible donors, patients suffering from severe pathologies causing inflammation may not benefit as they are at high risk for graft rejection. The Griffith laboratory is the first to use acellular human collagen implants to regenerate high‐risk corneas in a group of patients. For broader clinical applications, scalable collagen‐like peptide (CLP) synthetic hydrogels are being developed. It is important to identify design patterns to ensure the implants do not cause inflammation.

Methods: The growth of stromal fibroblasts cultured on CLP hydrogels with and without RGD groups are compared, with collagen gels and tissue culture plastic as controls. Cellular growth and viability on the different substrates were compared using the AmarBlue assay. Next, TGF‐β was added to the media to stimulate fibroblast differentiation into myofibroblasts. The latter has been linked to corneal scarring. The proportion of resulting myofibroblasts was determined by immunostaining using anti‐smooth muscle actin (SMA) antibody. Stromal cells seeded onto the hydrogels were also stained against fibronectin to study its implication due to RGD. Furthermore, the CLP‐based hydrogel was tested in vivo on alkali burnt BALB/c mice to investigate their practical biocompatibility and efficacy.

Results: α‐SMA expression was observed in cells grown on CLP‐RGD containing hydrogels but not on tissue culture plastic or CLP‐only control. There was a positive fibronectin expression by cells cultured on CLP‐RGD hydrogels, on 5% collagen hydrogels and on the issue culture control. The CLP‐RGD hydrogel is a smooth and soft gel with desirable water content. The in vivo test showed that there was no sign of inflammation or angiogenesis in the cornea after three months, which can prove the great biocompatibility of the prepared CLP‐based hydrogel.

Conclusions: This project allowed for the testing of cell growth on RGD‐containing CLP hydrogels, which has not been done before. Early results suggest that RGD groups within CLPs induced myofibroblast differentiation and potential pro‐inflammatory responses.
International standard pattern electroretinogram assessment of macular function is improved by additional large‐check responses
Authors: Georgiou Anne , Neveu Magella , Calcagni Antonio , Robson Anthony
Published: January 2025

Aims/Purpose: The 2024 ISCEV Standard for pattern electroretinography (PERG) acknowledges the use of a non‐standard large check size as a potentially useful adjunct to Standard testing. This study aims to audit the additional use of responses to a large check size (focal ERGs; FERGs) in a heterogeneous group of patients.

Methods: Recordings from successive patients tested at Moorfields Eye Hospital were retrospectively analyzed over 3 months. Best corrected visual acuity (VA) was recorded. A Standard checkerboard (0.75° checks; field size 13°x11°; 4.2 rps) was used to elicit PERGs and a coarse stimulus (check size 7.5°, field size 10°x10°, 4.4 rps) used to elicit FERGs for comparison. If the FERG (positive peak) was larger or of equal amplitude to P50, an optical contribution to PERG reduction was considered and remedial actions documented.

Results: Data was obtained from 434 patients (864 eyes). Data from 18 eyes were excluded due to artefacts. In most cases (724/846 eyes, 86%) the PERG was larger than the FERG. The FERG was larger or equal to the P50 component in 14% of eyes (122/846) suggesting an optical contribution to P50 reduction (possible cause for optical degradation on referral in 51/122). In 10/122 autorefraction was performed before testing due to an improvement in VA with pinhole. In 13/122 autorefraction was prompted due to the FERG data, with 11 of these showing subsequent improvement in PERG P50 (4/11 of which normalized).

Conclusions: The FERG helps to identify optical contributions to PERG P50 reduction, enabling adjustments that provide a more reliable and accurate assessment of macular function. The FERG is a useful adjunct to PERG testing, warranting consideration within future ISCEV Standard PERG protocols.

Reference

Thompson, D.A., Bach, M., McAnany, J.J. et al. ISCEV Standard for clinical pattern electroretinography (2024 update). Doc Ophthalmol 148, 75‐85 (2024).
Consequences of forced distance learning for patients with myopia
Authors: Boieva Yuliia , Bezditko Pavlo , Sinichenko Elena , Shelenkova Anastasia , Honchar Elena
Published: January 2025

Aims/Purpose: to evaluate and confirm the rate of progression of myopia of various degrees in school‐age children (patients – PT) on enhanced distance learning.

Methods: 49 PT (98 eyes) participated in the study with low myopia−0.5−3 D, moderate −3−6 D and high myopia > −6 D aged from 9 to 15 years were included in the examination. The control group (I group) included 20 PT, in the studied group (II group) – 29 PT. In addition to the standard ophthalmological examination, the axial length (AL) of the eye was measured and static retinoscopy (RS) was performed. Control indicators was visual acuity (VA), AL and RS. The exclusion criteria: PT with systemic diseases, myopia greater than 9.0D, strabismus and amblyopia, PT with corrective night lens. PT of the II group were on forced distance learning for 2.5 years and spent an average of 8 hours a day on monitors. PT of the I group were in full‐time education for 2.5 years and spent an average of 4 hours a day on monitors. Patients of 2 groups used correct optical correction (glasses or microcontact lenses) during the studied period. Control indicators were assessed at the first visit, after 3 months, 12 months, 24 months.

Results: negative dynamics were noted in groups I and II for all 3 control indicators, but with different values. The average indicative of VA decreased by 0.29 ± 0.05, AL increased by 0.81 ± 0.04mm, the RS increased by 1.41 ± 0.02 D (p < 0.05). The I group: VA decreased by 0.25 ± 0.08, AL increased by 0.38 ± 0.05mm, the RS increased by 0.73 ± 0.05 D (p < 0.05).

A significant increase in indicators in II group was observed in patients with low 31.03% (9 PT) and moderate 44.82% (13 PT) myopia. In 26.31% (5 PT) of the control group, the indicators remained without significant changes.

Conclusions: forced long‐term visual load during schooling in school‐age children significantly accelerates the progression of myopia and contributes to its primary occurrence.
Is there a common factor for vision?
Authors: Herzog Michael , Garobbio Simona , Pfau Maximilian , Scholl Hendrik
Published: January 2025

Aims/Purpose: Eye diseases are implicitly assumed to affect vision generally. However, only visual acuity and contrast sensitivity are usually measured to determine perceptual deficits. What about orientation and motion perception?

Methods: To address these questions, we first conducted 19 visual tests, including visual acuity (determined by Landolt Cs and verniers), various motion tests, etc., in a large sample of 104 young and 92 older healthy participants. Second, we investigated 50 patients with age‐related macular degeneration (AMD) and 49 age matched controls, administering a battery of six perceptual tests. In addition, OCT images of the retina, choroid, and optic nerve were recorded.

Results: Surprisingly, in the young and old healthy population, the tests correlated only weakly, and the factor structure was rather flat. Hence, single eye tests tell very little about vision in the healthy population. What about disease? AMD patients were impaired in all perceptual tests compared to age matched controls, except for motion perception. Detailed OCT analysis and retinal layer segmentation showed that the thickness of the retinal pigment epithelium drusen complex (RPEDC) determines deficits most strongly (r = 0.40). We found moderate correlations between the tests, which we attribute to the thickness of the RPEDC layer. However, motion perception was independent of RPEDC thickness, suggesting that AMD does not affect all visual abilities equally.

Conclusions: Our results show the need to investigate healthy and clinical vision with batteries of tests rather than with a single contrast or spatial acuity measure.
Adaptive optics fundus images: Automatic vs manual vessel segmentation
Authors: Bernardes Rui , Jordão João , Rodrigues Sérgio , Domingues Joana , Serranho Pedro , Guimarães Pedro
Published: January 2025

Aims/Purpose: This work aims to assess the performance of an automatic method for segmenting the lumen of retinal arterioles from adaptive optics (AO) high‐resolution fundus images in comparison to manual segmentation and its potential impact on the determination of the neurovascular coupling (NVC) response.

Methods: A total of 944 fundus images (4x4 degrees) within the macular region were acquired from 30 healthy adults (age (m+/‐sd): 33.7+/‐11.2 yrs.) and 15 type 1 Diabetes Mellitus (T1DM) patients (36.3+/‐13.3 yrs.), gender and imaged eye balanced by group, using the rtx1 AO camera (ImagineEyes, Orsay, France). Manual segmentations were performed by an experienced technician and assessed by an experienced retina specialist, and the average lumen diameter over a vessel segment was determined.

The automatic method first identifies the vessel axis using a low‐pass filter followed by morphological operations. Images are Gabor filtered, and lumen‐wall interfaces are detected by analyzing intensity profiles perpendicular to the vessel axis. Candidate locations are kept or removed based on vessel curvature smoothness and the vessel wall's parallelism. Local polynomial fits establish final lumen‐wall interfaces, and the lumen diameter is determined by their distance as measured perpendicularly to the vessel axis.

Results: The absolute value of the relative error (AVRE) (%) between methods was assessed, and outliers were determined based on their distribution, of which 89% (838/944) were inliers. Furthermore, all images for the same subject presented a systematic (positive or negative) difference uncorrelated to the lumen diameter (r = ‐0.17). The AVRE ranged from 0.0% to 6.3%, with an average of 1.8% (Q1: 0.9, Q2: 1.8, Q3: 3.1).

Conclusions: Achieved results show a consistent difference between manual and automatic segmentations, which might be explained by the difficulty in visually determining the exact interface location over grayscale images. However, these results show that no impact is expected in determining NVC response.