bluuebunny/crossref_metadata_2025 huggingface dataset:
Synchrotron‐based Fourier transform infrared microspectroscopy examined differences between the cultured and post‐operative human lens epithelial cells important for understanding posterior capsular opacification and lens regeneration
Authors: Andjelic Sofija , Kreuzer Martin , Hawlina Marko
Published: January 2024

Aims/Purpose: To compare the bio‐macromolecular composition and the differences between the human cultured and post‐operative lens epithelial cells (LECs) on lens capsules (LCs) for a better understanding of posterior capsular opacification (PCO)—the most common complication of cataract surgery, and lens regeneration.

Methods: The explants of the anterior portion of the LC containing the LECs, obtained from cataract surgery and cultivated under adherent conditions, as well as the post‐operative LC with LECs, were analysed by using synchrotron radiation‐based Fourier transform infrared (SR‐FTIR) microspectroscopy, a vibrational spectroscopic technique that allows monitoring of the entire biochemical status of the biological processes. The SR‐FTIR microspectroscopy setup installed on the beamline MIRAS at the Spanish synchrotron light source ALBA was used, where measurements were set to achieve single‐cell resolution, with high spectral stability and high photon flux.

Results: We found that the differences exist between the composites of cultured and post‐operative LECs on LCs on the level of all chemical constituents: proteins, lipids, nucleic acids and carbohydrates as well as oxidative stress. The strongest differences are found in protein secondary structure contribution where the composite of primary LECs cultures on LC have more α‐helix (1652 cm−1) and post‐operative LC have more β‐sheet (1624 cm−1 and 1697 cm−1) secondary structures. The oxidative stress is more expressed in the composite of primary LECs cultures on LC and relatively less in the composite of post‐operative lens epithelium LECs on LC.

Conclusions: Our results obtained by SR‐FTIR increase the knowledge about the total proteins, lipids, and nucleic acids in human primary cultures LECs while offering also evidence that SR‐FTIR is sensitive to the pathologic processes of LECs transdifferentiation. We showed that the composite of primary cultures LECs on LC have a distinct bio‐macromolecular composition compared to the composite of post‐operative LECs on LC, which gives additional information for a better understanding of PCO and lens regeneration.
Targeted fluorescence imaging using bevacizumab‐800CW within neovascular age‐related macular degeneration (AMD) patients to evaluate the upregulation of vascular endothelial growth factor (VEGF‐A) (preliminary results)
Authors: Volkmer Pia , Schmidt Iris , Westra Kim , Polman Janine , Ouwerkerk M. Stefan , Uwantege Liberata , Bolhuis Renée , Muskens Rogier , Huiskamp E. Angela , Nagengast Wouter
Published: January 2024

Aims/Purpose: With this phase 1 study, we aim to gain insight into the feasibility of using bevacizumab‐800CW to visualize the upregulation of VEGF‐A in AMD patients for treatment optimization.

Methods: First, six wet AMD patients who are currently undergoing treatment with anti‐VEGF agents were included to evaluate the optimal tracer dose and received either 4.5 or 15 mg bevacizumab‐800CW. For the ongoing analysis of targeted tracer accumulation, three additional on‐therapy and three naïve patients will be included with the optimal dose of 15 mg. Fluorescence images (Heidelberg Spectralis) were taken before, up to 60 min and 3–4 days after intravenous injection of bevacizumab‐800CW. The target‐to‐background ratios (TBR) were calculated and compared between dose groups to evaluate the optimal dose. To investigate targeted tracer uptake, images of different time points are normalized and aligned, and a fluorescence intensity line is plotted over the active lesion to locate interesting areas for further quantification.

Results: The preliminary results showed a clear inflow of the tracer into the eye vasculature after administration of 15 mg bevacizumab‐800CW. The fluorescence remains visible up to 1 h after tracer administration. Visual image comparison and TBR calculation in the first six patients showed that 15 mg bevacizumab‐800CW was the optimal tracer dose. In patients who received 15 mg bevacizumab‐800CW, accumulation of fluorescence signal in a smaller area within the active lesion was seen after 3–4 days.

Conclusions: For the first time, we show that bevacizumab‐800CW (4.5 mg/15 mg) can be imaged in AMD patients using a commercially available system. An increase in signal intensity 3–4 days after bevacizumab‐800CW injection predicts tracer accumulation in the diseased area indicating ongoing active disease. VEGF‐A imaging can act as a proof of concept and pave the way for a broad application to track the performance of drugs by fluorescence molecular imaging.
The association between dry eye with ocular aberrations and contrast sensitivity in 60 years old people and over
Authors: Yekta AbbasAli , Khabazkhoob Mehdi , Hashemi Hassan , Azami Mohammad , Ostadimoghaddam Hadi , Shandiz Javad Heravian , Ehsaei Asieh , Azimi Abbas , Yekta Yeganeh
Published: January 2024

Aims/Purpose: To determine the association between dry eye with higher order aberrations (HOAs) and contrast sensitivity in 60 years old people and over.

Methods: This population‐based study was conducted in Tehran, the capital of Iran, using stratified multistage random cluster sampling. All participants underwent complete ocular examination including measurement of uncorrected and best‐corrected visual acuity, refraction, slit‐lamp biomicroscopy. Zywave was used for measuring HOAs aberrations. Contrast sensitivity was measured with best correction visual acuity using the CVS1000 grating charts. Schirmer and tear break‐up time (TBUT) tests were used for evaluating dry eye in participants.

Results: After applying exclusion criteria, the data of 397 individuals were analysed. A total of 415 people were invited, of whom 397 (62.8%) were females. The mean age of the participants was 68.32 ± 5.49 years. After adjusting with age and sex, in the multiple regression model that the TBUT test has a direct association with spherical aberration (p = 0.017) and an inverse association with coma, trefoil and the third, fourth and fifth order aberrations (p < 0.05). Schirmer test results also had a positive relationship with spherical aberration (p = 0.046) and an inverse relationship with coma, trefoil and the third, fourth and fifth order aberrations (p < 0.05). Contrast sensitivity had a significant association with Schirmer test result only in spatial frequency of 3CPD.

Conclusions: The results of this study indicated the association between dry eyes and HOAs, and that the TBUT and Schirmer test results are of the most important factors in this relationship. Treating dry eye, can improve HOAs and quality of vision in elderly people.
Keratoconus: Ocular surface considerations, from bench to bedside
Authors: Doroodgar Farideh , Niazi Sana
Published: January 2024

Aims/Purpose: This comprehensive systematic narrative study is aimed to describe the close interactions between the ocular surface and keratoconus with its vast spectrum of diagnostic and treatment techniques, both basic and clinical.

Methods: This investigation searched PubMed, Scopus, Cochrane, Embase, and Web of Science for relevant papers published up to January 2023. The systematic review used MeSH and non‐MeSH terms. Unrestricted language and publishing schedule. After a comprehensive search, all of the search results were imported into Endnote software after a thorough search. Duplicate and less relevant citations have been eliminated in Endnote. In addition to the databases indicated, we searched Google Scholar for “Ocular surface” AND ((keratoconus) OR (“pellucid marginal degeneration”) OR (“corneal ectasia”) OR (“iatrogenic ectasia”)).

Results: Treating dry eye, MGD, and blepharitis may slow KC progression and relieve symptoms. Eye rubbing and mechanical injury could spread bacteria to the eyelids, causing blepharitis. Tarsorrhaphy is the most powerful manoeuvre to help heal epithelial defects, especially in moderate and severe forms of DED. Use high‐quality eyedrops, especially preservative‐free ones, to increase tissue viscosity on the ocular surface and protect tear film to reduce epithelium injury before and after surgery. Finally, Vitamins, minerals, metal ions, and antioxidants may prevent dry eye and KC. In addition, improper air quality, wind, pollution, low humidity, watching TV, reading, and surgical procedures can cause dry eye illness, increase MMP‐9 and IL‐6 and decrease EGF during exacerbation.

Conclusions: This is the first systematic narrative review to explore the mutual interaction between the ocular surface and KC and the wide spectrum of diagnostic and therapeutic options. Dry eye and tear film instability have been documented as a non‐ectatic differential diagnosis for KC and ectatic disorders. Nonetheless, KC and DED are both common topics. Future research should look into the effect of pre‐treating ocular surface health on postoperative outcome and the efficacy of the therapeutic strategy in reversing KC ocular surface changes.
Long‐term clinical course of amniotic membrane after permanent amniotic membrane transplantation
Authors: Kim TaeHwan , Noh Seungyoon , Kwon Yoon Hyung
Published: January 2024

Aims/Purpose: To investigate the long‐term clinical outcomes of transplanted amniotic membrane in patients who underwent permanent amniotic membrane transplantation (P‐AMT) on cornea.

Methods: From April 2014 to March 2021, medical records and digital photographs of 68 patients (72 eyes) who underwent P‐AMT were analysed retrospectively. The duration of complete re‐epithelization of cornea and wearing therapeutic contact lens (T‐lens) after surgery were investigated, the size of preserved amniotic membrane (AM) excluding the melted portion was analysed using the Image J program every year up to 6 years after surgery, and it was compared by dividing into a single‐layer group and a double‐layer group. In addition, when the AM melts, the cause, time, and related factors of melting were analysed.

Results: The average duration to complete re‐epithelialization after surgery was 12.2 ± 11.0 days, and T‐lens were worn on average up to 8.7 ± 8.5 months after surgery. In total group, the average ratio of preserved AM annually up to 6 years after surgery was 94.9%, 94.3%, 97.8%, 96.4%, 95.8%, 91.6% respectively, and there was no significant difference between the single‐layer group and the double‐layer group. AM melting appeared in 38.9% (28 eyes) of the total group, and melting was first observed on average 16.4 ± 17.2 months after surgery. The formation and rupture of bullae was the most common cause of melting at 71.4% (20 eyes), and there were no statistically significant related factors involved in the formation of bullae.

Conclusions: In the case of P‐AMT performed in various diseases of the cornea, the transplanted AM is partially melt but considered to be well preserved up to 6 years after surgery to form a stable ocular surface.
The effect of long‐term use of gadgets on the condition of the bulbar conjunctiva in young people
Authors: Hryzhymalska Olexandra , Melnyk Olha , Zhmud Tetiana , Andrushkova Olga
Published: January 2024

Aims/Purpose: To evaluate the condition of the bulbar conjunctiva in young people by the method of impression cytology in response to long‐term use of gadgets.

Methods: The research design consisted of 40 students (80 eyes) aged 18–20 years (19 ± 1.2). All students underwent general ophthalmological examinations, including blink rate per minute and impression cytology of the bulbar conjunctiva from the temporal side. Changes in the bulbar conjunctiva were evaluated according to Nelson's classification. Criterion for inclusion in the study: time spent on gadgets at least 6 h per day. Exclusion criteria: contact lens users, chronic eyelid diseases, diabetes, systemic connective tissue diseases, Sjögren's disease...).

Results: Morphological and morphometric studies of the bulbar conjunctiva showed that most of the subjects (35 students, which is 87.5%) had a normal epithelial state of the front surface of the eye, which corresponds to 0–1 degrees according to Nelson, while 5 students had changes in the form of partial squamous metaplasia, which corresponded to the II degree according to Nelson and amounted to 12.5%. Blink frequency was reduced in 27 subjects, which was 67.5%. In most cases (n = 34, 85%) had a reduced blink frequency while working with gadgets, and 27 students (67.5%) had it reduced even without using digital devices.

Conclusions: The results of our research showed that 12.5% of students had changes in the epithelium of the bulbar conjunctiva, corresponding to the II degree according to Nelson, which can be considered as adaptively compensatory processes, in response to long‐term use of gadgets. Therefore, it is necessary to prescribe moisturizing drops to young people, which do not contain preservatives, phosphates and buffers (for example, Thealoz duo).
Para‐phenylenediamine hair dye and dry eye symptoms: A cross‐sectional study
Authors: Jugnarain Davina , Birss Matthew , Mohamudally Raawiyah , Chaabane‐Rajah Nedjema , Carrim Zia
Published: January 2024

Aims/Purpose: Para‐phenylenediamine is a common constituent in black hair dye which is well‐associated with irritant dermatitis. Ocular complications include blepharoconjunctivitis, dry eye disease and allergic eye disease (1), mostly reported in case studies. We conducted a cross‐sectional study to establish the prevalence of dry eye symptoms in black hair dye users, and its association with irritant dermatitis, sleeping position and frequency of hair dye use.

Methods: This cross‐sectional study was conducted online among Facebook followers of an ophthalmology clinic based in Mauritius. 100 responses were gathered between November 2020 and May 2022. Participants included in the study were all users of black hair dye, over the age of 18 and of either sex. Patients with potential confounding causes of dry eye disease symptoms were not excluded from the study, but a separate analysis was conducted excluding them. Data was subsequently analysed using R statistical software.

Results: Most participants were female (88%) and excluding those with confounding causes of dry eye disease, 57% of participants reported ocular symptoms, such as grittiness, blurry vision and red eyes. 34% of these patients also reported scalp dermatitis. Prevalence of ocular symptoms increased with duration of hair dye use. However, no association was found between either rates of irritant scalp dermatitis, sleeping position or frequency of hair dye use and ocular symptoms.

Conclusions: We have found a high prevalence of dry eye symptoms among black hair dye users, compared to the prevalence previously described in the literature (28.2% by Golińska‐Zach et al.) (1), with a prolonged duration of hair dye use being a risk factor. Larger scale studies are needed to characterize the influence of para‐phenylenediamine hair dye on ocular surface disease, including assessment of tear film properties and meibomian gland dysfunction.

Reference

1. Golińska‐Zach A, Krawczyk‐Szulc P, Wiszniewska M, Nowakowska‐Świrta E, Świerczyńska‐Machura D, Tymoszuk D, et al. Sensitization to occupational allergens in hairdressing apprentices diagnosed already before entering vocational training. Med Pr [Internet]. 2016 [cited 2022 Apr 25]; 67(5): 567–75. Available from: https://pubmed.ncbi.nlm.nih.gov/27819696/
Smoking, diabetes mellitus and obesity as risk factors for the degree of fuchs endothelial corneal dystrophy (FECD)
Authors: Zwingelberg Sarah
Published: January 2024

Aims/Purpose: To detect environmental factors, which may be possible risk factors in the disease course of Fuchs endothelial corneal dystrophy (FECD).

Methods: Evaluation of patients with FECD registered in the FECD genetics database of the Center for Ophthalmology, University Hospital Cologne, from 2018 to 2019. For the evaluation, disease onset, central corneal thickness (CCT), best corrected visual acuity (BSCVA, logMAR), and age‐related Krachmer grading were correlated with the presence of diabetes mellitus (DM), body mass index (BMI), and smoking behaviour. Depending on the variables studied, differences between groups were examined by Mann–Whitney U test and chi‐square test. The significance level was 5%. Krachmer Grading was age‐corrected by using ordinal regression in the mediation analysis. For the mediation analysis the Kenny and Barron 4 Step Analysis was used.

Results: 403 patients with FECD were included in the analysis. The mean age at diagnosis was 63.1 (±13.2) years. The female‐to‐male ratio was 1.46:1. Patients with a BMI of 30.0–34.9 kg/m2 developed FECD significantly earlier than patients with a BMI < 30 kg/m2 (p = 0.001). Patients with DM showed significantly more often an age corrected Krachmer grade of 5 compared to patients without DM (p = 0.015). Using the mediation analysis, the presence of DM correlated with age‐corrected Krachmer Grade 5 (p = 0.015), and the presence of DM correlated with BMI of 30.0–34.9 kg/m2 (p = 0.012). BMI of 30.0–34.9 kg/m2 exerts a significant effect on age‐corrected Krachmer grading grade 5 with p = 0.005. The effect of DM on age‐corrected Krachmer Grading 5 is significantly mediated by BMI‐ Group 4 using Kenny and Barron 4 Step Analysis, p = 0.013.

Conclusions: Our study shows for the first time that obese individuals develop FECD significantly earlier than non‐obese individuals. Oestrogen secretion in premenopausal women occurs mainly in the ovaries, whereas postmenopausal oestrogens are produced in adipose tissue. Together with gender as a risk factor, this may indicate that oestrogens have a relevant influence on disease progression. Initial laboratory work has shown that oestrogen metabolites have genotoxic and apoptotic effects on corneal endothelial cells.
The role of exocytotic proteins in the (dys)regulation of human reflex tearing and aqueous‐deficient dry eye syndrome
Authors: Francis Alfred Francis Pakkam John , Manicam Caroline , Neumann Fabian , Pfeiffer Norbert , Grus Franz , Perumal Natarajan
Published: January 2024

Aims/Purpose: Reflex tears triggered by various external and internal stimuli play vital functions in the protection of the ocular surface and visual acuity. The impairment of the molecular processes involved in reflex tearing is conjectured to be associated with the progression of dry eye syndrome (DES). Therefore, this study was undertaken to unravel the intricate proteome changes in the reflex and DES tears.

Methods: Thirty six subjects underwent basic secretory test (BST) via Schirmer I (without anaesthetics) to determine the secretory rate of the lacrimal gland due to the irritating nature of the strip and were divided into reflex (RF, n = 12, BST = 35.0 ± 0.0), normal (NR, n = 12, BST = 15.3 ± 3.0) and severe aqueous‐deficient DES (DRY, n = 12, BST = 3.4 ± 1.4). The individual tear samples were analysed employing the state‐of‐the‐art mass spectrometry‐based proteomics strategy, followed by bioinformatics analyses to elucidate the underlying molecular processes.

Results: A total of 293 and 237 proteins were found to be significantly (p < 0.05) differentially regulated in the RFL vs. NR (up‐regulated, UR = 12; down‐regulated, DR = 281) and DRY vs. NR (UR = 197; DR = 40), respectively. The hallmark of this study was the identification of 10 lacrimal gland‐specific proteins (e.g., LYZ, LCN1, LTF, PRR4, ZG16B) secreted mainly via the exocytotic pathway, which were significantly up‐regulated in the RFL vs. NR but down‐regulated in the DRY vs. NR. Antibacterial response was also significantly activated in RFL (p = 1.9 × 10−2) compared to DRY (p > 0.05). The activated inflammatory response (e.g. S100A8/A9, ANXA1) associated with DRY (p = 2.7 × 10−8, z = 4.0) was found to be inhibited in the RFL (p = 2.7 × 10−9, z = −3.5). Likewise, proteins involved in glycolysis (z = −2.8), acute phase response (z = −2.7) and actin cytoskeleton signalling (z = −2.1) were also inhibited in the RFL compared to DRY.

Conclusions: In summary, this study has demonstrated that protein markers involved in the exocytotic pathway play major roles in the production of reflex tears and their regulation is impaired in the DES. Importantly, the abrogation of the vicious cycle of pathways involved in the progression of DES, especially inflammation, was observed in the reflex tears, which may be the key for the protection and maintenance of dynamic balance of the ocular surface.
In‐depth study of the mucoadhesive and lubricating properties of Hyalistil SYNFO and other sodium hyaluronate‐based eye drops
Authors: Abbate Ilenia , Pricoco Angelo , Spina Donato , De Pasquale Giuseppe , Zappulla Cristina , Curatolo Maria Cristina , Viola Santa
Published: January 2024

Purpose: Several sodium hyaluronate (SH) eye drops formulations are widely used for the management of dry eye disease (DED). Hyalistil SYNFO is an eye drops based on SH and xanthan gum and osmoprotectants (glycine and betaine). The aim of our study was to evaluate viscosity and mucoadhesion profiles of Hyalistil SYNFO with respect to other SH‐based eye drops, and to investigate their ability to protect the corneal surface from dehydration.

Methods: The physicochemical properties, in term of viscoelastic and mucoadhesive behaviour, were evaluated by means of a rheometer, TA‐XT2 texture analyzer and zeta potential determination. An in vitro dehydration model was used to demonstrate the lubricant effect of Hyalistil SYNFO compared to other commercially available SH‐based eye drops on human corneal epithelial cells (HCE).

Results: The rheological profiles indicated that Hyalistil SYNFO exhibits a viscoelastic behaviour under shear strain showing a characteristic curve owing to its specific molecular properties. Evaluations of detachment force of tested formulations resulting in a strengthening of the mucin‐formulation interface showed that Hyalistil SYNFO exhibited a stronger and significant mucoadhesion calculated as percentage compared to mucin and other SH‐based products. The occurring interaction between formulation and mucin was also demonstrated by the variations in zeta potential measured by the mucin‐eye drops mixture compared to mucin or product alone. The in vitro study on HCE cells demonstrated that Hyalistil SYNFO, compared to others formulation, was able to protect corneal epithelial cells from dehydration.

Conclusions: The pseudoplastic profile and increased mucoadhesive strength, due to the presence of both SH and xanthan gum, may lead to an improved residence time of Hyalistil SYNFO on the corneal epithelium ensuring relief during the treatment of DED. Moreover, the effect against dehydration improves eye lubrication and corneal cell protection.
Mask‐associated dry eye syndrome according to sex
Authors: Larraz Marta Sancho , Blasco‐Martinez Alejandro
Published: January 2024

Aims/Purpose: The aim of this study was to evaluate the impact of the mask on the ocular symptoms of dry eye, Mask‐Associated Dry Eye Syndrome (MADE syndrome); according to sex.

Methods: The population was divided into two groups: wearers, and non‐wearers of masks. Then, these groups were divided by sex. The group without mask was obtained from a database of control subjects. The group of subjects with a mask were people who use it for at least 3 h in a row every day. Subjects with pathologies with ophthalmological repercussion or previous surgeries were excluded. Subjective questionnaires were performed: OSDI, SANDE and CLEDQ‐8 tests adapted to the use of a mask. Psychological symptoms were also studied with the Brief Symptom Inventory (BSI). In addition, objective clinical signs were evaluated with Keratograph 5 M®, taking measurements of tear meniscus height, NIBUT and ocular redness.

Results: Subjects without masks showed statistically significant differences between men and women in the values of ocular redness (p‐value < 0.01); and in the rates of depression and interpersonal sensitivity (p‐value < 0.01). The group of subjects with a mask show significant differences between men and women in the values of CLEDQ‐8 and OSDI (p‐value < 0.05) and SANDE (p‐value < 0.01). Differences were also observed in tear meniscus height (p‐value < 0.05) and ocular redness (p‐value < 0.01); and in somatization and interpersonal sensitivity (p‐value < 0.05); obsession‐compulsion, depression and psychoticism (p‐value < 0.01).

Conclusions: The group of women with mask obtained an increase in the symptomatic tests compared to the group of men. The group of men showed higher values of ocular redness in mask carriers; but without the mask, the group of women showed the greatest redness. Finally, it was also observed that the group of women had an increase in BSI rates with and without wearing a mask; the first case being the most pronounced.
Is it really keratoconus ‐ topographic mimicry
Authors: Wykrota Agata , Seitz Berthold , Flockerzi Elias
Published: January 2024

Aims/Purpose: The aim of this case series is to present eyes with topographic keratoconus configuration, but in which objectifiable no keratoconus exists and thus a so‐called pseudo‐keratoconus is present.

Methods: Inclusion criteria were a topographic classification of the cornea as keratoconus by Scheimpflug imaging using the topographic keratoconus classification TKC and a typical elevation data profile with irregular astigmatism and slope (= Ansteilung) of the cornea. Clinical image by slit lamp examination, best‐corrected visual acuity and Scheimpflug tomography of the anterior segment of the eye (Pentacam®, OCULUS, Wetzlar, Germany) were analysed.

Results: In our case series, 33 eyes of 23 patients were included. The mean age was 51 (±16) years and the ratio of females to males was balanced. The mean Kmax was 51.1 (±7.1) dioptres. The mean corneal thickness at the thinnest point was 517 (±80) μm. The best‐corrected decimal visual acuity was 0.47 (±0.27). The study eyes were divided into 3 groups according to the underlying cause of the topographic changes. One group included corneal diseases with inferior slope in topography (corneal scar n = 9, Map‐Dot‐Fingerprint dystrophy n = 6, Fuchs endothelial dystrophy n = 5, vortex keratopathy n = 2). The second group had a superior corneal slope that could be interpreted as a superior keratoconus configuration (Map‐Dot‐Fingerprint dystrophy n = 5, irregular astigmatism without other corneal pathology n = 2, Salzmann corneal degeneration n = 1, corneal scar n = 1). The third group included eyes with postoperative newly occurring keratoconus configuration after phototherapeutic keratectomy (n = 2).

Conclusions: This case series shows that different corneal pathologies can imitate a topographic keratoconus configuration. The identification – not least at the slit lamp – and differentiation of these pathologies from keratoconus are important in daily practice with regard to counselling of the patients and further treatment.
Clinical phase 1 safety and tolerability evaluation of sustained release silica composite eye drops in human subjects
Authors: Kaarniranta Kai , Reay Marcus , Leino Lasse , Kievari Sari , Hartikainen Arto , Martikainen Oona , Kemiläinen Benjam
Published: January 2024

Aims/Purpose: Most ocular disease is managed at least in part by use of eye drops. Many of these eye drops require multiple doses per day, as well as good patient compliance to relieve patients from incapacitating symptoms. To address this treatment burden, a Silica Matrix long‐acting eye drop technology was developed to offer a once‐a‐day (QD) dosing schedule. The aim of this study was to evaluate safety and tolerability of QD repeated dosing of silica composite eye drop platform in healthy volunteers for 15 days.

Methods: 24 healthy volunteers were recruited to a randomized, double blinded, placebo‐controlled phase 1 clinical trial for repeated, QD dosing of silica composite eye drops over 15 days. Half of the subjects received a demulcent containing silica composite eye drops and the other half received plain silica composite eye drops (i.e., placebo). A single drop was applied QD in the cul‐de‐sac of one eye, and safety and tolerability was assessed by a blinded Investigator, including examination of outer eye structures and anterior chamber as well as interblink interval and tear fluid break‐up time (t0, 6h, D2, D3, D7, D11 and D15), lens examination (microscopic), change in visual acuity (EDTRS) and intra‐ocular pressure (t0 and D15). Ocular discomfort was assessed by volunteer questionnaire at t0, 6h, D3, D7, D11 and D15.

Results: At submission, 13 subjects have completed the study and 11 are still under investigation. No significant differences in tolerability were observed between treated and untreated eyes, with no relevant adverse events. Volunteer questionnaire results indicate that 71% regarded instillation discomfort as mild, 22% moderate and 7% had no symptoms. Discomfort lasted less than 1‐min in 99% of responses.

Conclusions: The results indicate that silica composite eye drops are safe and well tolerated in healthy volunteers when applied QD. This forms a good basis for development of sustained release topical ocular products for delivery of pharmacologically active agents in eye diseases.
Development of a novel multi‐stimulus ocular surface aesthesiometer system
Authors: Murphy Paul , Mungalsingh Melanie , Peterson Sean , Thompson Ben
Published: January 2024

Aims/Purpose: To report the development of a novel, air‐based, aesthesiometer capable of producing and applying multiple stimuli of differing intensity, separated by time and/or ocular surface location.

Methods: Individual micro‐blowers (Murata Manufacturing Co., Japan) were combined with an exit airflow nozzle into an integrated stimulus unit (ISU) that produced a controlled exit airflow through the nozzle exit. Stimulus intensity, duration, and repetition, as a feature of airflow, was managed for each ISU using a designed software. The software also controlled stimulus sequencing for multiple ISU in series. Stimulus airflow consistency and characteristics were assessed using two nozzle diameters (0.5 and 1.6 mm) for: (i) airflow pattern/trajectory; (ii) airflow surface dispersion; (iii) force of airflow; (iv) thermal effects; (v) time delay and spatial separation.

Results: Stimulus characteristics: (i) airflow is coherent at proposed test distance (1 cm) and spread rate is constant irrespective of stimulus strength, airflow diameter at 1 cm: 1.8–2.1 mm; (ii) airflow disperses over surface and dispersion increases with increasing airflow rate; (iii) consistent, small force (10−4 N) is produced and varies with airflow rate; (iv) size of thermal effects depends on airflow rate; (v) single stimuli, repeat single stimuli with variable time‐delay, simultaneous multiple stimuli or with inter‐stimulus time delay can be produced.

Conclusions: The novel ISU can produce repeatable, consistent air pulses (stimuli) under software control. Nozzle diameter has an influence on airflow coherence/dispersion. Single or multiple simultaneous stimuli with/without time delays, of differing intensity and duration, can be delivered to ocular surface. Multiple ISU allows presentation of multiple simultaneous stimuli that may provide an alternative method for assessing ocular surface sensitivity, and facilitate investigation of signal processing involved in ocular surface nerve summation.
Association between self‐reported eye health and self‐reported general health. Results from the FOREVER questionnaire
Authors: Andreasen Jens Rovelt , Freiberg Josefine , Kolko Miriam
Published: January 2024

Aims/Purpose: This study aimed to investigate the association between self‐reported eye health and general health using questionnaire data collected in the Project FOREVER (Finding Ophthalmic Risk and Evaluating the Value of Eye exams and their predictive Reliability).

Methods: A subset of questionnaire responses collected in Project FOREVER from June 2022 to May 11th, 2023, was analysed. Respondents rated their eye health and general on scales from 1 (excellent) to 5 (poor). Spearman's Rank Test and ordinal logistic regression models were employed to assess the correlation and association.

Results: The analysis included 42 568 respondents with a mean age of 55.0 (15.0) years, of whom 62.6% were women. Among them, 10% reported having an eye disease, with cataract, glaucoma, and age‐related macular degeneration being the most commonly reported eye diseases. The Spearman's rank test revealed a significant and moderate positive correlation (rho = 0.24) between self‐reported eye health and general health. Moreover, general health showed significant effects across its different levels, with higher ratings associated with an increased likelihood of being in a higher category of eye health. All p‐values for the associations were below 0.05.

Conclusions: Our findings indicate a strong association between self‐reported eye health and general health. Higher ratings of general health were linked to an increased likelihood of being in a higher category of eye health, underscoring the importance of considering both aspects in overall health assessments.
Molecular characterization of metastatic progression in patient derived xenograft models of malignant uveal melanoma
Authors: Demková Lucia , Furdova Alena , Kajabová Viera Horváthová , Babál Pavel , Smolkova Bozena , Šoltýsová Andrea
Published: January 2024

Aims/Purpose: It has been observed that large UM lesions with significant infiltration of macrophages and CD8+ T cells exhibit specific genetic profiles that increase the risk of liver metastasis. Additionally, recent discoveries of DNA methylation changes in Class 2 tumours undergoing metastasis suggest a potential role of epigenetic alterations in UM progression.

Methods: To identify factors involved in UM metastasis, we implanted 25 viable UM tumours (consisting of 11 Class 1 tumours with a good prognosis and 14 Class 2 tumours with a poor prognosis) subcutaneously into immunodeficient NSG mice. From these, we successfully established ten patient‐derived xenografts (PDXs) using Class 2 tumour tissues. Two metastatic PDXs were derived from liver (UM50) and peritoneal (UM58) metastases spontaneously developed on mice.

Results: Comprehensive characterization of both primary tumours and PDX tissues was performed using bulk transcriptomics and methylomics techniques. Among the enriched metabolic pathways identified in the liver metastasis‐derived PDX tissue of sample UM50 compared to the PDX tissue from the primary tumour, four were related to epigenetic regulation, including the activation of rRNA expression by ERCC6 and EHMT2, methylation of histones and DNA by Polycomb Repressive Complex 2 (PRC2), regulation of rRNA expression by NAD‐dependent Deacetylase Sirtuin‐1, and the DNA methylation pathway.

Conclusions: These findings highlight the potential importance of epigenetic deregulation in UM progression and provide a foundation for future investigations. Further analysis using the Chromium Single Cell ATAC platform to examine chromatin accessibility at the single‐cell level in primary and metastatic PDX tissues of UM50 and UM58 that are ongoing can contribute to unravelling the precise role of epigenetic alterations in UM metastasis. Continued research in this area may lead to the development of novel therapeutic strategies targeting epigenetic mechanisms and improving outcomes for patients with metastatic UM.
Clinical, phenotypic and genetic characteristics of macula‐sparing stargardt disease
Authors: Hristova Rozaliya , Shahinyan Lilit , Kuneva Yoanna , Petkova Iva , Veleva Nevyana
Published: January 2024

Aims/Purpose: Fundus flavimaculatus and Stargardt's disease are monogenic but heterogeneous disease entities leading to loss of central vision in adolescence, caused by more than 490 mutations in the ABCA4 gene. We herein report the clinical, phenotypic and genetic characteristics of adult onset fovea sparing Stargardt's disease.

Methods: Two Caucasian males in their 40s presenting with complaints of paracentral scotomata underwent complete ophthalmic exam, visual field testing, optical coherence tomography (OCT), fundus autofluorescence (FAF), fluorescein angiography (FA), electroretinography (ERG) and genetic testing.

Results: Visual acuity was 20/20 in both patients with normal IOP. Anterior segments were unremarkable. Posterior segment examination revealed pigment mottling in the macula with ring‐shaped perifoveal chorioretinal atrophy and numerous white deposits in the mid‐periphery. Visual fields confirmed the paracentral ring scotomata. OCT demonstrated concentric perifoveal loss of outer retinal layers with foveal sparing simulating oedema. Extensive hyperautofluorescence in the area of chorioretinal atrophy was revealed by FAF. Full‐field ERG confirmed incomplete loss of cone bioelectrical activity with preserved morphology of the foveal peak and normal rod function. Genetic testing discovered several pathogenic mutations in both patients with shared ABCA4 c.5603A>T, p.(Asn1868Ile), a risk factor mutation. None of the mutations of our patients were previously reported in foveal sparing Stargardt's disease.

Conclusions: The variant ABCA4 c.5603A>T, p.(Asn1868Ile) might be associated with foveal sparing Stargardt's disease. Further population studies are need to confirm this association.
Crosstalk between oxidative stress, inflammation, angiogenesis and apoptosis in diabetic macular edema
Authors: Andrés‐Blasco Irene , Gallego‐Martínez Alex , Palos Sarah Karam , Lleó Antonio , Casaroli Ricardo , Di Lauro Salvatore , Millas Sara Crespo , Pinazo‐Duran Maria Dolores
Published: January 2024

Aims/Purpose: To evaluate molecules involved in oxidative stress (OS), inflammation, angiogenesis, and apoptosis, and discern which of these are more implicated in diabetic retinopathy (DR) and diabetic macular edema (DME) by investigating the correlation between them in the plasma (PLS) and vitreous humour (VIT), and examining data obtained from ophthalmological examinations.

Methods: Type 2 diabetic (T2DM) patients with DR/DME (DRG/DMEG n = 112) and non‐DM subjects as the surrogate controls (SCG n = 48) were selected. Blood samples were processed to determine the glycaemic and lipid profiles, C reactive protein, malondialdehyde (MDA), 4‐hydroxynonenal (4HNE), superoxide dismutase (SOD), catalase (CAT) levels and total antioxidant capacity (TAC). In addition, interleukin 6 (IL6), vascular endothelial growth factor (VEGF), and caspase 3 were assayed. The VIT samples were collected to measure the expression levels of all the above‐mentioned molecules.

Results: Our findings support the presence of molecules involved in OS, inflammation, angiogenesis, and apoptosis in the PLS and VIT samples from T2DM. In PLS from DRG, there was a decrease in the antioxidant load and an increase in pro‐angiogenic molecules, but an increase in pro‐oxidants and a decline in antioxidants intravitreally. In PLS from DMEG, pro‐oxidants and pro‐inflammatory molecules were augmented and the antioxidant capacity diminished, but the pro‐oxidants increased, and antioxidants decreased intravitreally. Furthermore, we found a positive correlation between the PLS‐CAT and the VIT‐SOD levels in DRG, and a negative correlation between the PSD‐4HNE and the VIT‐TAC levels in DMEG.

Conclusions: We conclude that hyperglycaemia induces anomalies in biochemical pathways with crosstalk between them; MDA, 4HNE, TAC, VEGF, and IL6 are promoters of the clinical manifestations of PDR and DME. The above molecules have been selected as biomarker candidates for distinguishing T2DM patients at risk of DR, DME and vision loss.
The global incidence and prevalence of Acanthamoeba keratitis
Authors: Ceccarelli Francesca , Afflitto Gabriele Gallo , Han Yuyi , Turco Maria Vittoria , Aiello Francesco , Nucci Carlo
Published: January 2024

Aims/Purpose: To assess the global incidence and prevalence of Acanthamoeba keratitis (AK).

Methods: The review protocol was prospectively registered in PROSPERO (CRD42022363243) and the Cochrane Handbook was followed in the conduction of the analysis. The study included male and female participants worldwide (>15 years old). PubMed, Scopus, Web of Science, EMBASE, and CINHAL were the sources of data. The incidence of AK was determined by calculating the number of cases per centre per year, while the prevalence was evaluated for the entire population and the entire population of patients with non‐viral infectious keratitis. Based on the population prospects of the United Nations, actual and provisional estimates of the global epidemiological burden of AK, covering a period of up to 50 years, were provided.

Results: A total of 134 articles were included in the analysis. The analysis revealed a median incidence of 2.42 (95% CI: 1.67, 3.8) new cases of AK per centre per year, without any statistically significant difference among the continents (p = 0.1411). The percentage of AK cases within the total number of MK cases was found to be 1.62% (95% CI: 1.51, 1.74). Using a random effect model, the prevalence of AK in relation to the entire population was estimated to be 0.0003% (95% CI: 0.0001; 0.0006). The projected increase in the total and provisional numbers of AK cases indicates a rise of 20.4% (2003 AK cases) in 2053 and 24.8% (2076 AK cases) in 2073, compared to the baseline of 2023 (1663 AK cases).

Conclusions: Although rare, AK is a significant condition that is projected to increase in prevalence by up to 24% over the next 50 years.
Transcriptional profilling to identify the inhibitor effect of trehalose as an alternative natural therapeutic agent on pterygium cells
Authors: Yılmaz Uğur , Durkal Yasin , Tokgün Onur , İnci Kubilay
Published: January 2024

Aims/Purpose: The aim of this study to investigate transcriptome analysis of the inhibitory effects of trehalose on changing expression of regulator genes in pterygium development.

Methods: Human primary pterygium cells and normal conjunctiva cells were isolated from the pterygium and conjunctiva tissues of six individuals, three of whom were men and three of which were females. The MTT test was used to investigate cell proliferation in pterygium treated with different concentrations dosage of trehalose. Differential mRNA expression in pterygium cells following indicative treatment was measured using an mRNA microarray and evaluated using GO and KEGG pathways. In addition, we employed QRT‐PCR to confirm the expression levels of genes linked to pterygium pathogenesis.

Results: We have found that pterygium cells are more sensitive to trehalose treatment than conjunctival cell. In total, 419 probe were differentially expressed pterygium cells treated with trehalose compared with paired non‐treated pterygium cells. Gene‐Enrichment and Functional Annotation analysis indicated that differentially expressed RNAs were associated with cellular process including especially fibroblastic cell migration, sterol biosynthetic process (p < 0.00034), extracellular matrix recomposition (p < 0.000740288), cell proliferation (p < 0.004391252), steroid biosynthetic process (p < 0.00029971). Composed of Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, protein–protein interaction (PPI), and gene set enrichment analysis (GSEA) analysis, bioinformatic analyses showed that four hub genes were upregulated (MSMO, RANBP3L, DHCR7, CCL2) and five were downregulated (NR4A1, TENASTN C, CXCL8, CXCL12, ADAMTS12). Additionally, QRT‐PCR is used to confirm the expression of particular genes. Consistent with these findings, the migration capability of pterygium cells decreased after treatment of trehalose for 24 h.

Conclusions: We consider that this study provides a scientific basis for elucidating the effect of trehalose on the pathogenesis of pterygium and exhibited that trehalose affects cellular processes that have essential roles in the progression and development of pterygium.
Effect of melatonin‐induced exosomes on proregenerative and antifibrotic pathways involved in corneal scarring
Authors: Tasa Burcugül Altuğ , Soykan Merve Nur , Sarıboyacı Ayla Eker , Ozalp Onur , Atalay Eray
Published: January 2024

Aims/Purpose: Melatonin is a time‐and‐concentration dependent pro and antiinflammatory agent that also regulates cell proliferation, migration, angiogenesis, fibrosis, and extracellular matrix synthesis. This study aims to assess the effect of exosomes obtained from melatonin‐treated human limbal mesenchymal stem cells (hLMSCs) on naive hLMSCs and ascertain their influence on antifibrotic and proregenerative pathways involved in corneal scarring.

Methods: hLMSCs were harvested from the eye bank of Eskişehir Osmangazi University Hospital and were subsequently isolated and characterized. We then treated hLMSCs (Mel‐treated hLMSCs) with varying concentrations of melatonin followed by isolation and characterization of the procured exosomes. These exosomes were added to enrich cell culture media of naïve hLMSCs (Mel‐exo‐treated hLMSCs) to examine their antifibrotic and proregenerative effects. The expression of miR155, miR29 Transforming Growth Factor Beta 1 (TGFβ1), TGFβ3, Peroxisome Proliferator‐Activated Receptor Gamma (PPARγ), and Alpha‐Smooth Muscle Actin (α‐SMA) miRNA and genes were compared between Mel‐treated hLMSCs and Mel‐exo‐treated hLMSCs by using Real‐Time PCR.

Results: TGFβ3 expression increased dramatically in response to Mel‐exo, while the increase in TGFβ1 expression was only minimal in correlation with levels of miR155 expression. Likewise, PPARγ expression was increased while an inhibition was observed in α‐SMA expression and miR29 expression in Mel‐exo‐treated hLMSCs compared to Mel‐treated hLMSCs.

Conclusions: Melatonin treatment of hLMSCs resulted in expression of exosomes that could drive naïve hLMSCs in favour of antifibrotic and proregenerative effects as evidenced by higher TGFβ3 and PPARγ expressions and inhibition of α‐SMA. This approach could prove beneficial in cornea and ocular surface tissue engineering applications.

The authors acknowledge the support from Eskisehir Osmangazi University, Scientific Research Projects (Grant ID: TOA‐2022‐2458).
Kruppel‐like factor 5 (KLF5) as a genetic factor associated with the etiopathogenesis of Keratoconus
Authors: Regueiro Uxía , Pastoriza Yaiza , López‐López Maite , Venema Wouter , Lema Isabel , Kuiper Jonas , Wisse Robert
Published: January 2024

Aims: To analyse expression and genotype of Krüppel‐Like Factor 5 (KLF5) gene in the corneal epithelium of eyes with Keratoconus (KC) compared to normal eyes (controls); as well as, to determine the effect of several pro‐inflammatory cytokines on the KLF5 expression by an in vitro study.

Methods: 64 corneal epithelium samples from 53 KC and 11 controls were included in this study. KC samples were collected from patients who received crosslinking epi‐off or penetrating keratoplasty for their mild to advanced KC. Control samples were collected from dead donors with healthy corneas. Molecular determinations to measure KLF5 expression and genotype on these samples were performed respectively by qPCR and TaqMan targeting the SNP of interest (rs17285550). In addition, using a cell line of healthy corneal epithelial cells, incubations with increasing concentrations of interleukin 6 (IL6), interleukin 1 beta (IL1β), and tumour necrosis factor alpha (TNFα) were performed to determine the KLF5 response to a pro‐inflammatory environment. KLF5 expression in the stimulated cell cultures was assessed by qPCR analysis.

Results: KC samples evidenced significantly higher levels of KLF5 gene expression than the controls (p < 0.0001). The GG genotypes showed an upward tendency for higher expression of KLF5 in the KC group. Higher IL6, IL1β, and TNFα concentrations contribute to a significatively KLF5 overexpression in corneal epithelial cell cultures.

Conclusions: Overexpression of KLF5 in the corneal epithelium of KC patients and its upregulation against a proinflammatory microenvironment, could lead to an inadequate epithelial barrier function that destabilizes the surrounding corneal layers and contributes to the KC pathology. KLF5 represents a promising target for gene therapy in KC.