Ocular tear fluid biomarkers collected by contact lenses

PURPOSE

To collect tear fluid biomarkers from contact lenses (CLs) and determine the impact of CL wear duration.

METHODS

Rabbits were fitted with commercial etafilcon A CLs, which were collected after 1 min, 4 and 8 h (n = 4/time point). Tear fluid proteins and cytokines were extracted from the CLs and quantified. An exploratory comparison was performed between CLs and Schirmer Strips (SS) for a 1 min duration.

RESULTS

The concentration of MUC5AC was significantly higher after 4 h of CL wear. The expression of all investigated cytokines (IL-1α, IL-1β, IL-8, IL-17A, IL-21, Leptin, MIP-1β, MMP-9, NCAM-1, and TNF-α) was detectable after 1 min of CL wear, and over time, all showed significant variations throughout the 8-h CL wear period. Notably, IL-1α significantly increased by 8 h of CL wear, while MMP-9 decreased. Albumin and lysozyme did not show significant variations with CL wear. Differences between CLs and SS after 1 min were statistically significant for albumin, Leptin, TNF-α, IL-1α, IL-1β, and IL-8.

CONCLUSIONS

The duration of CL wear significantly affects the collection of some tear fluid biomarkers. Albumin, MUC5AC, and cytokines may have individual and synergistic diagnostic or prognostic potential. CLs and SS were similar for lysozyme and MUC5AC but differed in the collection of albumin and some cytokines. CLs are a viable tear fluid collection method for biomarker analyses and can be immediately added as a routine clinical test by being FDA-approved medical devices.

Association between insulin-like growth factor-1 and ocular surface parameters in obese prepubertal boys

The study aimed to investigate the correlation between insulin-like growth factor 1 (IGF-1) and ocular surface parameters in obese prepubertal boys. Thirty obese prepubertal boys and 30 age- and gender-matched healthy controls underwent physical measurements, laboratory tests, and ocular surface assessments. The obese group showed lower IGF-1 levels (P = 0.001), reduced Schirmer I tear test (SIT) (P <0.001), and higher meibomian gland scores (meiboscore) compared to controls (P = 0.015). Bivariate analysis revealed a positive association between IGF-1 and SIT (r = 0.677, P < 0.001), and a negative association with between IGF-1 and meiboscore (r =  - 0.487, P < 0.001). Multiple regression analysis indicated that IGF-1 (P < 0.001) and triglycerides (P = 0.028) independently influenced SIT. Logistic analysis showed a significant association between decreased IGF-1 and higher meiboscore values (OR 0.994, 95% confidence interval 0.988-1.000; P = 0.033).

CONCLUSION

The findings suggest that reduced IGF-1 in obese prepubertal boys is independently linked to decreased SIT and increased meiboscore, irrespective of obesity and traditional cardiovascular risk factors. This implies that monitoring ocular surface parameters in obese children might provide a new perspective for clinical practice to focus on.

WHAT IS KNOWN

• Obese children exhibit decreased levels of IGF-1, and this reduction in IGF-1 is associated with cardiovascular metabolic complications related to obesity. • Ocular surface tissues might act as targets for hormones, might experience local effects of these hormone.

WHAT IS NEW

• In prepubertal obese boys, the decrease in IGF-1 is independently linked to decreased SIT and increased meiboscore, irrespective of obesity and traditional cardiovascular risk factors. • This finding implies that monitoring ocular surface parameters in obese children might provide a new perspective for clinical practice to focus on.

In vivo lacrimal gland imaging artefact assessment based on swept-source optical coherence tomography for dry eye disease

BACKGROUND

This study aimed to characterise imaging artefacts in the lacrimal gland using swept-source optical coherence tomography (SS-OCT) in patients with dry eye disease (DED) and healthy participants and identify risk factors for these artefacts.

METHODS

In total, 151 eyes, including 104 from patients with DED and 47 from non-DED participants, were analysed. Demographic data collection, comprehensive ocular examinations and SS-OCT imaging of the palpebral lobe of the lacrimal gland were performed. Artefacts were classified into distinct categories with different severities. Univariate and multivariate logistic regression analyses were performed to evaluate the association of age, gender, best-corrected visual acuity, intraocular pressure (IOP) and the presence of DED with the presence of artefacts.

RESULTS

Eight artefact types and severity grading were defined by analysing 1208 lacrimal SS-OCT images. The three most prevalent artefacts were defocus (75.83%), cliff (67.47%) and Z-off (58.44%). The presence of artefacts was significantly associated with the presence of DED (OR=9.13; 95% CI, 2.39 to 34.88; p=0.001) and higher IOP (OR=1.34; 95% CI, 1.14 to 1.58; p<0.001). Furthermore, multivariate logistic analyses showed that lower tear film breakup time (OR=0.71; 95% CI, 0.55 to 0.92; p=0.009) and higher meibum quality score (OR=2.86; 95% CI, 1.49 to 5.48; p=0.002) were significantly associated with higher odds for the presence of artefacts.

CONCLUSIONS

DED eyes had more SS-OCT image artefacts than normal eyes. Stringent standardised image quality control should be implemented before further image analysis when using SS-OCT to assess lacrimal gland image.

A review of the application of in-vivo confocal microscopy on conjunctival diseases

Over the past few decades, the expanded applications of in-vivo confocal microscopy (IVCM) have greatly enhanced the knowledge of a variety of conjunctival diseases. IVCM allows non-invasively detailed observation of tarsal, palpebral and bulbar conjunctiva, from the superficial to the substantia propria at the cellular level. IVCM has been shown as a powerful tool for the assessment of morphological changes in both physiological and pathological conditions. High-resolution images of different cellular phenotypes, together with quantifiable results, open new insights into understanding the mechanisms of conjunctival diseases, as well as provide valuable and longitudinal information for the diagnosis and therapeutic evaluation. This review aims to provide an overview of the current knowledge on the applications of IVCM on conjunctival disorders, including aging changes, dry eye-related morphological changes, glaucoma and glaucoma surgery-related morphological changes, conjunctival neoplasm, pterygium, allergic conjunctivitis, trachomatous scarring, and the conjunctiva-associated lymphoid tissue (CALT) changes. In this review, we highlight the key findings of previous studies and discusses the current limitations and challenges of IVCM in assessing the structural characteristics of the conjunctiva. Furthermore, we consider possible future directions for unlocking the full potential of IVCM applications. The insights presented here will contribute to a more comprehensive understanding of the applications of IVCM in conjunctival diseases.

Experimental models for keratoconus: Insights and challenges

Keratoconus, a progressive corneal disorder characterized by the thinning and conical protrusion of the cornea because of collagen degradation, poses significant challenges to both clinicians and researchers. Most successful animal models of keratoconus are based on genetic mutations and knock-outs in mice and rats that hinder normal corneal stromal architecture, thickness, or strength. While mice and rat models are suitable to study the molecular mechanism and physiological changes to the cornea, they are not suitable for experimental research; especially for surgical interventions like: deep anterior lamellar keratoplasty (DALK), stromal lenticule addition keratoplasty, and other advanced therapies. This review article comprehensively examines recent advancements in experimental models for keratoconus, focusing on their potential for translational research and the challenges ahead. It explores the historical context of experimental models, focusing on animal-based models, mainly rabbits in particular. These advancements enable researchers to mimic the biomechanical and biochemical alterations observed in keratoconic corneas. While these models offer valuable insights into disease mechanisms and treatment development, several challenges remain in transforming experimental findings into clinical applications.

Long-term outcomes of glued (sutureless) amniotic membrane transplantation in acute Stevens-Johnson syndrome/toxic epidermal necrolysis: a comparative study

PURPOSE

To compare the effectiveness and efficiency of a glued (sutureless) technique for amniotic membrane transplantation (AMT) with a traditional sutured one in the setting of acute Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN).

METHODS

This retrospective cohort study evaluated all patients diagnosed with SJS/TEN between 2008 and 2020 within our hospital network who received AMT in the acute phase according to our protocol and had at least one ophthalmic follow-up in the chronic phase. Primary outcomes included best-corrected visual acuity (BCVA) at the most recent visit, presence of a severe ocular complication (SOC) via predefined criteria, time to procedure and duration of procedure. Random effects model analysis was used to evaluate the impact of potential covariates on outcome measures.

RESULTS

A total of 23 patients (45 eyes) were included: 14 patients (27 eyes) in the AMT suture group and 9 patients (18 eyes) in the AMT glue group. There was no difference between the two groups in BCVA at the most recent visit (p=0.5112) or development of a SOC (p=1.000). The glue method was shorter in duration than the suture method (p<0.001). Random effects model additionally indicated that there was no difference in BCVA at most recent follow-up between patients who had received glued versus sutured AMT (p=0.1460).

CONCLUSIONS

Our glued technique for AMT is as effective as our sutured technique in stabilising the ocular surface and mitigating chronic ocular complications in SJS/TEN. The glued technique is also shorter in duration and performed more expediently than the sutured technique.

Dry eye symptoms and health-related quality of life among Chinese individuals: a national-based study

AIMS

To assess the impact of dry eye symptoms (DESs) on health-related quality of life (HRQOL) among Chinese residents.

METHODS

A total of 21 916 participants were involved in this nationwide cross-sectional study. All of them completed the Ocular Surface Disease Index-6 and the five-level European Quality of Life 5-Dimensional (EQ-5D) Questionnaire to assess the severity of DES and HRQOL, respectively. Multiple linear regression models were used to explore the associations of DES with EQ-5D health utility score (HUS) and visual analogue scale (VAS) score. We used logistic regression models to assess the relationships between DES and self-reported problems in the EQ-5D dimensions.

RESULTS

Overall, 43.6% of participants reported DESs. Of them, 2511 (11.5%) were with mild symptoms, 2762 (12.6%) were with moderate symptoms and 4288 (19.6%) were with severe symptoms. Both EQ-5D HUS and VAS score were significantly negatively associated with the severity of DES. The difference in HUS between patients with no symptoms and severe symptoms (0.085) was larger than the minimally clinical important difference for EQ-5D. The loss in HRQOL was greater for patients with severe DES than those just with other comorbidities. Participants with DES had a significantly higher risk of reporting problems in all five EQ-5D dimensions, especially in pain/discomfort and anxiety/depression for patients with mild or moderate symptoms and in mobility, self-care and usual activities for severe patients.

CONCLUSION

Patients with more severe DES tend to have lower HRQOL. Effective interventions targeted at different HRQOL dimensions should be taken according to the severity of DES.

Structural and functional changes of binocular corneal innervation and ocular surface function after unilateral SMILE and tPRK

AIMS

To evaluate the bilateral changes in the sub-basal nerve plexus of the cornea and ocular surface function after unilateral small incision lenticule extraction (SMILE) and transepithelial photorefractive keratectomy (tPRK) procedures.

METHODS

34 patients were enrolled in the study and underwent unilateral SMILE (21 of 34 patients) or unilateral tPRK (13 of 34 patients). Complete ophthalmic examinations, tear film function tests and Cochet-Bonnet esthesiometry were conducted to assess the effects of the surgeries on the corneal nerves and tear function. Morphological changes were assessed using in vivo confocal microscopy to evaluate the corneal sub-basal nerve plexus and dendritic cells. ELISA was used to measure the tear neuromediators. Clinical and morphological data at each follow-up point were compared with preoperative baseline values.

RESULTS

All patients who underwent unilateral SMILE or tPRK procedures exhibited bilateral corneal nerve degenerative changes, decreased corneal sensitivity, worsening of dry eye symptoms and changes in bilateral tear neuromediators. In the SMILE group, bilateral corneal sensitivity was positively correlated with corneal nerve fibre length and negatively correlated with dendritic cell area. The dry eye severity was negatively correlated with corneal sensitivity. Tear levels of substance P and nerve growth factor were positively correlated with mean dendritic cell area and dry eye severity, but negatively correlated with corneal sensitivity. In the tPRK group, bilateral corneal sensitivity was positively correlated with corneal nerve fibre density.

CONCLUSIONS

Unilateral refractive surgery may bilaterally affect the morphology and function of corneal nerves and ocular surface status postoperatively.

Toxicity of nuclear-localized GFP in reporter mice

Various techniques using fluorescent reporter probes have been developed, such as GFP transgenic mouse lines that are used to detect spatial-temporal expression levels of genes. Although GFP expression is largely considered non-toxic, recent reports have indicated that under certain conditions GFP can display cellular toxicity. We hereby report the nuclear toxicity of H2B-GFP using a K14 specific Tet-on reporter mouse system. Using this system, GFP accumulates in the nucleus of all K14 expressing cells, such as the ocular surface epithelia and ocular adnexa. Expression of high levels of nuclear GFP during embryonic stages led to an eye open-at-birth (EOB) phenotype and abnormal ocular adnexa development and during adult and aging stages showed notable toxicity to ocular tissues. Other tissues, such as skin, also presented multiple defects associated with H2B-GFP expression. This toxicity was found to be concentration dependent, with homozygous mice presenting extremely high toxicity, while heterozygous mice presented limited toxicity. Upon induction, the accumulation of H2B-GFP in the nucleus of homozygous mice led to apoptosis within 2 weeks. This study therefore shows that although the use of nuclear GFP reporter mice is a valuable tool, at high levels, nuclear GFP can be toxic, leading to cell death and affecting tissue function.

Serial intravitreal injections in age-related macular degeneration patients from the dry eye disease perspective: a cross-sectional study

BACKGROUND

To evaluate the effects of serial intravitreal injections (IVI) on the ocular surface and meibomian glands in patients with neovascular age-related macular degeneration (nAMD).

METHODS

Patients receiving anti-vascular endothelial growth factor (anti-VEGF) agent injections for unilateral nAMD were included. Untreated fellow eyes served as the control group. All participants followed a pre-IVI asepsis protocol with povidone-iodine (PI). Ocular surface diseases index (OSDI) questionnaire scores, first and average non-invasive tear break-up time (fNITBUT and avgNITBUT), Schirmer-1 test results, corneal staining score (according to Oxford scale), meibomian gland (MG) loss rates of lower and upper eyelids were recorded four weeks after the last IVI.

RESULTS

Forty-two nAMD patients with a mean age of 63.3 ± 19.4 were included in the study. The mean OSDI score was 20.3 and the median of IVI number was 9 (6-22). There were no statistically significant difference between treated and untreated fellow eyes regarding fNITBUT (5.6 vs. 4.5, p = 0.872), avgNITBUT (6.2 vs. 7.2, p = 0.968), Shirmer-1 results (7 vs. 7, p = 0.854), corneal staining (0.3 vs. 0.2, p = 0.341), lower and upper MG loss rate (29.3 vs. 28.4, p = 0.162, and 27.1 vs. 26.9, p = 0.476, respectively). Only significant correlation was observed between age with lower and upper MG loss rate (r:0.396, p = 0.042, and r:0.365, p = 0.047).

CONCLUSION

The results of the present study demonstrated that serial IVI of anti-VEGF agents with PI asepsis is well tolerated by nAMD patients in terms of ocular surface, MG loss and DED measurements.

Efficacy of 100% autologous platelet-rich plasma and 100% autologous serum in dry eye disease: a randomised controlled trial

OBJECTIVE

The 0bjective is to compare treatment effects between undiluted autologous platelet-rich plasma (APRP) and autologous serum (AS) in patients with moderate-to-severe dry eye disease (DED).

METHODS AND ANALYSIS

A single-centre, randomised, double-masked, non-inferiority clinical trial was conducted. 96 adult DED patients with an Ocular Surface Disease Index (OSDI) Score of ≥23 and/or Oxford staining grade of ≥2 were randomised to receive either 100% APRP (n=48) or 100% AS (n=48) for 4 weeks. Primary outcomes included OSDI Score and ocular surface staining measured by Oxford grading scale at 4 weeks. Secondary outcomes included fluorescein tear break-up time, Schirmer's test, meibum quality and expressibility, and adverse events. The 95% CI for the mean difference in OSDI scores between groups was estimated to assess non-inferiority of the OSDI score at a prespecified margin of 4.18 points.

RESULTS

At week 4, there was no significant difference in decreased OSDI scores between groups, with the mean difference (100% APRP-100% AS) of 1.41 (95% CI -1.26, 4.08, p=0.299). The upper limit was less than the prespecified margin, indicating non-inferiority of 100% APRP vs 100% AS. The probabilities of achieving an Oxford grade 0-1 after treatment were not significantly different between groups, with an OR of 0.61 (95% CI 0.25, 1.52, p=0.288). No significant differences in secondary outcomes were observed between groups.

CONCLUSION

In the short-term, 100% APRP was not inferior to 100% AS in reducing dry eye symptoms and ocular surface staining in moderate-to-severe DED.

TRIAL REGISTRATION NUMBER

NCT04683796.

Observational Clinical Investigation Evaluating an Ophthalmic Solution Containing Xanthan Gum and Low Concentration Desonide Phosphate in Dry Eye Disease Treatment

INTRODUCTION

Patients with dry eye disease (DED) complain of a multitude of symptoms that affect their visual function and quality of life (QoL). This clinical investigation assessed the performance, tolerance, and safety of a novel preservative-free ophthalmic solution containing xanthan gum 0.2% and desonide sodium phosphate 0.025%.

METHODS

This was an observational, prospective, multicentric, and post-market clinical investigation to assess the effect of three times a day instillation of the study formulation in patients suffering from DED. The primary objective was to achieve a 50% reduction in conjunctival hyperemia index as assessed with the OCULUS Keratograph after 1 month of treatment compared to baseline values. The secondary objectives included patient-reported outcomes, clinical performance, and safety.

RESULTS

Thirty patients were enrolled (21 women, 9 men) with a mean age of 61.10 ± 14.53 years. The instillation of the study formulation was associated with a significant reduction in redness scores after 1 month of treatment compared to baseline (mean - 0.51 ± 0.51; p ≤ 0.0001). Although the primary endpoint was not completely met, a 50% reduction in the conjunctival hyperemia index was achieved in 23% of the participants, and 77% showed a reduction of 26% of the same index. In addition, the ophthalmic solution significantly increased tear film break-up time, and a significant reduction of corneal and conjunctival staining with fluorescein was achieved. It also reduced DED symptoms and had a very good safety profile.

CONCLUSIONS

the study formulation produced a significant improvement in the signs, symptoms, and QoL of patients with mild to moderate DED with a good safety profile after 1 month of treatment.

Association between short-term ozone exposure and allergic conjunctivitis in China: A multi-city case-crossover study

Short-term exposure to ozone has been linked to multiple allergic diseases, but the relationship between ozone exposure and allergic conjunctivitis (AC) remains unclear. This study aimed to investigate the association between short-term exposure to ozone and the risk of AC. We conducted a time-stratified case-crossover study across five Chinese cities from 2014 to 2022. Daily outpatient visit records for AC were identified in five hospitals using either the diagnosis name or ICD-10 code H10.1. Data on air pollution and meteorological conditions were also collected. We first examined the city-specific association between short-term ozone exposure and AC using conditional logistic regression. A random-effects meta-analysis was then conducted to obtain overall estimates. During the study period, 130,093 outpatient visits for AC occurred, with 58.8% (76,482) being male and 41.2% (53,611) female. A one-standard-deviation (SD) increase in ozone was associated with an 8.3% increase (95% CI: 3.8%, 13.0%) in AC outpatient visits. Similar positive associations were observed when adjusting for other pollutants (PM2.5, CO, SO2 and NO2) in two-pollutant and multi-pollutant models. Furthermore, the positive association remained consistent when using mixed-effects regression models or further adjusting for meteorological conditions. In addition, no effect modification of the AC-ozone association by sex, age and season was apparent. This study provides evidence supporting a positive association between short-term ozone exposure and AC risk in China. This highlights the potential value of mitigating ozone pollution to reduce the risk of ocular surface disorders.

Metabolomics of basal tears in amyotrophic lateral sclerosis: A cross-sectional study

PURPOSE

Amyotrophic lateral sclerosis (ALS) clinical variability, along with the lack of conclusive diagnostic instruments, result in average diagnosis delays of 9 months. This study aimed to assess whether metabolomic profiling of basal tears in ALS patients could act as a biological marker for diagnosing ALS, predicting prognosis, and discriminating between endophenotypes.

METHODS

A single-center prospective case-control study was conducted in France from September 2021 to March 2023 including patients with ALS according to the revised EI Escorial criteria. Two microliters of basal tears were collected using microcapillary glass tubes and analyzed with ultra-high performance liquid chromatography coupled with mass spectrometry. Both univariate and multivariate analyses were performed.

RESULTS

Twenty-five patients with ALS and 30 controls were included. No significant differences in metabolite levels were found between ALS and control groups (p > 0.05). The basal tear metabolome significantly discriminated bulbar and spinal forms of ALS based on 6 metabolites, among which 5 were decreased (aniline, trigonelline, caffeine, theophylline and methyl beta-D-galactoside) in the bulbar form and 1 was decreased in the spinal form (dodecanedioic acid).

CONCLUSION

This study represents the first prospective analysis of basal tear metabolomics in individuals with ALS. Despite the inability to distinguish between ALS patients and controls based on metabolic signatures, these findings could contribute to understanding the phenotypic diversity of ALS. Notably, distinct metabolic profiles were identified that differentiate between the bulbar and spinal forms of the disease.

Deep learning model for extensive smartphone-based diagnosis and triage of cataracts and multiple corneal diseases

AIM

To develop an artificial intelligence (AI) algorithm that diagnoses cataracts/corneal diseases from multiple conditions using smartphone images.

METHODS

This study included 6442 images that were captured using a slit-lamp microscope (6106 images) and smartphone (336 images). An AI algorithm was developed based on slit-lamp images to differentiate 36 major diseases (cataracts and corneal diseases) into 9 categories. To validate the AI model, smartphone images were used for the testing dataset. We evaluated AI performance that included sensitivity, specificity and receiver operating characteristic (ROC) curve for the diagnosis and triage of the diseases.

RESULTS

The AI algorithm achieved an area under the ROC curve of 0.998 (95% CI, 0.992 to 0.999) for normal eyes, 0.986 (95% CI, 0.978 to 0.997) for infectious keratitis, 0.960 (95% CI, 0.925 to 0.994) for immunological keratitis, 0.987 (95% CI, 0.978 to 0.996) for cornea scars, 0.997 (95% CI, 0.992 to 1.000) for ocular surface tumours, 0.993 (95% CI, 0.984 to 1.000) for corneal deposits, 1.000 (95% CI, 1.000 to 1.000) for acute angle-closure glaucoma, 0.992 (95% CI, 0.985 to 0.999) for cataracts and 0.993 (95% CI, 0.985 to 1.000) for bullous keratopathy. The triage of referral suggestion using the smartphone images exhibited high performance, in which the sensitivity and specificity were 1.00 (95% CI, 0.478 to 1.00) and 1.00 (95% CI, 0.976 to 1.000) for 'urgent', 0.867 (95% CI, 0.683 to 0.962) and 1.00 (95% CI, 0.971 to 1.000) for 'semi-urgent', 0.853 (95% CI, 0.689 to 0.950) and 0.983 (95% CI, 0.942 to 0.998) for 'routine' and 1.00 (95% CI, 0.958 to 1.00) and 0.896 (95% CI, 0.797 to 0.957) for 'observation', respectively.

CONCLUSIONS

The AI system achieved promising performance in the diagnosis of cataracts and corneal diseases.

Biomolecule-based hydrogels as delivery systems for limbal stem cell transplantation: A review

Limbal stem cell deficiency (LSCD) is a complex disease of the cornea resulting from dysfunction and/or loss of limbal stem cells (LSCs) and their niche. Most patients with LSCD cannot be treated by conventional corneal transplants because the donor tissue lacks the LSCs necessary for corneal epithelial regeneration. Successful treatment of LSCD depends on effective stem cell transplantation to the ocular surface for replenishment of the LSC reservoir. Thus, stem cell therapies employing carrier substrates for LSCs have been widely explored. Hydrogel biomaterials have many favorable characteristics, including hydrophilicity, flexibility, cytocompatibility, and optical properties suitable for the transplantation of LSCs. Therefore, due to these properties, along with the necessary signals for stem cell proliferation and differentiation, hydrogels are ideal carrier substrates for LSCD treatment. This review summarizes the use of different medical-type hydrogels in LSC transplantation from 2001 to 2024. First, a brief background of LSCD is provided. Then, studies that employed various hydrogel scaffolds as LSC carriers are highlighted to provide a multimodal strategic reference for LSCD treatment. Finally, an analysis of prospective future developments and challenges in the field of hydrogels as LSC carriers for treating LSCD is presented.

Comparison of two digital alignment systems for toric intraocular lens implantation

PURPOSE

To compare the two most used digital alignment systems regarding precision, repeatability and loss of track.

METHODS

15 eyes of 15 patients older than 21 years with cataracts were included in this prospective study. The two systems were intraoperatively superimposed and recorded, and the alignment of the two displayed alignment axes was analysed regarding precision, repeatability and loss of track.

RESULTS

There was a significant difference in precision and repeatability between the two digital alignment systems regarding the projected alignment axis. The deviation from the actual target axis was significantly different, with a mean of 0.34°±0.75° for the Zeiss system and 1.60°±1.08° for the Alcon system (p=0.03, n=14). The within-subject SD was significantly lower with 0.21° for the Zeiss system and 0.34° for the Alcon system (p=0.03, n=14).

CONCLUSIONS

The Zeiss Callisto system showed a significantly lower deviation from the target axis, higher stability with eye movements and less need for microscope illumination than the Alcon system. Both systems showed high precision when compared with manual marking methods.

TRIAL REGISTRATION NUMBER

NCT05220683.

A machine learning approach to predicting dry eye-related signs, symptoms and diagnoses from meibography images

Purpose

To use artificial intelligence to identify relationships between morphological characteristics of the Meibomian glands (MGs), subject factors, clinical outcomes, and subjective symptoms of dry eye.

Methods

A total of 562 infrared meibography images were collected from 363 subjects (170 contact lens wearers, 193 non-wearers). Subjects were 67.2 % female and were 54.8 % Caucasian. Subjects were 18 years of age or older. A deep learning model was trained to take meibography as input, segment the individual MG in the images, and learn their detailed morphological features. Morphological characteristics were then combined with clinical and symptom data in prediction models of MG function, tear film stability, ocular surface health, and subjective discomfort and dryness. The models were analyzed to identify the most heavily weighted features used by the algorithm for predictions.

Results

MG morphological characteristics were heavily weighted predictors for eyelid notching and vascularization, MG expressate quality and quantity, tear film stability, corneal staining, and comfort and dryness ratings, with accuracies ranging from 65 % to 99 %. Number of visible MG, along with other clinical parameters, were able to predict MG dysfunction, aqueous deficiency and blepharitis with accuracies ranging from 74 % to 85 %.

Conclusions

Machine learning-derived MG morphological characteristics were found to be important in predicting multiple signs, symptoms, and diagnoses related to MG dysfunction and dry eye. This deep learning method illustrates the rich clinical information that detailed morphological analysis of the MGs can provide, and shows promise in advancing our understanding of the role of MG morphology in ocular surface health.

Improvement of corneal epithelial damage after switching from the concomitant use of brinzolamide and brimonidine to a brinzolamide/brimonidine fixed-dose combination

PURPOSE

To assess the effectiveness of switching from the concomitant use of brinzolamide 1% (BZM) and brimonidine 0.1% (BMD) to a BZM/BMD fixed-dose combination (BBFC) for the reduction of corneal epithelial damage.

STUDY DESIGN

Retrospective cohort study.

METHODS

This study involved 52 eyes of 52 glaucoma patients (26 women, 26 men; mean age: 67.0 ± 14.0 years) followed for more than 3 months after being switched from concomitant BZM and BMD to BBFC. Superficial punctate keratitis (SPK) was assessed by fluorescein staining according to the National Eye Institute classification, with the cornea divided into 5 areas: center, superior, nasal, temporal, and inferior. SPK density was graded as 0 (no SPK), 1 (separate SPK), 2 (moderately dense SPK), and 3 (high SPK with overlapping lesions). SPK scores and intraocular pressure (IOP) at pre switching to BBFC (pre-BBFC) and at 3-months post switching to BBFC (post-BBFC) were then compared using the Wilcoxon signed-rank test.

RESULTS

At pre-BBFC and post-BBFC, respectively, mean IOP was 12.4 ± 2.5 and 12.4 ± 2.7 mmHg, thus illustrating no significant difference in IOP between pre and post switch (p = 0.924), and the mean SPK score for center, superior, nasal, temporal, and inferior was 0.06 ± 0.24, 0.04 ± 0.19, 0.52 ± 0.67, 0.15 ± 0.36, and 0.92 ± 0.74, and 0.04 ± 0.19, 0.02 ± 0.14, 0.37 ± 0.56, 0.04 ± 0.19, and 0.75 ± 0.62, thus clearly showing a significant reduction in SPK scores for the nasal, temporal, and inferior areas at post-BBFC compared to those at pre-BBFC (p < 0.05).

CONCLUSION

Our findings reveal that compared with the concomitant use of BZM and BMD, BBFC is effective in reducing corneal epithelial damage.

Efficacy and Safety of Preoperative Prophylaxis in Cataract Surgery with Combined Topical Antiseptics: A Microbiological Study

INTRODUCTION

To evaluate the antimicrobial efficacy of an ophthalmic formulation containing hexamidine diisethionate (HD) 0.05%, polyhexamethylene biguanide (PHMB) 0.0001%, and edetate disodium (EDTA) 0.01% (Keratosept®, Bruschettini, Genova, Italy) on the microbial flora of a healthy ocular surface.

METHODS

Patients were enrolled consecutively. Each patient applied two drops of Keratosept® in the eye scheduled for cataract surgery (study eye) three times daily in the 2 days prior to surgery and one time in the morning of surgery. The contralateral eyes were considered as control (control eye). Bilateral conjunctival swabs were collected before the first administration (T0) and the morning of surgery (T1). The swabs were processed within 3 h from sampling for the automated detection of the presence of replicating microorganisms (colony-forming units, CFU/mL) and the provision of real-time growth curves.

RESULTS

Conjunctival swabs of 32 patients (n = 128) were examined. Six patients were excluded from the efficacy analysis because of microbial load < 50 CFU/mL at T0 in the study eye. No difference between study and control eyes was observed at T0 (p = 0.40). Compared with T0, 20 (76.9%) study eyes and 10 (38.5%) control eyes showed a ≥ 1 log reduction of the microbial load at T1, with a significant difference between groups (p = 0.005). Keratosept® showed good tolerability, and no adverse events or eye discomfort were recorded.

CONCLUSIONS

This study showed that the low-dose combination of antiseptic agents in the Keratosept® ophthalmic solution effectively reduces the bacterial load of healthy flora on the ocular surface.

Evaluating the effectiveness of large language models in patient education for conjunctivitis

AIMS

To evaluate the quality of responses from large language models (LLMs) to patient-generated conjunctivitis questions.

METHODS

A two-phase, cross-sectional study was conducted at the Eye and ENT Hospital of Fudan University. In phase 1, four LLMs (GPT-4, Qwen, Baichuan 2 and PaLM 2) responded to 22 frequently asked conjunctivitis questions. Six expert ophthalmologists assessed these responses using a 5-point Likert scale for correctness, completeness, readability, helpfulness and safety, supplemented by objective readability analysis. Phase 2 involved 30 conjunctivitis patients who interacted with GPT-4 or Qwen, evaluating the LLM-generated responses based on satisfaction, humanisation, professionalism and the same dimensions except for correctness from phase 1. Three ophthalmologists assessed responses using phase 1 criteria, allowing for a comparative analysis between medical and patient evaluations, probing the study's practical significance.

RESULTS

In phase 1, GPT-4 excelled across all metrics, particularly in correctness (4.39±0.76), completeness (4.31±0.96) and readability (4.65±0.59) while Qwen showed similarly strong performance in helpfulness (4.37±0.93) and safety (4.25±1.03). Baichuan 2 and PaLM 2 were effective but trailed behind GPT-4 and Qwen. The objective readability analysis revealed GPT-4's responses as the most detailed, with PaLM 2's being the most succinct. Phase 2 demonstrated GPT-4 and Qwen's robust performance, with high satisfaction levels and consistent evaluations from both patients and professionals.

CONCLUSIONS

Our study showed LLMs effectively improve patient education in conjunctivitis. These models showed considerable promise in real-world patient interactions. Despite encouraging results, further refinement, particularly in personalisation and handling complex inquiries, is essential prior to the clinical integration of these LLMs.

Predicting visual outcomes in keratoprosthesis surgery with critical flicker fusion frequency, B-scan, visual electrophysiology and endoscopy

PURPOSE

This study evaluates the predictive power of the critical flicker fusion frequency (CFF) test for visual outcomes in keratoprosthesis (KPro) candidates, comparing its accuracy with B-scan ultrasound, flash visual evoked potentials (fVEP) and endoscopy.

METHODS

The study included 42 patients (42 eyes) scheduled for KPro surgery with a median follow-up period of 6 months. The receiver operating characteristic curve identified the cut-off threshold for CFF in the model development study (17 eyes). All patients in the comparison study (25 eyes) underwent preoperative assessments including trichromatic CFF (red, green and yellow), B-scan ultrasound, fVEP and perioperative endoscopy. Results were classified as either favourable or unfavourable predictors of visual outcomes based on predefined criteria. Sensitivity and specificity of each assessment were calculated based on postoperative best-corrected visual acuity (BCVA)≥20/200. The Bland-Altman test assessed the consistency between CFF-predicted BCVA and actual BCVA.

RESULTS

Among the trichromatic CFF tests, the yellow-CFF (yCFF) exhibited the highest area under the curve value of 0.97 and a cut-off threshold at 10 Hz for predicting postoperative BCVA≥20/200 (p<0.05). yCFF achieved 90% sensitivity and 80% specificity in predicting satisfactory postoperative outcomes. Endoscopy had 80% sensitivity and 80% specificity, B-scan showed 70% sensitivity and 60% specificity, and fVEP had 75% sensitivity and 40% specificity. yCFF showed a mean bias of 0.091 logarithm of the minimum angle of resolution (logMAR) in postoperative prediction.

CONCLUSIONS

The CFF test provides robust visual function evaluation in KPro candidates. It demonstrates superior predictive accuracy for visual prognosis compared with routine ophthalmologic examinations, such as B-scan ultrasonography, fVEP and endoscopy.

Duloxetine enhances PAX6 expression and suppresses innate immune responses in murine LPS-induced corneal inflammation

BACKGROUND-AIM

PAX6 is a key regulator of eye development and epithelial homeostasis in the cornea. When deficient, chronic corneal inflammation, neovascularization and limbal stem cell deficiency can occur. Here we investigated the potential of duloxetine, a generic serotonin reuptake inhibitor that can upregulate PAX6 in vitro, for its in vivo activity in the context of corneal inflammation.

METHODS

Duloxetine tolerance was tested in a human limbal stem cell line and isogenic CRISPR-knockout PAX6+/- cells. C57BL/6-Wildtype mice were administered duloxetine eye drops at concentrations of 1 μM - 2 mM and tested for toxicity and corneal PAX6 expression. In LPS-induced corneal inflammation in mice, duloxetine's effect on PAX6 expression, corneal opacification and inflammatory responses were evaluated by in vivo corneal imaging, immunostaining, and whole-transcriptome microarray analysis.

RESULTS

No toxicity was observed in vitro for duloxetine concentrations up to 10μΜ. In vivo, duloxetine drops were well-tolerated up to 50 μM. Duloxetine drops at 10μΜ significantly upregulated PAX6 protein levels in the cornea by 30 % within 2 days. In the LPS model, duloxetine resulted in a sustained 33 % PAX6 protein upregulation in the cornea at 7 days, and in reduced opacity within 2 days, accompanied by a significant dampening of IL-17A signaling, neutrophil degranulation, microglial activation, macrophage markers, and MMP expression, despite non-significant changes in total inflammatory cell infiltration.

CONCLUSION

Short-term administration of a repurposed generic drug, duloxetine, upregulates PAX6 protein levels in the cornea of mice and exerts an anti-inflammatory activity by dampening innate immune responses.