The pathophysiology, diagnosis, and treatment of dry eye disease

Autologous Serum Eye Drops Diluted with Cyclosporine A 0.05% and Sodium Hyaluronate 0.1%: An Experimental Comparative Study

PURPOSE

The purpose of this study was to assess in-vitro efficacy of a suffusion of autologous serum withcyclosporine 0.05% (CsA) and sodium hyaluronate 0.1% (SH).

METHODS

The expression of proinflammatory markers interleukin 6 (IL-6) and TNF-Alpha (TNF-α) in limbal epithelial cells was evaluated. Also, assessment of the stability of epithelial growth factor and transforming growth factor-beta (EGF, TGF-β) in the 50% combinations with autologous serum (AS) was done. The characteristics (pH, density, osmolality) of the two combinations were also evaluated. Additionally, cytotoxicity effect of given test compounds was evaluated on human limbal epithelial cells (LEpiC).

RESULTS

The percentage of cells expressing IL-6 subjected to AS + SH and AS + CsA were 6.23% and 5.69% respectively. There was no significant difference in percentage of cells expressing TNF-α between the formulations (5.87%, 5.83% respectively). The growth factors; EGF and TGF-β remained stable forone month duration (on 2 and 4 weeks) at 4 °C without significant difference between the time intervals tested. The results of MTT assay suggested that limbal epithelial cells treated with AS + CsA and AS + SH combinations showed minimal toxicity however it was not significant statistically (p ≤ 0.05).

CONCLUSION

Two test combinations (AS + CsA, AS + SH) showed stable growth factors (EGF, TGF-β) and good anti-inflammatory property against pro-inflammatory markers. Also, the 2 combinations were found safe on cultured limbal epithelial cells. The novel combination of autologous serum in CsA may provide added benefit in dry eye disease (DED) through their combined anti-inflammatory and epitheliotropic effects.

Recombinant human nerve growth factor (cenegermin) for moderate-to-severe dry eye: phase II, randomized, vehicle-controlled, dose-ranging trial

BACKGROUND

Dry eye disease (DED) includes neurosensory abnormalities as part of its multifactorial etiology. Nerve growth factor is important for maintaining corneal nerve integrity and wound healing. Cenegermin (recombinant human nerve growth factor) is a topical biologic that promotes corneal healing in patients with neurotrophic keratitis. The purpose of this study was to evaluate efficacy and safety of cenegermin in moderate-to-severe DED and identify an optimal dosing strategy.

METHODS

This was a phase II, multicenter, randomized, double-masked, vehicle-controlled, dose-ranging clinical trial in patients with moderate-to-severe DED, including Sjögren's DED (NCT03982368). Patients received 1 drop of cenegermin 3 times daily (t.i.d.; 20 mcg/mL), cenegermin 2 times daily (b.i.d.; 20 mcg/mL) and vehicle once daily, or vehicle t.i.d. for 4 weeks. Follow-up continued for 12 additional weeks. The primary endpoint was change in Schirmer I score from baseline to week 4. Other key endpoints included rate of responders (Schirmer I test > 10 mm/5 min) after treatment and change in Symptoms Assessment iN Dry Eye (SANDE) scores from baseline to end of follow-up. A 1-sided test (α = 0.025) was used to evaluate statistical significance.

RESULTS

At week 4, mean changes in Schirmer I scores were not statistically significantly different in either cenegermin group versus vehicle (cenegermin vs vehicle [treatment difference; 95% CI]: t.i.d., 2.60 mm and b.i.d., 3.99 mm vs 1.68 mm [t.i.d.: 0.93; -1.47 to 3.32, P = 0.078; b.i.d.: 2.31; -0.08 to 4.70, P = 0.066]). More patients responded to treatment with cenegermin t.i.d. and b.i.d. versus vehicle (t.i.d.: 25.9% [21/81, P = 0.028]; b.i.d.: 29.3% [24/82, P = 0.007] vs 11.9% [10/84]), with statistical significance (set at P < 0.025) observed in the b.i.d. group. Only cenegermin t.i.d. yielded statistically significant (P < 0.025) reductions in SANDE scores versus vehicle, which were sustained up to the end of follow-up (P value range, 0.002-0.008). Eye pain, primarily mild and transient, was the most frequently observed treatment-emergent adverse event with cenegermin. Similar results were observed in patients with Sjögren's DED.

CONCLUSIONS

Cenegermin was well tolerated and although this study did not meet its primary endpoint, significant improvement in patient-reported symptoms of dry eye was observed through follow-up. Larger studies evaluating cenegermin in patients with DED are warranted.

TRIAL REGISTRATION

NCT03982368; registered May 23, 2019.

Magnetically Controlled Intraocular Delivery of Dexamethasone Using Silica-Coated Magnetic Nanoparticles

Although the number of patients with eye diseases is increasing, efficient drug delivery to the posterior segment of the eyeball remains challenging. The reasons include the unique anatomy of the eyeball, the blood-aqueous barrier, the blood-retina barrier, and drug elimination via the anterior chamber and uveoscleral routes. Solutions to these obstacles for therapeutic delivery to the posterior segment will increase the efficacy, efficiency, and safety of ophthalmic treatment. Micro/nanorobots are promising tools to deliver therapeutics to the retina under the direction of an external magnetic field. Although many groups have evaluated potential uses of micro/nanorobots in retinal treatment, most experiments have been performed under idealized in vitro laboratory conditions and thus do not fully demonstrate the clinical feasibility of this approach. This study examined the use of magnetic nanoparticles (MNPs) to deliver dexamethasone, a drug widely used in retinal disease treatment. The MNPs allowed sustainable drug release and successful magnetic manipulation inside bovine vitreous humor and the vitreous humor of living rabbits. Therefore, controlled drug distribution via magnetic manipulation of MNPs is a promising strategy for targeted drug delivery to the retina.

BMSC Alleviates Dry Eye by Inhibiting the ROS-NLRP3-IL-1β Signaling Axis by Reducing Inflammation Levels

PURPOSE

Bone marrow mesenchymal stem cells (BMSC) have multiple biological functions and are widely involved in regulating inflammatory diseases, tissue repair and regeneration. However, the mechanism of their action in dry eye disease (DED) is currently unclear. The purpose of this study was to investigate the effect of BMSCs in the treatment of dry eye mice and to explore its specific therapeutic mechanism.

METHODS

Mouse corneal epithelial cells (MCECs) were treated with 500 mOsM sodium chloride hypertonic solution to induce a DED cell model. The dry eye animal model was constructed by adding 5 μL 0.2% benzalkonium chloride solution to mouse eyes. Western blotting was used to detect the expression of related proteins, and flow cytometry, enzyme-linked immunosorbent assay (ELISA), terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining, hematoxylin-eosin (HE) staining, and periodic acid schiff (PAS) staining were used to detect cell and eye tissue damage.

RESULTS

The experimental results showed that BMSCs can reduce the levels of reactive oxygen species (ROS) and inflammatory factors in MCECs, promote cell proliferation, inhibit cell apoptosis, improve the integrity of the corneal epithelial layer in vivo, promote an increase in the number of goblet cells, and alleviate DED. Further exploration of the molecular mechanism of BMSCs treatment revealed that BMSCs alleviate the progression of DED by inhibiting the ROS-NLRP3-IL-1β signaling pathway.

CONCLUSION

BMSCs inhibit ROS-NLRP3-IL-1β signaling axis, reducing inflammation levels and alleviating dry eye symptoms. These findings provide new ideas and a basis for the treatment of DED and provide an experimental basis for further research on the application value of BMSCs in alleviating DED.

A Standardized Extract of Green-Cotyledon Small Black Soybean (EYESOY®) Ameliorates Dry Eye Syndrome in an Animal Model

PURPOSE

Dry eye syndrome is a common ocular disease that causes morbidity, high healthcare burden, and decreased quality of life. In this study, we evaluated the beneficial effects of a standardized extract of small black soybean (EYESOY®) in a benzalkonium chloride (BAC)-induced murine model of dry eye.

METHODS

Experimental dry eye was induced by instillation of 0.02% BAC on the right eye of the Sprague-Dawley rats. Saline solution or EYESOY were administered orally every day for 8 weeks.

RESULTS

EYESOY significantly improved tear volume in the cornea compared with that in the BAC group. Moreover, EYESOY inhibited damage to the corneal epithelial cells and lacrimal glands by suppressing the oxidative and inflammatory responses in a mouse dry eye model. It also increased the goblet cell density and mucin integrity in the conjunctiva.

CONCLUSIONS

Our results suggest that EYESOY has the potential to alleviate dry eye syndrome.

An LC-MS/MS method for the determination of Lifitegrast in human plasma and tear and its application in the pharmacokinetic study

Aim: A new, selective and simple UPLC-MS/MS method was developed and validated for the determination of lifitegrast in human plasma and tear in order to obtain PK data. Materials & methods: Lifitegrast-d4 solutions were added in the samples, and then were extracted and transferred to a UPLC vial. Results: The respective working ranges were 25.00-2000.00 pg/ml in plasma and 4.00-1000.00 μg/ml in tear. The fully validated method complied with existing regulatory criteria for accuracy and precision, recovery, etc. It was applied to plasma and tear samples, which were from a clinical study, successfully. Conclusion: This method is useful in the evaluation of lifitegrast in plasma and tear.

Association of Dry Eye Symptoms and Signs in Patients with Dry Eye Disease

PURPOSE

To determine the correlations among symptoms and signs of dry eye disease (DED) in the Dry Eye Assessment and Management (DREAM) study.

METHODS

A total of 535 patients with moderate-to-severe DED were assessed for symptoms using the Ocular Surface Disease Index (OSDI) and four DED signs in both eyes (conjunctival lissamine green staining, corneal fluorescein staining, Schirmer's testing, and tear break-up time (TBUT)) following standardized protocols at baseline and follow-up visits (months 3, 6, and 12). Spearman correlation coefficients (rho) were calculated for correlations among symptoms and signs of DED at baseline and among changes in symptoms and signs from baseline at 12 months. The confidence intervals and p-values for correlation coefficients were calculated using a cluster bootstrapping to account for inter-eye correlation.

RESULTS

At baseline, OSDI total score was not correlated with signs; however, OSDI subscale score of ocular symptoms was weakly correlated with corneal staining score (rho = 0.14, p = .002) and Schirmer test score (rho = 0.11, p = .01). There were statistically significant correlations among the four signs (p < .001), with absolute correlation coefficient ranging from 0.14 (conjunctival staining score vs. TBUT) to 0.33 (conjunctival staining score vs. cornea staining score). The correlations among changes in symptoms and signs were weaker, with the highest correlation between change in conjunctival staining and corneal staining (rho = 0.21, p < .001).

CONCLUSIONS

Consistent with previous studies, among DREAM participants with moderate-to-severe DED at baseline, correlations of DED symptoms with signs were low and correlations among four objective signs were low to moderate. The correlations among changes in symptoms and signs were even weaker.

Cytisine eye drops for benzalkonium chloride-induced dry eye: safety and efficacy evaluation

This experiment aimed to investigate the feasibility of cytisine (CYT) in treating eye diseases with ocular topical application. An in vitro cytotoxicity test, a hen's egg test-chorioallantoic membrane (HET-CAM), and a mouse eye tolerance test were used to fully reveal the ocular safety profiles of CYT. For the efficacy evaluations, CYT's effects on cell wound healing, against H2O2-induced oxidative stress damages on cells, and on benzalkonium chloride (BAC)-induced dry eye disease (DED) in mice were evaluated. Results showed that CYT did not show any cytotoxicities at concentrations no higher than 250 μg/ml, while lipoic acid (α-LA) at 250 μg/ml and BAC at 1.25 μg/ml showed significant cytotoxicities within 48 h incubation. The HET-CAM and mouse eye tolerance test confirmed that 0.5% CYT eye drops demonstrated good safety characteristics. Efficacy evaluations showed that CTY significantly promoted cell migration and wound healing. CYT significantly improved cell survival against H2O2-induced oxidative stress damage by reversing the imbalance between the reactive oxygen species (ROS) and antioxidant defense mechanisms. The animal evaluation of the BAC-induced dry eye model revealed that CYT demonstrated a strong treatment effect, including reversing ocular surface damages, recovering corneal sensitivity, and inhibiting neovascularization; HMGB1/NF-κB signaling was involved in this DED treatment by CTY. In conclusion, CYT had strong experimental treatment efficacy against DED with good ocular safety profiles, and it might be a novel and promising drug for DED.

Recommendations for nutritional supplements for dry eye disease: current advances

Dry eye disease (DED) represents a prevalent ocular surface disease. The development of effective nutritional management strategies for DED is crucial due to its association with various factors such as inflammation, oxidative stress, deficiencies in polyunsaturated fatty acids (PUFAs), imbalanced PUFA ratios, and vitamin insufficiencies. Extensive research has explored the impact of oral nutritional supplements, varying in composition and dosage, on the symptoms of DED. The main components of these supplements include fish oils (Omega-3 fatty acids), vitamins, trace elements, and phytochemical extracts. Beyond these well-known nutrients, it is necessary to explore whether novel nutrients might contribute to more effective DED management. This review provides a comprehensive update on the therapeutic potential of nutrients and presents new perspectives for combination supplements in DED treatment.

The Long-Term Effect on Dry Eye of Posterior Approach Ptosis Surgery Vs. Upper Eyelid Blepharoplasty

PURPOSE

To examine the long-term effect of combined blepharoplasty and Müller muscle-conjunctival resection (MMCR) compared to an upper blepharoplasty procedure on dry eye syndrome.

METHODS

This is a Prospective comparative case series. Two groups of patients participated in this study: the blepharoplasty group included adult patients that underwent blepharoplasty at least 3 years earlier and the ptosis group consisting of adult patients that underwent MMCR with blepharoplasty at least 3 years earlier. The parameters that were compared for all patients before the procedure, on postoperative day 90, and at the long-term follow-up were: Schirmer-test 2, tear break-up time (TBUT), fluorescein staining, and lissamine green (LG) staining.

RESULTS

The participants included 25 post-MMCR patients with a mean follow-up of 4.94 ± 0.64 years and 15 post-blepharoplasty patients with a mean follow-up of 4.22 ± 0.32 years. There was a significant increase in the postoperative LG and fluorescein staining scores compared to the preoperative scores in the ptosis group (p < .01 and p < .01, respectively) as well as a decrease in postoperative TBUT compared to the preoperative values (p = .044). Those parameters were not significant in the blepharoplasty group.

CONCLUSIONS

Patients who underwent MMCR, but not those following upper blepharoplasty, showed signs of dry eye compared to the preoperative status after long-term follow-up. Dry eye signs should be examined before MMCR surgery, and patients should be aware of the high risk of developing dry eye and the need for long-term treatment. Surgeons should carefully consider performing MMCR for patients with severe dry eye.

Risk of Keratitis and Keratopathy in Hidradenitis Suppurativa Patients: A Global Federated Health Network Analysis

BACKGROUND/AIM

Hidradenitis suppurativa (HS) is linked to immune dysregulation and systemic inflammation. While previous studies indicate a higher prevalence of ocular manifestations in HS, the specific risk of keratopathy and keratitis remains unclear. The primary aim of this study was to assess the risk of keratitis and keratopathy in individuals with HS.

PATIENTS AND METHODS

In this retrospective cohort study conducted with data from the TriNetX database, 53,716 patients with HS were matched to an equivalent number of non-HS controls using propensity score matching. The study covered the period from January 1st, 2005, to December 31st, 2017. Hazard ratios and their respective 95% confidence intervals (CIs), were computed to evaluate the occurrences of keratitis and keratopathy over a 5-year duration in patients with HS, compared to non-HS controls.

RESULTS

HS was associated with a 1.52 times higher risk of keratitis over a 5-year period (95%CI=1.24-1.86) and a 1.47 times higher risk of keratopathy (95%CI=1.18-1.84). These risks remained consistent in sensitivity analyses. The elevated risk of keratitis was observed across both sexes. However, the risk of keratopathy was significantly higher in women with HS (HR=1.61, 95%CI=1.24-2.10) and individuals aged 18-64 years (HR=1.32, 95%CI=1.04-1.68).

CONCLUSION

HS was linked to an elevated risk of both keratitis and keratopathy over a 5-year period. Ophthalmologic manifestations are recommended to be considered in HS standard care.

Efficiency of Combining Heated Eye Mask with Intense Pulsed Light Therapy as a Treatment Option for Evaporative Dry Eye Disease

Background and objectives: The study aimed to establish the efficiency of combining the Posiforlid heated eye mask with intense pulsed light therapy (IPL), as a treatment strategy for evaporative dry eye disease. Materials and methods: This study included 110 patients, respectively 220 eyes, diagnosed with evaporative dry eye disease, patients between 18 and 86 years old, divided into two study groups. The first one, the control group, consisted of 73 patients treated with IPL therapy, and the second of 37 patients, who underwent IPL therapy associated with Posiforlid heated eye mask. Subjective evolution was assessed using an eye fitness test (EFT) regarding symptomatology. Objective assessment of the ocular surface was performed by tear film stability evaluation (TFSE), non-invasive first break-up time (NIFBUT), non-invasive average breakup time (NIABUT), ocular surface inflammatory evaluation (OSIE), measuring of the central tear meniscus height (CTMH) and thinnest tear meniscus height (TTMH). The assessment was performed at the beginning of the IPL treatment, during the IPL sessions, at the end of the IPL treatment, and afterward, at 3, 6, and 12 months. Results: Tear film stability has increased in both study cases, but no statistically significant difference was observed between the two groups studied. For the control group, tear film stability evaluation (TFSE) started from 310.56 ± 389.54 at baseline (time 1 presentation) to 114.40 ± 122.90 after 12 months, and for the heated mask group, from 391.11 ± 456.45 (time 1 presentation) to 97.38 ± 105.98 after 12 months. NIABUT increased from 10.72 ± 4.90 seconds to 14.79 ± 3.72 seconds in the control group, and from 11.11 ± 5.08 seconds to 15.84 ± 2.26 seconds in the second group. OSIE decreased, as expected, from 7.18 ± 7.93 percent in the control group to 2.24 ± 2.38 percent after 12 months and from 7.42 ± 7.77 percent to 2.47 ± 2.50 percent in the Posiforlid group. Although significantly lower, there was no significant difference between the two studied groups. No statistically significant changes were registered in the studied quantitative parameters. Using the EFT test, great improvements were registered regarding symptomatology, with a score increasing from 29.99 ± 8.60 to 39.10 ± 5.08 in the control group and from 27.35 ± 9.24 to 38.35 ± 4.62 in the other group. Again, the same statistical result was registered on this variable. Conclusions: The improvement of tear film stability, ocular surface inflammatory condition, and subjective symptoms during IPL therapy sessions and the first year of observation after the completion of the treatment was not necessarily increased by the additional use of a heated eye mask. Abbreviations: IPL = intense pulsed light therapy, EFT = eye fitness test, NIFBUT = non-invasive first break-up time, NIABUT = non-invasive average break-up time, OSIE = ocular surface inflammatory evaluation, TFSE = tear film stability evaluation, CTMH = central tear meniscus height, TTMH = thinnest tear meniscus height, DED = dry eye disease, MGD = meibomian gland dysfunction, SD = standard deviation.

Prevalence and Risk Factors of Dry Eye Disease in the South of Palestine

Background

The prevalence of dry eye disease (DED) is rising globally and needs to be urgently addressed by medical professionals because it lowers patients' quality of life. There are as yet no available data in the literature about the prevalence of and risk factors for DED in the Gaza Strip, a gap that the present study seeks to address.

Methods

A cross-sectional study was carried out between March and August 2022 in Gaza governorates using a proportional stratified sampling technique. Only Gazan individuals ≥ 18 years old and able to follow the instructions were included. The Ocular Surface Disease Index (OSDI) questionnaire, which has previously been translated into Arabic and validated, was applied to evaluate DED symptoms. Subjective clinical tests for DED conducted were tear meniscus height (TMH), meibomian gland dysfunctions (MGDs), Marx line (ML), conjunctival Lissamine green staining (LGS), tear film break-up time test (TBUT), corneal fluorescein staining (CFS) and Schirmer II tear test (STT). DED was defined based on an Arab-OSDI score ≥ 13 and at least one positive clinical sign.

Results

A total of 426 participants were assessed from four areas (North Gaza Strip, 82; Gaza City, 147; Mid-Zone Gaza Strip, 62; South Gaza Strip, 135). The prevalence of DED in the present study was 31.5% (95% CI: 27.1, 36.1). Age > 50 years old (odds ratio [OR] = 10.45; 95% CI: 2.95, 37.05; P < 0.001), female gender (OR = 3.24; 95% CI: 1.40, 7.52, P = 0.006), menopause or pregnancy (OR = 2.59; 95% CI: 1.25, 5.35; P = 0.03) and pharmacotherapy (artificial tears; OR = 9.91; 95% CI: 2.77, 35.46; P < 0.001) were each associated with DED symptoms. South Gaza Strip (OR = 0.04; 95% CI: 0.01, 0.12; P < 0.001), unemployed (OR = 11.67; 95% CI: 1.43, 95.44; P = 0.02), non-consumption of caffeine (OR = 0.40; 95% CI: 0.19, 0.88; P = 0.02) and TMH < 0.2 (OR = 1.80; 95% CI: 1.02, 3.19; P = 0.04) were associated with TBUT < 5 s. LGS was associated with those > 50 years old (OR = 2.70; 95% CI: 1.38, 5.28; P = 0.004), previous refractive or ocular surface surgeries (OR = 2.97; 95% CI: 1.34, 6.59; P = 0.008) and CFS ≥ 1 (OR = 1.91; 95% CI: 1.07, 3.44; P = 0.03).

Conclusion

Various aspects of DED were linked with different risk factors, suggesting that DED subtypes have different underlying pathophysiologies.

Ocular toxicity of psychotropic medications in a tertiary hospital in Lagos, Nigeria

Objective: This study aimed to determine the ocular toxicity of the psychotropic drugs used by patients and to proffer suggestions on how to prevent visual impairment or blindness in patients on antipsychotics. Methodology: This was a prospective, hospital-based cross-sectional study. Participants were adult patients between 18 and 70 years, diagnosed with psychosis, and who had been on antipsychotic medications for at least one year. All the recruited participants had an examination of the anterior and posterior segments of the eyes done. Schirmer's test, Tear film Break-up time (TBUT), Central Corneal thickness (CCT), Colour vision test, and Contrast sensitivity test were done. The collected data was analyzed using IBM SPSS 28.0. Results: The study enrolled patients who were mainly females (55.1%). The highest age group of the cases was 29-38 years (29.7%). The examination of the eyes and investigations revealed that 10.2% of the respondents on antipsychotics had color vision deficiency and 25.4% - loss of contrast sensitivity. Lid pigmentation was observed in 20.3% and cataract in 32.2%. Degeneration of the peripheral retina was observed in 4.2% of patients on antipsychotic medication. Schirmer's test showed mild, moderate, and severe dry eyes in 11%,17.8%, and 20.3% of the participants respectively. The test for Central Corneal Thickness (CCT) showed 50.0% of the respondents had a thin cornea and 24.6% had a thick cornea. 17.8% of the surveyed respondents manifested high eye pressure. Discussion: Psychotropics are the gold standard for the treatment of psychotic episodes and disorders. The choice of drug, dosing, and mode of administration depends on the severity of the psychotic disorder. Higher doses of psychotropics were reported to cause toxicity in different organs in the body including the eyes, especially on long-term use and high dosage and this can affect the quality of life of the individual negatively. Conclusion: The earliest and most prominent side effect seen in patients on psychotic medication was dry eyes. There were a few cases of blinding eye diseases like glaucoma, and cataract. For these reasons, ophthalmic assessments should be included as part of the management of psychiatric patients early at the start of antipsychotic treatment. Abbreviations: FGA = First Generation Antipsychotics, SGA = Second Generation Antipsychotics, TCAs = Tricyclic Antidepressants, CCT = Central Corneal Thickness, IOP = Intraocular Pressure, TBUT =Tear film Break-up Time, BIO = Binocular Indirect Ophthalmoscope.

Is there a relationship between the severity of disease in major depressive disorder patients and dry eye disease?

PURPOSE

To investigate dry eye disease (DED) in newly diagnosed patients with depressive disorder (MDD).

METHOD

This observational study included 48 MDD patients in Group 1 and 20 healthy controls in Group 2. Psychiatric and ophthalmic examinations, Beck Depression Inventory (BDI), Ocular Surface Disease Index (OSDI), Schirmer's test, tear breakup time (TBUT), Meibomian gland dysfunction (MGD), and ocular staining were conducted. The results were statistically compared.

RESULTS

The participants, comprising 32 men and 36 women, had a mean age of 31.08 ± 11.7 years (18-64 years). Group 1 had a mean BDI score of 30.87 ± 8.56, while Group 2 had a score of 1.3 ± 1.3 (p < 0.001). In Group 1, 28 patients were diagnosed with DED, whereas in Group 2, six subjects were diagnosed with DED. The mean Schirmer's results in Group 1 and Group 2 were (mm/5 min) 10.87 ± 2.44 and 12.70 ± 2.3, respectively, and were significantly lower in Group 1 (p < 0.001). The mean OSDI scores in Group 1 (34.95 ± 15.8) were significantly higher compared to Group 2 (3.2 ± 3.1) (p < 0.001). There was no significant difference in mean TBUT between Group 1 (9.41 ± 2.6 s) and Group 2 (9.8 ± 0.61 s) (p > 0.05). Significant correlations were found between BDI scores and Schirmer's results as well as OSDI scores (p < 0.05, p = 0.02, respectively). No statistically significant correlations were found between BDI scores and TBUT or MGD (p > 0.05).

CONCLUSION

DED was found to be more prevalent in the MDD group. The severity of MDD and DED, as indicated by BDI, OSDI, and Schirmer's results, was found to be correlated. It was observed that patients with higher depression scores had more severe dry eye. As a result, we recommend performing ophthalmic examinations in newly diagnosed MDD patients.

The efficacy of bandage contact lens in relieving the aggravation of dry eye disease after complicated cataract or/and IOL surgery

PURPOSE

In the present study, we aimed to evaluate the efficacy of the bandage contact lens (BCLs) in the treatment of dry eye disease (DED) after complicated cataract or/and intraocular lens (IOL) surgery.

METHODS

In this retrospective, single-centered, observational study, we collected data from 69 patients who underwent complicated cataract or/and IOL surgery. Of these, 35 cases wore their own BCLs immediately after the operation, while the other 34 cases did not have their own BCLs and were instead covered with gauze. The Ocular Surface Disease Index (OSDI) questionnaire, slit-lamp microscope examination, keratograph analysis, and Schirmer I test were measured at baseline, 1 week and 1 month postoperatively.

RESULTS

In the BCL group, the score of the OSDI questionnaire was significantly decreased at 1 week and 1 month postoperatively compared with baseline levels (P = 0.000, collectively). Moreover, the fluorescein staining score of the BCL group was remarkably decreased 1-week and 1-month postoperatively compared with the non-BCL group (P = 0.000 and P = 0.000, respectively). Furthermore, the redness score of the BCL group was also better compared with the non-BCL group at 1 week and 1 month postoperatively (P = 0.014 and P = 0.004, respectively).

CONCLUSIONS

Complicated cataract or/and IOL surgery would intensify the DED. Early application of BCLs postoperatively improved patients' comfort and alleviated dry eye-related symptoms and signs. Furthermore, this mechanism might involve the acceleration of corneal epithelial healing, the alleviation of ocular stress response and the stabilization of the tear film.

TRIAL REGISTRATION

Trial registration ClinicalTrials, NCT04120389. Registered 10 October 2019-retrospectively registered.

New targets of nascent lymphatic vessels in ocular diseases

Recent advancements in the field of endothelial markers of lymphatic vessels and lymphangiogenic factors have shed light on the association between several ocular diseases and ocular nascent lymphatic vessels. The immune privilege of corneal tissue typically limits the formation of lymphatic vessels in a healthy eye. However, vessels in the eyes can potentially undergo lymphangiogenesis and be conditionally activated. It is evident that nascent lymphatic vessels in the eyes contribute to various ocular pathologies. Conversely, lymphatic vessels are present in the corneal limbus, ciliary body, lacrimal glands, optic nerve sheaths, and extraocular muscles, while a lymphatic vasculature-like system exists in the choroid, that can potentially cause several ocular pathologies. Moreover, numerous studies indicate that many ocular diseases can influence or activate nascent lymphatic vessels, ultimately affecting patient prognosis. By understanding the mechanisms underlying the onset, development, and regression of ocular nascent lymphatic vessels, as well as exploring related research on ocular diseases, this article aims to offer novel perspectives for the treatment of such conditions.

Contact lens fitting and changes in the tear film dynamics: mathematical and computational models review

PURPOSE

This review explores mathematical models, blinking characterization, and non-invasive techniques to enhance understanding and refine clinical interventions for ocular conditions, particularly for contact lens wear.

METHODS

The review evaluates mathematical models in tear film dynamics and their limitations, discusses contact lens wear models, and highlights computational mechanical models. It also explores computational techniques, customization of models based on individual blinking dynamics, and non-invasive diagnostic tools like high-speed cameras and advanced imaging technologies.

RESULTS

Mathematical models provide insights into tear film dynamics but face challenges due to simplifications. Contact lens wear models reveal complex ocular physiology and design aspects, aiding in lens development. Computational mechanical models explore eye biomechanics, often integrating tear film dynamics into a Multiphysics framework. While different computational techniques have their advantages and disadvantages, non-invasive tools like OCT and thermal imaging play a crucial role in customizing these Multiphysics models, particularly for contact lens wearers.

CONCLUSION

Recent advancements in mathematical modeling and non-invasive tools have revolutionized ocular health research, enabling personalized approaches. The review underscores the importance of interdisciplinary exploration in the Multiphysics approach involving tear film dynamics and biomechanics for contact lens wearers, promoting advancements in eye care and broader ocular health research.

Recent progress of nanomedicine in managing dry eye disease

Background

Dry eye disease (DED) is a commonly reported ocular complaint that has garnered significant attention in recent research. The global occurrence of DED ranges from 5% to 50%, impacting a substantial proportion of individuals worldwide with increasing frequency. Although topical administration remains the mainstream drug delivery method for ocular diseases, it suffers from drawbacks such as low bioavailability, rapid drug metabolism, and frequent administration requirements. Fortunately, the advancements in nanomedicine offer effective solutions to address the aforementioned issues and provide significant assistance in the treatment of DED.

Main text

DED is considered a multifactorial disease of the ocular surface and tear film, in which the integrity of tear film function and structure plays a crucial role in maintaining the homeostasis of the ocular surface. The conventional treatment for DED involves the utilization of artificial tear products, cyclosporin, corticosteroids, mucin secretagogues, and nonsteroidal anti-inflammatory drugs. Furthermore, nanomedicine is presently a significant field of study, with numerous clinical trials underway for various nanotherapeutics including nanoemulsions, nanosuspensions, liposomes, and micelles. Notably, some of these innovative nanoformulations have already received FDA approval as novel remedies for DED, and the advancement of nanomedicine is poised to offer enhanced prospects to solve the shortcomings of existing treatments for DED partially.

Conclusions

This article provides an overview of the latest advancements in nanomedicine for DED treatment, while the field of DED treatment is expected to witness a remarkable breakthrough shortly with the development of nanomedicine, bringing promising prospects for patients worldwide suffering conditions.

Utilizing visual symptoms to distinguish dry eye from glaucoma, cataract, and suspect glaucoma patients: a cross-sectional study

BACKGROUND

The diagnosis of dry eye and other common ophthalmological conditions can be supported using patient reported symptoms, which is increasingly useful in contexts such as telemedicine. We aim to ascertain visual symptoms that differentiate dry eye from cataract, glaucoma, or glaucoma suspects.

METHODS

Adults with dry eye, glaucoma, cataract, and suspected glaucoma (controls) completed a questionnaire to rate the frequency and severity of 28 visual symptoms. Univariate, followed by multivariable logistic regression with backward stepwise selection (p < 0.05), determined the individual symptoms and set of symptoms best distinguishing dry eye from each of the other conditions.

RESULTS

Mean age of 353 patients (94 glaucoma suspect controls, 79 glaucoma, 84 cataract, and 96 dry eye) was 64.1 years (SD = 14.1); 67% were female and 68% White. Dry eye patients reported more frequent light sensitivity (OR = 15.0, 95% CI = 6.3-35.7) and spots in vision (OR = 2.8, 95% CI = 1.2-6.3) compared to glaucoma suspect controls. Compared to glaucoma patients, dry eye patients experienced more frequent light sensitivity (OR = 9.2, 95% CI = 2.0-41.7), but less frequent poor peripheral vision (OR = 0.2, 95% CI = 0.06-0.7), difference in vision between eyes (OR = 0.09, 95% CI = 0.01-0.7), and missing patches of vision (OR = 0.06, 95% CI = 0.009-0.3). Compared to cataract patients, dry eye patients reported more frequent spots in vision (OR = 4.5, 95% CI = 1.5-13.4) and vision variability across the week (OR = 4.7, 95% CI = 1.2-17.7) and were less likely to report worsening vision (OR = 0.1, 95% CI = 0.03-0.4) and blindness (OR = 0.1, 95% CI = 0.02-0.8).

CONCLUSION

Visual symptoms may serve as a complementary tool to distinguish dry eye from various ocular conditions, though the symptoms that best distinguish dry eye differ across comparisons. Differentiating how patients visually perceive common eye diseases may be used in a variety of clinical settings to rule out specific conditions.

Quality of life improvement in dry eye patients after intense pulsed light therapy compared to punctal plugs

PURPOSE

The purpose of the study was to evaluate the quality of life (QOL) improvement in evaporative dry eye patients after treatment with intense pulsed light (IPL) therapy compared to punctal plug insertion.

METHODS

A prospective comparative interventional study included 30 patients with moderate-to-severe evaporative dry eye. Patients' QOL affection before and after treatment was assessed by the Ocular Surface Disease Index (OSDI) questionnaire. Fifteen patients were treated with IPL therapy (Group 1). The other 15 patients were treated with silicone punctal plug insertion (Group 2).

RESULTS

Improvement of patients' QOL was noticed in all patients of Group 1, with significant improvement of OSDI score from a mean value of 56.9 to 22.9 (P = 0.001). Improvement was noticed in 80% of Group 2 patients (mean OSDI score pretreatment: 53.8 and posttreatment: 31.7, P = 0.017). The tear breakup time (TBUT) in Group 1 significantly improved from a mean of 3.2 s to 5.9 s (P = 0.001), whereas it showed no significant changes in Group 2 (mean TBUT pretreatment: 3.6 s and posttreatment: 3.9 s, P = 0.654). Complications occurred in 13.3% in Group 2, including punctal granuloma and proximal canalicular obstruction. No adverse effects were recorded in Group 1.

CONCLUSION

IPL therapy had better results with more improvement of patients' QOL compared to punctal plugs. It also showed a better safety profile with no reported complications.

Evaluation of Main Lacrimal Gland through Shear-wave Ultrasound Elastography in Patients with Low Schirmer Value

OBJECTIVE

To compare main lacrimal gland values through shear-wave elastography (SWE) in patients with low Schirmer value and unspecified Sjögren's syndrome (SS) with healthy controls.

MATERIAL AND METHOD

Admitted to the ophthalmology department with Schirmer value <10 mm, randomly selected 46 eyes of 46 patients evaluated for Sjögren's syndrome (SS) in the rheumatology department between December 2022 and April 2023 were classified as low Schirmer group (LSG). Randomly selected 48 eyes of 48 patients at a similar age with Schirmer value >10 mm were included as controls. Main lacrimal gland SWE measurements in LSG and control groups were recorded and compared as meter/second (m/sec).

RESULTS

Mean SWE values of the main lacrimal gland were measured as 2.78 ± 0.66 m/sec and 2.26 ± 0.29 m/sec in LSG and controls. SWE measurements were significantly higher in LSG patients than in controls (p<0.001). No significant correlation was found in the analysis between the Schirmer and the main lacrimal gland SWE values in LSG patients (p=0.702, r=0.058). No significant correlation was also detected between the Schirmer and main lacrimal gland SWE values in controls (p=0.097, r=0.242). No significant relationship was also found between age, gender, body mass index (BMI), and SWE values (p=0.351, p=0.493, p=0.328, respectively).

CONCLUSION

Mean SWE value of the main lacrimal gland was determined as significantly higher in patients with aqueous lacrimal insufficiency without SS than in controls. We consider that SWE measurements may be an imaging method to support the diagnosis of aqueous lacrimal insufficiency and used in follow-ups of those with dry eye syndrome (DES) in the future.

Prevalence of dry eye during the COVID-19 pandemic: A systematic review and meta-analysis

OBJECTIVE

During the COVID-19 pandemic, many people devoted longer time to screen viewing due to the need for study, work, and online social activities, instead of outdoor activities, which may have led to an increase in dry eye symptoms. This study aimed to evaluate the prevalence of dry eye during the COVID-19 pandemic.

METHODS

PubMed, Cochrane Library, Embase, and Web of Science were searched from January 1, 2020 to October 20, 2022. Cross-sectional surveys on dry eye prevalence conducted after January 1, 2020 were included. Two review authors independently performed data extraction and assessed study quality. The random-effects model was used to analyze the prevalence of dry eye, and the odds ratio was used to assess the strength of the association between variables. Subgroup analysis was performed to detect heterogeneity, the leave-one-out method for sensitivity analysis, and the Egger test for publication bias.

RESULTS

A total of eleven studies with 15692 individuals met the eligibility criteria. The prevalence of dry eye during the COVID-19 pandemic was 61.0% (95%CI: 51.8%-70.2%) globally and 56.7% (95%CI: 45.3%-68.1%) in Asia. The prevalence of dry eye had significant differences in sex and visual display time, with higher prevalence among females and visual display time of more than 4 hours per day. Subgroup analysis was performed based on diagnostic tools, study population, and average age. A significant difference was found in diagnostic tools, but no significant change in heterogeneity (P<0.05). The leave-one-out method showed stable results, and the Egger test identified no significant publication bias.

CONCLUSION

The prevalence of dry eye during the COVID-19 pandemic is significantly higher than before, and a higher prevalence is found among females and those having a visual display time of more than 4 hours per day.

Unveiling the Spectrum of Ophthalmic Manifestations in Nutritional Deficiencies: A Comprehensive Review

This comprehensive review explores the intricate relationship between nutrition and ocular health, focusing on the crucial roles of essential nutrients like Vitamin A, Vitamin B1 (thiamine), Vitamin B12, Vitamin C, Vitamin D, Vitamin E, Zinc, and Folate (Vitamin B9) in maintaining eye well-being. Nutrient deficiencies have significant consequences, leading to various eye-related issues, from night blindness to age-related conditions such as cataracts and macular degeneration. It is imperative to address these deficiencies, emphasizing the importance of a well-rounded diet with the necessary nutrients. When necessary, supplementation and regular eye examinations are vital components for effectively monitoring ocular health. Public health campaigns and educational initiatives also play a key role in raising awareness about the profound impact of nutrition on eye health. Future research should explore personalized nutrition plans, nutrigenomics, longitudinal studies, and targeted nutritional interventions. Such investigations will not only enhance our understanding of this crucial connection but also have the potential to reduce the global burden of eye diseases.

Influence of perfluorohexyloctane (Evotears®) on higher order aberrations

PURPOSE

To prospectively assess the effect of regular application of perfluorohexyloctane (F6H8; Evotears®) on the tear film lipid layer, higher order aberrations (HOA) and the repeatability of measurements in healthy eyes.

METHODS

This prospective clinical study included 104 eyes treated with F6H8 four times daily for four weeks (group A) and 101 eyes that served as controls (group B). Measurements were performed with the WASCA aberrometer (Carl Zeiss Meditec GmbH, Jena, Germany). Main outcome measurement in addition to subjective refraction were the root mean square values of HOA measured before and after the intervention.

RESULTS

Regular use of F6H8 over a period of four weeks significantly increases HOA in healthy eyes (p < 0.05). In addition, the repeatability of measurement increases after the application of F6H8.

CONCLUSION

F6H8 may be a suitable treatment option to improve the accuracy of refractive assessment, although it increases HOA. Further studies are needed to confirm the effect on HOA and the repeatability of measurement.

The Molecular Mechanisms Responsible for Tear Hyperosmolarity-Induced Pathological Changes in the Eyes of Dry Eye Disease Patients

Dry eye disease (DED) is a multifactorial disorder of the lacrimal system and ocular surface, characterized by a deficiency in the quality and/or quantity of the tear fluid. The multifactorial nature of DED encompasses a number of interconnected underlying pathologies, including loss of homeostasis, instability and hyperosmolarity of the tears, and the induction and propagation of detrimental inflammatory responses in the eyes, which finally results in the development of neurosensory dysfunction and visual disruption. Dryness, grittiness, scratchiness, discomfort, inflammation, burning, watering, ocular fatigue, pain, and decreased functional visual acuity are common symptoms of DED. Eye dysfunction drastically attenuates patients' quality of life. Accordingly, a better understanding of the pathogenic processes that regulate the development and progression of DED is crucially important for the establishment of new and more effective DED-related treatment approaches, which would significantly improve the quality of life of DED patients. Since the process of osmoregulation, which guards the ocular surface epithelia and maintains normal vision, is affected when the osmolarity of the tears is greater than that of the epithelial cells, tear hyperosmolarity (THO) is considered an initial, important step in the development, progression, and aggravation of DED. In order to delineate the role of THO in the pathogenesis of DED, in this review article, we summarize current knowledge related to the molecular mechanisms responsible for the development of THO-induced pathological changes in the eyes of DED patients, and we briefly discuss the therapeutic potential of hypo-osmotic eye drops in DED treatment.

Role of lymphotoxin alpha as a new molecular biomarker in revolutionizing tear diagnostic testing for dry eye disease

Dry eye disease (DED), primarily classified as multifactorial ocular surface disorder, afflicts tens of millions of individuals worldwide, adversely impacting their quality of life. Extensive research has been conducted on tear film analysis over the past decades, offering a range of tests to evaluate its volume, health, and integrity. Yet, early diagnosis and effective treatment for DED continue to pose significant challenges in clinical settings. Nevertheless, by recognizing key phenomena in DED such as ocular surface inflammation, hyperosmolarity, and tear film instability, this article provides a comprehensive overview of both traditional and recently developed methods for diagnosing and monitoring DED. The information serves as a valuable resource not only for clinical diagnosis but also for further research into DED.

Severe Dry Eye Disease in Charcot-Marie-Tooth Disease: A Comprehensive Case Report

BACKGROUND Charcot-Marie-Tooth disease (CMT) is a hereditary neurological disorder that primarily leads to peripheral neuropathy, characterized by progressive muscle weakness, atrophy, and loss of sensation in the extremities. It can also present with some ocular manifestations, such as glaucoma, nystagmus, and cranial nerve involvement. The purpose of this article was to report a case of severe dry eye disease (DED) possibly associated with Charcot-Marie-Tooth disease. CASE REPORT We report the clinical presentation, workup, and management of a woman diagnosed with CMT type 2EE based on genetic testing who suffered from severe DED sequelae. The patient had regularly followed up in the cornea service at our hospital due to DED for several years. A thorough workup to exclude causes associated with dry eye disease, including rheumatoid factor, erythrocyte sedimentation rate (ESR), anti-nuclear antibody (ANA), anti-Sjögren's-syndrome-related antigen A (anti-SSA), and anti-Sjögren's-syndrome-related antigen B (Anti-SSB), were performed, and all came out negative. She recently presented to the emergency room with redness, tearing, and a decline in visual acuity after minor ocular trauma 3 weeks before her presentation. The slit lamp examination showed central corneal perforation measuring 2×2 mm with a positive Seidel test. The case was managed first by multiple attempts to seal the defect with cyanoacrylate glue, and then a patch corneal graft was performed as the anterior chamber failed to deepen. CONCLUSIONS DED may be one of the many ocular manifestations associated with CMT. Hence, a thorough assessment and multidisciplinary approach, including supportive therapy, are warranted to prevent long-term ocular sequelae, including visual loss.

Symptomatic Dry Eye Disease and Associated Factors Among Adult Diabetic Patients in Adare General Hospital, Hawassa City, Southern Ethiopia, 2023

Introduction

Symptomatic dry eye disease is a multifactorial ocular surface condition caused by disruption of the precorneal tear film and is a common clinical finding in diabetic patients. However, there was no study on the prevalence and associated factors of symptomatic dry eye disease among diabetic patients in Ethiopia or in the study area.

Purpose

This study aimed to investigate the prevalence and associated factors of symptomatic dry eye disease among adult diabetic patients in Adare General Hospital, Hawassa City, Southern Ethiopia, in 2023.

Methods

A hospital-based cross-sectional study design was conducted on 493 adult diabetic patients who were selected using systematic random sampling, from April 23 to June 8, 2023. Data were collected through a face-to-face interview using an ocular surface disease index questionnaire. Binary logistic regression was performed to identify factors potentially associated with symptomatic dry eye disease. Variable with a P value of <0.05 was considered statistically significant.

Results

A total of 488 subjects participated in this study with a response rate of 99%. The prevalence of symptomatic dry eye disease was 34.8% (95% CI = 30.6-39.1). College and university educational status (AOR = 5.88, 95% CI = 2.25-15.38), government employed (AOR = 2.22, 95% CI = 1.05-4.68), use of visual display unit >5 hours (AOR = 4.41, 95% CI = 1.51-12.87), duration of diabetes ≥11 years (AOR = 3.57, 95% CI = 1.28-9.90), poor glycemic control (AOR = 2.13, 95% CI = 1.21-3.75), allergic conjunctivitis (AOR = 1.99, 95% CI = 1.12-3.54), and debris in the tear film (AOR = 3.63, 95% CI = 1.53-8.61) were positively associated with symptomatic dry eye disease.

Conclusion

The study revealed a high prevalence of symptomatic dry eye disease. Higher educational status, government employed, use of visual display unit, longer duration of diabetes, poor glycemic control, allergic conjunctivitis, and tear film debris were significantly associated with symptomatic dry eye disease. Breaks in screen use, good glycemic control, and treatment of ocular morbidities such as allergic conjunctivitis and debris in the tear film were recommended for all diabetic patients.

The influence of large-diameter multifocal contact lens on ocular surface, visual quality, and visual function for presbyopic adults with dry eye syndromes

This study investigated the influence of large-diameter multifocal contact lenses on the ocular surface, visual quality, and visual function for presbyopic adults with dry eye syndromes. The study enrolled 40-55-year-old adults with presbyopia and dry eye syndromes (DES). The subjects were randomly assigned to three groups wearing different designs of contact lenses (Proclear, SMR, and Optimum) for 6-8 h a day for two weeks. Ocular surface health, tear quality, visual quality, and visual function were measured before and after lens wear. No significant difference was observed across all three groups for the amount of conjunctival redness, blink frequency (lens on), and stereopsis vision before and after wearing. Although there seemed to be a significant declining trend for corneal staining and limbal redness, non-invasive tear break-up time (TBUT), and lipid layer thickness while lens wear, the measured values were all within the normal range. Vice-versa after lens removal, results also showed significant improvement on lipid layer thickness, blink frequency (lens off), and contact TBUT. A significant improvement was observed in the modulation transfer function (MTF) of the total area ratio after wearing contact lenses. In contrast, the MTF of the high-order aberration area ratio resulting from lens wear was lower than that of the baseline measurement. There are also significant improvements observed for SMR and Optimum regarding near visual acuity, near point of accommodation, and the subjective questionnaire (OSDI and VBP) scores. Although it is difficult to avoid a specific negative impact on the ocular surface and tear film, visual function and visual quality can still be positively improved, especially shown on larger diameter and distance-center designed multifocal contact lenses.

Investigating the Blink Reflex Abnormality in Dry Eye Patients

Introduction Dry eye is an ocular surface disorder caused by increased evaporation, decreased tear production, or mixed form. Tears are secreted by the lacrimal gland after lacrimal nerve stimulation connected to the facial nerve. In nerve damage, tear secretion decreases, and dry eye develops. Our aim is to investigate the presence of pathology in the facial trigeminal nerve and neuronal pathways that provide reflex connections between these nerves by measuring the blink reflex in patients with dry eyes. Methods Schirmer test and tear breakup time were performed. Tear breakup time measurement was repeated three times, and the average of three was accepted. Tear breakup time <10 seconds and Schirmer test <10 mm without local anesthesia were accepted as dry eye. Patients having traumatic corneal pathology, ectatic corneal disease, inflammatory and microbial keratitis, previous ocular surgery, glaucoma, diabetic retinopathy, and chronic neurological diseases were excluded. The control group was randomly formed from 42 eyes of 21 healthy volunteers. Blink reflex was measured in both groups, and the R1 and R2 responses of the two groups were compared. Written consent was obtained from the patient (or legal guardian) so that her medical data could be published. Results There was no significant difference between the two groups in R1 and R2 responses in both eyes. There was no significant difference in terms of gender between the two groups (p=0.100). The mean age in the patient group was significantly higher than in the control group (p<0.000). The mean Schirmer test in the patient group was 8.6±1.1 mm in the right eye and 8.97±1.0 mm in the left eye. Conclusion There was no central pathology observed in terms of reflex blinking in dry eye disease. However, in future studies, brainstem fiesta sequence magnetic resonance imaging (MRI) can be planned to evaluate central pathologies in more detail.

Elucidating the Molecular Interactions between Lipids and Lysozyme: Evaporation Resistance and Bacterial Barriers for Dry Eye Disease

Dry eye disease (DED) is a chronic condition characterized by ocular dryness and inflammation. The tear film lipid layer (TFLL) is the outermost layer composed of lipids and proteins that protect the ocular surface. However, environmental contaminants can disrupt its structure, potentially leading to DED. Although the importance of tear proteins in the TFLL functionality has been clinically recognized, the molecular mechanisms underlying TFLL-protein interactions remain unclear. In this study, we investigated tear protein-lipid interactions and analyzed their role in the TFLL functionality. The results show that lysozyme (LYZ) increases the stability of the TFLL by reducing its surface tension and increasing its surface pressure, resulting in increased TFLL evaporation and bacterial invasion resistance, with improved wettability and lubrication performance. These findings highlight the critical role of LYZ in maintaining ocular health and provide potential avenues for investigating novel approaches to DED treatment and patient well-being.

Optical Coherence Tomography Angiography for Evaluation of Conjunctival Vessels in Dry Eyes

Objective

This study aimed to evaluate conjunctival vessels in patients with dry eye disease (DED) using optical coherence tomography angiography (OCTA).

Methods

This was a cross-sectional, observational clinical study. Twenty-three eyes of 18 patients with DED and 28 eyes of 23 healthy controls were included for examination in this study. The evaluation included the application of an Ocular Surface Disease Index Questionnaire, Schirmer Basic Secretion Test, and anterior OCTA targeting the temporal conjunctiva. AngioTool software was used to quantify the total vessel length and vessel density in the 3 × 3 mm temporal region of interest.

Results

Blood vessel density measurements were compared across the OCTA systems. The total vessel length within the conjunctiva of the DED group (4799.34 ± 834.36) exceeded that of the control eye (3864.89 ± 1455.70) group (P < 0.05). However, the difference in vessel density between the two groups was not statistically significant.

Conclusion

Measurement and analysis of conjunctival blood vessels using OCTA exhibited robust repeatability. In dry eyes, the total number of conjunctival blood vessels increased in accordance with disease severity. Hypoxia of conjunctival tissue may be an important cause of dry eye disease.

Smart Contact Lenses as Wearable Ophthalmic Devices for Disease Monitoring and Health Management

The eye contains a complex network of physiological information and biomarkers for monitoring disease and managing health, and ocular devices can be used to effectively perform point-of-care diagnosis and disease management. This comprehensive review describes the target biomarkers and various diseases, including ophthalmic diseases, metabolic diseases, and neurological diseases, based on the physiological and anatomical background of the eye. This review also includes the recent technologies utilized in eye-wearable medical devices and the latest trends in wearable ophthalmic devices, specifically smart contact lenses for the purpose of disease management. After introducing other ocular devices such as the retinal prosthesis, we further discuss the current challenges and potential possibilities of smart contact lenses.

Randomized controlled trial on the efficacy and safety of autologous serum eye drops in dry eye syndrome

BACKGROUND

Autologous serum eye drops (ASEDs), a novel treatment derived from blood serum, have emerged as a groundbreaking solution for managing dry eye syndrome (DES). These drops have shown significant promise in relieving the distressing symptoms of DES. This study aimed to evaluate the safety and effectiveness of ASEDs compared to traditional treatments, which often prove inadequate or result in unwanted side effects, particularly in individuals with moderate-to-severe DES.

AIM

To evaluate whether ASEDs are safer and more effective than conventional artificial tears in the treatment of moderate-to-severe DES.

METHODS

This multi-centered randomized controlled trial included 240 patients with moderate-to-severe DES from three ophthalmology clinics in China. They were randomly assigned to receive either ASEDs or artificial tears for 12 wk. The primary outcome was the change in the ocular surface disease index (OSDI) score, with secondary outcomes including tear break-up time (TBUT), Schirmer I test, corneal fluorescein staining (CFS), and conjunctival impression cytology (CIC). Statistics analysis was performed using an analysis of covariance with adjustments made for baseline values.

RESULTS

Our findings revealed that both ASEDs and artificial tears significantly improved the OSDI score, TBUT, Schirmer I test, CFS, and CIC from baseline to week 12. The ASEDs group showed significantly greater improvement in all these measures than the artificial tears group (all P values < 0.05). The average difference in the OSDI score between the two cohorts was -10.3 (95% confidence interval: -13.6 to -7.0), indicating a substantial improvement in the ASEDs group. The occurrence of adverse events was comparable between cohorts, with no reports of severe adverse events.

CONCLUSION

ASEDs are more effective and safer than artificial tears for mitigating symptoms of moderate-to-severe DES. ASEDs could be an alternative/supplementary therapy for patients with DES less responsive to traditional treatments.

A Simple Step-by-Step Guide to Permanent Punctal Occlusion with the Ophthalmic Burr and Suture Technique

The medical treatment of dry eye disease usually follows a step-wise approach to achieve clinical improvement, ranging from non-surgical interventions with intensive lubrication to permanent surgical punctal occlusion. While frequent lubrication is essential, the intense regime is often too burdensome and difficult to maintain at the required frequency. Punctal plugs are an invaluable alternative approach, but also have limitations, especially in conscious children, in whom inserting and re-inserting punctum plugs in clinic can be challenging. If a patient has permanent and severe dry eye disease and responded well to a trial of temporary punctal plugging, a permanent surgical solution should be considered next. Liu et al showed that a more successful, yet simple technique to achieve permanent occlusion is to combine de-epithelialising the punctum and ampulla with the immediate firm apposition of the de-epithelialised surface using a self-absorbable suture - with a success rate of 92% in a prospective study. This article demonstrates this technique step-by-step in an 8-year-old child with severe chronic dry eye disease following proton beam therapy for orbital rhabdomyosarcoma. She underwent this procedure with excellent results.

Evaluating the Efficacy of Polyglycolic Acid-Loading Tetrandrine Nanoparticles in the Treatment of Dry Eye

INTRODUCTION

Dry eye disease (DED) is a multifactor-induced disease accompanied by increased osmolarity of the tear film and inflammation of the ocular surface. Traditional anti-inflammation agent corticosteroids applied in DED treatment could result in high intraocular pressure, especially in long-term treatment. Therefore, we explored a nano drug that aimed to block the formation pathway of DED which had anti-inflammatory, sustained release, and good biocompatibility characteristics in this study.

METHODS

We prepared a novel nanomedicine (Tet-ATS@PLGA) by the thin film dispersion-hydration ultrasonic method and detected its nanostructure, particle size, and zeta potential. Flow cytometry was used to detect the cell survival rate of each group after 24 h of drug treatment on inflammed Statens Seruminstitut Rabbit Corneal (SIRC) cells. Observed and recorded corneal epithelial staining, tear film rupture time, and Schirmer test to detect tear secretion on the ocular surface of rabbits. The corneal epithelial thickness, morphology, and number of bulbar conjunctival goblet cells were recorded by H&E staining. Finally, we detected the expression of VEGF, IL-1β, PGE2, and TNF-α by cellular immunofluorescence staining and enzyme-linked immunosorbent assay (ELISA).

RESULTS

The encapsulation efficiency and drug loading of Tet-ATS@PLGA were 79.85% and 32.47%, respectively. At eye surface temperature, Tet can easily release from Tet-ATS@PLGA while that it was difficult to release at storage temperature and room temperature. After 2 weeks medication, Tet-ATS@PLGA can effectively improve the tear film rupture time and tear secretion time in a DED model (p <0.05). Compared with the normal group (62.34 ± 4.86 mm), the thickness of corneal epithelium in ATS (29.47 ± 3.21 mm), Tet-ATS (46.23 ± 2.87 mm), and Tet-ATS@PLGA (55.76 ± 3.95 mm) gradually increased. Furthermore, the flow cytometry indicated that Tet-ATS@PLGA can effectively promote the apoptosis of inflammatory SIRC cells, and the cellular immunofluorescence and ELISA experiments showed that the expression intensity of inflammatory factors such as VEGF, IL-1β, PGE2, and TNF-α decreased in this process. Interestingly, Tet also had the effect of reducing intraocular pressure.

CONCLUSION

Tet-ATS@PLGA can effectively promote the apoptosis of inflammatory corneal epithelial cells, thus inhibiting the expression of inflammatory factors to block the formation of DED and improve the secretion of tear on the ocular surface.

Next-generation nanomaterials: advancing ocular anti-inflammatory drug therapy

Ophthalmic inflammatory diseases, including conjunctivitis, keratitis, uveitis, scleritis, and related conditions, pose considerable challenges to effective management and treatment. This review article investigates the potential of advanced nanomaterials in revolutionizing ocular anti-inflammatory drug interventions. By conducting an exhaustive analysis of recent advancements and assessing the potential benefits and limitations, this review aims to identify promising avenues for future research and clinical applications. The review commences with a detailed exploration of various nanomaterial categories, such as liposomes, dendrimers, nanoparticles (NPs), and hydrogels, emphasizing their unique properties and capabilities for accurate drug delivery. Subsequently, we explore the etiology and pathophysiology of ophthalmic inflammatory disorders, highlighting the urgent necessity for innovative therapeutic strategies and examining recent preclinical and clinical investigations employing nanomaterial-based drug delivery systems. We discuss the advantages of these cutting-edge systems, such as biocompatibility, bioavailability, controlled release, and targeted delivery, alongside potential challenges, which encompass immunogenicity, toxicity, and regulatory hurdles. Furthermore, we emphasize the significance of interdisciplinary collaborations among material scientists, pharmacologists, and clinicians in expediting the translation of these breakthroughs from laboratory environments to clinical practice. In summary, this review accentuates the remarkable potential of advanced nanomaterials in redefining ocular anti-inflammatory drug therapy. We fervently support continued research and development in this rapidly evolving field to overcome existing barriers and improve patient outcomes for ophthalmic inflammatory disorders.

Efficacy and safety of 1% and 2% rebamipide clear solution in dry eye disease: a multicenter randomized trial

BACKGROUND

To evaluate the efficacy of 1% and 2% rebamipide clear solution in the treatment of dry eye disease (DED).

METHODS

Two hundred twenty patients with DED were randomly assigned to one of three groups: the 1% rebamipide, 2% rebamipide, or placebo (eye drops containing the same ingredients, except for the active components). Each eye drop was instilled four times daily for 12 weeks. Changes in tear film break-up time (TBUT), corneal and conjunctival staining score, Schirmer 1 test, and the Ocular Surface Disease Index (OSDI) from baseline to 12-week visit between the study groups were compared for efficacy assessment.

RESULTS

The mean age of study patients was 43.8±14.2 years. The 1% and 2% rebamipide groups showed greater improvement in TBUT (1.99±1.87 and 2.02±2.21 s) at 12 weeks from baseline than the placebo group (1.25±2.93 s). The 2% rebamipide group showed greater improvement in the corneal staining score (- 3.15±2.00) at 12 weeks from baseline than the placebo group (- 2.85±1.80). The 1% and 2% rebamipide groups showed improvement in Schirmer 1 test (1.27±3.86 and 1.50±4.14 mm) at 12 weeks of treatment, but not the placebo group (0.55±2.99 mm). Both the rebamipide groups and the placebo group showed significantly improved OSDI after treatment for 12 weeks; however, there was no significant difference among the three groups.

CONCLUSIONS

1% and 2% rebamipide clear solutions are an effective therapeutic option for improving TBUT and tear volume, and stabilizing the corneal staining score in DED.

Effect of Lutein on Ocular Goblet Cell, IFN-γ, and IL-17 Concentration in Dry Eye-Induced Mice Model

Introduction Dry eye disease affects a substantial number of individuals globally and significantly impacts their quality of life and productivity. Understanding the underlying mechanisms and managing dry eye disease poses substantial challenges. Recent research has highlighted the involvement of various inflammatory mediators in the pathogenesis of dry eye disease, including the cytokines interferon (IFN)-γ and interleukin (IL)-17. Activation of stress signaling pathways and residential immune cells on the ocular epithelial surface ignites epithelial changes, destabilizes tear film, amplifies inflammation and creates an endless loop. Lutein is a β-carotenoid antioxidant which has been proven to be beneficial in many ocular diseases due to its protective and anti-inflammatory effect induced by various stimulators. Lutein also acts as a direct and indirect antioxidant agent, suppressing oxidative stress and mitigating oxidative damage. The purpose of this research is to investigate the potential therapeutic effects of lutein in a mouse model of dry eye, aiming to elucidate its impact on ocular manifestation, goblet cells count, IFN-γ and IL-17 level. Methods Desiccating stress was induced in C57BL/6 mice. In a separate group, lutein was administered subcutaneously on a daily basis throughout the experimental period. Clinical manifestations of dry eye, including ocular surface changes, were documented photographically. Goblet cell concentration was assessed through Periodic Acid-Schiff (PAS) staining, and the levels of IFN-γ and IL-17 were measured using enzyme-linked immunosorbent assay (ELISA). Data obtained from these assessments were compared between the experimental groups to determine the potential effects of lutein on dry eye pathology and cytokine levels. Results Significant differences were observed in clinical observations and goblet cell concentrations among the groups; however, no statistically significant differences were found in the levels of IFN-γ and IL-17 between the groups. The untreated group exhibited significantly higher opacities and irregularities compared to the lutein-treated group, whereas the mean goblet cell count was highest in the lutein-treated group. Conclusion Lutein administration improves clinical observations and goblet cell concentrations in a mouse model of dry eye. The treated group exhibited improved ocular surface integrity, but no significant differences in the tested cytokine levels were observed. These findings suggest that lutein supplementation could be a promising therapeutic option for managing dry eye disease. Further research is needed to understand the underlying mechanisms and long-term effects of lutein in dry eye management.

Randomized Controlled Study of Cooled vs Room-Temperature Artificial Tears for Reducing Ocular Surface Irritation After Intravitreal Injection

Purpose: To evaluate the efficacy of cooled vs room-temperature artificial tears in reducing ocular discomfort after intravitreal injections (IVIs). Methods: Patients receiving a standard intravitreal injection in the retina clinic who met the eligibility criteria and provided informed consented were enrolled in the study. Patients were randomized to the cooled tears or room-temperature tears intervention group. Both groups rated their ocular discomfort following IVI after cooled or room-temperature tears were administered. Results: The cooled group comprised 48 patients and the room-temperature group, 61 patients. There was no significant difference in the reduction of ocular discomfort between the cooled vs room-temperature artificial tears groups (P = .387). In addition, there was a similar level of reduction in ocular discomfort after either intervention (P = .681) regardless of whether or not the patients routinely used artificial tears after previous IVIs. Conclusions: Cooled tears provided no additional benefit in reducing ocular discomfort post-IVI compared with room-temperature tears. Baseline tear use after an IVI may have no true benefit other than a potential placebo effect, recall bias, or both.

Prevalence and Risk Factors for Symptomatic Dry Eye Disease Based on McMonnies Questionnaire Among Medical Students, Saudi Arabia; a Cross-Sectional Study

Purpose

Dry eye disease (DED) is a common ocular problem that worsens patients' quality of life. This study aimed to assess DED prevalence and risk factors among medical students at the University of Tabuk.

Patients and Methods

This is an analytical, cross-sectional, survey-based study. An online questionnaire was distributed by email to all medical students at the University of Tabuk. A self-administered McMonnies questionnaire was used in the assessment.

Results

We included 247 medical students who completed the questionnaire. Most participants were females (71.3%) and were <25 years old (85.8%). DED prevalence rate was 18.2% (95% CI=13.61% to 23.61%). Furthermore, DED was found to be significantly associated with the presence of irritation of eyes when waking up from sleep (OR=19.315), sleeping with partially opened eyes (OR=19.105), redness and irritation of the eyes when swimming in chlorinated fresh water (OR=7.863), and having prescription eyedrops or other dry eye treatments (OR=3.083).

Conclusion

Our study at the University of Tabuk found that 18.2% of medical students had dry eye disease and identified the associated risk factors. Early diagnosis and treatment are crucial to prevent complications due to the high prevalence of DED.

A clinical decision support system for diagnosing and determining severity of dry eye disease

INTRODUCTION

Dry eye and its related symptoms are the most common causes of referrals to the ophthalmology centers. Since people with dry eye may suffer from different levels of the disease severity, this study aimed to develop a clinical decision support system for diagnosing and determining severity of dry eye disease.

METHODS

This research was carried out in two phases in 2020. In the first phase, a questionnaire was designed to identify the most important diagnostic parameters from the cornea specialists' perspectives (n = 37). In the second phase of the research, a clinical decision support system was designed and implemented by using MATLAB software. Finally, the system was evaluated using patient data which were collected in a teaching hospital (n = 50).

RESULTS

The diagnostic parameters for dry eye disease were filamentary keratitis, meibomian gland dysfunction, score of ocular surface disease index, Schirmer's test result, tear meniscus height, tear breakup time, and fluorescein staining score. The system output variables were the diagnosis and severity of dry eye disease at four levels for the right and left eyes, separately. The results of the evaluation study showed that the accuracy, sensitivity and specificity of the system were 96.9%, 97.5%, and 93.7%, respectively.

CONCLUSION

It seems that the system designed in this study can help ophthalmologists to diagnose dry eye disease more accurately and quickly. However, it is recommended to conduct more evaluation studies and include more patients in the future research.

Symptoms and signs of dry eye in children with Graves' ophthalmopathy

PURPOSE

The purpose of this study is to evaluate the tear secretion and ocular surface properties in children with Graves' ophthalmopathy (GO) and to compare the results with those of healthy children.

METHODS

This was a cross-sectional study. Forty-three patients with GO (Group 1) and 41 healthy children without any ocular and/or systemic disorder (Group 2) were examined clinically and underwent tests for dry eye. We performed analyses including the Ocular Surface Disease Index (OSDI) questionnaire, Schirmer's test under topical anesthesia (<5 mm was abnormal), slit-lamp biomicroscopy (corneal fluorescein staining and tear breakup time (TBUT) under blue-light illumination), and fundoscopic evaluation.

RESULTS

Dry eye symptoms and the mean OSDI score were significantly (P < 0.02) higher (15.6 ± 18.7) in patients with GO compared with controls (5.67 ± 3.6). The mean Schirmer's (basal tear secretion) tests value was significantly reduced in Group 1 (5.25 ± 3.1 mm) compared with Group 2 (17.1 ± 5.2), respectively. The difference was statistically significant (p < 0.005), suggesting inadequate tear production. The mean tear film breakup time in children was lower in patients with GO (8.3 ± 3.42 s,) compared with controls (13.2 ± 4.74 s), (P < 0.001) suggesting an unstable tear film. Decrease of corneal sensitivity (23.3%) was noted in patients with GO compared with controls. GO patients showed a significant increase of the frequency of corneal fluorescein staining (6.9%) in patients with GO compared with controls.

CONCLUSION

Patients with GO had a statistically significant higher incidence of dry eye symptoms and the increase of OSDI score. Significantly lower Schirmer's and TBUT tests results were seen in the study group when compared with the controls. These findings may indicate a tendency for dry eye in pediatric GO patients.

Perfluorohexyloctane Eye Drops for Dry Eye Disease Associated With Meibomian Gland Dysfunction in Chinese Patients: A Randomized Clinical Trial

Importance

Meibomian gland dysfunction (MGD) is a leading cause of evaporative dry eye disease (DED). Medical and surgical management for DED is limited; therefore, new treatment options are sought.

Objective

To evaluate the efficacy and safety of SHR8058 (perfluorohexyloctane) eye drops in Chinese patients with DED associated with MGD through 57 days.

Design, Setting, and Participants

This was a randomized, multicenter, double-masked, saline-controlled, phase 3 clinical trial conducted from February 4, 2021, to September 7, 2022. Patients were recruited from the departments of ophthalmology in 15 hospitals in China. Patients with DED associated with MGD were enrolled between February 4 and July 1, 2021. The diagnosis was based on patient complaint of DED symptoms, an ocular surface disease index of 25 or higher, tear film break-up time of 5 seconds or less, Schirmer I test without anesthesia results of 5 mm or more at 5 minutes, total corneal fluorescein staining (tCFS) score of 4 to 11, and an MGD score of 3 or higher.

Interventions

Eligible participants were randomly assigned 1:1 to receive perfluorohexyloctane eye drops or 0.6% sodium chloride [NaCl]) 4 times per day.

Main Outcomes and Measures

The primary end points were the changes from baseline in tCFS and eye dryness scores at day 57.

Results

A total of 312 participants were included in the analysis: 156 (mean [SD] age, 45.4 [15.2] years; 118 female [75.6%]) in the perfluorohexyloctane group and 156 (mean [SD] age, 43.7 [15.1] years; 127 female [81.4%]) in the NaCl group. Both primary end points were achieved, ie, changes from baseline at day 57 of tCFS score (mean [SD], -3.8 [2.7] vs -2.7 [2.8]) and eye dryness score (mean [SD], -38.6 [21.9] vs -28.3 [20.8]) in the perfluorohexyloctane group were superior to the control group, with estimated mean differences of -1.14 (95% CI, -1.70 to -0.57; P < .001) and -12.74 (95% CI, -17.20 to -8.28, P < .001), respectively. Improvements on both end points appeared to be noted on day 29 and day 15, respectively, and maintained through day 57. Compared with the control, perfluorohexyloctane eye drops also alleviated symptoms including pain (mean [SD] tCFS score, 26.7 [23.7] vs -18.7 [22.5]; P = .003), awareness of DED symptoms (mean [SD] tCFS score, -38.1 [25.1] vs -23.7 [27.6]; P < .001), and frequency of dryness (mean [SD] tCFS score, -43.3 [23.8] vs -29.1 [24.8]; P < .001). Treatment-emergent adverse events occurred in 34 participants (21.8%) and 40 participants (25.6%) in the perfluorohexyloctane and control groups, respectively.

Conclusions and Relevance

Results of this randomized clinical trial demonstrate that perfluorohexyloctane eye drops significantly ameliorated the signs and symptoms of DED associated with MGD with a rapid efficacy as well as satisfactory tolerability and safety through 57 days. Findings support the use of these eye drops if results can be confirmed independently and over longer time periods.

Trial Registration

ClinicalTrials.gov Identifier: NCT05515471.

Evaluation of pre-processing methods for tear fluid proteomics using proximity extension assays

Tear fluid forms a potential source for biomarker identification, and can be minimal invasively collected via Schirmer strips. The lack of knowledge on the processing of Schirmer strips however complicates the analysis and between-study comparisons. We studied two different pre-processing methods, specifically the use of punches of the strip versus elution of the strip in a buffer. Tear fluid filled Schirmer strips were collected from 5 healthy participants, and divided into two halves over the length of the strip. In either part, punches or eluates were obtained from 4 different locations, from the first part touching the eye (head) to the end, to assess the protein distribution along the strips. The levels of 92 inflammatory proteins were measured in the punches/eluates using proximity extension assays. The punch method yielded higher protein detectability compared to the elution method (76% vs 66%; p ≤ 0.001). Protein expression level was found to be slightly higher in the head of the strip, however, 3 out of 5 punches from the head failed quality control. Protein expression levels over the remaining parts of the strips were similar. Our study showed beneficial use of punches of any part of the strip except the head in future biomarker research.

The relationship between habitual water intake and dry eye disease

PURPOSE

The purpose of this study is to test the hypothesis that greater habitual water intake is associated with lower risk of dry eye disease (DED).

METHODS

We included 51 551 participants from the population-based Lifelines cohort (mean age = 51.2 years) in this cross-sectional association study. DED was assessed using the Women's Health Study (WHS) dry eye questionnaire. Water intake was calculated from food frequency questionnaires. Logistic regressions were used to analyse the relationship between DED and water intake or 24-h urine volume, corrected for age, sex, body mass index, physical activity, smoking status, education, income, 48 comorbidities, and 15 medication groups. The main outcome measure was WHS-defined DED. Highly symptomatic dry eye and clinical diagnosis of DED were secondary outcomes.

RESULTS

In total, 9.1% of the population had WHS-defined DED. Higher water intake was associated with increased prevalence of WHS-defined DED (OR: 1.011 per 100 ml/day, 95% CI: 1.004-1.017, p = 0.003). After excluding those with a clinical diagnosis, greater water intake was still tied to increased risk of having DED symptoms (OR: 1.010 per 100 ml/day, 95% CI: 1.006-1.015, p < 0.001). Higher 24-h urine volumes were also associated with higher risk of WHS-defined DED (OR: 1.010 per 100 ml/day, 95% CI: 1.005-1.015, p < 0.001).

CONCLUSIONS

In this large, population-based study, higher water intake was not tied to reduced risk of DED. Rather, it was associated with a modest increased risk of DED. Interventional studies are needed to fully understand the effect of water intake on DED, but this study found no evidence that greater water intake is beneficial for DED.

Tear film instability is associated with weakened colocalization between occludin and MUC5AC in scopolamine-induced dry eye disease (DED) rats

PURPOSE

Dry eye disease (DED) is a disease with tear film instability because of multiple factors. This study was conducted to explore roles of occludin and MUC5AC in tear film instability in DED rat model.

METHODS

A total of 20 SD rats were divided into DED group (n = 10) and normal control (NC) group (n = 10). DED rat model was established by subcutaneously injecting with scopolamine hydrobromide. Clinical examinations, including tear breakup time (tBUT), Schirmer's test and corneal fluorescein staining, were conducted to determine corneal functions. Transmission electron microscopy was used to measure the ultrastructures of corneal epithelial cells. Western blotting assay was used to identify occludin expression in corneal tissues of DED rats. Real-time PCR (RT-PCR) was performed to verify gene transcription of occludin and MUC5AC. Colocalization between occludin and MUC5AC was identified with confocal fluorescence microscopy.

RESULTS

Tear breakup time was significantly shorter, and corneal fluorescein staining score was predominantly higher in DED rats compared to those in normal rats (P < 0.05). Normal rats showed a steady tear secretion throughout the whole experiments, while DED rats showed a dramatic reduction on day 14. DED rats demonstrated ultrastructural damage of Golgi apparatus and endoplasmic reticulum in corneal epithelial cells. Occludin and MUC5AC expressions were significantly downregulated in corneal tissue of DED rats compared with those of normal rats (P < 0.05). Percentage of occludin-MUC5AC-colocalized corneal epithelial cells in DED rats was significantly less compared with those in normal rats (P < 0.01).

CONCLUSIONS

Tear film stability was damaged in scopolamine-induced DED rats because of the weakened colocalization between occludin and MUC5AC molecule. This study would provide a potential clue for the pathogenesis and a promising theoretical basis for clinical work of DED.

The Significance of Inter-Eye Osmolarity Difference in Dry Eye Diagnostics

Purpose

The purpose of this study was to evaluate the diagnostic value of inter-eye osmolarity differences in relation to dry eye symptoms and other non-osmolar signs of dry eye disease.

Patients and Methods

One hundred ninety one participants who attended a larger interventional study of dry eye disease prior to and after cataract surgery were analyzed for dry eye disease (DED). Dry eye diagnostics were performed for all subjects according to the DEWS II criteria: tear osmolarity was collected from both eyes with the TearLab system, non-invasive Tear film break up time (NIKBUT) was obtained on the test eye with Keratograph and ocular surface staining (OSS) was evaluated using the Oxford schema. The Ocular Surface Disease Index (OSDI) questionnaire was used to assess symptoms. Inter-eye osmolarity greater than 8, which is considered as a sign of DED according to the TearLab user manual, was evaluated and compared with other non-osmolar signs of DED.

Results

The 191 subjects were divided into three groups according to osmolarity measurements. Sixty-five subjects had normal osmolarity (below 308 mOsmol/L in both eyes and less than 9 mOsmol/L difference between the eyes), 107 had high osmolarity (308 mOsmol/L or higher in one of the eyes) and 19 had an inter-eye difference >8 mOsmol/L or higher, with neither eye having osmolarity higher than 307 mOsmol/L. Signs and symptoms in this last group were not correlated with the high osmolarity group or the normal group, though they appeared more similar to the normal group.

Conclusion

The diagnostic value of inter-eye osmolarity difference in predicting symptoms or other non-osmolar signs of dry eyes appears weak. Our study suggests that the criterion of an inter-eye difference of 8 mOsmol/L is not a useful cut-off for diagnosing dry eyes based on osmolarity.

Post-LASIK dry eye disease: A comprehensive review of management and current treatment options

Laser-assisted in situ keratomileusis (LASIK) is a unique corneal stromal laser ablation method that uses an excimer laser to reach beneath corneal dome-shaped tissues. In contrast, surface ablation methods, such as photorefractive keratectomy, include removing epithelium and cutting off the Bowman's layer and the stromal tissue of the anterior corneal surface. Dry eye disease (DED) is the most common complication after LASIK. DED is a typical multi-factor disorder of the tear function and ocular surface that occurs when the eyes fail to produce efficient or adequate volumes of tears to moisturize the eyes. DED influences quality of life and visual perception, as symptoms often interfere with daily activities such as reading, writing, or using video display monitors. Generally, DED brings about discomfort, symptoms of visual disturbance, focal or global tear film instability with possible harm to the ocular surface, the increased osmolarity of the tear film, and subacute inflammation of the ocular surface. Almost all patients develop a degree of dryness in the postoperative period. Detection of preoperative DED and committed examination and treatment in the preoperative period, and continuing treatments postoperatively lead to rapid healing, fewer complications, and improved visual outcomes. To improve patient comfort and surgical outcomes, early treatment is required. Therefore, in this study, we aim to comprehensively review studies on the management and current treatment options for post-LASIK DED.