Unique composition of ocular surface microbiome in the old patients with dry eye and diabetes mellitus in a community from Shanghai, China

BACKGROUND

This study investigates the variations in microbiome abundance and diversity on the ocular surfaces of diabetic patients suffering from dry eye within a community setting. The goal is to offer theoretical insights for the community-level prevention and treatment of dry eye in diabetic cohorts.

METHODS

Dry eye screening was performed in the Shanghai Cohort Study of Diabetic Eye Disease (SCODE) from July 15, 2021, to August 15, 2021, in the Xingjing community; this study included both a population with diabetes and a normal population. The population with diabetes included a dry eye group (DM-DE, n = 40) and a non-dry eye group (DM-NoDE, n = 39). The normal population included a dry eye group (NoDM-DE, n = 40) and a control group (control, n = 39). High-throughput sequencing of the 16 S rRNA V3-V4 region was performed on conjunctival swab from both eyes of each subject, and the composition of microbiome on the ocular surface of each group was analyzed.

RESULTS

Significant statistical differences were observed in both α and β diversity of the ocular surface microbiome among the diabetic dry eye, diabetic non-dry eye, non-diabetic dry eye, and normal control groups (P < 0.05).

CONCLUSIONS

The study revealed distinct microecological compositions on the ocular surfaces between the diabetic dry eye group and other studied groups. Firmicutes and Anoxybacillus were unique bacterial phyla and genera in the dry eye with DM group, while Actinobacteria and Corynebacterium were unique bacterial phyla and genera in the normal control group.

Associations between dry eye disease and sleep quality: a cross-sectional analysis

BACKGROUND/AIMS

To investigate relationships between dry eye (DE) disease and sleep quality, with a focus on which aspects of sleep most closely relate to DE.

METHODS

141 veterans (mean age: 56±5) seen at the Miami Veterans Affairs eye clinic filled out questionnaires to quantify the severity of DE symptoms (5-Item Dry Eye Questionnaire (DEQ-5) and Ocular Surface Disease Index (OSDI)) and ocular pain (Numerical Rating Scale (NRS) and Neuropathic Pain Symptom Inventory modified for the Eye (NPSI-E)). All individuals also underwent an ocular surface examination. Aspects of sleep quality were assessed using the Pittsburgh Sleep Quality Index (PSQI). DE metrics were examined by PSQI scores and subscores.

RESULTS

Most participants (76%) reported mild or greater DE symptoms (DEQ-5 ≥6). Overall, ocular symptoms were more related to sleep metrics than signs. The strongest DE symptom association was between the OSDI and sleep disturbances (PSQI subscore 5, r=0.49, p<0.0005). For DE signs, ocular surface inflammation and meibum quality were related to subjective sleep quality (PSQI subscore 1, r=0.29, p=0.03, for both). On linear regression analyses, most ocular symptom questionnaires remained associated with sleep disturbances (PSQI subscore 5: NRS (r=0.52, p<0.0005), DEQ-5 (r=0.36, p<0.0005), and OSDI (r=0.31, p<0.0005)). For DE signs, ocular surface inflammation and meibum quality remained associated with subjective sleep quality (r=0.26, p=0.01; r=0.46, p<0.0005, respectively).

CONCLUSION

DE symptom and ocular pain intensity were closely related to sleep metrics, most strongly to sleep disturbances. Relationships were weaker for DE signs, with subjective sleep quality relating to inflammation and meibum quality.

Melanocytic Nevus of the Superior Conjunctival Fornix: A Case Report

Introduction

Conjunctival nevi are benign tumors that are commonly located at the nasal or temporal limbus and rarely in the fornix or tarsus. We report a case of a patient presenting with a solitary compound cystic nevus of the conjunctival fornix in the background of bilateral complexion-associated melanosis.

Case Presentation

A 71-year-old African-American female was referred for evaluation of an incidentally noted melanocytic lesion of the right conjunctival fornix. The patient underwent an excisional biopsy, revealing histological features consistent with a compound cystic nevus.

Conclusion

This finding is noteworthy due to the rarity of conjunctival nevi originating in the fornix. The case underscores the importance of excisional biopsy in evaluating conjunctival forniceal melanocytic lesions to exclude malignant melanoma, a critical consideration for prognosis.

Ocular surface changes in mice with streptozotocin-induced diabetes and diabetic polyneuropathy

PURPOSE

Diabetes mellitus (DM) is a leading risk factor for corneal neuropathy and dry eye disease (DED). Another common consequence of DM is diabetic peripheral polyneuropathy (DPN). Both complications affect around 50 % of the DM patients but the relationship between DM, DED and DPN remains unclear.

METHODS

In this study, we examined mice with early onset of DM and PN after streptozotocin (STZ)-induced diabetes (DPN). We compared the early morphological changes of the sciatic nerve, dorsal root and trigeminal ganglia with the changes in the ocular surface, including tear proteomic and we also investigated respective changes in the gene expressions and morphological alterations in the eye tissues involved in tear production.

RESULTS

The lacrimal gland, conjunctival goblet cells and cornea showed morphological changes along with alterations in tear proteins without any obvious signs of ocular surface inflammation. The gene expression for respectively altered tear proteins i.e., of Clusterin in cornea, Car6, Adh3a1, and Eef1a1 in eyelids, and Pigr in the lacrimal gland also showed significant changes compared to control mice. In the trigeminal ganglia like in the dorsal root ganglia neuronal cells showed swollen mitochondria and, in the latter, there was a significant increase of NADPH oxidases and MMP9 suggestive of oxidative and neuronal stress. In the dorsal root ganglia and the sciatic nerve, there was an upregulation of a number of pro-inflammatory cytokines and pain-mediating chemokines.

CONCLUSION

The early ocular changes in DM Mice only affect the lacrimal gland. Which, is reflected in the tear film composition of DPN mice. Due to the high protein concentration in tear fluid in humans, proteomic analysis in addition to noninvasive investigation of goblet cells and cornea can serve as a tools for the early diagnosis of DPN, DED in clinical practice. Early treatment could delay or even prevent the ocular complications of DM such as DED and PN.

Assessment of Mucin-Associated Gene Expression Levels on the Ocular Surface

The ocular surface is covered with a mucus layer. The mucin-associated genes expressed in the ocular surface cells include MUC1, MUC4, MUC5AC, and MUC16. Impression cytology is useful for collecting specimens from the ocular surface, their histological examination, and measuring mucin-associated gene expression levels. The expression of mucin-associated gene levels was assessed by quantitative polymerase chain reaction. The expression levels of these mucin-associated genes are potential biomarkers for ocular surface diseases, including dry eye disease.

Biological effects of stored platelet-rich plasma eye-drops in corneal wound healing

BACKGROUND/AIMS

This study aimed to assess the efficacy and sterility of stored platelet-rich plasma (PRP) eye-drops for corneal epithelial wound healing compared with those of autologous serum (AS) eye-drops.

METHODS

At our single institution, PRP and AS eye-drops were prepared using peripheral blood obtained from six healthy volunteers and stored at 4°C. Platelet and leucocyte counts and transforming growth factor (TGF)-β1, epidermal growth factor (EGF), and fibronectin levels were assessed during storage for up to 4 weeks. Sterility was assessed by culturing 4-week poststorage samples. PRP, AS, and phosphate-buffered saline (PBS) eye-drop efficacies were compared using corneal epithelial wound healing assays in vitro and in vivo and monitoring wound areas under a microscope every 3 hours.

RESULTS

Higher platelet and lower leucocyte counts were seen in PRP than in whole blood on the day of preparation. After storage, TGF-β1, EGF, and fibronectin levels were significantly higher in PRP than in AS eye-drops. In vitro and in vivo, PRP eye-drops used on the day of preparation significantly promoted corneal epithelial wound healing compared with PBS. Moreover, PRP eye-drops stored for 4 weeks significantly promoted corneal wound healing compared with PBS and AS eye-drops.

CONCLUSION

PRP eye-drops stored at 4°C for 4 weeks promoted corneal epithelial wound healing with higher levels of growth factors than those observed in AS eye-drops, while maintaining sterility, suggesting that this preparation satisfies the unmet medical needs in the treatment of refractory keratoconjunctival epithelial disorders.

Early ocular surface and tear film status in congenital aniridia indicates a supportive treatment window

AIM

To evaluate changes in the ocular surface and tear film with age and mutational status in congenital aniridia.

METHODS

45 participants with congenital aniridia (89 eyes) in a prospective, cross-sectional study. Whole-exome sequencing identified the causative mutation. Examinations included slit-lamp biomicroscopy, in vivo confocal microscopy, Ocular Surface Disease Index (OSDI) score, blink rate, Schirmer I test, Oxford Staining Score (OSS), tear film break-up time (TFBUT) and Ocular Protection Index (OPI).

RESULTS

There were age-dependent increases in OSDI (β=0.34, 95% CI 0.03 to 0.66; p=0.030), blink rate (β=0.18, 95% CI 0.08 to 0.27; p<0.001) and OSS (β=0.05, 95% CI 0.03 to 0.07; p<0.001) and age-dependent reductions in tear production (β=-0.23, 95% CI -0.43 to 0.02; p=0.029) and TFBUT (β=-0.10, 95% CI -0.17 to -0.04; p<0.001). Perturbed OSDI, OSS, blink rate, tear production and TFBUT were noted after the age of ten and OSDI, OSS, blink rate and TFBUT correlated with deficient corneal nerves and limbal stem cell function. OSDI, blink rate, Schirmer, OSS, TFBUT and OPI were not associated with type of PAX6 mutation, but OSDI, OSS and blink rate associated with grade of aniridia-associated keratopathy.

CONCLUSIONS

Ocular surface damage and dry eye signs appear in congenital aniridia regardless of mutation, appearing after 10 years of age and progressing thereafter. An early treatment window may exist for therapies to protect the ocular surface homoeostasis and limbal function, to possibly delay keratopathy development and progression.

Characteristics of the Ocular Surface in Myopic Child Candidates of Orthokeratology Lens Wear

INTRODUCTION

The purpose of this study was to investigate the characteristics of objective ocular surface parameters using non-invasive objective instruments in children with myopia who are candidates for orthokeratology lens wear.

METHODS

Children with myopia who are candidates for orthokeratology lens wear were retrospectively investigated. The subjects were divided into three age groups. The Keratograph 5M and LipiView interferometry were used to assess non-invasive tear meniscus height (TMH), non-invasive tear film break-up time (NIBUT), conjunctival hyperemia redness score (RS), meibomian gland loss (MGL) score, lipid layer thickness (LLT), and blink pattern analysis, including the number of partial blinks (PB) and total blinks (TB), as well as the partial blink rate (PBR).

RESULTS

A total of 1119 children with myopia (2070 eyes) aged 7-18 years were selected. The mean TMH, NIBUT, and LLT of the subjects was 0.21 mm, 12.45 s, and 65.28 nm, respectively. The mean RS and upper and lower MGL scores were 0.64, 1.00, and 1.06, respectively. The mean PB, TB, and PBR was 5.13, 6.46, and 0.81, respectively. Age was significantly correlated to all ocular surface parameters (p = 0.00), except for PB. NIBUT and LLT did not differ between male participants and female participants (all p > 0.05). TMH, RS, and upper and lower MGL were significantly higher in male participants than in female participants (all p < 0.01). In addition, NIBUT was positively associated with TMH (r = 0.13, p = 0.00) and LLT (r = 0.28, p = 0.00). Both upper and lower MGL were positively correlated with TMH, PB, and TB (all p = 0.00), whereas upper MGL was negatively correlated with NIBUT and LLT (all p < 0.05). TB was negatively correlated with NIBUT and LLT (all p = 0.00). PB had no relation with TMH, NIBUT, and LLT (all p > 0.05). In addition, PBR was positively correlated with NIBUT and LLT (all p = 0.00) but not with TMH, RS, or MGL (all p > 0.05). Overall, 57.00% had a TMH ≤ 0.2 mm, 43.20% had a NIBUT ≤ 10 s, 48.10% had an LLT ≤ 60 nm, and 88.10% had a PBR > 0.4.

CONCLUSIONS

Child orthokeratology candidates have enhanced tear secretion and increased meibomian gland deficiency with aging. In addition, the adult dry eye diagnostic criteria may apply to orthokeratology candidates aged 12-18 years but should be lower for younger candidates. Given the proportion of abnormal risk, it is necessary to assess tear film status and blink pattern by reliable and feasible objective examination before fitting orthokeratology.

Behaviour of hTERT in the tears of neophyte contact lens wearers during the sleep/wake cycle

PURPOSE

To investigate the behaviour of telomerase reverse transcriptase (hTERT) in the tears of healthy neophyte contact lenses-wearing individuals during the sleep/wake cycle. A subsequent aim was to investigate whether hTERT behaviour was associated with inflammatory mediators interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α) in tears.

METHODS

Flush tears were collected from 19 healthy, non-contact lens-wearing participants (11 males, 8 females, mean age 31.9 ± 5.7 years), before and during contact lens wear. Tears were collected at noon, before sleep and upon awakening and levels of hTERT, IL-6 and TNF-α, were determined using enzyme-linked immunosorbent assays (ELISA).

RESULTS

hTERT levels (median [interquartile range]) during contact lens wear were significantly higher before sleep (436.5 (263.9 - 697.7) ng/ml compared to the same time point without contact lenses (256.1 (0.0 - 590.9) ng/ml (p = 0.01). There was no difference between contact lens wear (851.3 [353.2 - 2109.9]) ng/ml, and no wear (1091.0 [492.3 - 3045.4]) ng/ml, upon awakening (p = 0.94). A significant increase was found upon awakening compared to before sleep, irrespective of the presence of a contact lens (p = 0.02). IL-6 and TNF-α levels in tears were below the limit of detection.

CONCLUSIONS

The study showed that hTERT increases after a contact lens is placed on the eye, but this change is small, compared to the impact of overnight eye closure. Taken together with the lack of responses of the inflammatory markers monitored at the same time points, this may suggest that hTERT can respond both to low-level stress stimuli acting on the ocular surface, and to situations where inflammation is a likely factor.

Evaluation of recovery time of tear film function and ocular surface after discontinuing oral isotretinoin treatment for acne vulgaris : Correlation between oral isotretinoin and tear film function

PURPOSE

This study aimed to evaluate the recovery time of tear film function and ocular surface after discontinuing systemic isotretinoin treatment.

METHODS

This was a prospective, cross-sectional study. 34 eyes of 17 patients treated with low- dose oral isotretinoin (< 0.5 mg/kg/day) were enrolled. The modified OSDI score, tear break-up time, Schirmer test, and corneal staining were performed in all patients at baseline, during the course of treatment and after withdrawing treatment every two weeks until the result returned to baseline.

RESULTS

Tear breakup time appeared to be the most sensitive and changed significantly at 2 weeks after starting treatment (p < 0.001) and returned to baseline at 4 weeks after withdrawal from treatment (p < 0.001). The Schirmer test results significantly decreased at 6 weeks and returned to baseline at 4 weeks after withdrawal from treatment (p < 0.001). OSDI scores were significantly changed at 6 weeks after treatment (81.8%) and returned to baseline at 2 weeks (54.5%) after withdrawal from treatment. No significant change was found in the MGD. Corneal staining was significantly positive 90.9% 6 weeks after starting treatment and returned to baseline 6 weeks after withdrawal from treatment (p < 0.001).

CONCLUSION

Dry eye disease can return to baseline levels after treatment withdrawal. At least 6 weeks later, they could wear contact lenses again, and it was useful to prepare all patients requiring further ocular surgery.

Fundamental Aspects and Relevance of Components in Antihistamine Eye Drops

Ocular allergy covers a series of immune-allergic inflammatory diseases of the ocular surface, with different degrees of involvement and severity. These pathologies are caused by a variety of IgE- and non-IgE-mediated immune mechanisms and may involve all parts of the external eye, including the conjunctiva, cornea, eyelids, tear film, and commensal flora. The most frequent is allergic conjunctivitis, a condition with different clinical forms that are classified according to the degree of involvement and the presence or absence of proliferative changes in the palpebral conjunctiva, associated atopic dermatitis, and mechanical stimuli by foreign bodies, including contact lenses. Treatment guidelines for allergic conjunctivitis propose a stepwise approach that includes medications for both ophthalmic and oral administration depending on symptom severity, allergic comorbidities, and degree of control. In the case of antihistamines, eye drops are the most prescribed ophthalmic formulations. To avoid disrupting the delicate balance of the ocular surface, topical ophthalmic medications must be well tolerated. The primary aim of this article is to review the physicochemical characteristics and other features of excipients (preservative agents, buffers, pH adjusters, viscosity enhancers, wetting agents or cosolvents, antioxidants, tonicity adjusters, and osmo-protectants) and active compounds (ocular antihistamines) that must be considered when developing formulations for ophthalmic administration of antihistamines. We also provide a brief overview of antihistamine eye drops that could be of interest to professionals treating ocular allergy and encourage the use of preservative-free formulations when possible.

Age related changes in hyaluronan expression leads to Meibomian gland dysfunction

The prevalence of dry eye disease (DED) ranges from ∼5 to 50 % and its associated symptoms decrease productivity and reduce the quality of life. Approximately 85 % of all DED cases are caused by Meibomian gland dysfunction (MGD). As humans and mice age, their Meibomian glands (MGs) undergo age-related changes resulting in age related-MGD (ARMGD). The precise cause of ARMGD remains elusive, which makes developing therapies extremely challenging. We previously demonstrated that a hyaluronan (HA)-rich matrix exists surrounding the MG, regulating MG morphogenesis and homeostasis. Herein, we investigated whether changes to the HA matrix in the MG throughout life contributes towards ARMGD, and whether altering this HA matrix can prevent ARMGD. For such, HA synthase (Has) knockout mice were aged and compared to age matched wild type (wt) mice. MG morphology, lipid production, PPARγ expression, basal cell proliferation, stem cells, presence of atrophic glands and MG dropout were analyzed at 8 weeks, 6 months, 1 year and 2 years of age and correlated with the composition of the HA matrix. We found that as mice age, there is a loss of HA expression in and surrounding the MGs of wt mice, while, in contrast, Has1-/-Has3-/- mice present a significant increase in HA expression through Has2 upregulation. At 1 year, Has1-/-Has3-/- mice present significantly enlarged MGs, compared to age-matched wt mice and compared to all adult mice. Thus, Has1-/-Has3-/- mice continue to develop new glandular tissue as they age, instead of suffering MG atrophy. At 2 years, Has1-/-Has3-/- mice continue to present significantly larger MGs compared to age-matched wt mice. Has1-/-Has3-/- mice present increased lipid production, increased PPARγ expression and an increase in the number of proliferating cells when compared to wt mice at all-time points analyzed. Taken together, our data shows that a loss of the HA matrix surrounding the MG as mice age contributes towards ARMGD, and increasing Has2 expression, and consequently HA levels, prevents ARMGD in mice.

Adverse events of antibody-drug conjugates on the ocular surface in cancer therapy

Antibody-drug conjugates consist of a monoclonal antibody attached to a cytotoxic therapeutic molecule by a connector. This association allows a highly specific therapy, which increases their effectiveness and decreases their potential toxicity. This new therapy emerged approximately 20 years ago; since then, numerous combinations have appeared in the field of treatment-related neoplasms as an alternative for patients who do not achieve good results with conventional treatment options. Adverse effects of these drugs on the ocular surface are frequent and varied. Their prevalence ranges from 20 to 90% depending on the drug and administration condition, probably due to multiple receptor-mediated factors or mechanisms not mediated by specific receptors, such as macropinocytosis. These adverse events can greatly limit patients' comfort; thus, the objectives of this article were, in the first place, to compile the information currently available on different types of adverse effects of antibody-drug conjugates on the ocular surface, including pathophysiology, prevalence, and treatment, and in second place, to contribute to the correct identification and management of these events, which will result in a lower rate of cessation of treatment, which is necessary for the survival of candidate patients.

Application of topical 2% cyclosporine A in inflammatory ocular surface diseases

PURPOSE

To report our experience with the 2% cyclosporin A (CsA) in a series of challenging inflammatory ocular surface diseases due to different etiologies.

METHODS

The records of patients who received topical 2% CsA for different indications were reviewed retrospectively. Demographic characteristics, indications for treatment, patient symptoms and clinical findings were recorded.

RESULTS

Fifty-two eyes of 52 patients were included. Mean age was 43.2 ± 14.3 (11-66) years with a F/M ratio of 34/18. Indications included pediatric acne rosacea (n = 4), adenoviral corneal subepithelial infiltrates (n = 12), filamentary keratitis (n = 14), pterygium recurrence (n = 15), herpetic marginal keratitis (n = 2) and graft versus host disease (n = 5 patients). Mean duration of treatment was 7.3 ± 2.8 (3-10) months. Forty-three (83%) patients reported favorable outcome with improvement in symptoms after a mean time of 4.4 ± 2.7 (2-6) months.

CONCLUSIONS

Topical 2% CsA may address the needs of different cases with ocular surface inflammation, as a safe option for long-term therapy.

Metagenomic analysis of microbiological changes on the ocular surface of diabetic children and adolescents with a dry eye

BACKGROUND

Microbiome changes on the ocular surface may cause dry eyes. A metagenome assay was used to compare the microbiome composition and function of the ocular surface between diabetic children and adolescents with dry eye, diabetic children and adolescents without dry eye, and normal children.

MATERIALS AND METHODS

Twenty children and adolescents aged 8 to 16 with diabetes were selected from the Shanghai Children and Adolescent Diabetes Eye Study. Ten healthy children and adolescents belonging to the same age group were selected from the outpatient clinic during the same period. The participants were classified into the dry eye group (DM-DE group, n = 10), the non-dry eye group (DM-NDE group, n = 10) and the normal group (NDM group, n = 10). A conjunctival sac swab was collected for metagenomic sequencing, and the relationship between the microbiome composition and functional gene differences on the ocular surface with dry eye was studied.

RESULTS

The classification composition and metabolic function of the microorganisms on the ocular surface of children in the 3 groups were analyzed. It was found that children's ocular microbiota was composed of bacteria, viruses and fungi. There were significant differences in α diversity and β diversity of microbial composition of ocular surface between DM-DE group and NDM group(P<0.05). There were significant differences in α and β diversity of metabolic pathways between the two groups(P<0.05). The functional pathways of ocular surface microorganisms in diabetic children with dry eyes were mainly derived from human disease, antibiotic resistance genes, carbohydrate, coenzyme and lipid transport and metabolism-related functional genes; In normal children, the functional pathways were mainly derived from replication, recombination, repair, signal transduction and defense-related functional genes.

CONCLUSION

The DM-DE group have unique microbial composition and functional metabolic pathways. The dominant species and unique metabolic pathways of the ocular surface in the DM-DE group may be involved in the pathogenesis of dry eye in diabetic children.

Contact lenses and ocular dysbiosis, from the transitory to the pathological

Normal ocular microbiota is composed of different Gram-negative and positive bacterial communities that act as commensals on the ocular surface. An imbalance in the homeostasis of the native species or dysbiosis triggers functional alterations that can eventually lead to ocular conditions, indicating the use of contact lenses as the most relevant predisposing factor. Through a bibliographic review that added scientific articles published between 2018 and 2022, the relationship between healthy ocular microbiota and dysbiosis associated with the use of contact lenses that trigger ocular conditions was analyzed. The ocular microbiota in healthy individuals is mainly composed of bacteria from the phyla: Proteobacteria, Actinobacteria and Firmicutes. These bacterial communities associated with the use of contact lenses develop dysbiosis, observing an increase in certain genera such as Staphylococcus spp. and Pseudomonas spp., which under normal conditions are commensals of the ocular surface, but as their abundance is increased, they condition the appearance of various ocular conditions such as corneal infiltrative events, bacterial keratitis and corneal ulcer. These pathologies tend to evolve rapidly, which, added to late detection and treatment, can lead to a poor visual prognosis. It is suggested that professionals in the ophthalmology area learn about the composition of the communities of microorganisms that make up this ocular microbiota, in order to correctly distinguish and identify the causative agent, thereby providing a adequate and effective treatment to the user.

Ocular Surface Evaluation after Switch from Latanoprost 0.005% to Latanoprostene Bunod 0.024

Aim and background

To evaluate the ocular surface of patients treated with latanoprost (LT) 0.005% who switched to latanoprostene bunod (LBN) 0.024%.

Materials and methods

A prospective and nonrandomized clinical study of a case series was performed, including patients with chronic open-angle glaucoma who were on previous LT-only treatment and, after a washout period, switched to LBN, with a 3-month follow-up. The main parameter to be evaluated was the ocular surface disease index (OSDI) test. In addition, best-corrected visual acuity (BCVA), intraocular pressure (IOP), biomicroscopic aspect of the ocular surface, measuring tear breakup time, fluorescein staining (grading performed on Oxford scale) and Schirmer I test were evaluated.

Results

A total of 36 patients (72 eyes) were included, 21 women (58.3%) and 15 men (41.7%, with a mean age of 65.6 ± 10.9 years (37-86). The initial OSDI score was 17.8 ± 12.1 and improved to 11.1 ± 10.5 (p < 0.01). From the data evaluated at biomicroscopy, an improvement was observed in the Oxford scale from 0.6 ± 0.7 to 0.2 ± 0.8 (p: 0.01), but no statistically significant changes were observed in the break-up time (BUT) and Schirmer. BCVA remained stable, as did IOP, which was initially 13.4 ± 2.1 mm Hg and, after performing the LBN treatment change, went to 13.1 ± 1.7 mm Hg.

Conclusion

After the change of treatment from LT 0.005% to LBN 0.024%, the patients had an improvement in the ocular surface, maintaining control of their IOP. The need to investigate possible beneficial mechanisms on the ocular surface in glaucoma patients treated with LBN, potentially related to nitric oxide, is raised.

Clinical significance

Patients treated with LT 0.005% who switched to LBN 0.024% had an improvement in ocular surface symptoms and signs, keeping IOP under control.Latanoprostene bunod (LBN) 0.024% may have beneficial effects on the ocular surface, which should be further studied.

How to cite this article

Zanutigh V, Galetto L, Valvecchia F, et al. Ocular Surface Evaluation after Switch from Latanoprost 0.005% to Latanoprostene Bunod 0.024%. J Curr Glaucoma Pract 2023;17(4):205-209.

Purinergic 2X 4 (P2X4), but not P2X7, receptors increase cytosolic [Ca2+] and stimulate mucin secretion in rat conjunctival goblet cells to maintain ocular surface health

Ionotropic purinergic receptors (P2XRs) are activated by ATP and ATP analogs. ATP can be released through ATP-permeable channels such as the pannexin hemichannels. Upon activation, the P2XRs become permeable to Ca2+, a potent stimulator of mucin secretion in conjunctival goblet cells (CGCs). The purpose of this study was to investigate the presence and function of P2XRs in CGCs. We also examined the presence of pannexin hemichannels. Rat first passage CGCs were stained with the goblet cell marker anti-cytokeratin 7 antibody and specific antibodies to P2X1-7 receptors and pannexin 1-3. mRNA expression was determined by RT-PCR using primers specific to P2XRs and pannexins. Proteins were identified with Western blotting (WB) using the same antibodies as for immunofluorescence (IF) microscopy. To study receptor function, CGCs were incubated with Fura 2-AM, exposed to agonists and antagonists, and intracellular [Ca2+] ([Ca2+]i) measured. [Ca2+]i was also measured after knock down of P2X4 and P2X7 receptor expression, and when exploiting P2XR specific characteristics. Lastly, mucin secretion was measured after the addition of several P2XR agonists. All P2XRs and pannexins were visualized with IF microscopy, and identified with RT-PCR and WB. [Ca2+]i was significantly increased when stimulated with ATP (10-7-10-4 M). Suramin, a non-selective P2XR antagonist at 10-4 M did not reduce ATP-induced peak [Ca2+]i. The potent P2X7 agonist, BzATP (10-7-10-4 M) increased the [Ca2+]i, although to a lesser extent than ATP. When measuring [Ca2+]i the effect of repeated applications of ATP at 10-5 or 10-6 M the response "desensitized" after 30-60 s. The P2X4 specific antagonist 5-BDBD decreased the P2X4 agonist, 2MeSATP,-induced [Ca2+]i increase. Furthermore, siRNA against the P2X4R, but not the P2X7R, decreased agonist-induced peak [Ca2+]i. ATP (10-5 M), BzATP (10-4 M) and 2MeSATP (10-5 M) induced mucin secretion. We conclude that all seven P2XRs are present in cultured rat CGCs. Of the P2XRs, only activation of the homotrimeric P2X4R appears to increase [Ca2+]i and induce mucin secretion. The P2X4R in CGCs offers a new therapeutic target for protective mucin secretion.

Molecular nature of ocular surface barrier function, diseases that affect it, and its relevance for ocular drug delivery

The structural and functional integrity of the ocular surface, a continuous epithelial structure comprised of the cornea, the conjunctiva, and the ductal surface of the lacrimal as well as meibomian glands, is crucial for proper vision. The ocular surface barrier function (OSBF), sum of the different types of protective mechanisms that exist at the ocular surface, is essential to protect the rest of the eye from vision-threatening physical, chemical, and biological insults. OSBF helps maintain the immune privileged nature of the cornea and the aqueous humor by preventing entry of infectious agents, allergens, and noxious chemicals. Disruption of OSBF exposes the dense nerve endings of the cornea to these stimuli, resulting in discomfort and pain. This review summarizes the status of our knowledge related to the molecular nature of OSBF, describes the effect of different ocular surface disorders on OSBF, and examines the relevance of this knowledge for ocular drug delivery.

Up-to-date molecular medicine strategies for management of ocular surface neovascularization

Ocular surface neovascularization and its resulting pathological changes significantly alter corneal refraction and obstruct the light path to the retina, and hence is a major cause of vision loss. Various factors such as infection, irritation, trauma, dry eye, and ocular surface surgery trigger neovascularization via angiogenesis and lymphangiogenesis dependent on VEGF-related and alternative mechanisms. Recent advances in antiangiogenic drugs, nanotechnology, gene therapy, surgical equipment and techniques, animal models, and drug delivery strategies have provided a range of novel therapeutic options for the treatment of ocular surface neovascularization. In this review article, we comprehensively discuss the etiology and mechanisms of corneal neovascularization and other types of ocular surface neovascularization, as well as emerging animal models and drug delivery strategies that facilitate its management.

Bibliometric analysis of the uveitis literature and research trends over the past two decades

OBJECTIVE

This study aimed to examine the publication patterns and present a current view of the field of uveitis using a bibliometric analysis.

DESIGN

Bibliometric analysis.

METHODS AND ANALYSIS

A comprehensive search of three databases including MEDLINE, EMBASE and Cochrane was conducted from 1 January 2000 to 31 December 2022. Search results from all three databases were subjected to analysis by Bibliometrix, an R programme that analyses large literature dataset with statistical and mathematical models. Visualisation of collaboration networks and relevance between countries was presented with VOSviewer.

RESULTS

A total of 26 296 articles were included in the analysis. The field of uveitis has undergone a significant exponential growth since 2000, with an average growth rate of 4.14%. The most substantial annual growth was between the years 2021 and 2022 (36%). According to the corresponding author's countries, the three most productive countries were Turkey (3288, 12.6%), the USA (3136, 12%) and Japan (1981, 7.6%). The USA (243, 31.4%), England (117, 15%) and Germany (62, 8%) are the top three countries that contributed to clinical trials. The average international collaboration of all countries was 2.5%.

CONCLUSIONS

Uveitis literature has undergone significant growth in the past two decades. The demographic factors of publishing countries lead to their various productivity and types of these uveitis studies, which is closely associated with the countries' scientific research resources and patient populations.

The effects of chalazion and the excision surgery on the ocular surface

Purpose

To evaluate the effects of chalazion excision on the ocular surface, taking into account the subjective symptoms and the objective parameters of the tear film.

Methods

This prospective, interventional clinical study included 52 eyes from 26 patients with eyelid chalazion who underwent excision of the lesions between March and August 2022. Chalazion excision was performed on the patient's chalazion eye, and the contralateral eye served as the control. The following parameters were investigated both preoperatively and 1 week, 1 month, and 3 months postoperatively: the Ocular Surface Disease Index (OSDI), Schirmer I test, corneal fluorescein stain (CFS), tear meniscus height (TMH), noninvasive first breakup time (NifBUT), noninvasive average breakup time (NiaBUT), bulbar conjunctival redness score, the thickness of the lipid layer, and meibomian gland loss.

Results

Before surgery, the OSDI score of the chalazion eye was significantly higher than the contralateral eye. The bulbar conjunctival redness score (p = 0.043) and the OSDI score (p = 0.004) improved significantly in the first month after surgery. In the third month after surgery, the objective parameters showed significant improvements, including TMH (p = 0.032), NiaBUT (p = 0.028), bulbar conjunctival redness score (p < 0.001), the thickness of the lipid layer (p = 0.021), and meibomian gland loss (p = 0.005).

Conclusions

Our study revealed that chalazion excision can significantly improve the subjective symptoms and the objective tear film parameters of the ocular surface.

Rheumatoid arthritis-associated peripheral ulcerative keratitis outcomes after early immunosuppressive therapy

BACKGROUND/AIMS

To evaluate the role of early immunosuppressive therapy (IMT) in the management of rheumatoid arthritis (RA)-associated peripheral ulcerative keratitis (PUK).

METHODS

Single-centre, retrospective, comparative cohort study. Patients with RA-associated PUK were divided into two groups; those exposed to and those not exposed to early IMT, defined as administrating therapy within the first 4 weeks from the PUK onset. Outcomes included PUK recurrence, control of inflammation and development of ocular complications, including corneal scarring and perforation, cataract formation or progression and permanent visual loss.

RESULTS

A total of 52 eyes from 36 patients were included for analysis; 37 (71.2%) eyes received early IMT and 15 (28.8%) eyes did not. Follow-up time was 41.2+53.3 months (range: 4-236 months). While early IMT was a protective factor (HR 0.345, 95% CI 0.126 to 0.946, p=0.039), late RA diagnosis after PUK onset (HR 4.93, 95% CI 1.75 to 13.85, p=0.002) and retarded (≥2 months) control of inflammation (HR 8.37, 95% CI 1.88 to 37.16, p=0.005) were risk factors for PUK recurrence. Late IMT (OR 7.75, 95% CI 2.00 to 29.99, p=0.003), an unknown diagnosis of RA at first visit (OR 4.14, 95% CI 1.15 to 14.91, p=0.030) and at least one PUK recurrence (OR 6.42, 95% CI 1.71 to 24.07, p=0.006) were risk factors for visual loss. Survival analysis rendered eyes exposed to early IMT a lower risk of PUK recurrence (p=0.039).

CONCLUSION

Eyes with RA-associated PUK exposed to early IMT were more likely to achieve earlier inflammatory control, fewer recurrences and had better visual outcomes.

Ocular surface and glaucoma, a mutual relationship. Practical suggestions for classification and management

The chronic use of glaucoma medications could improve the development of an ocular comorbidity, the glaucoma therapy-related ocular surface disease. This could be related to the exposure of the conjunctiva to preservatives, but also active compounds such as prostaglandin analogues may improve the risk of ocular surface inflammation. Inflammation has a negative impact on tolerability and adherence to eyedrops and to the outcome of filtration surgery as well. A stratification of glaucoma patients based not only on visual field progression but also on glaucoma therapy-related ocular surface disease would be desirable for a strategic management. Early diagnosis, individualized treatment, and safe surgical management should be the hallmarks of glaucoma treatment. One of the main issues for the proper and successful management of patients is the right timing, effectiveness and safety for both medical and surgical treatment options leading to a precision medicine in glaucoma disease as the best modern treatment.

Cellular senescence implication in mustard keratopathy

Mustard agents are vesicants that were used in warfare multiple times. They are potent alkylating agents that activate cellular pathways of apoptosis, increase oxidative stress, and induce inflammation. Eyes are particularly susceptible to mustard exposure with a wide range of ocular surface damage. Three main categories of mustard-related eye injuries are acute, chronic, and delayed-onset manifestations. Mustard keratopathy (MK) is a known complication characterized by corneal opacification, ulceration, thinning, and neovascularization that can lead to severe vision loss and discomfort. Recently, a few reports demonstrated the role of senescence induction as a new pathological mechanism in mustard-related injuries that could affect wound healing. We ran the first murine model of delayed-onset MK and nitrogen mustard-induced senescence, evaluating the pathological signs of senescence in the cornea using beta-galactosidase staining. Our results suggest that nitrogen mustard exposure causes senescence in the corneal cells, which could be the underlying mechanism for chronic and late-onset ocular surface damage. We also found a significant correlation between the percentage of positive beta-galactosidase staining and the degree of fibrosis in the cornea. This provides valuable insight into the possible role of anti-senescence drugs in the near future for accelerating corneal healing and restricting fibrosis in patients with mustard keratopathy.