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The advent of drug-eluting contact lenses (DECLs) has opened up new avenues for the treatment of eye diseases. DECLs is expected to partially overcome the shortcomings of eye drops due to single-dose packaging, accurate dosing, prolonged drug elution behavior, and simplified dosing procedures. Currently, a significant proportion of the DECLs design effort has been directed towards enhancing the compatibility of contact lenses with drugs. The appropriate elution time for the drug remains unclear. Additionally, it is ambiguous for which ophthalmic diseases DECLs offers the greatest therapeutic advantage. To rationally design DECLs in practice, it is necessary to understand the acceptance of DECLs by patients and practitioners and to clarify the indications for DECLs. This review will first focus on the acceptance of DECLs by different patients and practitioners and discuss the factors that influence its acceptance. Secondly, this review presents an overview of the current effectiveness of DECLs treatments in animals and in the clinical phase, with a particular focus on the suitability of DECLs for the treatment of ophthalmic diseases. Overall, patients and practitioners expressed positive attitudes towards DECLs. However, this is related to factors such as DECLs' treatment cycle, safety, and price. In addition, DECLs has good application prospects for ocular wound healing, postoperative management, and treatment of contact lenses-related complications. Furthermore, chronic diseases such as glaucoma that necessitate long-term medication and intraocular diseases that require implants or injections represent additional potential applications for DECLs. It is hoped that this review will facilitate a deeper understanding of DECLs acceptance and indications, thereby supporting the rational design of DECLs. At the same time, this review provides a reference for the design of other drug-device combination products., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Purpose: This prospective study aimed to assess the impact of topical latanoprost 0.005% treatment on the microvasculature of the macula and optic nerve head (ONH) in primary open-angle glaucoma (POAG)., Methods: Fifty-seven eyes of 31 subjects were enrolled. ONH whole-image (wiVD), peripapillary (ppVD), and macular vascular density (VD) parameters were measured using optical coherence tomography angiography before treatment, at the 1st month, and at the 3rd month of treatment., Results: There was a significant reduction in IOP post treatment, with a decrease of 17.0 ± 2.3 mmHg in the 1st month and 16.3 ± 2.5 mmHg in the 3rd month (P < 0.001 for both). ONH wiVD and ppVD significantly increased at the post-treatment 1st month (P = 0.001 for both) but decreased by the 3rd month, returning to baseline levels (P < 0.001 for both), indicating a return to pre-treatment levels (P > 0.05 for both). Similarly, macular wiVD and perifoveolar VD (pefVD) increased significantly at the 1st month (P = 0.013 and P < 0.001, respectively) but returned to baseline by the 3rd month (P < 0.001 for both). No significant difference was observed between before-treatment and post-treatment 3rd month regarding the macular wiVD and pefVD (P > 0.05 for both). Deep capillary plexus and foveal avascular zone parameters did not change during follow-up (P > 0.05 for both)., Conclusion: The initial increase in ONH and peripapillary VD, as well as macular VD, is attributed to the acute reduction in IOP from topical latanoprost 0.005%. However, the diminishment of sustained differences by the 3rd month indicates adaptation of the ONH and retinal microvasculature to decreased IOP through compensatory mechanisms., (Copyright © 2024 Copyright: © 2024 Indian Journal of Ophthalmology.)

Introduction: Various adjuvant therapies have been used to prevent recurrence after pterygium excision. However, no single agent has been proven to be a gold standard for completely preventing recurrence with no associated complications., Purpose: This study aims to compare the recurrence rate following preoperative topical mitomycin C (MMC) and 5-fluorouracil (5-FU) eye drops in pterygium excision surgery., Methods: In this interventional longitudinal comparative study, 90 patients with primary pterygium attending the Ophthalmology Clinic were enrolled and randomized into three equal groups of 30 each. Groups A, B, and C received preoperative 0.02% MMC eye drops, 1% 5-FU eyedrops, and placebo treatment respectively for one week before surgery followed by pterygium excision with conjunctival autograft and histopathological analysis. Patients were followed for 6months to identify recurrence., Results: At the end of the 6months, the recurrence rate in the preoperative MMC group (6.7%) was less than the 5-FU (13.3%) and placebo (20%) groups. The histopathological findings were consistent with pterygium tissues. There were high grades of inflammation, degeneration, and vascularization in both the MMC and 5-FU groups in the specimens which recurred within a period of 6months. Five patients had a novel finding of smooth muscle choristoma tissue with bundles of smooth muscle cells and fat cells clustered among the conjunctival tissue., Conclusion: Based on our study results, we demonstrate that preoperative topical MMC and 5-FU eyedrops have efficacy in reducing recurrence in pterygium surgeries. The eyedrop route of administration has been proven to be an effective and easier alternative, enabling us to monitor for adverse effects of adjuvant drugs. Histopathological evaluation provides indices to predict features of future recurrence in pterygium specimens. This is the first study in which the efficacy of preoperative MMC and 5-FU is studied in eyedrop formulation along with histopathological correlation with recurrence., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Clinical Relevance: There are many methods to control the progression of myopia. However, it is currently unknown which method could better control myopia progression: 0.02% atropine eye drops, peripheral myopic defocus design spectacle lenses (PMDSL), or orthokeratology (OK)., Background: To compare the efficacy of 0.02% atropine, PMDSL, and OK to control axial length (AL) elongation in children with myopia., Methods: This study was analysed based on a previous cohort study (0.02% atropine group) and retrospective data (PMDSL and OK group). Overall, 387 children aged 6-14 years with myopia - 1.00D to - 6.00D in the three groups were divided into four subgroups according to age and spherical equivalent refraction (SER). The primary outcome was changed in AL over 1-year., Results: The mean axial elongation was 0.30 ± 0.21 mm, 0.23 ± 0.16 mm, and 0.17 ± 0.19 mm in the 0.02% atropine, PMDSL, and OK groups, respectively. Multivariate linear regression analyses showed significant differences in axial elongation among the three groups, especially in children aged 6-10, but not in children aged 10.1-14; the corresponding axial elongation was 0.35 ± 0.21 mm, 0.23 ± 0.17 mm, and 0.21 ± 0.20 mm ( P  < 0.05 between any two groups, except between PMDSL and OK groups at P  > 0.05) and 0.22 ± 0.20 mm, 0.21 ± 0.13 mm, and 0.13 ± 0.18 mm ( P  < 0.05 between any two groups, except between 0.02% atropine and PMDSL groups at P  > 0.05) in children with SER from - 1.00D to - 3.00D and from - 3.01D to - 6.00D, respectively., Conclusions: Within the limits of this study design and using only the current brand of PMDSL, OK appeared to be the best method, followed by PMDSL and then 0.02% atropine, for controlling AL elongation over one year. However, different effects were found in the various age and SER subgroups.

Purpose: Levodopa has been investigated as a therapeutic solution for ocular disorders involving dysregulation of the dopaminergic system, especially in the context of myopia. However, given the critical role dopamine plays in normal vision, this phase I trial examined whether levodopa/carbidopa eye drops induce any regional changes in retinal structure and function., Methods: Twenty-nine healthy male subjects 18 to 30 years of age were randomly assigned to receive either a low (1.4/0.34 µmoles/day, n = 14) or high (2.7/0.68 µmoles/day, n = 15) dose of levodopa/carbidopa eye drops in 1 eye for 28 consecutive days. A placebo solution was applied to all fellow eyes. Measures included visual acuity, regional frequency doubling perimetry, regional multifocal electroretinogram (mfERG) and optical coherence tomography (retinal thickness). Outcome measures were undertaken at baseline, end-of-treatment (4 weeks), and at a follow-up (4 months post-treatment)., Results: For low dose treated eyes, regional analysis showed a small, statistically significant change in mfERG recordings (increase in ring 5 amplitude in low dose treated eyes, P < 0.05) and the retinal thickness map (localized retinal thinning in low dose treated eyes, P < 0.05). These changes were not clinically significant. No significant changes were observed in high dose treated eyes. Pharmacokinetic analysis (rabbits) demonstrated that levodopa was not detectable within blood and peaked within the eye at 15 to 30 minutes (and eliminated within 4 hours)., Conclusions: No clinically significant effects of levodopa/carbidopa eye drops were found with regard to normal retinal structure and function following short-term use., Translational Relevance: This study further demonstrates the safety of topical levodopa, which may support its use in the treatment of ocular disorders in which the dopamine system is dysregulated.

Purpose: microRNA-328 has been reported as a risk factor for myopia development. SHJ002 is an antisense for microRNA-328, and SHJ002 was formulated as ophthalmic solution for a novel microRNA therapy. We aimed to investigate the safety and tolerability of SHJ002 ophthalmic solution in children., Methods: This was a single-center, open-label, first-in-human trial in healthy children (NCT04928144). All subjects received the study medication. The trial had 2 stages. Stage 1 was an intrasubject dose-escalation study, and stage 2 was the highest tolerable dose study. The SHJ002 ophthalmic solution was instilled in a randomly selected study eye in each participant, whereas the other untreated eye served as a negative control. Three participants were assigned to stage 1, and they received eye drops of 3 concentrations (0.025%, 0.08%, and 0.25%), each of which was used for 3 consecutive days. The highest tolerable dose from stage 1 was used in stage 2 where another 9 participants were recruited for 28-day treatment. Ocular assessments, physical examination, and vital signs were measured to evaluate safety and tolerability., Findings: There were 4 boys and 8 girls with a mean age of 12.3 years and a SD of 1.56. All participants were Asians. All 3 concentrations used in stage 1 were well tolerated, and the dose of 0.25% was used in stage 2. There were no reports of discomfort. There was only 1 mild adverse event (punctate keratitis) in the untreated eye in 1 participant, which was deemed as "unrelated to study drug.", Implications: SHJ002 is a novel microRNA therapy that uses eye drop instillation. SHJ002 ophthalmic solution is generally safe and tolerable, which warrants further investigations in Phase II and III trials., Clinicaltrials: gov identifier: NCT04928144., Competing Interests: Declaration of competing interest C.-L. Liang and S.-H.H. Juo are the authors for the patent of anti-miR-328 oligonucleotides and the founders and stockholders of Sunhawk Vision Biotech, Inc. The authors have indicated that they have no other conflicts of interest regarding the content of this article., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Aim: The purpose of this study was to conduct and interpret a pooled 12-month analysis of two prospective, multi-center, randomized, double-masked, controlled trials designed to assess the efficacy and safety of the travoprost intracameral implant (slow-eluting [SE] implant in development as a new therapeutic and fast-eluting [FE] implant included for masking purposes) in subjects with open-angle glaucoma (OAG) or ocular hypertension (OHT)., Methods: Subjects with OAG or OHT, on 0-3 intraocular pressure (IOP)-lowering medications, baseline unmedicated mean diurnal IOP of ≥ 21 mmHg, and IOP ≤ 36 mmHg at each baseline diurnal timepoint, received either a travoprost implant and twice-daily (BID) placebo eye drops or BID timolol 0.5% eye drops and a sham procedure. Subjects were followed through 12 months and assessed for IOP, reduction in topical IOP-lowering medications, and safety parameters including treatment-emergent adverse events (TEAEs). IOP at 8AM was prospectively collected at all study visits through 12 months and diurnal IOP, measured at 8AM, 10AM, and 4PM, was prospectively collected at baseline, day 10, week 6, and months 3 and 12., Results: A total of 1150 subjects were randomized (385 FE implant, 380 SE implant, and 385 sham/timolol) across the two trials. Statistical non-inferiority to timolol and clinically relevant reductions in 8AM IOPs were demonstrated at month 12. In more detail, both implant groups demonstrated statistical non-inferiority to timolol and clinically relevant reductions from baseline in mean diurnal IOP at all visits over the 12-month evaluation period when diurnal IOP was collected. Additionally, both implant groups demonstrated robust treatment effect based on 8AM average IOP from day 10 through the specified visit which ranged from day 10 to month 12 from 6.9 to 8.5 mmHg in the FE implant group; 6.8 to 8.5 mmHg in the SE implant group; and 7.3 to 7.5 mmHg in the sham/timolol group. With regards to reduction in topical pharmacotherapy, at month 12, 77.6% of FE and 81.4% of SE implant eyes were completely free of all topical IOP-lowering medications and a significantly greater proportion of FE and SE implant eyes (89.9% and 93.0%) versus sham/timolol eyes (66.9%) were on the same or fewer topical IOP-lowering medications compared with pre-study (p <  0.0001). Furthermore, of subjects on topical IOP medications at screening, a significantly greater proportion of FE implant (80.2%) and SE implant (85.1%) eyes versus sham/timolol (22.8%) eyes were on fewer topical IOP-lowering medications at month 12 compared with pre-study (p <  0.0001). Lastly, of SE implant eyes on same or fewer topical IOP-lowering medications at month 12, the average through month 12 decreased by 0.9 medications, and of those SE implant eyes on fewer topical IOP-lowering medications compared with pre-study, the average through month 12 decreased by 1.4 medications. The most common TEAEs related to study treatment were hyperemia (conjunctival or ocular), iritis, and IOP increased., Conclusion: The travoprost intracameral implant demonstrated robust IOP-lowering efficacy that was sustained and statistically non-inferior to timolol over the entire 12 months, resulting in a significant reduction in topical IOP-lowering medication use, with the majority of SE implant eyes remaining completely free of all topical IOP-lowering medications. In addition, the implant demonstrated a favorable safety and tolerability profile based on this pooled 12-month analysis of two pivotal trials., Trial Registration: ClinicalTrials.gov identifiers NCT03519386 (registered May 09, 2018) and NCT03868124 (registered March 08, 2019)., (© 2024. The Author(s).)

Over the past decade, atropine has emerged as an effective intervention for preventing myopia in children. Multiple randomized controlled trials, mainly from Asia, have demonstrated the safety and efficacy of topical atropine for myopia control. Both efficacy and side effects exhibit a positive dose-response relationship. This review focuses on new data from studies with predominantly white populations, ethnicity-dependent differences in efficacy and side effects, and primary prevention of incident myopia with atropine., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

Purpose of Review: Cyclosporine is a versatile immunomodulatory drug commonly employed in modern medicine. Although cyclosporine was initially used to prevent solid organ transplant rejection, its indications have extended to treat many inflammatory or autoimmune diseases. Cyclosporin is available for use in oral, intravenous, and topical forms, including eye drops to treat corneal and ocular surface conditions. It is naturally advantageous to administer cyclosporin directly into the eye, avoiding potential and dose limiting systemic adverse effects. However, the transition from systemic to topical administration has been a challenging one. This report reviews the evolution of ophthalmic cyclosporine treatment and explores its clinical impacts and future research directions., Recent Findings: Latest advancements in formulations - from oil-based solutions to nanomicelle and gel systems and waterless formulations - have improved the therapeutic efficacy and tolerability of topically applied cyclosporine, demonstrating greater effectiveness in treating ocular surface parameters compared to oil-based solution., Summary: Cyclosporine continues to be a safe and effective immunomodulatory drug in the field of ophthalmology to treat various chronic inflammatory ocular surface diseases and dry eye. Currently, there are several commercially available topical preparations available for ophthalmic use each with unique formulation and clinical outcomes., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: Fingolimod (FTY720; FT), a structural analog of sphingosine, has potential ocular applications. The goal of this study was to develop an FT-loaded nanoemulsion (NE; FT-NE) formulation for the efficient and prolonged delivery of FT to the posterior segment of the eye through the topical route. Methods: FT-NE formulations were prepared using homogenization followed by the probe sonication method. The lead FT-NE formulations (0.15% and 0.3% w/v loading), comprising soybean oil as oil and Tween ® 80 and Poloxamer 188 as surfactants, were further evaluated for in vitro release, surface morphology, filtration sterilization, and stability at refrigerated temperature. Ocular bioavailability following topical application of FT-NE (0.3%) was examined in Sprague-Dawley rats. Results: The formulation, at both dose levels, showed desirable physicochemical characteristics, a nearly spherical shape with homogenous nanometric size distribution, and was stable for 180 days (last time point checked) at refrigerated temperature postfiltration through a polyethersulfone (0.22 µm) membrane. In vitro release studies showed prolonged release over 24 h, compared with the control FT solution (FT-S). In vivo studies revealed that effective concentrations of FT were achieved in the vitreous humor and retina following topical application of FT-NE. Conclusions: The results from these studies demonstrate that the FT-NE formulation can serve as a viable platform for the ocular delivery of FT through the topical route.

Topical ophthalmic drug product development is a niche research domain as the drug formulations need to be designed to perform in the unique ocular physiological conditions. The most common array of small molecule drug formulations intended for topical ophthalmic administration include solutions, suspensions, emulsions, gels, and ointments. The formulation components such as excipients and container closure are unique to serve the needs of topical ophthalmic delivery compared to other parenteral products. The selection of appropriate formulation platform, excipients, and container closure for delivery of drugs by topical ophthalmic route is influenced by a combination of factors like physicochemical properties of the drug molecule, intended dose, pharmacological indication as well as the market trends influenced by the patient population. In this review, data from literature and packaging inserts of 118 reference listed topical ophthalmic medications marketed in the US are collected and analyzed to identify trends that would serve as a guidance for topical ophthalmic formulation development for small molecule drugs. Specifically, the topics reviewed include current landscape of the available small molecule topical ophthalmic drug products in the US, physicochemical properties of the active pharmaceutical ingredients (APIs), formulation platforms, excipients, and container closure systems., Competing Interests: Declaration of Competing Interest Anand Ubhe, Heidi Oldenkamp, Ke Wu are employees of AbbVie and may own AbbVie stock. AbbVie sponsored and funded the study; contributed to the design; participated in the collection, analysis, and interpretation of data, and in writing, reviewing, and approval of the final publication., (Copyright © 2024 American Pharmacists Association. Published by Elsevier Inc. All rights reserved.)

Objectives: This study aimed to assess the effectiveness and safety of intense pulsed light (IPL) therapy plus topical 0.05% cyclosporine A (CsA) eye drops to treat Sjögren's Syndrome-related dry eyes (SS-DE)., Research Design and Methods: In this prospective, randomized trial included, 60 individuals with SS-DE symptoms were randomized to receive topical eye drops containing either 0.1% sodium hyaluronate (Group S) or 0.05% CsA (Group C) plus IPL therapy. Before the first treatment (baseline), and at 12, 16, and 20 weeks after treatment commencement, we assessed the best corrected visual acuity (BCVA), the Ocular Surface Disease Index (OSDI) score, the Schirmer I test (SIT), noninvasive tear breakup time (NBUT), corneal fluorescein staining (CFS), meibomian gland (MG) dropout, lid margin abnormality, MG expressibility, and meibum quality., Results: Both groups showed significant improvements in the OSDI, NBUT, CFS, MG expressibility, and meibum quality (all p  < 0.05). Group C showed a greater increase in OSDI, NBUT, MG expressibility, and meibum quality (all p  < 0.05). Moreover, SIT and lid margin abnormalities significantly improved in Group C (both p  < 0.05), but not in Group S., Conclusion: Treatment with 0.05% CsA eyedrops plus IPL therapy could significantly reduce the issues and physical discomfort of patients with SS-DE., Clinical Trial: Registered on 20 July 2021, with the registration number ChiCTR2100049059.

Purpose: Emerging data suggest that acetaminophen lowers intraocular pressure (IOP) and has the potential to be repurposed as pharmacotherapy to treat open-angle glaucoma. However, pharmacokinetic data are lacking. This study aims to describe the pharmacokinetics of topical acetaminophen and its metabolite [ N -arachidonoylaminophenol (AM404)] when administered individually and in combination, and to determine its effect on IOP in the ocular normotensive adult New Zealand White Rabbit (NZWR). Methods: A randomized control trial was conducted using topical 1% acetaminophen and 1% AM404. The study was divided into two sub-studies using both paired-eye and two-eye designs. Results: The mean [95% confidence interval of the mean (95% CI)] concentration of acetaminophen detected in the aqueous humor (AH) was 4.09 ppm (3.18-5.00) at 2 h and 0.92 ppm (0.60-1.24) at 4 h after an immediate dose of topical acetaminophen. The integral IOP, defined as the integral of IOP change from baseline over time, was -5.1 mmHg⋅h (95% CI: -10 to 0.41) for control,-7.5 mmHg⋅h (95% CI: -14 to -1.1) for half-hourly acetaminophen, and -4.4 mmHg⋅h (95% CI: -14 to 5.5) for hourly acetaminophen over a 4-h period. When comparing topical acetaminophen with AM404 dosed half-hourly over a 4-h period, the integral IOP was -2.3 mmHg⋅h (95% CI: -5.9 to 1.3) for control,-2.0 mmHg⋅h (95% CI: -5.6 to 1.7) for AM404, -1.7 mmHg⋅h (95% CI: -4.5 to 1.2) for acetaminophen, and -3.2 mmHg⋅h (95% CI: -5.4 to -0.96) for acetaminophen/AM404 combined. Conclusions: Acetaminophen, but not its metabolite AM404, penetrated the multilayered cornea via passive diffusion in a dose-dependent fashion. There was a nonsignificant tendency to cause a lowering of IOP over the 4-h dosing period with higher AH concentrations of acetaminophen. Topical AM404 did not show a significant IOP-lowering effect.

The modulation of inflammation is effective to treat many ocular surface diseases. Thus the low bioavailability of common anti-inflammatory eye-drops urges the development of ocular drug delivery systems to extend the ocular retention and enhance the cellular uptake for improving anti-inflammatory effect of eye-drops. Here we covalently conjugate two molecules of clinically anti-inflammatory drug (i.e., dexamethasone) with a small peptide (i.e., Tyr-Glu-Asn-Pro-Thr-Tyr) to generate an anti-inflammatory hydrogel eye-drop. With a self-assembled ability, the designed supramolecular hydrogel achieves gel-sol-gel transition by varying shearing forces which increases the pre-corneal retention of drug. The fluorescent imaging reveals the efficient cellular uptake of designed conjugate via clathrin-mediated endocytosis. A rodent model of endotoxin-induced uveitis verifies that the supramolecular hydrogel eye-drop suppresses inflammation responses without ocular irritation. As a rational approach to design anti-inflammatory drugs as eye-drops, this work overcomes the frequent instillation of clinical eye-drops and further improves the bioavailability of anti-inflammatory drugs, which may provide an effective and household way to fight ocular surface inflammation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Long-acting diquafosol ophthalmic solution (DQS-LX) has significant advantages regarding patient adherence owing to the reduced frequency of required eye drops; however, some patients prefer conventional diquafosol ophthalmic solution (DQS) over DQS-LX. Herein, to clarify the characteristics of patients according to their preference for ophthalmic solutions, dry eye (DE) and meibomian gland (MG) findings were retrospectively investigated. This study enrolled 341 patients with DE (mean age, 62.1 ± 11.7 years) treated at the Itoh Clinic between November 8, 2022, and July 31, 2023, who switched from DQS to DQS-LX. Patients were divided into two groups: those who continued DQS-LX administration (DQS-LX group) and those who wished to revert to conventional DQS (DQS group). Data regarding subjective symptoms assessed using the Standard Patient Evaluation of Eye Dryness (SPEED) questionnaire, tear film breakup time (BUT), tear meniscus height (TMH), corneal and conjunctival fluorescein staining (CFS), conjunctival hyperemia/papilla, meiboscore, plugging, vascularity, meibum grade, and Schirmer's score at the time of DQS-LX switch were evaluated. Of the 341 patients, 31 (9.1%) wished to revert to conventional DQS. In total, 16 eyes of 16 patients in the DQS group and 32 eyes of 32 patients in the DQS-LX group-for whom complete data were available-were included in the analysis. The DQS-LX group had higher SPEED scores, lower TMHs (P < 0.001, respectively), shorter FBUTs, greater CFS findings, larger meibum grades, lower Schirmer scores, and more pluggings compared with the DQS group (P = 0.005, 0.001, 0.001, 0.046, 0.003, respectively). Meiboscores and vascularity did not differ significantly between the two groups (P = 0.73 and 0.39, respectively). In conclusion, patients with low tear film volume and DE complicated by moderate or severe meibomian gland dysfunction (MGD) preferred DQS-LX, while those with allergic findings preferred conventional DQS., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Arita et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The purpose of this study was to improve the efficacy of olopatadine hydrochloride (OT) in treating allergic conjunctivitis (AC). To achieve this goal, we developed an eye formulation without antimicrobial agents using a temperature-pH dual-sensitive in situ gel technology combined with heat sterilization. Various types of carbomers were evaluated and their optimal doses determined. The prescription containing poloxamer 407 (P407) and poloxamer 188 (P188) was optimized using central composite design for response surface methodology (CCD-RSM). The final optimized dual-sensitive in situ gel (TP-gel) consisted of 0.1% olopatadine hydrochloride, 18.80% P407, 0.40% P188, 0.30% Pemulen™TR-1(TR-1), 4.0% mannitol, and 0.08% Tri(hydroxymethyl)aminomethane(Tris).Sterilization was performed at a temperature of 121℃ for a duration of 20 min. Experimental results showed that TP-gel had good safety profile and remained on the ocular surface for approximately (65.83 ± 8.79) minutes, which is four times longer than eye drops. The expression levels of IL-13, IL-17, and OVA-IgE in mouse ocular tissues with allergic conjunctivitis treated with TP-gel were significantly reduced. This suggests that TP-gel has the potential to be an effective treatment method for allergic conjunctivitis., (© 2024. The Author(s), under exclusive licence to American Association of Pharmaceutical Scientists.)

Objective: To explore the difference in myopia control efficacy between spectacle lenses with highly aspherical lenslets (HAL) combined with 0.01% atropine eye drops and spectacle lenses with HAL alone or single vision spectacle lenses (SVL) in children and adolescents., Methods: A retrospective cohort study was conducted with a total of 105 myopic children aged 6-15 years. According to the specific myopia correction and control methods of each subject, they were evenly divided into the HAL+0.01% atropine (HAL+AT) group, the HAL group, and the SVL group, with 35 subjects in each group. Relevant data, such as cycloplegic refraction and axial length (AL) at baseline and 12 months after wearing spectacles, were retrieved. One-way analysis of variance, or the Kruskal-Wallis test, was used to analyze the changes in AL and spherical equivalent refraction (SER) after wearing spectacles for 12 months in comparison to those at baseline in the three groups., Results: There was no statistically significant difference in the baseline parameters and duration of wearing spectacles among the three groups ( P >0.05). After wearing spectacles for 12 months, the changes in SER were －0.13 (－0.25, 0.00) D, －0.25 (－0.63, －0.25) D, and －0.63 (－1.00, －0.25) D in the HAL+AT group, HAL group, and SVL group, respectively; AL elongation in the three groups was (0.09±0.11) mm, (0.19±0.16) mm, and (0.34±0.16) mm, respectively. The HAL+AT group exhibited slower SER changes ( P HAL+AT vs. HAL =0.001, P HAL+AT vs. SVL =0.002) and AL elongation ( P HAL+AT vs. HAL =0.009, P HAL+AT vs. SVL =0.001) than those of the HAL and the SVL groups. Compared with those of the SVL group, myopia progression was reduced by 79.4% and AL elongation was slowed down by 73.5% in the HAL+AT group, while in the HAL group, myopia progression and AL elongation were reduced by 60.3% and 44.1%, respectively. According to stratified analysis based on age and myopia progression rate, among younger children aged 6 to 8 years and older children aged 9 to 15 years, the HAL+AT group had a significantly lower proportion of subjects experiencing fast AL elongation (AL>0.36 mm/year) and a significantly higher proportion of subjects experiencing slow AL elongation (AL≤0.18 mm/year) compared to the SVL group ( P <0.017)., Conclusion: The combination intervention of spectacle lenses with HAL and 0.01% atropine eye drops is effective in controlling myopia progression in children and adolescents, with better myopia control effect achieved using this combination intervention in myopic children of all ages., Competing Interests: 利益冲突　本文作者刘陇黔是本刊编委会编委。该文在编辑评审过程中所有流程严格按照期刊政策进行，且未经其本人经手处理。除此之外，所有作者声明不存在利益冲突。, (© 2024《四川大学学报（医学版）》编辑部 版权所有Copyright ©2024 Editorial Office of Journal of Sichuan University (Medical Sciences).)

Purpose: To evaluate the correlation between the timing of instilling anesthetic eyedrops prior to intravitreal injection and the patient's perception of pain associated with the injection., Methods: A prospective observational study which included 192 eyes of 192 patients. Time interval between instillation of Oxybuprocaine-0.4% and Tetracaine-0.5% eyedrops upon checking-in and injection was measured and pain level was evaluated by the 101-point-Numeric Rating Scale., Results: We found significant correlation between time interval from the first eyedrops to injection and injection related pain. The lowest pain score (11 ± 18) was found in the 11-15 min group, while the highest was found in the 0-6 min (26 ± 25) and in the > 35 min (31 ± 28) groups. The highest percentage of patients without pain was found in the 11-15 min (64%), followed by the 7-10 min (56%) and 16-20 min (47%) groups. 10% or 17% of the 0-6 min or > 35 min. groups, respectively, reported no pain. No patients in 11-15 min group reported severe pain versus 10% in the 0-6 min and 17% in the > 35 min groups. The highest percentage of patients with 'absent-to-mild' pain was in the 11-15 min (89%) and the 7-10 min (87%) compared to all other groups., Conclusions: Administration of first dose of anesthetic eyedrops within 11-15 min before intravitreal injection yields the lowest levels of injection-related pain, with 7-10 min being second best. Administration of eyedrops outside of this time-window results in higher pain levels avoidable with more attention to the timing issue., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Background: To compare and evaluate objective and subjective clinical parameters between 0.05% cyclosporine nanoemulsion (CsN) and 0.15% hyaluronic acid (HA) administration in patients with mild-to-moderate dry eyes., Methods: In this prospective, randomized, double-masked, single-center, and placebo-controlled parallel study, patients with mild-to-moderate dry eyes were randomly allocated to be treated with 0.05% CsN or 0.15% HA twice daily. Patients were followed-up at 4, 8, and 12 weeks. Objective and subjective parameters were evaluated during each visit., Results: A total of 35 patients were enrolled in this study. Compared with baseline, tear film break-up time and fluorescein staining scores at 4, 8, and 12 weeks significantly improved in the CsN group. However, the Schirmer I test showed no statistically significant change until week 12. Using the Symptom Assessment in Dry Eye (SANDE) score, both groups gradually showed significant improvement compared with baseline values. However, the Dry Eye-Related Quality-of-life Score Questionnaire (DEQS) showed no statistically significant change during the treatment period., Conclusions: Both 0.05% CsN and 0.15% HA administration twice a day effectively improved the objective signs and subjective symptoms of patients with mild-to-moderate dry eyes. However, patients treated with 0.05% CsN experienced greater and faster improvement., (© 2024. The Author(s).)

Drug delivery is an important factor for the success of ocular drug treatment. However, several physical, biochemical, and flow-related barriers limit drug exposure of anterior and posterior ocular target tissues during drug treatment via topical, subconjunctival, intravitreal, or systemic routes. Mathematical models encompass various barriers so that their joint influence on pharmacokinetics (PKs) can be simulated in an integrated fashion. The models are useful in predicting PKs and even pharmacodynamics (PDs) of administered drugs thereby fostering development of new drug molecules and drug delivery systems. Furthermore, the models are potentially useful in interspecies translation and probing of disease effects on PKs. In this review article, we introduce current modeling methods (noncompartmental analyses, compartmental and physiologically based PK models, and finite element models) in ocular PKs and related drug delivery. The roles of top-down models and bottom-up simulations are discussed. Furthermore, we present some future challenges, such as modeling of intra-tissue distribution, prediction of drug responses, quantitative systems pharmacology, and possibilities of artificial intelligence.

Corneal abrasion is a frequent complication in critically ill, intubated patients, potentially leading to visual impairment. This study compares the efficacy of three ocular care methods in preventing corneal abrasion among this vulnerable population. We conducted a randomized controlled trial involving 156 intubated adult patients admitted to the ICU. Participants were randomly allocated to one of three intervention groups (n = 52 per group): (1) polyethylene cover only, (2) polyethylene cover with artificial tear drops, and (3) polyethylene cover with Lubratex eye ointment. One eye per patient was randomly assigned as the control, receiving standard ICU eye care. Daily assessments over five days included a standardized dryness and corneal abrasion checklist, graded strip evaluation of eye dryness, and documentation of corneal abrasion incidence. Data were analyzed using descriptive and inferential statistics (SPSS-18). The incidence of corneal abrasion was significantly lower in the group receiving polyethylene cover with Lubratex eye ointment (4%) compared to the polyethylene cover with artificial tears group (36%, p < 0.001) and the polyethylene cover only group (60%, p < 0.001). The combined application of a polyethylene cover with Lubratex eye ointment effectively prevents corneal abrasion in intubated ICU patients. This method demonstrates superior efficacy compared to polyethylene covers used alone or with artificial tears. We recommend its implementation as standard practice for corneal abrasion prophylaxis in this high-risk population.Trial Registration. This study is registered with the Iranian Registry of Clinical Trials (IRCT201506294736N8) and can be accessed at www.IRCT.ir ., (© 2024. The Author(s).)

Purpose: To assess the effectiveness of atropine 0.01% in slowing the progression of myopia in young patients., Methods: 2,387 patients with progressive myopia (more than -0.50 spherical diopters ‹D› increased in the last year) were enrolled. They received, every evening, one drop of atropine 0.01% in each eye. Refraction was then measured at baseline (T0) and once a year (T1, T2, T3, T4) for a 4-years follow-up period, and compared with a non-treated control group., Results: A reduction in the myopic progression was observed in the treated group respect to the control one. The average spherical refraction after 4 years increased by 27.06% in the treated group versus 241% of the control one. The difference in spherical increase between the two groups respect to time 0 was appreciable already at the first control, (T1 -T0, -0.21D vs. -1D) and continued to increase for all the 4-years follow-up period (T2-T0, -0.38D vs. -1.91D;T3-T0, -0.52D vs. -2.74D; T4-T0, -0.73D vs. -3.63D, respectively). It was always significant (P<0.01). Compared to the previous year, the average spherical increase was quite stable in the two groups (0.17 vs. 0.87, respectively). No significant tachyphylaxis or adverse effects were observed throughout the examination period., Conclusions: 0.01% atropine was effective in slowing the progression of myopia in the treated group vs. control one. The clinical effect was noticeable already from the first control, and continued for all the observation period. The results of this study agree with those already reported in literature, and confirm the validity of this treatment.

Purpose: This study aimed to investigate the relationship between diclofenac sodium ophthalmic solution (DFNa) and corneal epithelial cell damage and to evaluate the preventive effect of rebamipide (RBM) on it. Methods: DFNa, DFNa/preservative-free (PF), or 0.5% chlorobutanol (CB) solution was instilled into the conjunctival sac of a normal rabbit eye, and corneal resistance measurement (using a corneal resistance device [CRD]) was performed 120 min after the end of instillation. Then, fluorescent staining (FL), corneal tissue staining (hematoxylin and eosin [H&E]), and immunostaining (zona occlusion-1) were performed (RBM-untreated group). However, RBM was instilled into the eyes of another group of normal rabbits, followed by each of the solutions; 120 min after the end of instillation, all evaluations were performed for this group (RBM treatment group). Results: Using the CRD method, in the RBM-untreated group, corneal resistance (CR; %) was found to be significantly reduced in DFNa (79.9 ± 19.4%), DFNa/PF (89.1 ± 17.3%), and 0.5% CB (83.8 ± 10.6%). In addition, DFNa and 0.5% CB solutions showed positive staining in the FL staining method. In the H&E staining method, some clear voids were observed in the outermost layer of the cornea using DFNa and 0.5% CB solutions. However, corneal epithelial damage was suppressed in the RBM treatment group. ZO-1 immunostaining in DFNa and 0.5% CB solutions revealed discontinuous localization of ZO-1 at the cell periphery. Conclusions: RBM eye drops were effective in preventing corneal epithelial damage caused by DFNa eye drops, and CB was considered to be the main causative agent of this damage.

In spite of available treatment options, glaucoma continues to be a leading cause of irreversible blindness in the world. Current glaucoma medications have multiple limitations including: lack of sustained action; requirement for multiple dosing per day, ocular irritation and limited options for drugs with different mechanisms of action. Previously, we demonstrated that pregabalin, a drug with high affinity and selectivity for CACNA2D1, lowered IOP in a dose-dependent manner. The current study was designed to evaluate pregabalin microemulsion eye drops and to estimate its efficacy in humans using in silico methods. Molecular docking studies of pregabalin against CACNA2D1 of mouse, rabbit, and human were performed. Pregabalin microemulsion eye drops were characterized using multiple in vivo studies and its stability was evaluated over one year at different storage conditions. Molecular docking analyses and QSPR of pregabalin confirmed its suitability as a new IOP-lowering medication that functions using a new mechanism of action by binding to CACNA2D1 in all species evaluated. Because of its prolonged corneal residence time and corneal penetration enhancement, a single topical application of pregabalin ME can provide an extended IOP reduction of more than day in different animal models. Repeated daily dosing for 2 months confirms the lack of any tachyphylactic effect, which is a common drawback among marketed IOP-lowering medications. In addition, pregabalin microemulsion demonstrated good physical stability for one year, and chemical stability for 3-6 months if stored below 25 °C. Collectively, these outcomes greatly support the use of pregabalin eye drops as once daily IOP-lowering therapy for glaucoma management., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Purpose: To estimate the effect of atropine eyedrops at different concentrations for myopia control in children., Methods: We conducted a Bayesian random-effects network meta-analysis based on randomized controlled trials (RCT). Primary outcomes include changes in spherical equivalent error (SER) and changes in axial length (AL), mean difference (MD) together with 95% credible interval (CrI) were used to evaluate the efficacy., Results: 28 RCTs (6608 children) were included in this review. Comparing ten atropine eyedrops (0.0025%, 0.005%, 0.01%, 0.02%, 0.025%, 0.05%, 0.1%, 0.25%, 0.5% and 1% concentrations) with the placebo, the MDs and 95%CrIs of changes in SER are -0.006 (-0.269, 0.256) D, 0.216 (-0.078, 0.508) D, 0.146 (0.094, 0.199) D, 0.167 (0.039, 0.297) D, 0.201 (0.064, 0.341) D, 0.344 (0.251, 0.440) D, 0.255 (0.114, 0.396) D, 0.296 (0.140, 0.452) D, 0.331 (0.215, 0.447) D, and 0.286 (0.195, 0.337) D, respectively. The MDs and 95%CrIs of changes in AL are -0.048 (-0.182, 0.085) mm, -0.078 (-0.222, 0.066) mm, -0.095 (-0.130, -0.060) mm, -0.096 (-0.183, -0.009) mm, -0.083 (-0.164, -0.004) mm, -0.114 (-0.176, -0.056) mm, -0.134 (-0.198, -0.032) mm, -0.174 (-0.315, -0.061) mm, -0.184 (-0.291, -0.073) mm, and -0.171 (-0.203, -0.097) mm, respectively.Whether evaluated by SER or AL, 1% concentration ranks first in efficacy, but the risk of photophobia is 17 times higher than 0.01% concentration., Conclusions: 0.01% or higher concentration atropine eyedrops are effective for myopia control, while 0.0025% and 0.005% concentrations may not. As the concentration increases, the effect tends to increase, 1% concentration may have the strongest effect., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Purpose: To evaluate the therapeutic efficacy of topical application of a neurokinin-1 receptor (NK1R) antagonist in a rabbit model of nonallergic ocular redness. Methods: Nonallergic ocular redness was induced in rabbits by a single, topical application of dapiparzole hydrochloride eye drops (0.5%, 1%, 2%, or 5%). The NK1R antagonist L-703,606 was topically applied to the eye at the same time of induction or 20 min after induction, and phosphate buffered saline (PBS) treatment served as the control. Superior bulbar conjunctival images were taken every 30 s for the first 2 min, followed by every 4 min for 8 min, and then every 10 min until 1 h. The severity of ocular redness was evaluated on the images using ImageJ-based ocular redness index (ORI) calculations. Results: The ORI scores were significantly increased after the application of 0.5%, 1%, 2%, or 5% dapiparzole at each time point evaluated, with the most severe redness induced by the 5% dapiprazole that led to a maximal mean increase in ORI score of 14 at 20 min post-induction and thus used for subsequent evaluation of therapeutic efficacy of NK1R antagonism. Topical L-703,606, when applied at the same time as dapiprazole induction, significantly suppressed the increase of ORI scores at all time points (∼40% decrease). Furthermore, when applied at 20 min after dapiprazole induction, L-703,606 rapidly and effectively suppressed the increase of ORI scores at 30, 40, 50, and 60 min (∼30% decrease). Conclusions: Topical blockade of NK1R effectively prevents and alleviates nonallergic ocular redness in a novel animal model.

Purpose: To assess the clinical efficacy and safety of T2769, a new preservative-free eye drop combining hyaluronic acid (HA), trehalose and N-acetyl-aspartyl-glutamic acid (NAAGA), in dry eye patients., Patients and Methods: This was a multicenter, non-comparative, open-label study. After a run-in period with NaCl 0.9% solution, 62 patients with moderate-to-severe dry eye disease (DED) were included and treated with T2769, 3 to 6 times/day for 42 days. The primary efficacy endpoint was the change in global ocular symptomatology assessed on a visual analog scale between Day 1 (D1) and D42. Other efficacy endpoints included ocular surface disease index (OSDI), soothing sensation, individual dry eye symptoms, conjunctival hyperemia, global ocular staining, tear break-up time, Schirmer test, and global efficacy assessed by the investigator. Safety was assessed throughout the study., Results: A marked reduction in ocular symptomatology was observed from D1 to D42 with a mean change of -55.9±23.1mm (P<0.001). This was accompanied by a mean change in OSDI score from baseline of -44.6±15.9 (P<0.001) and a substantial soothing sensation in 82.3% of patients. Clinically significant improvements were observed for all ocular symptoms (mainly burning/irritation, stinging/pain, feeling of ocular dryness, foreign body sensation, itching/pruritus). Conjunctival hyperemia significantly decreased in 96.8% of patients (56.5% displayed no conjunctival hyperemia at D42 versus 0% at baseline). All signs and symptoms improved by D14 and further improved at D42. Investigators assessed the ocular efficacy of T2769 as very satisfactory or satisfactory for 91.9% of patients at D42. T2769 was well tolerated, with no ocular adverse events and only a few ocular symptoms upon instillation., Conclusion: Management of moderate-to-severe DED patients with the new formulation T2769, combining NAAGA to HA and trehalose, led to rapid and significant improvements in dry eye signs and symptoms with good tolerability., (Copyright © 2024. Published by Elsevier Masson SAS.)

Purpose: To examine if 12.5 μl timolol maleate 0.5% microdrops dispensed with the Nanodropper Adaptor provide noninferior intraocular pressure (IOP) reduction compared with conventional 28 μl drops in patients with open-angle glaucoma (OAG) and ocular hypertension (OHT)., Design: Prospective, noninferiority, parallel, multicenter, single-masked, active-controlled, randomized trial., Participants: Treatment-naïve subjects who were recently diagnosed with OAG and OHT at the Aravind Eye Care System., Methods: Both eyes of subjects received 1 commercially available drop or both eyes of subjects received 1 microdrop of timolol maleate 0.5%. We measured IOP, resting heart rate (HR), and blood pressure (BP) at baseline and 1, 2, 5, and 8 hours after timolol administration., Main Outcome Measures: The IOP was the primary outcome measure. Secondary outcomes were resting HR, systolic BP (sBP), and diastolic BP (dBP)., Results: Adaptor-mediated microdrops and conventional drops of timolol significantly decreased IOP compared with baseline at all timepoints. Noninferiority was established at 3 of 4 timepoints. Heart rate decreases with Nanodropper were approximately 3 beats per minute (bpm) less than with conventional drops., Conclusions: Timolol microdrops appear to be as effective in ocular hypotensive action as conventional drops with a slightly attenuated effect on resting HR and BP., Financial Disclosure(s): Proprietary or commercial disclosure may be found after the references., (Copyright © 2024 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Topical ocular sustained-release drug delivery systems represent an effective strategy for the treatment of ocular diseases, for which a suitable carrier has yet to be sufficiently developed. Herein, an eye-compatible sodium polystyrene sulfonate resin (SPSR) was synthesized with a uniform particle size of about 3 μm. Ligustrazine phosphate (LP) was adsorbed to SPSR by cation exchange to form LP@SPSR. LP@SPSR suspension eye drops were further developed using the combination of Carbopol 934P and xanthan gum as suspending agents. The LP@SPSR suspension showed a sustained release in vitro, which was consistent with the observed porcine corneal penetration ex vivo. Pharmacokinetics in tear fluid of rabits indicated that LP@SPSR suspension led to prolonged ocular retention of LP and a 2-fold improved the area under the drug concentration-time curve (AUC 0-t ). Pharmacokinetics in the aqueous humor of rabbits showed 2.8-fold enhancement in the AUC 0-t compared to LP solution. The LP@SPSR suspension exhibited no cytotoxicity to human corneal epithelial cells, nor irritation was observed in rabbit eyes. Thus, the LP@SPSR suspension has been validated as a safe and sustained release system leading to enhanced ophthalmic bioavailability for treating ocular diseases., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2024 American Pharmacists Association. Published by Elsevier Inc. All rights reserved.)

Treatment of ocular diseases presents unique challenges and opportunities for the clinician and for the clinical pharmacologist. Ophthalmic pharmaceuticals, typically given as liquids, require consideration of solubility, physiological pH, and osmolarity, as well as sterility and stability, which in turn requires optimal pharmaceutics. Ocular tissue levels are challenging to obtain in humans, and the clinical pharmacokinetics is typically blood levels, which are primarily related to safety, rather than efficacy. The eye is a closed compartment with multiple physiological barriers with esterases and transporters, but relatively little cytochrome oxidases. Delivery routes include topical, intravitreal, and systemic. Patient dosing involves not only adherence issues common to all chronic diseases, but also performance requirements on eye drop instillation. Therapeutically, ocular diseases and their pharmacological treatments include both those analogous to systemic diseases (e.g., inflammation, infection, and neuronal degeneration) and those unique to the eye (e.g., cataract and myopia)., (© 2024, The American College of Clinical Pharmacology.)

Exploiting a convenient and highly bioavailable ocular drug delivery approach is currently one of the hotspots in the pharmaceutical industry. Eyelid topical application is seen to be a valuable strategy in the treatment of chronic ocular diseases. To further elucidate the feasibility of eyelid topical administration as an alternative route for ocular drug delivery, pharmacokinetic and pharmacodynamic studies of pilocarpine were conducted in rabbits. Besides, a novel physiologically based pharmacokinetic (PBPK) model describing eyelid transdermal absorption and ocular disposition was developed in rabbits. The PBPK model of rabbits was extrapolated to human by integrating the drug-specific permeability parameters and human physiological parameters to predict ocular pharmacokinetic in human. After eyelid topical application of pilocarpine, the concentration of pilocarpine in iris peaked at 2 h with the value of 18,724 ng/g and the concentration in aqueous humor peaked at 1 h with the value of 1,363 ng/mL. Significant miotic effect were observed from 0.5 h to 4.5 h after eyelid topical application of pilocarpine in rabbits, while that were observed from 0.5 h to 3.5 h after eyedrop instillation. The proposed eyelid PBPK model was capable of reasonably predicting ocular exposure of pilocarpine after application on the eyelid skin and based on the PBPK model, the human ocular concentration was predicted to be 10-fold lower than that in rabbits. And it was suggested that drugs applied on the eyelid skin could transfer into the eyeball through corneal pathway and scleral pathway. This work could provide pharmacokinetic and pharmacodynamic data for the development of eyelid drug delivery, as well as the reference for clinical applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 American Pharmacists Association. Published by Elsevier Inc. All rights reserved.)

Purpose: To evaluate the safety and tolerability of pooled human immune globulins, Flebogamma ® 5% DIF and Flebogamma ® 10% DIF, administered by topical ophthalmic instillation to New Zealand White (NZW) rabbits., Methods: Male NZW rabbits were used in this study. In the acute single dose tolerability study, rabbits (n = 12) received a single topical dose of Flebogamma ® 5% DIF. In the two-week repeated-dose tolerability study, rabbits (n = 5 for each group) were administered either Flebogamma ® 5% DIF or Flebogamma ® 10% DIF by topical bilateral administration four times daily (q.i.d.) between 8 am and 6 pm for a period of two weeks. Full ophthalmic examinations were conducted to evaluate ocular tolerability at baseline, Day 7, and Day 14., Results: In the acute single dose study, mild hyperaemia was observed in 1 out of 4 eyes at each 4 h and 24 h post-instillation of Flebogamma ® 5% DIF. In the repeated dose study, no ocular signs were detected after q.i.d. topical instillation of Flebogamma ® 5% DIF, while Flebogamma ® 10% DIF resulted in mild hyperaemia in 8 out of 10 eyes on Day 7, and 5 out of 10 eyes on Day 14. No positive corneal fluorescein staining was detected. Schirmer tear test results were unremarkable. No other ocular signs were observed. Administration of immune globulins had no effect on intraocular pressure., Conclusions: Flebogamma ® 5% DIF and Flebogamma ® 10% DIF were well-tolerated by NZW rabbits following single and repeat dose topical ophthalmic administration, supporting the future development of topical pooled human immune globulins for the treatment of ocular surface disease.

Purpose: To investigate the effects of topically applied 1% tropicamide, 2.5% phenylephrine and 1% cyclopentolate on retinal vessel calliper (VC) using optical coherence tomography (OCT)., Methods: Patients who came to the ophthalmology clinic for routine examination and whose OCT films were taken before dilatation and after 30 min of last dilatation drop were included in the study. 90 ophthalmologically healthy subjects were divided into 3 groups of 30 subject each according to the application of the drops as follows: Tropicamide group (Group 1), Phenylephrine group (Group 2), Cyclopentolate group (Group 3). The right eyes of the subjects were dilated with drops and the left eyes were taken as the control group. VC of retinal artery and vein passing through an area one-half to one-disc diameter from the optic disc margin were measured from OCT films. The mean of the sum of superior retinal artery (SRA) and inferior retinal artery (IRA) VC and the mean of the sum of superior retinal vein (SRV) and inferior retinal vein (IRV) VC before and after the drop were compared., Results: There was no statistically significant change in the mean sum of SRA and IRA VC and the mean sum of SRV and IRV VC before and after dilatation drops in all three groups., Conclusion: Dilatation drops have no statistically significant effect on retinal artery and vein VC.

Purpose: To evaluate a commercially available dexamethasone intracanalicular insert to treat dry eye., Design: Single-center, double-masked randomized controlled trial., Participants: Patients with clinically significant aqueous-deficient dry eye (combined ocular surface staining score, ≥ 3 [0-12]; corneal fluorescein staining score, ≥ 2 [0-6]; and Schirmer's wetting, < 10 mm at 5 minutes in both eyes) with symptoms (dryness, eye discomfort, or visual fatigue, ≥ 30 [0-100]) despite treatment with at least 1 prescription drop and deemed candidates for topical steroid therapy., Methods: Seventy-five adult patients were enrolled. A 1:1 randomization sequence was used to determine which eye of each patient would receive the treatment (dexamethasone 0.4-mg intracanalicular insert with 30-day elution time) or sham (collagen plug). The fellow eye received the opposite treatment. Patients were masked to treatment assignment. Follow-up visits (at weeks 2, 4, and 6) were performed by a masked investigator., Main Outcome Measures: Dry eye parameters and patient symptoms were used for efficacy, and intraocular pressure (IOP) was used for safety assessment., Results: The severity of dry eye was comparable between the treatment arms (fellow eyes) at baseline. Eyes that received the dexamethasone insert showed significantly less corneal staining at week 4 (mean difference [MD], -0.55; 95% confidence interval [CI], -0.91 to -0.19) and conjunctival staining at week 4 (MD, -0.68; 95% CI, -1.05 to -0.30) and week 6 (MD, -0.34; 95% CI, -0.65 to -0.02). Schirmer's wetting was comparable between the two treatment arms. Although the patients reported less dryness in eyes that received the insert at week 4 (MD, -5.5; 95% CI, -11.4 to 0.4), no statistically significant differences were found in any patient-reported symptoms. At week 4, dexamethasone-treated eyes were more likely to show an IOP increase (by 5-10 mmHg; 9 eyes vs. 1 eye; relative risk, 9.00; 95% CI, 1.14-71.0). All cases of increased IOP were managed with short-term topical β-blockers and subsided., Conclusions: The dexamethasone intracanalicular insert may be considered a dropless dual treatment for clinically significant aqueous-deficient dry eye when topical steroid treatment is deemed appropriate., Financial Disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article., (Copyright © 2024 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Background: Topical non-steroidal anti-inflammatory drugs have the potential to reduce treatment burden and improve outcomes of anti-VEGF therapy for a number of retinal disorders, including neovascular age-related macular degeneration, diabetic macular edema, and retinal vein occlusions. In this review, we focused on the advantages of topical bromfenac as an adjunct to intravitreal anti-VEGF therapy in VEGF-driven maculopathies., Methods: Cochrane Library, PubMed, and EMBASE were systematically reviewed to identify the relevant studies of neovascular age-related macular degeneration, diabetic macular edema, macular edema associated with retinal vein occlusion, myopic choroidal neovascularization, and radiation maculopathy which reported changes in central retinal thickness, visual acuity, and the number of anti-VEGF injections needed when anti-VEGF therapy was combined with topical bromfenac., Results: In total, ten studies evaluating bromfenac as an adjunct to anti-VEGF therapy were identified. Five studies were included in meta-analysis of the number of injections and five studies were included in the analysis of changes in central retinal thickness. A statistically significantly lower number of intravitreal injections (p = 0.005) was required when bromfenac was used as an adjunct to anti-VEGF therapy compared to anti-VEGF monotherapy with pro re nata regimen. At the same time, eyes receiving bromfenac as an adjunct to anti-VEGF therapy demonstrated non-inferior outcomes in central retinal thickness (p = 0.07). Except for one study which reported better visual outcomes with combined treatment, no difference in visual acuity or clinically significant adverse effects were reported., Conclusions: This literature review and meta-analysis showed that topical bromfenac can be considered as a safe adjunct to anti-VEGF therapy with a potential to reduce the treatment burden with anti-VEGF drugs requiring frequent injections without compromising improvement of central retinal thickness or visual acuity., (© 2024. The Author(s).)

In a joint study carried out by Gerresheimer, Sterigenics and Früh, it could be shown that also NO 2 is well suited to terminally sterilize prefilled ophthalmic syringes. In detail 5 topics were addressed: (1) Compare EtO vs. NO 2 penetration into the filled syringe; (2) Analyze gas ingress though 4 different plunger stoppers including silicone oil free and standard rubber plungers; (3) Scrutinize gas ingress through 2 different cap designs based on different elastomer properties; (4) Investigate gas permeation through COP plastic barrels compared to glass; (5) Check if the Tyvek®-layer has an influence on either sterilization.Depending on the needs a suitable sterilization method, packaging and syringe type can be suggested to customers., (© PDA, Inc. 2024.)

Purpose: This study investigated the effects of an eye care protocol (ECP) on patients in the intensive care unit (ICU)., Methods: This study utilized a randomized controlled design. Participants were patients who met the inclusion criteria and were admitted to the ICU (36 in the experimental group and 38 in the control group). The experimental group received an ECP, while the control group received standard eye care, starting the day after admission, for a duration of 10 days. The ECP classifies the degree of eyelid obstruction into three stages based on the degree of exposure to the lower eyelid conjunctiva and cornea. The protocol included cleansing with normal saline gauze, administering eye drops, applying silicone and polyurethane films, and recommending consultation with an ophthalmologist if necessary. The effectiveness of ECP was assessed by analyzing tear volume, hyperemia, chemosis, and eye discharge. Data analysis was conducted using SPSS 27.0, employing the Mann-Whitney U-test and generalized estimating equations., Results: On day 5, the experimental group demonstrated a significant increase in tear volume in both eyes compared with the control group. However, no statistically significant differences were observed in the incidence of hyperemia, chemosis, and eye discharge on days 5 and 10 of the intervention., Conclusion: The application of the ECP in this study increased tear volume in ICU patients, thereby reducing discomfort caused by dry eyes. It has the potential to prevent complications such as damage to the surface of the eyeball resulting from decreased tear volume., Competing Interests: The authors declared no conflict of interest., (© 2024 Korean Society of Nursing Science.)

To investigate the changes in meibomian gland dysfunction (MGD) and tear matrix metalloproteinase-9 (MMP-9) levels in patients with moderate-to-severe MGD after combined treatment with intense pulsed light (IPL) therapy and cyclosporine 0.05%. Thirty-six patients concurrently treated with IPL and cyclosporine 0.05% ophthalmic drops were retrospectively enrolled. Tear break up time (TBUT), corneal and conjunctival staining scores, Schirmer test, and ocular surface disease index (OSDI) questionnaire responses were recorded. Meibum quality, consistency, and eyelid margin telangiectasia were evaluated. MMP-9 levels were examined by the positivity and signal intensity of red lines (scored 0-4). IPL was performed four times with a vascular filter at 2-week intervals, followed by a 1-month follow-up after treatment cessation. Immediately after each IPL treatment, gentle meibomian gland expression was performed in both the upper and lower eyelids using meibomian gland expressor forceps. TBUT (1.88 ± 1.02 s to 3.12 ± 1.08 s, p < 0.001), corneal and conjunctival staining (6.19 ± 2.11 to 3.12 ± 1.89, p < 0.001), Oxford staining grade (2.66 ± 0.89 to 1.35 ± 0.76, p < 0.001), and OSDI (52.97 ± 21.86 to 36.36 ± 22.45, p < 0.001) scores significantly improved after the combined treatment. Meibum quality, consistency and lid margin telangiectasia showed significant post-treatment improvement in both the upper and lower eyelids. MMP-9 positivity showed a significant decrease (97-69%, p = 0.026) with a reduction in signal intensity (2.72 ± 0.87 to 2.09 ± 0.95, p = 0.011). The combination of IPL therapy and 0.05% cyclosporine eye drops effectively treats moderate-to-severe MGD by reducing symptoms and signs of MGD and by decreasing ocular surface MMP-9-associated inflammation., (© 2024. The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature.)

Purpose: The purpose of this study was to evaluate the safety and efficacy of topical losartan in the therapeutic treatment of established corneal scaring fibrosis at 1 month after alkali burn in rabbits., Methods: Standardized alkali burns were performed in 1 eye of 24 rabbits with 0.75N NaOH for 15 seconds. Corneas were allowed to heal and develop scaring of the cornea for 1 month. Twelve eyes per group were treated with 50 µL of topical 0.8 mg/mL losartan in balanced salt solution (BSS), pH 7.0, and 12 eyes were treated with vehicle BSS 6 times per day. Six corneas were analyzed at 1 week or 1 month in each group. Standardized slit lamp photographs were obtained at the end point for each cornea and opacity was quantitated using ImageJ. Corneoscleral rims were cryofixed in optimum cutting temperature (OCT) solution and combined duplex immunohistochemistry for myofibroblast marker alpha-smooth muscle actin (α-SMA), mesenchymal cell marker vimentin, and TUNEL assay for apoptosis was performed on all corneas., Results: Topical losartan was effective in the treatment of established stromal fibrosis following alkali burn injury to the rabbit cornea. Stromal myofibroblast density was decreased and stromal cell apoptosis was increased (included both α-SMA-positive myofibroblasts and α-SMA-negative, vimentin-positive cells) at both 1 week and 1 month in the topical losartan-treated compared with vehicle-treated groups., Conclusions: Topical losartan is effective in the treatment of established stromal fibrosis in rabbits. Most myofibroblasts disappear from the stroma within the first month of losartan treatment. Longer treatment with topical losartan is needed to allow time for corneal fibroblast regeneration of the epithelial basement membrane (in coordination with epithelial cells) and the removal of disordered extracellular matrix produced by myofibroblasts.

Purpose: The aim of this study was to evaluate the 1-year outcomes of using processed amniotic fluid (pAF) postoperatively after photorefractive keratectomy (PRK)., Methods: Sixty-one participants were randomized to receive either placebo or pAF drops. The drops were instilled 4 times daily for 1 week after PRK along with routine postoperative medications. The primary outcome measures included uncorrected visual acuity, topographic corneal irregularity measurement, and surface staining over 1 year., Results: A statistically significant difference in uncorrected distance visual acuity between the placebo and treatment groups was seen at 1 month post-PRK, with a visual advantage evident in the pAF group. A suggestive difference in corneal irregularity measurement was also seen between the placebo and treatment groups at 1 month postsurgery, with less irregularity noted in the pAF group. No differences in uncorrected distance visual acuity or corneal irregularity measurement were found at 3, 6, and 12 months. There was also no significant difference in corneal staining scores between the 2 groups at any of the measured time points., Conclusions: This 1-year study evaluating the safety and efficacy of pAF as an additional postoperative topical medication after PRK demonstrated that pAF offered a mild visual advantage at 1 month post-PRK. There were no late adverse events, and the intervention proved safe at 1 year., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background and Aims: Serum eye drops alleviate ocular symptoms of diseases such as sicca syndrome, or chronic graft-versus-host disease. This study was designed for good manufacturing practice validation of our standard manufacturing, storage and transport processes for both autologous and allogenic SEDs. Specifications of quality parameters are lacking and were aimed to be defined., Methods: Using sterile collected, coagulated whole blood, serum was separated by centrifugation and filled into single-use eye drop applicator vials. Quality control tests included visual inspection, sterility, leukocyte concentration, pH, vitamin A, TGF-ß and VEGF-A. Samples were collected after manufacture and after 24 h and 6 months of frozen storage (-20°C). Sterility testing was performed after opening the SED applicators at specified intervals. For transport validation, SEDs were packed in insulated transport bags and stored at 20-24°C and 30-32°C for 8 h., Results: Vitamin A, TGF-ß and VEGF-A assays showed no difference in concentration between fresh and 24 h frozen serum. All specifications for pH (aim 7.4) and cellular contamination were met and microbiological contamination tests were negative. Shelf-life was defined as 6 months at -20°C. Once opened, the product must be used within 24 h to avoid bacterial outgrowth. Transporting frozen SEDs from the manufacturer via a local pharmacy to the patient within a maximum of 4 h was demonstrated., Conclusions: The GMP compliance of our production, storage and transport processes for autologous and allogenic SEDs was successfully validated. 100% serum eye drops in single-use applicators can be safely used for up to 24 h after opening., (© 2024 The Author(s). Transfusion Medicine published by John Wiley & Sons Ltd on behalf of British Blood Transfusion Society.)

Purpose: To assess the safety and efficacy of transzonular moxifloxacin and dexamethasone versus standard postoperative topical drug regimen in phacoemulsification., Design: Nonrandomized prospective study., Methods: The study included 100 eyes of 100 age and gender-matched individuals with senile cataract undergoing routine phacoemulsification. The patients were consecutively divided into transzonular (TZ = 50) and topical (TP = 50) groups. Both the groups were followed up for 4 weeks and assessed for intraocular inflammation, visual acuity, changes in intraocular pressure (IOP), and any adverse events., Results: The grades of inflammation were significantly lower in TZ as compared to the TP group ( P < 0.001). The IOP remained normal and comparable in both the groups. Most of the patients in the two groups attained a visual acuity of 0.2 or better at the end of the follow-up. No adverse effects and increased rate of endophthalmitis were noted in TZ group., Conclusion: A one-time peroperative TZ moxifloxacin and dexamethasone combination is a safe and effective method to control postoperative inflammation after cataract surgery. A word of caution though, due precautions to be exercised to prevent the risk of inflammation and endophthalmitis., (Copyright © 2024 Copyright: © 2024 Indian Journal of Ophthalmology.)

Objectives: To investigate the effect of topical 0.05% cyclosporine A (CsA) eye drops as an adjunct to conventional therapy in maintaining post-femtosecond-assisted laser in situ keratomileusis (FS-LASIK) ocular surface stability., Methods: Sixty-six patients (eyes) undergoing FS-LASIK were randomized into 2 groups: 33 patients (eyes) in group I (conventional treatment group) and 33 patients (eyes) in group II (CsA group). Conventional treatments include topical levofloxacin, fluorometholone, and artificial tears. Group II received topical 0.05% CsA eye drops twice daily for three months in addition to conventional treatment. Ocular Surface Disease Index (OSDI), numerical rating scale (NRS), tear break-up time (TBUT), Schirmer I test (SIt), corneal fluorescein staining (CFS), conjunctival lissamine green (LG) staining, corneal sensitivity, and corneal nerve morphology were measured. In addition, tear inflammatory cytokine levels were measured using the Luminex assay. Follow-up was performed preoperatively and 1 and 3 months postoperatively., Results: In the CsA group, OSDI, TBUT, LG, corneal sensitivity, and corneal nerve fiber total branch density recovered better than in the conventional treatment group. As for tear inflammatory cytokines, interferon (INF) -γ, interleukin (IL)-10, and IL-6 levels were significantly higher in the conventional treatment group as compared with the CsA group. In addition, no significant differences in NRS, SIt, and CFS scores were observed between the two groups., Conclusion: In conclusion, 0.05% CsA eye drops is a useful adjunct to conventional treatment for restoring the ocular surface stability after corneal refractive surgery and is more potent in sustaining anti-inflammatory effects., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the Contact Lens Association of Opthalmologists.)

Efficient topical drug delivery remains a significant challenge in glaucoma management. Although nanoparticle formulations offer considerable promise, their complex preparation processes, co-delivery issues, and batch consistency have hindered their potential. A scalable fabrication strategy is developed here for preparing solid drug nanoparticles (SDNs) with enhanced drug delivery efficiency. Utilizing hydrophobic antiglaucoma drugs brimonidine (BM) and betaxolol (BX), uniform fixed combination BM/BX SDNs are fabricated through a continuous process, improving batch-to-batch consistency for combined glaucoma treatment. With trehalose being used as a lyoprotectant, BM/BX SDNs can be stored as dry powder and easily reconstituted in phosphate buffered saline. Importantly, reconstituted BM/BX SDNs form clear, homogenous solutions, and exhibit negligible cytotoxicity and irritation, making them well-suited for topical administration as eyedrops. Ex vivo and in vivo studies demonstrated that topically applied BM/BX SDNs permeate through the cornea significantly (about two fold to three fold) compared to their hydrophilic counterparts, i.e., brimonidine tartrate, and betaxolol hydrogen chloride. Notably, BM/BX SDNs displayed consistent intraocular pressure lowering effects in vivo in both normotensive rats and glaucoma mice. Collectively, this study demonstrates the potential of the scalable fabrication strategy and the resultant BM/BX SDNs for improving glaucoma management through eyedrops., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Purpose: To assess the feasibility of theranostics to determine the riboflavin concentration in the cornea using clinically available ophthalmic formulations during epithelium-off (epi-off) and transepithelial (epi-on) corneal cross-linking procedures., Methods: Thirty-two eye bank human donor corneas were equally randomized in eight groups; groups 1 to 3 and groups 4 to 8 underwent epi-off and epi-on delivery of riboflavin respectively. Riboflavin ophthalmic solutions were applied onto the cornea according to the manufacturers' instructions. The amount of riboflavin into the cornea was estimated, at preset time intervals during imbibition time, using theranostic UV-A device (C4V CHROMO4VIS, Regensight srl, Italy) and expressed as riboflavin score (d.u.). Measurements of corneal riboflavin concentration (expressed as µg/cm 3 ) were also performed by spectroscopy absorbance technique (AvaLight-DH-S-BAL, Avantes) for external validation of theranostic measurements., Results: At the end of imbibition time in epi-off delivery protocols, the average riboflavin score ranged from 0.77 ± 0.38 (the average corneal riboflavin concentration was 213 ± 190 µg/cm 3 ) to 1.79 ± 0.07 (554 ± 103 µg/cm 3 ). In epi-on delivery protocols, the average riboflavin score ranged from 0.17 ± 0.01 to 0.67 ± 0.19 (corneal riboflavin concentration ranged from 6 ± 5 µg/cm 3 to 122 ± 39 µg/cm 3 ) at the end of imbibition time. A statistically significant linear correlation (P ≤ 0.05) was found between the theranostic and spectrophotometry measurements in all groups., Conclusions: Real-time theranostic imaging provided an accurate strategy for assessing permeation of riboflavin into the human cornea during the imbibition phase of corneal cross-linking, regardless of delivery protocol. A large variability in corneal riboflavin concentration exists between clinically available ophthalmic formulations both in epi-off and epi-on delivery protocols., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: To compare the efficacy of a 0.15% HA with that of 0.1% HA eye drops for DES after cataract surgery., Methods: This study was double blinded, randomized and prospective study, and conducted in 69 participants (70 eyes) from Pusan National University Yangsan Hospital and executed from February 1, 2022 to November 30, 2022. Participants were adult cataract patients with normal lid position, not suffering from any other ocular disease and not meet the exclusion cirteria of clinical trial. Participants were randomly divided into two groups: 35 participants (17 males and 18 females) in the 0.1% HA group and 34 participants (19 males and 15 females) in the 0.15% HA group, receiving treatment six times daily for 6 weeks following cataract surgery. Subjective and objective assessments were performed at preoperative and postoperative visits, including ocular surface disease index score, tear break up time, corneal staining score, Schirmer's I test score, lipid layer thickness), meiboscore, and biochemical analysis of the eye drops., Results: Throughout the study, the postoperative ocular surface disease index score was significantly lower in the group receiving 0.15% hyaluronic acid than in the group receiving 0.1% hyaluronic acid. Additionally, the postoperative ocular surface disease index score showed a significant positive correlation with the postoperative use of 0.15% hyaluronic acid and the preoperative Schirmer's I test score. In multivariate analysis, treatment with 0.15% hyaluronic acid and the preoperative ocular surface disease index score were significant independent parameters affecting the postoperative ocular surface disease index score., Conclusion: The use of 0.15% hyaluronic acid is recommended for its potential advantages in alleviating symptoms following cataract surgery, making it a viable alternative to traditional 0.1% hyaluronic acid treatment., Trial Registration: ISRCTN95830348., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Yang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Purpose: This study evaluates the long-term adjunctive use of netarsudil ophthalmic solution 0.02% in lowering IOP in patients with refractory glaucoma., Methods: This retrospective chart review study was conducted at a tertiary care center. Patients who were prescribed add-on netarsudil therapy and on ≥ 3 topical glaucoma medications from 01/01/2018 to 08/31/2020 were reviewed. 47 patients (69 eyes) met the inclusion criteria. Baseline IOPs prior to the addition of netarsudil were compared to IOPs measured at 3-, 6-, and 12-month intervals. Any patients with inadequate follow-up or who had glaucoma surgery after netarsudil initiation were excluded., Results: Median baseline IOP (± SD) was 21 ± 5.8 mmHg (median of 2 visits prior to initiation of netarsudil). At 3-month follow-up, 64 eyes had a median IOP of 16 ± 6.7 mmHg (p < 0.01). At 6-month follow-up, 56 eyes had a median IOP of 18 ± 4.6 mmHg (p < 0.01). At 12-month follow-up, 44 eyes had a median IOP of 15 ± 6.8 mmHg (p < 0.01). At the conclusion of the study, 64% of eyes reached 1 year follow-up due to several reasons., Conclusions: Patients with refractory glaucoma showed statistically and clinically significant IOP reductions on netarsudil. IOP reduction was stable long-term with the largest decrease in IOP seen at 12 months. Although some patients will still go on to require further laser or incisional surgery, for most patients netarsudil is an effective treatment for adjunctive use in refractory glaucoma., (© 2024. The Author(s).)

Atropine sulfate (ATS) eye drops at low concentrations constitute a limited selection for myopia treatment, with challenges such as low ophthalmic bioavailability and inadequate stability. This study proposes a novel strategy by synthesizing ophthalmic sodium polystyrene sulfonate resin (SPSR) characterized by a spherical shape and uniform size for cationic exchange with ATS. The formulation of ATS@SPSR suspension eye drops incorporates xanthan gum and hydroxypropyl methylcellulose (HPMC) as suspending agents. In vitro studies demonstrated that ATS@SPSR suspension eye drops exhibited sustained release characteristics, and tropic acid, its degradation product, remained undetected for 30 days at 40 °C. The ATS levels in the tear fluids and aqueous humor of New Zealand rabbits indicated a significant increase in mean residence time (MRT) and area under the drug concentration-time curve (AUC 0-12 h ) for ATS@SPSR suspension eye drops compared to conventional ATS eye drops. Moreover, safety assessment confirmed the non-irritating nature of ATS@SPSR suspension eye drops in rabbit eyes. In conclusion, the cation-responsive sustained-release ATS@SPSR suspension eye drops enhanced the bioavailability and stability of ATS, offering a promising avenue for myopia treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

With an ever-increasing burden of vision loss caused by diseases of the posterior ocular segment, there is an unmet clinical need for non-invasive treatment strategies. Topical drug application using eye drops suffers from low to negligible bioavailability to the posterior segment as a result of static and dynamic defensive ocular barriers to penetration, while invasive delivery systems are expensive to administer and suffer potentially severe complications. As the cornea is the main anatomical barrier to uptake of topically applied drugs from the ocular surface, we present an approach to increase corneal permeability of a corticosteroid, dexamethasone sodium-phosphate (DSP), using a novel penetration enhancing agent (PEA). We synthesised a novel polyacetylene (pAc) polymer and compared its activity to two previously described cell penetrating peptide (CPP) based PEAs, TAT and penetratin, with respect to increasing transcorneal permeability of DSP in a rapid ex-vivo porcine corneal assay over 60 min. The transcorneal apparent permeability coefficients (P app ) for diffusion of pAc, and fluorescein isothiocyanate (FITC) conjugated TAT and penetratin were up to 5 times higher (p < 0.001), when compared to controls. When pAc was used in formulation with DSP, an almost 5-fold significant increase was observed in P app of DSP across the cornea (p = 0.0130), a significant 6-fold increase with TAT (p = 0.0377), and almost 7-fold mean increase with penetratin (p = 0.9540). Furthermore, we investigated whether the PEAs caused any irreversible damage to the barrier integrity of the corneal epithelium by measuring transepithelial electrical resistance (TEER) and immunostaining of tight junction proteins using zonula occludens-1 (ZO-1) and occludin antibodies. There was no damage or structural toxicity, and the barrier integrity was preserved after PEA application. Finally, an in-vitro cytotoxicity assessment of all PEAs in human retinal pigment epithelium cells (ARPE-19) demonstrated that all PEAs were very well-tolerated, with IC 50 values of 64.79 mM for pAc and 1335.45 µM and 87.26 µM for TAT and penetratin, respectively. Our results suggest that this drug delivery technology could potentially be used to achieve a significantly higher intraocular therapeutic bioavailability after topical eye drop administration, than currently afforded., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)