Patient Acceptance of Sustained Glaucoma Treatment Strategies

Melanin-Binding-Based Discovery of Topically Instilled Carbonic Anhydrase Inhibitors for Targeted Delivery and Prolonged Action in the Eye

Glaucoma is a vision-threatening disease that is currently treated with intraocular-pressure-reducing eyedrops that are instilled once or multiple times daily. Unfortunately, the treatment is associated with low patient adherence and suboptimal treatment outcomes. We developed carbonic anhydrase II inhibitors (CAI-II) for a prolonged reduction of intraocular pressure (IOP). The long action is based on the melanin binding of the drugs that prolongs ocular drug retention and response. Overall, 63 new CAI-II compounds were synthesized and tested for melanin binding in vitro. Carbonic anhydrase affinity and IOP reduction of selected compounds were tested in rabbits. Prolonged reduction of IOP in pigmented rabbits was associated with increasing melanin binding of the compound. Installation of a single eye drop of a high melanin binder carbonic anhydrase inhibitor (CAI) resulted in ≈2 weeks' decrease of IOP, whereas the effect lasted less than 8 h in albino rabbits. Duration of the IOP response correlated with melanin binding of the compounds. Ocular pharmacokinetics of a high melanin binder compound was studied after eye drop instillation to the rat eyes. The CAI showed prolonged drug retention in the pigmented iris-ciliary body but was rapidly eliminated from the albino rat eyes. The melanin-bound drug depot maintained effective free concentrations of CAI in the ciliary body for several days after application of a single eye drop. In conclusion, melanin binding is a useful tool in the discovery of long-acting ocular drugs.

Liposomal topical drug administration surpasses alternative methods in glaucoma therapeutics: a novel paradigm for enhanced treatment

OBJECTIVES

Glaucoma is a leading cause of permanent blindness. Despite therapeutic advancements, glaucoma management remains challenging due to limitations of conventional drug delivery, primarily topical eye drops, resulting in suboptimal outcomes and a global surge in cases. To address these issues, liposomal drug delivery has emerged as a promising approach.

KEY FINDINGS

This review explores the potential of liposomal-based medications, with a particular focus on topical administration as a superior alternative to enhance therapeutic efficacy and improve patient compliance compared to existing treatments. This writing delves into the therapeutic prospects of liposomal formulations across different administration routes, as evidenced by ongoing clinical trials. Additionally, critical aspects of liposomal production and market strategies are discussed herein.

SUMMARY

By overcoming ocular barriers and optimizing drug delivery, liposomal topical administration holds the key to significantly improving glaucoma treatment outcomes.

Elucidating acceptance and clinical indications to support the rational design of drug-eluting contact lenses

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.

A Survey on Patients' Opinions of Alternative Drug Delivery Systems for the Treatment of Glaucoma in South-South Nigeria

PURPOSE

Despite the human ocular surface being easily accessible, ocular drug delivery can be challenging. When applied improperly, topical medications, the most popular first-line treatment used to treat glaucoma, can have a very brief contact time with the ocular surface and may not have the desired therapeutic impact. Drug delivery devices are gadgets that can address some of these problems. This study aims to determine patients' opinions on ocular drug delivery devices used in the treatment of primary open-angle glaucoma (POAG).

METHODS

A pretested interviewer-administered questionnaire was used in a cross-sectional study of 115 POAG patients recruited from outpatient clinics in two Nigerian tertiary health institutions. Participants were asked about their understanding and acceptance of five Ocular drug delivery systems (ODD), namely drug-emitting contact lenses (CL), punctual plugs, subconjunctival injections, intracameral implants, and trabecular meshwork micro-stents, for the treatment of POAG.

RESULTS

Sixty (52.2%) participants, whose average age was 50 ± 9.8 years, were men. Self-pay was used for eye health treatments by 65% of participants. Of the participants, 68.7% admitted to using eye drops on their own. 57% of people were said to take their glaucoma medications consistently. CL and subconjunctival implants were seen to be most acceptable according to 39% and 30% of participants, respectively. Major factors determining the acceptability of ODD for POAG treatment were observed to be cost and effectiveness.

CONCLUSION

Patients in our cohort who are being treated for POAG have a fairly positive attitude towards ODD. The prospective use of these devices for POAG treatment in Nigeria will depend on their efficacy and cost, as well as how ophthalmologists will weigh ODD options.

Applying the Health Belief Model to predict preference for surgical intervention versus medical therapy among patients with open-angle glaucoma

Objective

To determine the factors influencing patient preference of surgical intervention versus medical therapy for open-angle glaucoma based on the Health Belief Model.

Methods and analysis

The study is a cross-sectional study. The study was conducted on 309 patients having open-angle glaucoma attending glaucoma clinic at Alexandria Ophthalmology Hospital, Alexandria, Egypt. The patients were subjected to an interview questionnaire comprising demographic data, patient knowledge and beliefs about glaucoma, glaucoma medications and treatment options, and patient preference of treatment modality, based on the Health Belief Model.

Results

About half of the patients (46%) were found to prefer surgical intervention. Patients were less knowledgeable about glaucoma, in general, but knowledge scores of patients preferring surgical intervention were significantly higher than those preferring medical therapy (Percentage Mean Score, PMS: 42.46%–37.37%, respectively). Male and female patients using more medications were significantly more likely to prefer surgical intervention (p=0.015 and p=0.003, respectively). Patients having preference for surgical intervention reported higher scores for perceived susceptibility and severity of long-term medical therapy (PMS=72.61% vs 54.62%–68.62% versus 52.83%, respectively), higher scores for perceived benefits of surgical intervention (PMS=92.90% vs 43.96%, respectively) and higher scores for self-efficacy (PMS=97.18% vs 50.37%, respectively). Meanwhile, they obtained lower scores for perceived barriers to surgical intervention (PMS=53.43% vs 86.07%, respectively).

Conclusions

Male gender, increased number of used eye-drops and more knowledge about glaucoma were significantly associated with patient preference for surgical intervention. Perceived benefits and barriers and self-efficacy were the significant predictors for patient surgical interference preference.

Enhanced topical corticosteroids delivery to the eye: A trade-off in strategy choice

Topical corticosteroids are the primary treatment of ocular inflammation caused by surgery, injury, or other conditions. Drug pre-corneal residence time, drug water solubility, and drug corneal permeability coefficient are the major factors that determine the ocular drug bioavailability after topical administration. Although growing research successfully enhanced local delivery of corticosteroids utilizing various strategies, rational and dynamic approaches to strategy selection are still lacking. Within this review, an overview of the various strategies as well as their performance in retention, solubility, and permeability coefficient of corticosteroids are provided. On this basis, the tradeoff of strategy selection is discussed, which may shed light on the rational choice and application of ophthalmic delivery enhancement strategies.

Aiding Adherence to Glaucoma Medications: A Systematic Review

PURPOSE

To provide a comprehensive assessment of the strategies studied to date that focus on improving glaucoma medication adherence.

METHODS

A systematic review of the literature was conducted in MEDLINE (PubMed), Embase (Elsevier), and Scopus (Elsevier) from inception to March 1, 2021, of publications describing a device or strategy used to improve glaucoma medication adherence.

RESULTS

42 studies described by 50 papers were included. Five categories were identified: reminder systems, medication simplifications, behavioral change programs, education, and alternative engagement strategies.

CONCLUSION

Most studies (40 of the 42) addressed the question of improved adherence directly, with 26 finding improved adherence. Notably, 14 examined the clinical effects of the intervention, either in terms of intraocular pressure (IOP) or visual fields. Only three found an improvement in IOP. None demonstrated a between group difference in visual field progression.

A Comparison of Patient Acceptance of 3 Eye Drop Instillation Aids

PRECIS

Patients can be quite amenable to using eye drop instillation aids. We should consider recommending these devices to patients who otherwise struggle with drop instillation and medication adherence.

PURPOSE

The purpose of this study was to compare patient acceptance of 3 commercially available eye drop instillation aids in a diverse tertiary care population.

METHODS

In this prospective, randomized controlled study, 39 patients being treated with topical antihypertensives were assigned to Arm A (no intervention) or Arm B (AutoDrop, AutoSqueeze, or SimplyTouch). Subjects in Arm B were instructed to administer their eye drop with the assigned drop aid at every use for ~6 weeks. Satisfaction surveys were administered at 3 and 6 weeks, where patients also reported the number of drops missed.

RESULTS

Thirty-two of 39 subjects completed study participation and full data analysis. Within this total group, 24 subjects were randomized to drop aids (AutoDrop N=10, AutoSqueeze N=8, SimplyTouch N=6), and 8 were randomized to no drop aid. At the 3 and 6-week timepoints, patients found instillation easier with AutoDrop (70.0%, 60.0%) followed by the AutoSqueeze (62.5%, 75.0%), and lastly SimplyTouch (33.3%, 33.3%). For the AutoSqueeze, the mean number of drops missed with and without the drop aid were significantly different (P=0.015 at 3 wk, P=0.008 at 6 wk). There was no difference in the mean number of drops missed with the AutoDrop and SimplyTouch at either timepoint.

CONCLUSIONS

For the AutoDrop and AutoSqueeze groups, over 60% of the patients found the devices helpful and would consider using them long-term. Our results suggest that patients would be amenable to using eye drop instillation aids, although more objective data is needed to determine whether these devices would improve medication compliance and clinical outcomes.

Sustained-release drug delivery systems for the treatment of glaucoma

Glaucoma, a leading cause of irreversible blindness, affects more than 64 million people worldwide and is expected to grow in number due to the aging global population and enhanced methods of detection. Although topical therapies are often effective when used as prescribed, the drawbacks of current medical management methods include poor patient adherence, local and systemic side effects, and in some cases, limited therapeutic efficacy. Novel ocular drug delivery platforms promise to deliver differentiated drug formulations with targeted delivery leveraging patient-independent administration. Several platforms are in various stages of development with promising pre-clinical and clinical data. The Bimatoprost Sustained Release (SR) intracameral implant was approved in the United States in March of 2020, making it the first long-term injectable therapy available for the treatment of glaucoma. This review aims to provide an update on novel sustained release drug delivery systems that are available today as well as those that might be commercialized in coming years.

In Vivo Efficacy of Contact Lens Drug-Delivery Systems in Glaucoma Management. A Systematic Review

Adherence is crucial in medical glaucoma therapy, although half of the patients skip eyedrops. In recent years alternative drug-delivery systems have been developed. One of the most promising seems the contact lens (CL). This systematic review aims to present the in vivo efficacy of different CL drug-delivery systems. A total of 126 studies were identified following a literature search adhering to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. After full-text evaluation, 19 studies about CL drug-delivery systems were included. To date, the following drug-delivery systems have been investigated in vivo: drug-soaked CL, CL with physical barriers (vitamin E), molecularly imprinted CL, CL with implants, and nanoparticle-loaded CL. Nanoparticle-loaded CL and CL with implants seem the most promising drug-delivery systems, although initial burst drug release and patient acceptance may limit their widespread use in current practice. Clinical trials are warranted to understand the role of CL as a drug-delivery system in improving glaucomatous patient care.

[Anti-scarring effect of rapamycin following filtering surgery in rabbit eyes]

OBJECTIVE

To study the effect of rapamycin on scar formation in rabbit eyes following filtering operation and explore the possible mechanism.

METHODS

Ninety-six healthy adult rabbits were subjected to trabeculectomy of the left eye and subsequently randomly divided into 4 groups (n=24) for treatment with castor oil (control) or rapamycin (1%, 3%, or 5%) eye drops of the operated eyes 4 times a day. The morphology and function of the filtering blebs of the rabbits were compared at 7, 14, 21 and 28 days after the operation; at each of the time points, 6 rabbits from each group were euthanized for detection of expressions of proliferating cell nuclear antigen (PCNA) and α-smooth muscle actin (α-SMA) in the tissues in the surgical area using immunohistochemistry. Cultured rabbit subconjunctival fibroblasts (RTFSs) were treated with different concentrations of rapamycin (0.06, 0.25, 1, and 4 mg/L) and the cell apoptosis was detected using flow cytometry.

RESULTS

In the first, second and third weeks after the operation, the rate of functional follicle formation was significantly higher in the 3 rapamycin groups than in the control group (P < 0.05), and the number of α- SMA-positive fibroblasts decreased over time in the 3 rapamycin groups. In cultured RTFSs, treatment with rapamycin at different concentrations resulted in increased apoptosis of the cells, and rapamycin above 0.25 mg/L significantly increased the cell apoptosis in a dose-dependent manner.

CONCLUSIONS

Rapamycin can inhibit hyperplasia of the filtering passage tissue, helps to preserve the functional filtering blebs and prolong their life span, and induces apoptosis of RTFS.

Bioinspired hydrogels for drug-eluting contact lenses

Efficient ocular drug delivery that can overcome the challenges of topical application has been largely pursued. Contact lenses (CLs) may act as light-transparent cornea/sclera bandages for prolonged drug release towards the post-lens tear fluid, if their composition and inner architecture are fitted to the features of the drug molecules. In this review, first the foundations and advantages of using CLs as ocular drug depots are revisited. Then, pros and cons of common strategies to prepare drug-loaded CLs are analyzed on the basis of recent examples, and finally the main section focuses on bioinspired strategies that can overcome some limitations of current designs. Most bioinspired strategies resemble a reverse engineering process to create artificial receptors for the drug inside the CL network by mimicking the human natural binding site of the drug. Related bioinspired strategies are being also tested for designing CLs that elute comfort ingredients mimicking the blinking-associated renewal of eye mucins. Other bioinspired approaches exploit the natural eye variables as stimuli to trigger drug release or take benefit of bio-glues to specifically bind active components to the CL surface. Overall, biomimicking approaches are being revealed as valuable tools to fit the amounts loaded and the release profiles to the therapeutic demands of each pathology. STATEMENT OF SIGNIFICANCE: Biomimetic and bioinspired strategies are remarkable tools for the optimization of drug delivery systems. Translation of the knowledge about how drugs interact with the natural pharmacological receptor and about components and dynamics of anterior eye segment may shed light on the design criteria for obtaining efficient drug-eluting CLs. Current strategies for endowing CLs with controlled drug release performance still require optimization regarding amount loaded, drug retained in the CL structure during storage, regulation of drug release once applied onto the eye, and maintenance of CL physical properties. All these limitations may be addressed through a variety of recently growing bioinspired approaches, which are expected to pave the way of medicated CLs towards the clinics.

21st century glaucoma care

Glaucoma care has evolved dramatically over the past generation, with changes that have incorporated new technology and improved understanding of the disease process. A major need is to construct a useful definition of glaucomatous optic neuropathy that can be used to compare data across clinical research studies. The treatment of glaucoma should now be based on achievement of a goal target for intraocular pressure, unique to each patient. Adherence with eye drop treatment is far from ideal and can be improved using reminder systems. Sustained delivery of glaucoma medication is on the horizon. New surgical approaches to glaucoma are being actively studied but have not as yet found their place in its care, with rigorous testing against present treatments needed.