Pharmacoepidemiological assessment of adherence and influencing co-factors among primary open-angle glaucoma patients-An observational cohort study

Barriers and facilitators to medication adherence in chronic diseases: a scoping review

To guide the interventions of health professionals, it is necessary to identify the reasons for non-adherence to treatment. This scoping review aims to identify and discuss barriers and facilitators for adherence to pharmacotherapy in chronic diseases. Of the 3,482 eligible studies, it was observed that in the 114 studies that met the selection criteria, facilitators such as income, social support, older age, education, motivation to use pharmacotherapy, formation of a bond with the health professional, health education, believe in pharmacotherapy, realize the benefits of pharmacotherapy, motivation for self-care, and disease severity, were common to the various chronic health conditions. Regarding the common barriers, were: cost of the medication, complexity of pharmacotherapy; adverse drug reaction, greater number of prescribers and pharmacies used, greater number of visits to urgent and emergency services, believing that the medication is not necessary, and having depression. The analysis of these factors provides support for the health professional to identify the reasons that led to non-adherence and guide the interventions to be carried out, promoting adherence to treatment.

Epidemiology and Treatment of Patients With Primary Open Angle Glaucoma in Germany: A Health Claims Data Analysis

PRCIS

Based on a large administrative database of German claims data, our study provides current estimates of the prevalence and incidence of primary open angle glaucoma (POAG) in Germany and describes selected outcomes for prevalent patients with POAG.

PURPOSE

To estimate the prevalence and incidence of POAG in Germany, to describe the patient population in terms of comorbidity burden, routine care, and overall healthcare resource utilization (HCRU) and associated costs, and to describe treatment patterns over time in patients undergoing relevant laser procedures.

MATERIALS AND METHODS

Based on anonymized German claims data, we carried out a retrospective, noninterventional study covering calendar years 2016-2021.

RESULTS

For the adult German population (≥18 y), we estimated a POAG 1-year prevalence of 1.70% and a 1-year incidence of 0.17% in 2018; both increased with age, peaking in 80- to 89-year-olds. Prevalence and incidence were lower in 2020 (1.65% and 0.16%, respectively), the first year of the SARS-CoV-2 pandemic. Most patients solely received topical treatment. Most surgically treated patients underwent laser trabeculoplasty, followed by laser iridotomy, trabeculectomy, and filtration operations with implant. In patients undergoing laser trabeculoplasty, the treatment regimen was nearly unchanged in the second year after, compared with 2 years before the procedure. Multimorbidity was commonly observed; 75.5% of patients had arterial hypertension and 50.0% had disorders of lipoprotein metabolism and other lipidemias, compared with 60.1% and 39.2%, respectively, in an age- and sex-matched control sample.

CONCLUSIONS

Our study provides insights into epidemiology and routine care of POAG in Germany and HCRU in prevalent patients. There was little change in treatment regimens in patients who underwent laser trabeculoplasty, 2 years after the procedure. Most patients were multimorbid highlighting the need for comprehensive care.

[Awareness for glaucoma in the general population]

BACKGROUND

Glaucoma is not a rare entity but because very few symptoms occur and visual field defects are frequently first recognized at a late stage, a large proportion of glaucoma diseases remain undetected. The aim of this study was to identify the proportion of undiagnosed glaucoma in German population-based cohort studies and to contextualize them in the context of the literature.

MATERIAL AND METHODS

The prevalence of glaucoma in the Gutenberg Health Study (GHS) and the age-related investigations on health of the University of Regensburg (AugUR) was evaluated based on visual field examinations and optic disc color photography according to the ISGEO criteria. Furthermore, the self-reported glaucoma diagnoses were collected and the proportion of undiagnosed glaucoma was determined.

RESULTS

The proportion of undiagnosed glaucoma was 55% in the GHS, and 53% in the AugUR study. The results correlate with results from previous studies from other countries in which the proportion of unrecognized glaucoma ranged from 33% to 78%. In the GHS and the AugUR study the proportion of undiagnosed glaucoma was higher in younger age groups and in women.

DISCUSSION

Roughly every second case of glaucoma is undetected. As the symptoms are often nonspecific or take a long time to appear, there is a risk of advanced glaucomatous visual field defects or blindness due to a lack of glaucoma awareness. Studies have shown that a systematic screening can halve this risk.

Adherence and Persistence to Medical Therapy in Glaucoma: An Overview

Glaucoma is a group of progressive optic neuropathies characterized by loss of retinal ganglion cells and visual field deterioration. Despite the fact that the underlying pathophysiology of glaucoma remains unknown, elevated intraocular pressure (IOP) is a well-established risk factor, and the only factor that can be modified. Robust evidence from epidemiological studies and clinical trials has clearly demonstrated the benefits of IOP control in reducing the risk of glaucoma progression. IOP-lowering therapy by the means of eye drops remains a first-line treatment option. However, like other chronic and asymptomatic conditions, many patients with glaucoma have difficulties in maintaining high rates of adherence persistence to prescribed medications. On average, patients with chronic medical conditions take 30-70% of the prescribed medication doses, and on average 50% discontinue medications in the first months of therapy. The ophthalmic literature shows similarly low rates of adherence to treatment. Indeed, poor adherence is associated with disease progression and increased complication rates, as well as healthcare costs. The present review analyzes and discusses the causes of variability of the adherence to the prescribed drugs. The education of patients about glaucoma and the potential consequences of insufficient adherence and persistence seems fundamental to maximize the probability of treatment success and therefore prevent visual disability to avoid unnecessary healthcare costs.

Patient Preferences for Long-Term Implant Care in Cochlear, Glaucoma and Cardiovascular Diseases

In the process of developing and implementing innovative implant technologies the consideration of patient preferences can be beneficial for patients, doctors and developers. Nevertheless, in existing literature, there is still scarce knowledge of patients' perspectives on long-term implant care. In this study, three discrete choice experiments (DCEs) were conducted in the context of cochlear implants (CI, n = 92), glaucoma implants (GI, n = 21) and cardiovascular implants (CVI, n = 23), examining the relative importance of attributes of long-term implant care from the patients' perspective. The participants chose between differently shaped options for implant-related care. The attributes of these care options were generated and selected based on previous literature reviews, group discussions and a diary study with patients. The choice data were analyzed via binary logit regression. In CI-DCE, the technological compatibility of the implant with newer implant models, accessories or devices from other manufacturers was highly valued by participants, whereas in GI-DCE the (in)dependency on glaucoma medication post-implantation had the greatest influence on participants' choice behavior. In CVI-DCE, the attribute with the highest relative importance related to the means of securing long-term treatment success. In all three DCE, shared decision making was relatively important for participants. Our results emphasized the importance of an adequate transfer of technological advancements in implant care for promoting patient benefits, such as the availability of comprehensible, understandable, high-quality information about current developments. Similarly, promoting technological health literacy and further pushing the technological compatibility, durability and safety of implants are directions for future implant development in accordance with patients' preferences. Therefore, the participation of implant wearers in the development process is encouraged.

Quantitative systems pharmacology of the eye: Tools and data for ocular QSP

Good eyesight belongs to the most-valued attributes of health, and diseases of the eye are a significant healthcare burden. Case numbers are expected to further increase in the next decades due to an aging society. The development of drugs in ophthalmology, however, is difficult due to limited accessibility of the eye, in terms of drug administration and in terms of sampling of tissues for drug pharmacokinetics (PKs) and pharmacodynamics (PDs). Ocular quantitative systems pharmacology models provide the opportunity to describe the distribution of drugs in the eye as well as the resulting drug-response in specific segments of the eye. In particular, ocular physiologically-based PK (PBPK) models are necessary to describe drug concentration levels in different regions of the eye. Further, ocular effect models using molecular data from specific cellular systems are needed to develop dose-response correlations. We here describe the current status of PK/PBPK as well as PD models for the eyes and discuss cellular systems, data repositories, as well as animal models in ophthalmology. The application of the various concepts is highlighted for the development of new treatments for postoperative fibrosis after glaucoma surgery.

Review of glaucoma medication adherence monitoring in the digital health era

Current glaucoma treatments aim to lower intraocular pressure, often with topical ocular hypotensive medications. Unfortunately, the effectiveness of these medications depends on sustained patient adherence to regimens which may involve instilling multiple medications several times daily. Patient adherence to glaucoma medications is often low. Recent innovations in digital sensor technologies have been leveraged to confirm eyedrop medication usage in real-time and relay this information back to providers. Some sensors have also been designed to deliver medication reminders and notifications as well as assist with correct eyedrop administration technique. Here, we review recent innovations targeted at improving glaucoma medication adherence and discuss their limitations.

Does Diabetes Influence Adherence in Glaucoma Patients?

With chronic diseases, patient adherence plays a crucial role in delaying disease progression and in determining the success of therapy. Problems arise not only from low medication adherence, but also non-adherence to recommended follow-up examinations. Obtaining an accurate estimate of adherence is difficult, especially in glaucoma patients, due to the fact that most antihypertensive drugs are administered in the form of eye drops. There is great variability in the published adherence values for glaucoma patients. Most studies report an average medication adherence of approximately 70%, with around 50% of patients having good adherence (at least 80% of medication administered as planned). Furthermore, 6.8 - 31.4% of the eye drops do not end up in the patient's eye, which means there is even less active ingredient to achieve a therapeutic effect. Glaucoma patients also show low persistence and adherence to follow-up appointments. Since diabetes increases the risk for POAG and secondary glaucoma and given that diabetics have particularly low adherence, the question arose whether a diabetes diagnosis is associated with reduced adherence in glaucoma patients. Previous studies found no significant association between diabetes and reduced adherence in glaucoma patients, although a significant impact of elevated HbA_1c on adherence in glaucoma patients was found in one study. However, this connection still needs to be examined more closely in studies with larger samples.

The Antibiotic Kitasamycin-A Potential Agent for Specific Fibrosis Preventing Therapy after Fistulating Glaucoma Surgery?

One major complication after fistulating glaucoma surgeries are fibroblast-mediated scarring processes and their specific prevention is key in the development of novel pharmaceutical concepts. Within this study a possible antifibrotic potential of kitasamycin (KM) in a transforming growth factor (TGF)-β1-mediated fibroblast model was evaluated in vitro. Primary ocular fibroblasts were isolated, cultivated and a dose-response test including determination of the half maximal effective concentration (EC50) for KM was conducted. Transformation of fibroblasts into myofibroblasts was induced by TGF-β1and immunofluorescence (IF), and Western blot (WB) analyses were performed with fibroblasts and myofibroblasts. IF analyses were carried out using antibodies against α-smooth muscle actin (α-SMA) and fibronectin, and protein detection of intracellular and extracellular proteins was performed by WB. Using the dose-response test, the viability, cytotoxicity and EC50 of KM after 24 and 48 h were determined. Fibroblasts exposed to various KM concentrations showed no increase in α-SMA and extracellular matrix expression. In TGF-ß1-stimulated myofibroblasts, KM inhibited the expression of α-SMA and fibronectin in a concentration-dependent manner. These findings demonstrate that KM could impair the transformation of fibroblasts into myofibroblasts and the expression of proteins involved in fibrotic processes, representing a potential agent for specific fibrosis prevention in future therapeutic concepts.

[How can one learn to perform a trabeculectomy? : The Mainz treatment scheme]

Trabeculectomy represents the glaucoma surgical procedure that achieves the greatest reduction in intraocular pressure and enables a low pressure regulation especially in normal pressure glaucoma. For the beginner the operation is challenging due to potential intraoperative and postoperative difficulties. With this in mind this article explains how to learn to perform a trabeculectomy and explains the various steps from assessing the indications via training, performing the surgery independently and follow-up care. The article points out the challenges during the procedure and the possible solutions and explains the individual aftercare using the Mainz treatment scheme as an example. In this way, the risk of serious complications can be reduced to a minimum and in the vast majority of patients a sufficient regulation of intraocular pressure can be achieved without the need for eye drops.

Effect of pigmentation intensity of trabecular meshwork cells on mechanisms of micropulse laser trabeculoplasty

The intraocular pressure (IOP)-lowering mechanisms of micropulse laser trabeculoplasty (MLT) remain unclear. The present study was performed to investigate the mechanism of action of MLT, and to determine whether the pigmentation intensity of trabecular meshwork (TM) cells is associated with the treatment effects. Primary human TM cells were exposed to melanin granules to artificially introduce different levels of pigmentation. Micropulse (MP) laser irradiation was performed, and interleukin (IL)-1α/β, matrix metalloproteinases (MMPs), tissue inhibitor of metalloproteinases (TIMPs), and extracellular matrix (ECM) protein expression were evaluated by RT-qPCR and immunocytochemistry. IL-1α/β and MMP-1, -3, and -9 mRNA expression were significantly upregulated at 4 and 24 h after MP laser irradiation, respectively, but there were no significant changes in TIMP expression. The extent of these upregulation was greater in cells with strong pigmentation intensity. Protein expressions of fibronectin and collagen I were significantly decreased in cells with strong staining intensity. These results suggested that MP laser irradiation alter the MMP/TIMP ratio and enhance ECM turnover, resulting in increased outflow of aqueous humor. The pigmentation intensity of the TM tissues may affect the treatment efficacy of MLT, because TM cells with strong staining intensity showed a significantly enhanced response to MP laser irradiation.

Demographic, Clinical, and Psychosocial Predictors of Change in Medication Adherence in the Support, Educate, Empower Program

PURPOSE

To investigate whether demographic, clinical, or psychosocial factors act as moderators of change in medication adherence in the Support, Educate, Empower (SEE) program.

DESIGN

Prospective, single-arm pilot study with a pre-post design.

PARTICIPANTS

Patients with glaucoma aged ≥ 40 years and taking ≥ 1 glaucoma medication were recruited from the University of Michigan Kellogg Eye Center. Those who had electronically measured adherence ≤ 80% in the 3-month eligibility monitoring period were enrolled in the SEE program.

METHODS

Medication adherence was monitored electronically during the 7-month intervention and calculated as the percentage of doses taken correctly. Change in adherence at different points in the SEE program and cumulative change in adherence were modeled with linear regression, and baseline demographic, clinical, and psychosocial factors were investigated for significant associations.

MAIN OUTCOME MEASURES

Demographic, clinical, and psychosocial variables associated with change in medication adherence in the SEE program.

RESULTS

Thirty-nine participants completed the SEE program. These participants were on average 63.9 years old (standard deviation [SD], 10.7 years), 56% (n = 22) were male, 44% (n = 17) were White, and 49% (n = 19) were Black. Medication adherence improved from an average of 59.9% (SD, 18.5%) at baseline to 83.6% (SD, 17.5%) after the final SEE session, for an increase of 23.7% (SD, 17.5%). Although participants with lower income (< $25 000 and $25 000-50 000 vs. >$50 000) had lower baseline adherence (48.4% and 64.1% vs. 70.4%), these individuals had greater increases in adherence during the first month of medication reminders (19.6% and 21.6% vs. 10.2%; P = 0.05 and P = 0.007, respectively). Participants taking fewer glaucoma medications also had significantly greater increases in adherence with medication reminders (P < 0.001). Those with higher levels of glaucoma-related distress (GD) had lower baseline adherence and greater increases in adherence with glaucoma coaching (P = 0.06).

CONCLUSIONS

Patient-level factors associated with relatively greater improvements in medication adherence through the SEE Program included lower income, fewer glaucoma medications, and increased GD. These findings demonstrate that the SEE program can improve glaucoma self-management even among participants with social and psychological barriers to medication adherence.

Patterns and Facilitators for the Promotion of Glaucoma Medication Adherence-A Qualitative Study

Primary open-angle glaucoma (POAG) is a chronic optic neuropathy causing irreversible nerve fiber damage. Initially asymptomatic, it progresses slowly without any notable sign of vision loss, thus early detection and treatment is essential. The standard treatment being non-invasive topical administration of eye drops harbors the problem of patients not being adherent. This study aimed to explore the experiences and thoughts of glaucoma patients about their medication management to improve our knowledge on how adherence works for the individual patient. Narrative interviews were conducted with 21 glaucoma patients. Data were analyzed using inductive content analysis and the documentary method. Different patterns of adherence were identified which depended on personal biographies, living conditions, or the patient's knowledge about the disease. Interpreting eye drop medication as a ritual, a task, or routine was helpful for some patients, whereas other patients, who were aware of the consequences of not taking the drops, were motivated by intrinsic or extrinsic factors. The patterns identified here represent strategies for managing and adhering to daily glaucoma medication at an individual level. Linking daily drop application or medication intake to these patterns may help to promote correct medication management of patients with chronic diseases who lack a regular medication regimen.

[Glaucoma surgery today]

BACKGROUND

The main goals of glaucoma treatment are to preserve the visual function and maintain as high a quality of life as possible at a cost acceptable to society. Therefore, it is crucial to carefully observe each individual patient in order to determine an individual and personalized treatment approach.

MATERIAL AND METHODS

This article summarizes the advantages and disadvantages of medicinal glaucoma treatment as well as traditional methods of glaucoma surgery, based on the current state of knowledge. The article explains the various mechanisms of action of new minimally invasive procedures, introduces the methods mostly commonly used in Germany and gives recommendations for preoperative care and postoperative follow-up.

RESULTS/CONCLUSION

In addition to the plethora of medicinal glaucoma treatments and classical surgical procedures, new minimally invasive treatment alternatives have become available in the past few years. The latter are an option for an earlier surgical intervention, especially in naïve or previously treated patients who appear to be unsuitable for medicinal treatment.

Viscotrabeculotomy versus trabeculectomy in the surgical treatment of open angle glaucoma: a single center, randomised controlled trial

PURPOSE

The aim of the study was to compare the effect of viscotrabeculotomy and the effect of trabeculectomy on the intraocular pressure (IOP) in cases of open angle glaucoma (OAG).

STUDY DESIGN

Prospective comparative study.

PATIENTS AND METHODS

The study was conducted on 148 eyes of 148 patients (87 men) presenting with and operated upon for OAG at Mansoura Ophthalmic center of Mansoura University in Mansoura, Egypt from 2012 to 2016. Patients were randomized into viscotrabeculotomy and trabeculectomy groups. Postoperative follow up visits were scheduled at weeks 1 and 2 then months 1, 2, 3, 6, 9, 12, 15, 18, 21 and 24. Complications were noted and managed according to needs. The primary outcome measure was IOP.

RESULTS

The study was conducted on 148 eyes (74 right) of 148 patients (87 men). The mean ± SD (range, median) age of the study patients was 50.1 ± 11.5 (20-67, 53) and 51.1 ± 10.0 (27-65, 54.5) years respectively. The mean ± SD (range, median) IOP of the study eyes on maximal tolerated IOP lowering therapy was 23.15 ± 2.31 (19-30, 23.0) and 23.64 ± 1.87 (20-28, 23.0) mmHg respectively and at the end of the 24 months of follow up was 14.91 ± 2.4 (12-23, 14) and 16.64 ± 2.8 (14-25, 16) mmHg respectively (p =  < 0.0005). Notable complications included a mild hyphema in the viscotrabeculotomy group and an IOP spike in the trabeculectomy group.

CONCLUSIONS

Viscotrabeculotomy and trabeculectomy showed efficacy and safety in OAG patients. The former resulted in better IOP reduction.

Treatment Complexity in Primary Open-Angle Glaucoma (POAG): Perspectives on Patient Selection in Micro-Invasive Glaucoma Surgery (MIGS) Using Stents

BACKGROUND

Primary open-angle glaucoma (POAG) is still one of the most common causes of impaired vision worldwide, despite the further development of therapy options, and can lead to blindness. Micro-invasive glaucoma surgery (MIGS) using stents aims at reducing intraocular pressure (IOP), as it is the main risk factor. With regard to adherence and adverse drug reactions it also aims at reducing the drug burden on patients. The study investigates under everyday conditions the criteria according to which ophthalmologists in Germany select patients for MIGS using stents. In addition, it will be investigated which patients (could) benefit most from the therapy.

MATERIAL AND METHODS

In this qualitative study, 11 narrative interviews were conducted between May 2017 and July 2018 with ophthalmologists working in the hospital or in a private practice. They were interviewed on their experiences in the treatment of POAG with microstents. The interviews were analysed by an interdisciplinary team using the qualitative content analysis.

RESULTS

The stages of therapy escalation form the frame of reference for patient selection in MIGS using stents. Only if the IOP cannot be sufficiently reduced by drop therapy or when this causes drug-related side effects that are intolerable for the patients, stents are apparently used as the next higher escalation stage. The intensive post-operative medication and the frequent check-up appointments are perceived as barriers by the interviewees, especially for people with or without disabilities, who are dependent on external help and/or those living in rural areas. The active cooperation of the patients in the demanding aftercare seems to be indispensable for the ophthalmologists. In addition, necessary revisions are sometimes stressful for patients (physical/psychological) and doctors (work organisation/therapy). Against the background of the organisational and economic challenges in the outpatient spectrum of tasks, especially physicians in private practice seem to weigh up carefully for which patients microstent therapy would be reasonable.

CONCLUSION

In view of the therapeutic requirements, the current microstent therapy seems to be used in a selected, adherent patient group. Further qualitative and quantitative studies (in other health care regions and structures) are necessary to verify and extend the available results.

Systematic review: non-adherence and non-persistence in intravitreal treatment

PURPOSE

Intravitreal injection of VEGF inhibitors has become the standard of care for different macular diseases within the last years resulting in improved visual outcomes. Under real-life conditions, however, the necessity for frequent retreatments and reexaminations poses a burden for patients and treatment centers. Non-adherence and non-persistence to intravitreal treatment may lead to inferior clinical outcomes, and knowledge of contributing factors is crucial to improve adherence. This systematic review analyzes current literature for potential factors involved in non-adherence and non-persistence.

METHODS

A systematic search was conducted in PubMed and Embase including three different aspects of intravitreal injection therapy: (1) diseases with intravitreal injections as treatment, (2) intravitreal injection, and (3) aspects of therapy adherence or therapy persistence. Data from identified quantitative studies were further extracted and grouped according to WHO criteria (condition, socio-economy, therapy, patient, and health system). The methodological quality of identified studies was graded. Identified qualitative studies (i.e., interviews) were descriptively analyzed and their findings narratively reported.

RESULTS

Twenty-four publications were included. In 16 of those publications, a quantitative data analysis was conducted, analyzing factors associated with non-adherence. Worse visual acuity at baseline and unfavorable development of visual acuity, higher age, and greater distance to the treatment center were associated with non-adherence, while there was inconsistent evidence for an association of comorbidity. In qualitative studies, high follow-up/treatment burden, fear and anxiety, disappointed patient expectations, and lack of motivation to continue treatment were reported as reasons for non-persistence.

CONCLUSIONS

Knowledge of potential barriers in IVT treatment may improve adherence and potentially clinical results. Improvements can be achieved particularly in the healthcare complex (organizational improvements) and the "patient" complex by establishing realistic expectations. Recurrent education of the patient may be necessary.

The Diagnosis and Treatment of Glaucoma

BACKGROUND

Glaucoma is a group of chronically progressive disorders of the optic nerve. In this article, we present the epidemiology of and risk factors for glaucoma, as well as the diagnostic work-up and treatment options.

METHODS

This review is based on pertinent publications retrieved by a selective search in Medline and the Cochrane Library, supplemented by further articles chosen by the authors.

RESULTS

In Europe, the prevalence of glaucoma is 2.93% among persons aged 40 to 80 years. The prevalence rises with age, reaching 10% in persons over 90 years old. The available diagnostic methods include ophthalmoscopy, tonometry, perimetry, and imaging techniques. The treatment of glaucoma is focused on lowering the intraocular pressure with topical drugs, laser therapy, and glaucoma surgery. In patients with manifest glaucoma, lowering the intraocular pressure prevents the progression of visual field defects, with a number needed to treat of 7.

CONCLUSION

The diagnostic evaluation of glaucoma rests on multiple pillars, all of which must be considered for establishing the diagnosis and defining the desired target pressure: these are, among others, the intraocular pressure and ocular function and morphology. Individually tailored pressure-lowering treatment should be evaluated in regularly scheduled follow-up visits for assessment of function and morphology and adjusted as necessary to minimize the risk of progression.

Co-Delivery of Timolol and Brimonidine with a Polymer Thin-Film Intraocular Device

PURPOSE

We developed a polycaprolactone (PCL) co-delivery implant that achieves zero-order release of 2 ocular hypotensive agents, timolol maleate and brimonidine tartrate. We also demonstrate intraocular pressure (IOP)-lowering effects of the implant for 3 months in vivo.

METHODS

Two PCL thin-film compartments were attached to form a V-shaped co-delivery device using film thicknesses of ∼40 and 20 μm for timolol and brimonidine compartments, respectively. In vitro release kinetics were measured in pH- and temperature-controlled fluid chambers. Empty or drug-loaded devices were implanted intracamerally in normotensive rabbits for up to 13 weeks with weekly measurements of IOP. For ocular concentrations, rabbits were euthanized at 4, 8, or 13 weeks, aqueous fluid was collected, and ocular tissues were dissected. Drug concentrations were measured by liquid chromatography-tandem mass spectrometry.

RESULTS

In vitro studies show zero-order release kinetics for both timolol (1.75 μg/day) and brimonidine (0.48 μg/day) for up to 60 days. In rabbit eyes, the device achieved an average aqueous fluid concentration of 98.1 ± 68.3 ng/mL for timolol and 5.5 ± 3.6 ng/mL for brimonidine. Over 13 weeks, the drug-loaded co-delivery device resulted in a statistically significant cumulative reduction in IOP compared to untreated eyes (P < 0.05) and empty-device eyes (P < 0.05).

CONCLUSIONS

The co-delivery device demonstrated a zero-order release profile in vitro for 2 hypotensive agents over 60 days. In vivo, the device led to significant cumulative IOP reduction of 3.4 ± 1.6 mmHg over 13 weeks. Acceptable ocular tolerance was seen, and systemic drug levels were unmeasurable.

Miniaturization in Glaucoma Monitoring and Treatment: A Review of New Technologies That Require a Minimal Surgical Approach

In the management of glaucoma, recent and upcoming innovations have the potential to contribute to both the efficacy of intraocular pressure (IOP) monitoring and the number of available treatment options. These new devices and procedures have two things in common: they are part of the trend in medicine towards miniaturization, and they require a limited surgical procedure to become effective. This review focuses on the Eyemate (Argos) intraocular sensor, which offers a new way to reliably measure 24 h IOP, and on intraocular sustained release systems for pharmacological glaucoma therapy. It also briefly reflects on the miniature implants currently used in minimally invasive glaucoma surgery (MIGS).

Correction: Pharmacoepidemiological assessment of adherence and influencing co-factors among primary open-angle glaucoma patients-An observational cohort study

[This corrects the article DOI: 10.1371/journal.pone.0191185.].