Updates on the Diagnosis and Management of Glaucoma

The decline in the clinical relevance of pilocarpine and physostigmine monitored in pharmacology textbooks from 1878 to 2023: nine take-home messages for future (pharmacology) textbook authors

In a recent study, using hydrogen cyanide as paradigm, we have shown that pharmacological knowledge evolves non-linearly ( https://pubmed.ncbi.nlm.nih.gov/38900251/ ). The aim of this study was to investigate the changes in the presentation of the drugs pilocarpine and physostigmine in textbooks from 1878 to 2023. The categories of structure, molecular mechanism of action, pharmacokinetics, effects, indications, adverse drug reactions, interactions, and contraindications were evaluated. The pharmacological knowledge on the molecular mechanism, chemical structure, and pharmacokinetics of pilocarpine and physostigmine changed the most during the period of 150 years. Until 1944, textbooks did not mention a molecular mechanism of action of pilocarpine and from 1951 onwards they described the activation of muscarinic acetylcholine receptors as the molecular basis of pilocarpine's effect. Until 1944, most textbooks on physostigmine also did not mention the molecular mechanism of action. From 1951 onwards, the reversible inhibition of acetylcholinesterase is mentioned as the mechanism of action of physostigmine. In contrast, in the categories effects, indications, adverse drug reactions, interactions, and contraindications, the detected changes in the pharmacological knowledge presented were comparatively smaller. Older pharmacology textbooks were better than newer ones at discussing changes in knowledge and scientific errors. We noted substantial differences in the presentation of pilocarpine and physostigmine among German and US pharmacology textbooks. We show a decline of the clinical relevance of both drugs and their presentation in pharmacological textbooks with physostigmine being virtually irrelevant. But modern textbooks still discuss physostigmine substantially, fitting to studies on the obsolete drug reserpine ( https://pubmed.ncbi.nlm.nih.gov/38103060/ ). Thus, textbooks often far lag clinical practice. Google Scholar conveys the incorrect impression that physostigmine is clinically more relevant than it is. An exponential decline in prescription numbers is a robust indicator of clinical obsolescence. From our study, we extract nine easily implementable take-home messages for future (pharmacology) textbook authors to ensure that this traditional teaching format will prevail against the competition of allegedly more "modern" teaching media.

Flow characterization and structural alterations in Ahmed glaucoma FP7 tubes after in-vitro aging in silicone oil

PURPOSE

Patients with intraocular silicone oil (SO) display higher odds of surgical failure after Ahmed glaucoma valve (AGV) implantation compared to patients without SO. However, the structural impact of SO exposure on silicone-made AGV tubes and the resulting changes in flow rate remain unexplored. This in-vitro study evaluated changes in tube dimensions and flow rates of AGV FP7 tubes after SO exposure to inform clinicians how such changes may impact AGV functionality.

METHODS

AGV FP7 tube segments underwent accelerated aging to approximate 90 days of exposure to the following media: Balanced Salt Solution (BSS), 1000 centistokes (cs) SO, and 5000cs SO. Tube dimensions were measured before and after aging. A constant gravity flow test setup was created to measure flow rates through tubes before and after aging. The students' T-test was used to compare the mean change between groups post-aging.

RESULTS

Post-exposure, 1000cs and 5000cs SO tube segments increased in length by 5.94% and 5.55%, respectively, compared to 0.38% of BSS tubes (P < 0.05 for both). The inner lumen area expanded for tube segments in 1000cs and 5000cs SO by 11.75% and 2.70%, respectively, but contracted for tubes in BSS by -2.70% (P < 0.01 and P = 0.068 for 1000cs and 5000cs SO, respectively). Post aging, the flow rates increased on average by 61.0% and 98.6% for 1000cs and 5000cs SO, respectively, whereas flow rates for BSS tube segments slightly decreased by -4.92%. The difference was statistically significant for BSS vs. SO groups (P < 0.01 for both).

CONCLUSIONS

Prolonged exposure to SO structurally altered the AGV FP7 tube segments by expanding their cross-sectional area, potentially leading to increased flow rates. These results may inform clinicians about potential in-vivo interactions in patients with the simultaneous presence of glaucoma drainage devices and intraocular SO.

Growth Hormone Neuroprotective Effects After an Optic Nerve Crush in the Male Rat

Purpose

Growth hormone (GH) has neuroprotective effects that have not been evaluated in the mammalian visual system. This study tested the hypothesis that GH administration can promote retinal neuroprotection in an optic nerve crush (ONC) model in male rats.

Methods

The ON was compressed for 10 seconds, and bovine GH was injected concomitantly to injury for 14 days (0.5 µg/g every 12 hours). At 24 hours and 14 days after ONC, we evaluated the effects of GH upon several markers by quantitative PCR (qPCR), Western blot, and immunohistochemistry; the ON integrity was assessed using CTB Alexa 488 anterograde tracer, and retinal function was tested by full-field electroretinogram.

Results

GH partially prevented the ONC-induced death of retinal ganglion cells (RGCs), as well as the increase in gliosis marker GFAP at 14 days. Most of the ONC-induced changes in mRNA retinal levels of several neurotrophic, survival, synaptogenic, gliosis, and excitotoxicity markers were prevented by GH, both at 24 hours and 14 days, and treatment also stimulated the expression of antiapoptotic proteins Bcl-2 and Bcl-xL at 24 hours. Additionally, GH partially maintained the ON integrity and active anterograde transport, as well as retinal function by avoiding the reduced amplitude and slowing of the A- and B-waves and oscillatory potentials associated with the ONC at 14 days.

Conclusions

GH has neuroprotective effects in the ONC model in male rats, it promoted RGC survival, gliosis reduction, and axonal transport increase, likely through the regulation of genes involved in neuroprotection, survival, and synaptogenesis. Furthermore, GH prevented functional impairment, indicating its potential as a therapeutic option for retinal neurodegenerative diseases.

Intraocular Pressure Response to Perceived Stress in Juvenile-Onset Open Angle Glaucoma

PRCIS

High perceived stress from academic pressure is associated with intraocular pressure (IOP) elevation and reduced fluctuation in juvenile-onset open angle glaucoma patients. Personalized stress assessment and relief strategies may serve as an adjunct therapy in glaucoma.

OBJECTIVE

To evaluate the effect of higher perceived stress, resulting from academic pressure, on IOP in juvenile-onset open angle glaucoma (JOAG) patients compared with healthy individuals.

METHODS

The study included 48 university students aged 18-27 years, comprising 24 JOAG patients on antiglaucoma eyedrops and 24 healthy controls. In an examiner-blind pretest-posttest design, participants' IOP was measured weekly using Goldmann tonometry during three follow-up visits at the beginning and end of the academic semester. Perceived Stress Scale (PSS) scores were also evaluated at these 2-time points to capture the contrast in perceived stress between periods of low and high academic pressure.

RESULTS

The baseline PSS score at the semester's start was lower in both groups (14.1±1.9 in glaucoma vs. 13.5±2.4 in control) and significantly increased by the end of the semester (29.2±2.1 vs. 28.5±1.3; P <0.001), indicating increased perceived stress. Concurrently, IOP rose from 22.01±5.87 to 25.08±5.84 mm Hg in the glaucoma group and from 11.36±2.03 to 13.65±2.11 mm Hg in the control group. Factorial analysis revealed a significant interaction between stress and JOAG ( F(1,94) =15.94, P =0.001), partial η 2 =0.08, with stress having a greater increase on IOP in the glaucoma group (+3.10 mm Hg) compared with the control group (+2.23 mm Hg) ( t(94) =4.457, P <0.001).

CONCLUSIONS

Higher perceived stress significantly increases IOP, especially in JOAG patients, suggesting personalized stress management as a potential adjunct therapy for patients.

Trends in glaucoma surgery in a tertiary hospital in Spain: 2010-2022

OBJECTIVE

This study aims to conduct an analysis glaucoma surgeries performed over a 13-year period at a tertiary hospital affiliated with the Spanish National Health System, with the goal of assessing temporal trends.

METHODS

This retrospective observational study scrutinized surgeries undertaken in the glaucoma unit of a tertiary center in Spain between 2010 and 2022. Data collected included surgical dates, procedure performed, whether it was standalone or combined, as well as patient demographics including age, sex, and type of underlying glaucoma. Surgeries on individuals under 18 years of age were excluded. An annual comparative analysis was performed to ascertain the evolving trends in glaucoma surgical interventions.

RESULTS

A total of 12,944 surgeries were included in the analysis, comprising 9428 isolated cataract surgeries and 2975 glaucoma procedures. Trabeculectomy, glaucoma drainage devices (GDD), and cyclodestruction, collectively referred to as traditional surgery, demonstrated a decline from 93.2% to 23.6% over the study duration. Minimally invasive glaucoma surgery (MIGS) and minimally invasive bleb surgery (MIBS) demonstrated a significant increase from 3.8% in 2010 to 74.7% in 2022, relative to the total glaucoma surgeries. Furthermore, combined surgeries manifested a noteworthy increase from 39.0% in 2010 to 44.2% in 2022, with 86.4% of combined procedures in 2022 being MIGS or MIBS.

CONCLUSION

In recent years, there has been a noticeable change in the trend of glaucoma surgeries, with MIGS and MIBS procedures experiencing a significant increase and becoming the most commonly performed glaucoma procedures. Consequently, traditional glaucoma surgeries have decreased in frequency.

Artificial Intelligence and Advanced Technology in Glaucoma: A Review

BACKGROUND

Glaucoma is a leading cause of irreversible blindness worldwide, necessitating precise management strategies tailored to individual patient characteristics. Artificial intelligence (AI) holds promise in revolutionizing the approach to glaucoma care by providing personalized interventions.

AIM

This review explores the current landscape of AI applications in the personalized management of glaucoma patients, highlighting advancements, challenges, and future directions.

METHODS

A systematic search of electronic databases, including PubMed, Scopus, and Web of Science, was conducted to identify relevant studies published up to 2024. Studies exploring the use of AI techniques in personalized management strategies for glaucoma patients were included.

RESULTS

The review identified diverse AI applications in glaucoma management, ranging from early detection and diagnosis to treatment optimization and prognosis prediction. Machine learning algorithms, particularly deep learning models, demonstrated high accuracy in diagnosing glaucoma from various imaging modalities such as optical coherence tomography (OCT) and visual field tests. AI-driven risk stratification tools facilitated personalized treatment decisions by integrating patient-specific data with predictive analytics, enhancing therapeutic outcomes while minimizing adverse effects. Moreover, AI-based teleophthalmology platforms enabled remote monitoring and timely intervention, improving patient access to specialized care.

CONCLUSIONS

Integrating AI technologies in the personalized management of glaucoma patients holds immense potential for optimizing clinical decision-making, enhancing treatment efficacy, and mitigating disease progression. However, challenges such as data heterogeneity, model interpretability, and regulatory concerns warrant further investigation. Future research should focus on refining AI algorithms, validating their clinical utility through large-scale prospective studies, and ensuring seamless integration into routine clinical practice to realize the full benefits of personalized glaucoma care.

Characterization of infectious bacterial keratitis in Östergötland County, Sweden: a 10-year retrospective study

BACKGROUND

The aim of this study was to characterize bacterial species, aetiology and antibiotic susceptibility connected to bacterial keratitis infections in Östergötland, Sweden.

METHODS

Retrospective cross-sectional study based on electronic health records for the period 2010-2019. Records of patients diagnosed with infectious keratitis were screened for microbiology confirmed infectious bacterial keratitis. Bacterial species and their susceptibility to antibiotics were determined from microbiology test results.

RESULTS

One-hundred and ninety patients with lab culture-confirmed infectious bacterial keratitis were included in the analysis. The most frequently found bacterial species were coagulase-negative staphylococci (39%), Staphylococcus aureus (17%) and Cutibacterium acnes (10%). Pseudomonas spp. was the most frequently found Gram-negative bacterial species (7%). Contact lens wear and severely ill/blind eye were the top two aetiologies associated with bacterial keratitis, 22% of the patients with bacterial keratitis were also diagnosed with glaucoma. Most isolates, 157 out of 173, were susceptible to fluoroquinolones, and 145 out of 155 isolates were susceptible to chloramphenicol.

CONCLUSION

Our results revealed a positive rate of bacterial keratitis of 59% for the samples sent to the laboratory. There was a high susceptibility of the bacterial species to the recommended antibiotics. Our results indicate that it is likely that patients are receiving the correct treatment. Future studies are necessary to monitor changes in antibiotic susceptibility.

Clinical Outcomes of Excisional Goniotomy with the Kahook Dual Blade: 6-Year Results

INTRODUCTION

This study aims to evaluate the long-term clinical outcomes of excisional goniotomy with the Kahook Dual Blade (KDB) in the management of various types of glaucoma.

METHODS

This was a retrospective, noncomparative chart review of 90 eyes of 53 patients with glaucoma that underwent standalone KDB goniotomy (KDB-alone group) or KDB goniotomy with concomitant phacoemulsification (KDB-phaco group) between October 2015 and October 2017. Surgical success was defined as an intraocular pressure (IOP) reduction by ≥ 20% at the last follow-up with no surgical reinterventions required and a final IOP ≥ 4 mmHg and ≤ 21 mmHg. We also report on changes from baseline in IOP, number of glaucoma medications, best-corrected visual acuity (BCVA), and visual field parameters, for up to 72 months.

RESULTS

At 72 months, mean (standard deviation [SD]) IOP was reduced from 17.5 (5.7) to 13.6 (3.0) mmHg (P < 0.0001) in the KDB-phaco group and from 23.3 (5.9) to 15.1 (6.2) mmHg (P = 0.0593) in the KDB-alone group. The mean (SD) number of glaucoma medications was reduced from 1.3 (1.0) to 0.8 (0.9) (P < 0.0001) in the KDB-phaco group and from 1.2 (1.0) to 0.7 (0.8) (P = 0.3409) in the KDB-alone group. During the 72-month follow-up, surgical success was achieved in 24 of the 52 available eyes (46.2%). Four eyes underwent a glaucoma surgical reintervention by 72 months.

CONCLUSIONS

Excisional goniotomy with the KDB effectively lowered the IOP (by an average of 28.0% from baseline) and maintained or further reduced glaucoma medication burdens (by an average of 30.8% from baseline) under an excellent safety profile, independent of phacoemulsification status. The procedure exhibited favorable success for up to 6 years, providing valuable insights into its long-term efficacy as a glaucoma treatment.

Age, Sex, and Clinical Characteristics of Juvenile Open-Angle Glaucoma Patients in a Saudi Tertiary Hospital: A Retrospective Study of Surgical and Non-Surgical Outcomes

Background/Objectives: Juvenile Open Angle Glaucoma (JOAG) is a condition that presents peculiar issues because it starts at a very early age and, in the end, causes substantial vision loss. This study aimed to analyze the age and gender distribution and treatment outcomes in JOAG patients. Methods: We carried out a retrospective study at King Abdul Aziz University Hospital, Riyadh, Saudi Arabia, from 2015 to 2022. We extracted data from the medical records. Visual acuity data were converted to the logarithm of the minimum angle resolution (LogMAR) for standardized analysis. The CARL ZEISS Humphrey 745i Field Analyzer/HFA II-i Visual Field Analyzer was used to perform visual field examinations under the 24-2 program SITA standard. Results: The study involved 45 JOAG patients (87 affected eyes) with a mean age of 26.91 years. Myopia was the prevailing trait (93%), and a family history of glaucoma was found in 51.1% of cases. Most of the patients presented with severe visual field defects in both eyes (right-57.1%, left-44.4%). Regarding visual acuity, we found that the majority of affected categories belonged to either mild or moderate in both eyes. Initial and final Intraocular pressure (IOP) measurements together showed a significant reduction (p < 0.001) and clearly demonstrated the need for IOP control. Surgical and non-surgical treatments significantly reduced IOP, with no gender or eye differences Conclusions: This research offers important data concerning JOAG demographics (age and gender), clinical picture, and treatment results. Though early-onset presents challenges, multidimensional therapeutic methods have great potential to get JOAG under control and maintain visual function. Additional research is needed to study the genetic causes of JOAG and assess the long-term treatment outcomes.

Antioxidants and neurodegenerative eye disease

Neurodegenerative ocular disorders mostly develop with aging and present great complications in the quality of life. Glaucoma and age-related macular degeneration (ARMD) rank as the third and fourth leading causes of blindness and low vision. Oxidative stress is one factor in the pathogenesis of neurodegenerative eye disease. In addition, ocular ischemia and neuroinflammation play an important role. It can be hypothesized that the influence of antioxidants through diet or oral supplementation can counteract the harmful effects of reactive oxygen species accumulated secondary to oxidative stress, ischemia, and inflammation. A range of studies has been published over the past decades focusing on the possible adjuvant effect of antioxidants in ARMD, while there were fewer reports on the potential role of antioxidants in glaucoma. Although certain reports demonstrated positive results, others were discouraging. As there is a controversy between the studies favoring and disfavoring supplementation with different types of antioxidants, it is important to revise the existing evidence on the role of antioxidants in neurodegenerative ocular disorders with a special focus on glaucoma and ARMD.

Evaluation of Macular Thickness in Glaucoma Patients Using Prostaglandin Analog Eye Drops Undergoing Trabeculectomy with Mitomycin C: Prospective, Comparative, Randomized, Masked Examiner Study

INTRODUCTION

The aim of the study was to evaluate the macular thickness of glaucomatous patients undergoing trabeculectomy (TREC) with mitomycin C (MMC) with or without the use of prostaglandin analog (PA) eye drops.

METHODS

In this prospective, comparative clinical trial, patients with glaucoma and indications for TREC with MMC using PA and without previous macular changes were randomized into 2 groups: the study group (SG) and the control group (CG). In the CG, PA was suspended between 30 and 60 days after the preoperative exams. The subjects were evaluated, including optical coherence tomography (OCT) with the Cirrus 4000 macular protocol preoperatively and in the postoperative period on 3 occasions: 1-3 days ("PO1"), 6-9 days ("PO7"), and 27-30 days ("PO30") after surgery. The results were compared between groups.

RESULTS

Thirty-five eyes of 35 patients were included (17 in the CG and 18 in the SG). There was no statistically significant difference in age (p = 0.2), the preoperative visual field mean deviation (p = 0.08), or the preoperative intraocular pressure (SG: 24.8 ± 7.8 mm Hg vs. CG: 22.8 ± 6.0 mm Hg, p = 0.4). The preoperative macular OCT parameters were equivalent between the groups (p > 0.05). When comparing the variation of parameters between the groups between preop and PO30 there was equivalence in all of the comparisons evaluated. The presence (or absence) of the lens did not affect the results.

CONCLUSION

PA eye drops did not affect macular thickness after TREC with MMC in glaucomatous patients.

How Would Nature See Our Corneal Triumphs? The LXXIX Edward Jackson Lecture

PURPOSE

To describe discrepancies between clinical observation and current teachings in corneal endothelial disease, particularly in Fuchs endothelial dystrophy and its potential association with primary open angle glaucoma.

DESIGN

Perspective.

METHODS

A perspective is presented on Fuchs dystrophy, a disorder that commonly presents with a compromised endothelium but minimal stromal edema, indicating that the corneal imbibition pressure is relatively "too high."

RESULTS

The discrepancy between the relative lack of stromal edema in the absence of an endothelial cell layer cannot be explained by the current theories involving a circulatory pumping mechanism over the endothelial cell layer, but may point to the following: (1) secondary involvement of the corneal endothelium in Fuchs dystrophy; (2) separate hydration systems for maintaining the imbibition pressure (vertical static hydration) and corneal nutrition (horizontal dynamic hydration); (3) the cornea as net contributor of aqueous humor; (4) a close relationship between the corneal imbibition and intraocular pressure, with potentially a shared regulatory system; and (5) a potential steroid-type hormone dependency of this regulatory system.

CONCLUSIONS

Clinical observation shows that the stromal imbibition pressure is "too high" in Fuchs endothelial dystrophy, indicating that it may not primarily be an endothelial disease, but a type of "corneal glaucoma."

Unveiling Novel Structural Biomarkers for the Diagnosis of Glaucoma

Glaucoma, a leading cause of irreversible blindness, poses a significant global health burden. Early detection is crucial for effective management and prevention of vision loss. This study presents a collection of novel structural biomarkers in glaucoma diagnosis. By employing advanced imaging techniques and data analysis algorithms, we now can recognize indicators of glaucomatous progression. Many research studies have revealed a correlation between the structural changes in the eye or brain, particularly in the optic nerve head and retinal nerve fiber layer, and the progression of glaucoma. These biomarkers demonstrate value in distinguishing glaucomatous eyes from healthy ones, even in the early stages of the disease. By facilitating timely detection and monitoring, they hold the potential to mitigate vision impairment and improve patient outcomes. This study marks an advancement in the field of glaucoma, offering a promising avenue for enhancing the diagnosis and possible management.

The effect of trifocal and extended-depth-of-focus intraocular lenses on optical coherence tomography parameters

PURPOSE

Optical properties of commonly used multifocal and extended-depth-of-focus (EDOF) intraocular lenses (IOLs) can induce artifacts or changes in optical coherence tomography (OCT) measurements. Our purpose was to investigate the possible effects of different IOLs on peripapillary and macular OCT parameters.

METHODS

The preoperative and postoperative third-month peripapillary OCT and ganglion cell analysis (GCA) parameters of patients having monofocal (Alcon IQ), multifocal (PanOptix), or EDOF (Vivity) IOL implanted during cataract surgery were compared.

RESULTS

Sixty-four eyes of 64 patients were included (21 monofocal, 24 multifocal, and 19 EDOF). Although all OCT image qualities increased postoperatively, only GCA image quality changes in the monofocal and multifocal groups reached statistical significance. Most peripapillary retinal nerve fiber layer (RNFL) and GCA parameters were similar preoperatively and postoperatively. The superior RNFL thickness in the monofocal group and the temporal RNFL thickness in the EDOF group were higher postoperatively ( P = 0.04 and P = 0.02, respectively). Most GCA and RNFL value changes between preoperative and postoperative measurements were similar between groups. In the parameters that changed, postoperative values were higher in the monofocal group ( P = 0.02 for minimum ganglion cell layer and inner plexiform layer, P = 0.04 for average RNFL).

CONCLUSION

Trifocal and EDOF IOLs do not seem to have a negative effect on OCT parameters.

Wound Modulations in Glaucoma Surgery: A Systematic Review

Excessive fibrosis and resultant poor control of intraocular pressure (IOP) reduce the efficacy of glaucoma surgeries. Historically, corticosteroids and anti-fibrotic agents, such as mitomycin C (MMC) and 5-fluorouracil (5-FU), have been used to mitigate post-surgical fibrosis, but these have unpredictable outcomes. Therefore, there is a need to develop novel treatments which provide increased effectiveness and specificity. This review aims to provide insight into the pathophysiology behind wound healing in glaucoma surgery, as well as the current and promising future wound healing agents that are less toxic and may provide better IOP control.

Validation of Diagnostic Codes to Identify Glaucoma in Taiwan's Claims Data: A Multi-Institutional Study

Background

Healthcare databases play a crucial role in improving our understanding of glaucoma epidemiology, which is the leading cause of irreversible blindness globally. However, the accuracy of diagnostic codes used in these databases to detect glaucoma is still uncertain.

Aim

To assess the accuracy of ICD-9-CM and ICD-10-CM codes in identifying patients with glaucoma, including two distinct subtypes, primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG).

Methods

We analyzed electronic medical records data from a 2% random sample of patients who newly underwent visual field examination in Taiwan's largest multi-institutional healthcare system from 2011 to 2020. The diagnosis of glaucoma was confirmed by two ophthalmologists, based on the glaucoma diagnostic criteria. The positive predictive value (PPV), negative predictive value (NPV), sensitivity and specificity for ICD-9-CM codes 365.1X and 365.2X, and ICD-10-CM codes H4010X, H4011X, H4012X, H4020X, H4021X, H4022X, H4023X and H4024X for glaucoma were calculated.

Results

We randomly selected 821 patients (mean age: 56.9 years old; female: 50.5%) from the original cohort of 41,050 newly receiving visual field examination in the study. Among 464 cases with an ICD-9-CM glaucoma code, the sensitivity, specificity, PPV and NPV for glaucoma were 86.5, 96.5, 91.9, and 90.9%, respectively. Among 357 cases with an ICD-10-CM glaucoma code, the sensitivity, specificity, PPV and NPV for glaucoma were 87.0, 92.8, 92.2 and 87.9%, respectively. The accuracy of diagnostic codes to identify POAG and PACG remained consistent.

Conclusion

The diagnostic codes were highly reliable for identifying cases of glaucoma in Taiwan's routine healthcare practice. These results provide confidence when using ICD-9-CM and ICD-10-CM codes to define glaucoma cases in healthcare database research in Taiwan.

The Effect of Yoga on Intraocular Pressure Using the "iCare HOME2" Tonometer

BACKGROUND

Various yoga positions may have an unfavorable impact on intraocular pressure (IOP) and may therefore be seen as a potential risk factor for the progression of glaucoma. The new "iCare HOME2" is a handheld self-tonometer for IOP measurements outside clinical settings. This is the first study to evaluate the immediate effect of common yoga postures on the IOP of healthy and glaucomatous eyes using the "iCare HOME2" self-tonometer and to compare the time of IOP recovery in both groups.

METHODS

This is a single-center, prospective, observational study including 25 healthy and 25 glaucoma patients performing the following yoga positions: "legs up" (Viparita Karani), "bend over" (Uttanasana), "plough pose" (Halasana), and the "down face dog" (Adho Mukha Svanasana) for 90 s each, with a 2-min break in between. IOP was measured with the "iCare HOME2" before, during, and after each position.

RESULTS

IOP significantly increased in all eyes in all positions (p < 0.05), showing no statistically significant difference between healthy or glaucomatous eyes (p > 0.05). The mean rise in IOP in healthy subjects was 1.6 mmHg (SD 1.42; p = 0.037), 14.4 mmHg (SD 4.48; p < 0.001), 7.5 mmHg (SD 4.21; p < 0.001), and 16.5 mmHg (SD 3.71; p < 0.001), whereas in glaucoma patients, IOP rose by 2.8 mmHg (SD 2.8; p = 0.017), 11.6 mmHg (SD 3.86; p < 0.001), 6.0 mmHg (SD 2.24; p < 0.001), and 15.1 mmHg (SD 4.44; p < 0.001) during the above listed yoga positions, repsectively. The highest increase in IOP was seen in the down face position, reaching mean IOP values above 31 mmHg in both study groups. IOP elevation was observed immediately after assuming the yoga position, with no significant change during the following 90 s of holding each pose (p > 0.05). All IOP values returned to baseline level in all individuals, with no significant difference between healthy and glaucoma participants.

CONCLUSION

Our data show that common yoga positions can lead to an acute IOP elevation of up to 31 mmHg in healthy as well as glaucoma eyes, with higher IOP values during head-down positions. Given that IOP peaks are a major risk factor for glaucomatous optic neuropathy, we generally advise glaucoma patients to carefully choose their yoga exercises. If and to what extent practicing yoga leads to glaucoma progression, however, remains unclear and warrants further research.

Molecular pathways in experimental glaucoma models

Glaucoma is a complex and progressive disease that primarily affects the optic nerve axons, leading to irreversible vision loss. Although the exact molecular mechanisms underlying glaucoma pathogenesis are not fully understood, it is believed that except increased intraocular pressure, a combination of genetic and environmental factors play a role in the development of the disease. Animal models have been widely used in the study of glaucoma, allowing researchers to better understand the underlying mechanisms of the disease and test potential treatments. Several molecular pathways have been implicated in the pathogenesis of glaucoma, including oxidative stress, inflammation, and excitotoxic-induced neurodegeneration. This review summarizes the most important knowledge about molecular mechanisms involved in the glaucoma development. Although much research has been done to better understand the molecular mechanisms underlying this disease, there is still much to be learned to develop effective treatments and prevent vision loss in those affected by glaucoma.

Long-Term Efficacy of Successful Excisional Goniotomy with the Kahook Dual Blade

Purpose

To report clinical outcomes of successful excisional goniotomy with the Kahook Dual Blade (KDB), through 60 months.

Patients and methods

This was a noncomparative, single-surgeon, retrospective review of eyes receiving successful KDB goniotomy with or without concomitant phacoemulsification between October 2015 and January 2016 with five years of uninterrupted follow-up. Intraocular pressure (IOP), number of glaucoma medications, best corrected visual acuity (BCVA), and complications were recorded. Primary outcomes included changes from baseline in IOP, medication use, and BCVA, through five years.

Results

Fifty-two eyes of 28 patients were analyzed. Most eyes had mild primary open angle glaucoma (73%). Of the eyes analyzed, 41 underwent combined surgery and 11 underwent standalone surgery. With all eyes combined, mean (standard deviation) baseline IOP was 21.0 (4.1) mmHg and mean baseline medication use was 1.8 (1.1) medications per eye. Across time points at months 6, 12, 24, 36, 48, and 60, mean postoperative IOP ranged from 13.0 to 13.7 mmHg, representing mean reductions of 7.3-8.0 mmHg (34.7-38.3%; p <0.0001 at every time point). Similarly, mean medication use ranged from 0.4 to 0.6 medications per eye, representing mean reductions of 1.2-1.4 medications (66-75.5%; p <0.0001 at every time point). Mean logMAR BCVA improved from 0.321 (0.177) preoperatively to 0.015 (0.035) at month 60 (p < 0.0001).

Conclusion

In eyes not requiring secondary surgical procedures (eg, long-term surgical successes), excisional goniotomy provided clinically and statistically significant reductions in both IOP and the need for medications that were highly consistent through five years of follow-up. KDB goniotomy appears to be highly successful in Caucasian patients with open angle glaucoma on ≥1 IOP-lowering medications at baseline and with no history of prior ocular surgery. Successful excisional goniotomy with the KDB can be expected to improve long-term glaucoma-related visual outcomes through IOP reduction and to improve quality of life through medication reduction.

Prevalence and Characteristics of Glaucoma Among Patients Presenting to Ophthalmology Clinics in a Tertiary Hospital in the Kingdom of Bahrain

Introduction The aim of this study was to determine the prevalence and characteristics of glaucoma in patients presenting to the ophthalmology department in a tertiary hospital in Bahrain for the first time. Methods A retrospective study was conducted at the Salmaniya Medical Complex, Manama, Bahrain. The medical records of all patients who presented for the first time to an eye clinic between January and December 2019 were reviewed. Patients who were diagnosed with glaucoma were included in this study. Data regarding age, sex, ethnicity, type of glaucoma, previous treatment, best corrected visual acuity, cup-to-disc ratio, intraocular pressure, central corneal thickness, optical coherence tomography (OCT) retinal nerve fiber layer (RNFL), and visual field findings were collected. Results Of a total of 18,238 new patients in 2019, 173 patients (0.97%) had glaucoma. The mean age of patients with glaucoma was 59.6 ± 11.3 years and approximately 60% of them were males (n=103, 59.5%). In 93% of the cases, glaucoma involved both eyes (n=161). Primary open-angle glaucoma (n=97, 56.1%), normal tension glaucoma (n=28, 16.2%), and chronic angle closure glaucoma (n=15, 8.7%) were the most frequently encountered types of glaucoma. Approximately 16.76% (n=29) of the patients were blind in one or two eyes at the time of presentation. Conclusion There seems to be a low prevalence of glaucoma among the encountered cases on the first visit to ophthalmology clinics in Bahrain, with primary open-angle glaucoma being the most common type.

Evaluation of the nutraceutical Palmitoylethanolamide in reducing intraocular pressure (IOP) in patients with glaucoma or ocular hypertension: a systematic review and meta-analysis

Intraocular pressure (IOP) positively correlates with both normal and high-tension glaucoma. To date, IOP targeting remains the validated pharmacological approach in counteracting glaucoma progression as well as in halting vision loss. Among the different adjuvant compounds, evidence highlighted the potential effectiveness of Palmitoylethanolamide (PEA), an endogenous fatty acid amide. Thus, a systematic review of the literature was conducted, thoroughly evaluating PEA treatment regimen in decreasing IOP in patients with eye disorders. We checked for articles across the scientific databases Pubmed (MEDLINE), Embase (OVID), and Web of Science from the inception to 30 August 2023, and a total of 828 articles were recovered. Six of these studies (199 patients) were included in the systematic review after the study selection process, and three studies for meta-analysia. Overall, PEA showed significant efficacy in reducing IOP in patients, this encourages its clinical use in glaucoma as well as across different forms of eye disorders.

Beyond Vision: An Overview of Regenerative Medicine and Its Current Applications in Ophthalmological Care

Regenerative medicine (RM) has emerged as a promising and revolutionary solution to address a range of unmet needs in healthcare, including ophthalmology. Moreover, RM takes advantage of the body's innate ability to repair and replace pathologically affected tissues. On the other hand, despite its immense promise, RM faces challenges such as ethical concerns, host-related immune responses, and the need for additional scientific validation, among others. The primary aim of this review is to present a high-level overview of current strategies in the domain of RM (cell therapy, exosomes, scaffolds, in vivo reprogramming, organoids, and interspecies chimerism), centering around the field of ophthalmology. A search conducted on clinicaltrials.gov unveiled a total of at least 209 interventional trials related to RM within the ophthalmological field. Among these trials, there were numerous early-phase studies, including phase I, I/II, II, II/III, and III trials. Many of these studies demonstrate potential in addressing previously challenging and degenerative eye conditions, spanning from posterior segment pathologies like Age-related Macular Degeneration and Retinitis Pigmentosa to anterior structure diseases such as Dry Eye Disease and Limbal Stem Cell Deficiency. Notably, these therapeutic approaches offer tailored solutions specific to the underlying causes of each pathology, thus allowing for the hopeful possibility of bringing forth a treatment for ocular diseases that previously seemed incurable and significantly enhancing patients' quality of life. As advancements in research and technology continue to unfold, future objectives should focus on ensuring the safety and prolonged viability of transplanted cells, devising efficient delivery techniques, etc.

Transforming glaucoma diagnosis: transformers at the forefront

Although the Vision Transformer architecture has become widely accepted as the standard for image classification tasks, using it for object detection in computer vision poses significant challenges. This research aims to explore the potential of extending the Vision Transformer for object detection in medical imaging, specifically for glaucoma detection, and also includes an examination of the Detection Transformer for comparative analysis. The analysis involves assessing the cup-to-disc ratio and identifying signs of vertical thinning of the neuroretinal rim. A diagnostic threshold is proposed, flagging a cup-to-disc ratio exceeding 0.6 as a potential indicator of glaucoma. The experimental results demonstrate a remarkable 90.48% accuracy achieved by the pre-trained Detection Transformer, while the Vision Transformer exhibits competitive accuracy at 87.87%. Comparative evaluations leverage a previously untapped dataset from the Standardized Fundus Glaucoma Dataset available on Kaggle, providing valuable insights into automated glaucoma detection. The evaluation criteria and results are comprehensively validated by medical experts specializing in the field of glaucoma.

Evaluation of Reporting Quality of Glaucoma Randomized Controlled Trial Abstracts: Current Status and Future Perspectives

The aim of this study was to explore adherence to the Consolidated Standards of Reporting Trials (CONSORT) reporting standards in abstracts of randomized controlled trials on glaucoma. A cross-sectional observational study was conducted on the aforementioned abstracts, indexed in MEDLINE/PubMed between the years 2017 and 2021. In total, 302 abstracts met the inclusion criteria and were further analyzed. The median score of CONSORT-A items was 8 (interquartile range, 7-10) out of 17 (47.0%). Most analyzed studies were conducted in a single center (80.5%) and the abstracts were predominantly structured (95.0%). Only 20.5% of the abstracts adequately described the trial design, while randomization and funding were described by 6.0% of the abstracts. Higher overall scores were associated with structured abstracts, a multicenter setting, statistically significant results, funding by industry, a higher number of participants, and having been published in journals with impact factors above four (p < 0.001, respectively). The results of this study indicate a suboptimal adherence to CONSORT-A reporting standards, especially in particular items such as randomization and funding. Since these factors could contribute to the overall quality of the trials and further translation of trial results into clinical practice, an improvement in glaucoma research reporting transparency is needed.

Glaucoma Animal Models beyond Chronic IOP Increase

Glaucoma is a complex and multifactorial disease defined as the loss of retinal ganglion cells (RGCs) and their axons. Besides an elevated intraocular pressure (IOP), other mechanisms play a pivotal role in glaucoma onset and progression. For example, it is known that excitotoxicity, immunological alterations, ischemia, and oxidative stress contribute to the neurodegeneration in glaucoma disease. To study these effects and to discover novel therapeutic approaches, appropriate animal models are needed. In this review, we focus on various glaucoma animal models beyond an elevated IOP. We introduce genetically modified mice, e.g., the optineurin E50K knock-in or the glutamate aspartate transporter (GLAST)-deficient mouse. Excitotoxicity can be mimicked by injecting the glutamate analogue N-methyl-D-aspartate intravitreally, which leads to rapid RGC degeneration. To explore the contribution of the immune system, the experimental autoimmune glaucoma model can serve as a useful tool. Here, immunization with antigens led to glaucoma-like damage. The ischemic mechanism can be mimicked by inducing a high IOP for a certain amount of time in rodents, followed by reperfusion. Thereby, damage to the retina and the optic nerve occurs rapidly after ischemia/reperfusion. Lastly, we discuss the importance of optic nerve crush models as model systems for normal-tension glaucoma. In summary, various glaucoma models beyond IOP increase can be utilized.

European Glaucoma Society - A guide on surgical innovation for glaucoma

PROLOGUE: Glaucoma surgery has been, for many decades now, dominated by the universal gold standard which is trabeculectomy augmented with antimetabolites. Tubes also came into the scene to complement what we use to call conventional or traditional glaucoma surgery. More recently we experienced a changing glaucoma surgery environment with the "advent" of what we have become used to calling Minimally Invasive Glaucoma Surgery (MIGS). What is the unmet need, what is the gap that these newcomers aim to fill? Hippocrates taught us "bring benefit, not harm" and new glaucoma techniques and devices aim to provide safer surgery compared to conventional surgery. For the patient, but also for the clinician, safety is important. Is more safety achieved with new glaucoma surgery and, if so, is it associated with better, equivalent, or worse efficacy? Is new glaucoma surgery intended to replace conventional surgery or to complement it as an 'add-on' to what clinicians already have in their hands to manage glaucoma? Which surgery should be chosen for which patient? What are the options? Are they equivalent? These are too many questions for the clinician! What are the answers to the questions? What is the evidence to support answers? Do we need more evidence and how can we produce high-quality evidence? This EGS Guide explores the changing and challenging glaucoma surgery environment aiming to provide answers to these questions. The EGS uses four words to highlight a continuum: Innovation, Education, Communication, and Implementation. Translating innovation to successful implementation is crucially important and requires high-quality evidence to ensure steps forward to a positive impact on health care when it comes to implementation. The vision of EGS is to provide the best possible well-being and minimal glaucomainduced visual disability in individuals with glaucoma within an affordable healthcare system. In this regard, assessing the changes in glaucoma surgery is a pivotal contribution to better care. As mentioned, this Guide aims to provide answers to the crucial questions above. However, every clinician is aware that answers may differ for every person: an individualised approach is needed. Therefore, there will be no uniform answer for all situations and all patients. Clinicians would need, through the clinical method and possibly some algorithm, to reach answers and decisions at the individual level. In this regard, evidence is needed to support clinicians to make decisions. Of key importance in this Guide is to provide an overview of existing evidence on glaucoma surgery and specifically on recent innovations and novel devices, but also to set standards in surgical design and reporting for future studies on glaucoma surgical innovation. Designing studies in surgery is particularly challenging because of many subtle variations inherent to surgery and hence multiple factors involved in the outcome, but even more because one needs to define carefully outcomes relevant to the research question but also to the future translation into clinical practice. In addition this Guide aims to provide clinical recommendations on novel procedures already in use when insufficient evidence exists. EGS has a long tradition to provide guidance to the ophthalmic community in Europe and worldwide through the EGS Guidelines (now in their 5th Edition). The EGS leadership recognized that the changing environment in glaucoma surgery currently represents a major challenge for the clinician, needing specific guidance. Therefore, the decision was made to issue this Guide on Glaucoma Surgery in order to help clinicians to make appropriate decisions for their patients and also to provide the framework and guidance for researchers to improve the quality of evidence in future studies. Ultimately this Guide will support better Glaucoma Care in accordance with EGS's Vision and Mission. Fotis Topouzis EGS President

Genetics and Glaucoma: the state of the art

Glaucoma is the second leading cause of irreversible blindness worldwide. Although genetic background contributes differently to rare early-onset glaucoma (before age 40) or common adult-onset glaucoma, it is now considered an important factor in all major forms of the disease. Genetic and genomic studies, including GWAS, are contributing to identifying novel loci associated with glaucoma or to endophenotypes across ancestries to enrich the knowledge about glaucoma genetic susceptibility. Moreover, new high-throughput functional genomics contributes to defining the relevance of genetic results in the biological pathways and processes involved in glaucoma pathogenesis. Such studies are expected to advance significantly our understanding of glaucoma's genetic basis and provide new druggable targets to treat glaucoma. This review gives an overview of the role of genetics in the pathogenesis or risk of glaucoma.

Therapeutic strategies for glaucoma and optic neuropathies

Glaucoma is a neurodegenerative eye disease that causes permanent vision impairment. The main pathological characteristics of glaucoma are retinal ganglion cell (RGC) loss and optic nerve degeneration. Glaucoma can be caused by elevated intraocular pressure (IOP), although some cases are congenital or occur in patients with normal IOP. Current glaucoma treatments rely on medicine and surgery to lower IOP, which only delays disease progression. First-line glaucoma medicines are supported by pharmacotherapy advancements such as Rho kinase inhibitors and innovative drug delivery systems. Glaucoma surgery has shifted to safer minimally invasive (or microinvasive) glaucoma surgery, but further trials are needed to validate long-term efficacy. Further, growing evidence shows that adeno-associated virus gene transduction and stem cell-based RGC replacement therapy hold potential to treat optic nerve fiber degeneration and glaucoma. However, better understanding of the regulatory mechanisms of RGC development is needed to provide insight into RGC differentiation from stem cells and help choose target genes for viral therapy. In this review, we overview current progress in RGC development research, optic nerve fiber regeneration, and human stem cell-derived RGC differentiation and transplantation. We also provide an outlook on perspectives and challenges in the field.

Preventing Blindness with Early Cataract Surgery and Micro-Invasive Glaucoma Surgery in Patients Over 50: Guidance for Patients, Physicians and World Governments in Dealing with Glaucoma

Purpose

To offer clinical guidance and address safety and efficacy concerns regarding the growing use of micro-invasive glaucoma surgery (MIGS) as an initial treatment for glaucoma in adult patients.

Design

Narrative literature review.

Methods

A review was conducted to assess outcomes and complications of MIGS in the treatment of glaucoma, both alone and in combination with lens replacement. These outcomes were compared with those of standard glaucoma surgery and/or glaucoma management with medication.

Results

MIGS are effective at lowering intraocular pressure (IOP) over long periods of follow-up. These techniques share a similarly high safety profile between one another. MIGS were found to have lower complication rates and to be more effective in reducing the total amount of medication needed to maintain control of intraocular pressure than standard surgery approaches.

Conclusion

MIGS techniques are growing in popularity and have been demonstrated to be a safe and effective alternative to standard glaucoma surgery. Guidance in the implementation of these procedures has been outlined.

miRNA Studies in Glaucoma: A Comprehensive Review of Current Knowledge and Future Perspectives

Glaucoma, a neurodegenerative disorder that leads to irreversible blindness, remains a challenge because of its complex nature. MicroRNAs (miRNAs) are crucial regulators of gene expression and are associated with glaucoma and other diseases. We aimed to review and discuss the advantages and disadvantages of miRNA-focused molecular studies in glaucoma through discussing their potential as biomarkers for early detection and diagnosis; offering insights into molecular pathways and mechanisms; and discussing their potential utility with respect to personalized medicine, their therapeutic potential, and non-invasive monitoring. Limitations, such as variability, small sample sizes, sample specificity, and limited accessibility to ocular tissues, are also addressed, underscoring the need for robust protocols and collaboration. Reproducibility and validation are crucial to establish the credibility of miRNA research findings, and the integration of bioinformatics tools for miRNA database creation is a valuable component of a comprehensive approach to investigate miRNA aberrations in patients with glaucoma. Overall, miRNA research in glaucoma has provided significant insights into the molecular mechanisms of the disease, offering potential biomarkers, diagnostic tools, and therapeutic targets. However, addressing challenges such as variability and limited tissue accessibility is essential, and further investigations and validation will contribute to a deeper understanding of the functional significance of miRNAs in glaucoma.

Factors Associated with Large Cup-to-Disc Ratio and Blindness in the Primary Open-Angle African American Glaucoma Genetics (POAAGG) Study

BACKGROUND/AIMS

Primary open-angle glaucoma (POAG) disproportionately affects individuals of African ancestry. In these patients' eyes, a large cup-to-disc ratio (LCDR > 0.90) suggests greater retinal ganglion cell loss, though these patients often display varied visual ability. This study investigated the prevalence and risk factors associated with LCDR in African ancestry individuals with POAG and explored the differences between blind (>20/200) and not blind (≤20/200) LCDR eyes.

METHODS

A case-control methodology was used to investigate the demographic, optic disc, and genetic risk factors of subjects in the Primary Open-Angle African American Glaucoma Genetics Study. Risk factors were analyzed using univariable and multivariable logistic regression models with inter-eye correlation adjusted using generalized estimating equations.

RESULTS

Out of 5605 eyes with POAG, 1440 eyes (25.7%) had LCDR. In the multivariable analysis, LCDR was associated with previous glaucoma surgery (OR = 1.72), increased intraocular pressure (OR = 1.04), decreased mean deviation (OR = 1.08), increased pattern standard deviation (OR = 1.06), thinner retinal nerve fiber layer (OR = 1.05), nasalization of vessels (OR = 2.67), bayonetting of vessels (OR = 1.98), visible pores in the lamina cribrosa (OR = 1.68), and a bean-shaped cup (OR = 2.11). Of LCDR eyes, 30.1% were classified as blind (≤20/200). In the multivariable analysis, the statistically significant risk factors of blindness in LCDR eyes were previous glaucoma surgery (OR = 1.72), increased intraocular pressure (OR = 1.05), decreased mean deviation (OR = 1.04), and decreased pattern standard deviation (OR = 0.90).

CONCLUSIONS

These findings underscore the importance of close monitoring of intraocular pressure and visual function in African ancestry POAG patients, particularly those with LCDR, to preserve visual function.

Technological Advances in a Therapy of Primary Open-Angle Glaucoma: Insights into Current Nanotechnologies

Glaucoma is a leading cause of irreversible blindness and is characterized by increased intraocular pressure (IOP) and progressive optic nerve damage. The current therapeutic approaches for glaucoma management, such as eye drops and oral medications, face challenges including poor bioavailability, low patient compliance, and limited efficacy. In recent years, nanotechnology has emerged as a promising approach to overcome these limitations and revolutionize glaucoma treatment. In this narrative review, we present an overview of the novel nanotechnologies employed in the treatment of primary open-angle glaucoma. Various nanosystems, including liposomes, niosomes, nanoparticles, and other nanostructured carriers, have been developed to enhance the delivery and bioavailability of antiglaucoma drugs. They offer advantages such as a high drug loading capacity, sustained release, improved corneal permeability, and targeted drug delivery to the ocular tissues. The application of nanotechnologies in glaucoma treatment represents a transformative approach that addresses the limitations of conventional therapies. However, further research is needed to optimize the formulations, evaluate long-term safety, and implement these nanotechnologies into clinical practice. With continued advancements in nanotechnology, the future holds great potential for improving the management and outcomes of glaucoma, ultimately preserving vision and improving the lives of millions affected by this debilitating disease.

Spotlight on Schlemm's Canal MicroStent Injection in Patients with Glaucoma

Minimally invasive glaucoma surgery (MIGS) has revolutionized glaucoma care with its favorable safety profile and ability to delay or minimize the need for traditional, bleb-based procedures. Microstent device implantation is a type of angle-based MIGS, which reduces intraocular pressure (IOP) through bypass of the juxtacanalicular trabecular meshwork (TM) and facilitation of aqueous outflow into the Schlemm's canal. Although there are limited microstent devices on the market, multiple studies have evaluated the safety and efficacy of iStent^® (Glaukos Corp.), iStent Inject^® (Glaukos Corp.), and Hydrus^® Microstent (Alcon) in the treatment of mild-to-moderate open-angle glaucoma, with and without concurrent phacoemulsification. This review attempts to provide a comprehensive evaluation of injectable angle-based microstent MIGS devices in the treatment of glaucoma.

Use Pattern of Ophthalmic Antiglaucoma Agents with and without Preservatives: A Cross-Sectional Study

BACKGROUND

Different drugs have been approved to reduce the intraocular pressure. However, most of them contain preservatives to maintain sterility and these can be toxic to the ocular surface. The aim was to determine the patterns of use of antiglaucoma agents and ophthalmic preservatives in a group of patients from Colombia.

METHODS

A cross-sectional study that identified ophthalmic antiglaucoma agents from a population database of 9.2 million. Sociodemographic and pharmacological variables were considered. Descriptive and bivariate analyses were performed.

RESULTS

A total of 38,262 patients were identified, with a mean age of 69.2 ± 13.3 years, and 58.6% were women. A total of 98.8% were prescribed antiglaucoma drugs in multidose containers. The most widely used were prostaglandin analogs (59.9%), especially latanoprost (51.6%) and β-blockers (59.2%). A total of 54.7% of patients received combined management, especially with fixed-dose combination (FDC) drugs (41.3%). A total of 94.1% used antiglaucoma drugs with preservatives (benzalkonium chloride, 68.4%).

CONCLUSIONS

The pharmacological treatment of glaucoma was very heterogeneous, but the most commonly used therapeutic groups were in accordance with the recommendations of clinical practice guidelines but with differences by sex and age. Most of the patients were exposed to preservatives, especially benzalkonium chloride, but the wide use of FDC drugs can minimize toxicity on the ocular surface.

Meldonium Inhibits Cell Motility and Wound-Healing in Trabecular Meshwork Cells and Scleral Fibroblasts: Possible Applications in Glaucoma

Meldonium (MID) is a synthetic drug designed to decrease the availability of L-carnitine-a main player in mitochondrial energy generation-thus modulating the cell pathways of energy metabolism. Its clinical effects are mostly evident in blood vessels during ischemic events, when the hyperproduction of endogenous carnitine enhances cell metabolic activities, leading to increased oxidative stress and apoptosis. MID has shown vaso-protective effects in model systems of endothelial dysfunction induced by high glucose or by hypertension. By stimulating the endothelial nitric oxide synthetase (eNOS) via PI3 and Akt kinase, it has shown beneficial effects on the microcirculation and blood perfusion. Elevated intraocular pressure (IOP) and endothelial dysfunction are major risk factors for glaucoma development and progression, and IOP remains the main target for its pharmacological treatment. IOP is maintained through the filtration efficiency of the trabecular meshwork (TM), a porous tissue derived from the neuroectoderm. Therefore, given the effects of MID on blood vessels and endothelial cells, we investigated the effects of the topical instillation of MID eye drops on the IOP of normotensive rats and on the cell metabolism and motility of human TM cells in vitro. Results show a significant dose-dependent decrease in the IOP upon topic treatment and a decrease in TM cell motility in the wound-healing assay, correlating with an enhanced expression of vinculin localized in focal adhesion plaques. Motility inhibition was also evident on scleral fibroblasts in vitro. These results may encourage a further exploration of MID eye drops in glaucoma treatment.

Recent Progress in Chitosan-Based Nanomedicine for Its Ocular Application in Glaucoma

Glaucoma is a degenerative, chronic ocular disease that causes irreversible vision loss. The major symptom of glaucoma is high intraocular pressure, which happens when the flow of aqueous humor between the front and back of the eye is blocked. Glaucoma therapy is challenging because of the low bioavailability of drugs from conventional ocular drug delivery systems such as eye drops, ointments, and gels. The low bioavailability of antiglaucoma agents could be due to the precorneal and corneal barriers as well as the low biopharmaceutical attributes of the drugs. These limitations can be overcome by employing nanoparticulate drug delivery systems. Over the last decade, there has been a lot of interest in chitosan-based nanoparticulate systems to overcome the limitations (such as poor residence time, low corneal permeability, etc.) associated with conventional ocular pharmaceutical products. Therefore, the main aim of the present manuscript is to review the recent research work involving the chitosan-based nanoparticulate system to treat glaucoma. It discusses the significance of the chitosan-based nanoparticulate system, which provides mucoadhesion to improve the residence time of drugs and their ocular bioavailability. Furthermore, different types of chitosan-based nanoparticulate systems are also discussed, namely nanoparticles of chitosan core only, nanoparticles coated with chitosan, and hybrid nanoparticles of chitosan. The manuscript also provides a critical analysis of contemporary research related to the impact of this chitosan-based nanomedicine on the corneal permeability, ocular bioavailability, and therapeutic performance of loaded antiglaucoma agents.