Advanced glaucoma at diagnosis: current perspectives

The impact of air pollution and climate change on eye health: a global review

Climate change has important implications on human health, affecting almost every system in the body. Multiple studies have raised the possibility of climate change impacting eye health. In this review, we aimed to summarize current literature on the impact of air pollution and climate change on eye health. We performed a search in four different databases, including Medline, Scopus, Cochrane, and Web of Sciences databases. The search strategy combined terms regarding eye health and environmental/climate changes. The outcome of interest included all eye conditions. The search yielded 2,051 unique articles. After applying inclusion and exclusion criteria, 61 articles were included in this systematic review with data covering 2,620,030 participants. Most studies originated from China, India, South Korea, and USA. Climate change adversely affected different eye conditions, with ocular surface diseases (e.g., conjunctivitis and dry eye) being most affected. Moreover, higher particulate matter (PM) was the most widely assessed pollutant and was adversely associated with the majority of eye conditions, increasing the burden on patients and healthcare providers. We found a low frequency of publications related to the delivery of eye care and its impact on climate change in countries with high air pollution and climate change burden.

MP-3 microperimeter in early primary open angle glaucoma with a new pattern

AIM

To investigate macular microperimetry in patients with early primary open angle glaucoma (POAG) using a new custom-made pattern, and analyze the characteristics of macular sensitivity.

METHODS

This case-control study included 38 patients with POAG, who were divided into pre-perimetric glaucoma (18 eyes of 18 patients), early-stage (20 eyes of 20 patients), and control (20 eyes of 20 patients) groups. All subjects underwent standard 24-2 humphrey visual field test. An MP-3 microperimeter with a new custom-made pattern (28 testing points distributed in four quadrants, covering the central 10° of the retina) was used to evaluate macular sensitivity. Ganglion cell complex (GCC) thicknesses were examined using an RS-3000 Advance OCT system. The features of structure and function were analysed per quadrant.

RESULTS

The pre-perimetric glaucoma group had significantly lower inferior hemifield macular sensitivity compared to controls (P<0.05). The early-stage POAG group had significantly lower average, inferior hemifield, inferonasal, and inferotemporal mean sensitivities compared to the pre-perimetric glaucoma group (P<0.05), and lower macular sensitivity in all sectors compared to controls (P<0.05). Regarding GCC thickness, all sectors in the early-stage POAG group became thinner compared to those in controls (P<0.05); whereas all sectors in the early-stage POAG group, except the superonasal quadrant, became thinner compared to those in the pre-perimetric glaucoma group (P<0.05). Macular sensitivity and GCC thickness were significantly associated in each sector. The inferotemporal quadrant had the highest correlation coefficients (0.840). The structure-function relationship for the inferonasal and inferotemporal sectors was stronger compared to the corresponding superior sectors.

CONCLUSION

Microperimetry reveals variations in macular sensitivity in patients with early glaucoma earlier than conventional perimetry, particularly in pre-perimetric glaucoma cases in which it might be undetectable by conventional methods. The new custom-made pattern may improve the accuracy of microperimetry by enhancing point arrangement and reducing fatigue effects. Macular sensitivity measured by MP-3 with this pattern shows statistically significant structural and functional associations with the thicknesses of the GCC.

Measures of multiple deprivation and visual field loss in glaucoma clinics in England: lessons from big data

BACKGROUND/OBJECTIVES

To examine the association between multiple deprivation with late diagnosis and rapid worsening of glaucoma in patients in English hospital eye services (HES).

METHODS

602,439 visual fields (VFs) were extracted from five regionally different glaucoma clinics in England. Mean Deviation (MD) worse than -12 dB was used as a surrogate definition for advanced VF loss at diagnosis in patients with ≥2 reliable VF records. MD loss worse than -1 dB per year was used to define rapid VF progression in patients with ≥6 VFs. Patient data were stratified into deciles of the Index of Multiple Deprivation (IMD) from residential postcodes.

RESULTS

There was an association between IMD and advanced VF loss at diagnosis in 44,956 patients with 18% (293/1608) and 11% (771/6929) in the most and least deprived IMD decile, respectively. Age-corrected odds ratio (OR) for having advanced VF loss at entry into HES was 1.42 (95% confidence interval [CI] 1.21-1.67) and 0.75 (95% CI: 0.66-0.85) in the most and least deprived IMD decile respectively (reference = fifth decile). In 15,094 patients with follow up data (median [interquartile range] of 6.9 [4.5, 10.0] years), the proportion having rapid VF progression did not differ across the IMD spectrum.

CONCLUSION

Large-scale VF data from clinics indicates that glaucoma severity at presentation to English HES is associated with levels of multiple deprivation. We found no evidence to suggest likelihood of having rapid VF progression during follow-up is associated with IMD; this hints at equity of glaucoma care and outcomes once patients are in English HES.

Chronic Open Angle Glaucoma: a Biopsychosocial Approach to Patient Care

It is estimated that 2.2 billion people are affected by impaired vision resulting from eye conditions. Chronic open angle glaucoma (COAG) is one such condition, which primarily affects older adults, and is linked to other factors such as genetic predisposition, high blood pressure, diabetes and smoking. By 2025, it is projected that 44% of the UK's ageing population will have COAG. Vision loss due to this condition is irreversible. In this article, Penelope Stanford discusses the bioscience of COAG, and provides information on access to care and patient interventions.

Long-term Impact of Immediate Versus Delayed Treatment of Early Glaucoma: Results From the Early Manifest Glaucoma Trial

PURPOSE

To compare long-term visual outcomes in the 2 arms of the Early Manifest Glaucoma Trial (EMGT) and determine if delayed treatment was associated with a penalty in terms of visual function.

DESIGN

Long-term follow-up of a prospective, randomized controlled clinical trial.

METHODS

EMGT was carried out at 2 centers in Sweden; 255 subjects with newly detected, untreated glaucoma were randomized to immediate treatment with topical betaxolol and argon laser trabeculoplasty or to no initial treatment as long as no progression was detected. Subjects were followed prospectively with standard automated perimetry, visual acuity measurements, and tonometry for up to 21 years. Outcomes included vision impairment (VI), the perimetric mean deviation (MD) index and rate of progression, and visual acuity.

RESULTS

At study end, percentages of eyes with VI or blindness were slightly higher in the treated group than in the untreated control group, 12.1% vs 11.0%, and 9.4.% vs 6.1% respectively, as were subjects with VI in at least one eye, 19.5% vs 18.7%. The differences were not statistically significant, nor were cumulative incidences of VI in at least one eye. The control group had more field loss than the treatment group, with median MD in the worse eye of -14.73 dB vs -12.85 dB, and rate of progression of -0.74 vs -0.60 dB/y, which was not statistically significant. Differences in visual acuity were minimal.

CONCLUSIONS

Delaying treatment did not result in serious penalties. VI occurred at similar proportions in both treatment arms with a slight preponderance in the treatment group, whereas visual field damage was slightly higher in the control group.

A rare optineurin mutation in an Indian family with coexistence of JOAG and PCG

Purpose

This study focused on the genetic screening of Myocilin (MYOC), Cytochrome P450 family 1 subfamily B member 1 (CYP1B1), Optineurin (OPTN), and SIX homeobox 6 (SIX6) genes in a family with coexistence of primary congenital glaucoma (PCG) and juvenile open-angle glaucoma (JOAG).

Methods

Sanger sequencing was used to examine the coding region of all four genes. Six different online available algorithms were used for the pathogenicity prediction of missense variant. Structural analysis was done using Garnier-Osguthorpe-Robson (GOR), PyMol, ChimeraX, and Molecular Dynamic (MD) Simulations (using Graphics Processing Unit (GPU)-enabled Desmond module of Schrödinger).

Results

There were a total of three sequence variants within the family. All seven algorithms determined that a single mutation, G538E, in the OPTN gene is pathogenic. The loops connecting the strands became more flexible, as predicted structurally and functionally by pathogenic mutations. Mutations create perturbations and conformational rearrangements in proteins, hence impairing their functioning.

Conclusion

In this study, we describe a North Indian family in which members were having JOAG and PCG due to a rare homozygous/heterozygous mutation in OPTN. The coexistence of two types of glaucoma within a single pedigree suggests that certain OPTN mutations may be responsible for the onset of different glaucoma phenotypes.

Factors associated with delayed first ophthalmological consultation for primary glaucoma: a qualitative interview study

Background

Glaucoma has an insidious onset with non-specific early symptoms, often leading patients to delay in seeking help. However, postponing the first ophthalmological consultation can result in delayed diagnosis and treatment, with adverse effects on vision. This study explored the factors associated with delayed first ophthalmological consultation in patients with primary glaucoma, with the overarching aim of informing measures to reduce delayed consultation and avoid the consequent adverse outcomes.

Methods

We adopted a phenomenological approach. Semi-structured interviews were conducted with patients admitted to a tertiary eye hospital in Tianjin, China, from January 2021 to April 2021. Data were analyzed by Colaizzi's seven-step method.

Results

We identified 46 patients with primary glaucoma who delayed their first ophthalmological consultation for various reasons. There were four major themes and 16 sub-themes. The major themes were as follows: (1) occult symptoms that are difficult to identify; (2) insufficient knowledge and understanding of glaucoma-related risks and harm; (3) perceived difficulties in accessing medical care; and (4) inadequate support system.

Conclusion

In order to avoid patient delay and consequent irreversible damage to the visual field in patients with primary glaucoma, it is essential that medical staff identify symptoms more effectively, change habitual medical behavior of the patients, adopt a medical union model, and promote the use of a social medical support system to address practical difficulties in delivering adequate care.

Implementing Smartphone Tutorials for Patients With Severe Glaucoma

Purpose The purpose of the study is to determine if instructional videos detailing the use of smartphone accessibility features may be used to improve quality of life and comfort with phone usage among patients with severe glaucoma. Design The design of the present study is an interventional case series. Methods The patients with vision loss due to severe glaucoma were recruited from one institution. Two surveys were completed to provide baseline data: one detailed their current use of smartphone accessibility features, and the other provided survey was the EuroQol 5 Dimension 5 Level (EQ-5D-5L) (EuroQol Group, Rotterdam, Netherlands), which is used to assess the quality of life. Then, the patients were shown a brief video with instructions on configuring the use of voice-over, magnification, and zoom functions, along with other features. To conclude, the patients completed the same surveys either at follow-up visits or by phone calls. Results Fifteen patients were recruited to participate in the study. At baseline, the participants used a median of one accessibility feature, with the most common feature being "text sizing/bolding." At follow-up, the participants averaged the gain of use of one accessibility feature and reported a decrease in text messaging visual limitation, although these findings did not reach statistical significance. Overall, the quality of life, as measured by the EQ-5D-5L, demonstrated a non-statistically significant increase of six points. Conclusions Despite the lack of statistical significance, our results indicate that providing instructional videos may benefit the patients' ability to navigate on their smartphones. Incorporating links or Quick Response (QR) codes to these instructional videos provides an opportunity to improve the quality of life at no additional risk to the patient. Further studies are needed with an increased population to investigate for any significance of our findings.

What do eye care workers do when their patients go blind?

Sometimes even with the best efforts by the eye care worker (ECW), patients cannot be stopped from losing vision even in the best of centers anywhere in the world. However, in developing countries, most vision loss happens in rural and suburban areas away from where ECWs are majorly located due to poor facilities, adverse living conditions, and poverty. Once irreversible blindness happens, rehabilitation should follow. However, the numbers of those who are not referred for rehabilitation by far outstrips those who are, for various reasons. To find out why this is so, 150 ECWs with 1:2 M:F ratio were contacted through Google links sent through WhatsApp groups. Glaucoma was statistically the commonest cause of irreversible blindness (χ2 = 66.17, p-value < .0001) mostly from late presentation ( n = 146 of 150 responses, 97.7%). When patients go blind, most ( n = 132, 87.4%) of the ECW advise them to go to a blind school (81.2%). Only about a quarter of the respondents properly ensure that they go. A third admitted ( n = 78, 39%) that knowing the patients personally improved their willingness to refer. Many do not think the government is doing enough to help the blind ( n = 118, 78.7%). Even though many ECWs have given sensitization talks on blindness (124 of 164 responses), very few focus on what happens after blindness occurs (42.4% of respondents). A third of the ECW admitted to not doing enough for the blind in their practice ( n = 51, 34%). Majority have, however, heard about The Lens Eye Clinic (TLEC) rehab center, one of the foremost rehabilitation centers for the blind in Nigeria ( n = 103, 68.7%). ECW should ensure those who live in rural areas have poor socioeconomic background, less educated, female, elderly, or born blind should have regular screening and awareness programs in the areas of practice to catch the condition on time with provision made for early counseling and support services.

Advanced glaucoma. Clinical practice guideline

OBJECTIVE

To present an update clinical practice guideline that serve as a guide for the detection, evaluation and treatment of adults patients with advanced glaucoma.

METHODS

After defining the objectives and scope of the guide, the working group was formed and structured clinical questions were formulated following the PICO (Patient, Intervention, Comparison, Outcomes) format. Once all the existing clinical evidence had been independently evaluated with the AMSTAR 2 (Assessment of Multiple systematic Rewiews) and Cochrane "Risk of bias" tools by at least two reviewers, recommendations were formulated following the Scottish Intercollegiate methodology. Guideline Network (SIGN).

RESULTS

Recommendations with their corresponding levels of evidence that may be useful in the diagnosis, monitoring and treatment of adults patients with advanced glaucoma.

CONCLUSIONS

Despite the fact that for many of the questions the level of scientific evidence available is not very high, this clinical practice guideline offers an updated review of the different existing aspects related to the evaluation and management of advanced glaucoma.

Pupillary response to chromatic light stimuli as a possible biomarker at the early stage of glaucoma: a review

Glaucoma is a multifactorial neurodegenerative disease of the optic nerve currently considered a severe health problem because of its high prevalence, being the primary cause of irreversible blindness worldwide. The most common type corresponds to Primary Open-Angle Glaucoma. Glaucoma produces, among other alterations, a progressive loss of retinal ganglion cells (RGC) and its axons which are the key contributors to generate action potentials that reach the visual cortex to create the visual image. Glaucoma is characterized by Visual Field loss whose main feature is to be painless and therefore makes early detection difficult, causing a late diagnosis and a delayed treatment indication that slows down its progression. Intrinsically photosensitive retinal ganglion cells, which represent a subgroup of RGCs are characterized by their response to short-wave light stimulation close to 480 nm, their non-visual function, and their role in the generation of the pupillary reflex. Currently, the sensitivity of clinical examinations correlates to RGC damage; however, the need for an early damage biomarker is still relevant. It is an urgent task to create new diagnostic approaches to detect an early stage of glaucoma in a prompt, quick, and economical manner. We summarize the pathology of glaucoma and its current clinical detection methods, and we suggest evaluating the pupillary response to chromatic light as a potential biomarker of disease, due to its diagnostic benefit and its cost-effectiveness in clinical practice in order to reduce irreversible damage caused by glaucoma.

Eye drop instillation technique among patients with glaucoma and evaluation of pharmacists' roles in improving their technique: an exploratory study

OBJECTIVES

This study aimed to explore the eye drop instillation technique of patients with glaucoma and whether a pharmacist-led counselling session can improve their technique. Patients' perceptions of pharmacists' role in providing the counselling were also explored.

METHODS

This cross-sectional study was conducted between December 2020 and March 2021 at Sarawak General Hospital, Malaysia. Convenience sampling was used to recruit patients with glaucoma who self-administered their eye drops. Participants' background information were obtained using an investigator-administered questionnaire before their eye drop instillation technique was assessed. Those with imperfect techniques were counselled by a pharmacist before being reassessed. Differences in eye drop instillation competency were determined using paired T-test.

KEY FINDINGS

A total of 138 participants were recruited. Participants were on a median of two eye drops (IQR 2-4) for a median of five years (IQR 2-8). Prior to being counselled, they demonstrated a mean total of 8.4/13 steps (SD 2.33) correctly. A statistically significant improvement in eye drop instillation technique was observed post-pharmacists' counselling, with a mean increase of 4.3 steps demonstrated correctly (95% CI, 4.0 to 4.7, P < 0.001). The majority of participants agreed that pharmacists are knowledgeable in providing counselling on eye drop administration techniques.

CONCLUSIONS

Patients with glaucoma treated at Sarawak General Hospital had imperfect eye drop instillation techniques, despite most having used their eye drops for several years. Interventions by pharmacists to improve eye drop instillation are crucial to optimise the medical treatment of patients with glaucoma.

TUBE VERSUS TRABECULECTOMY IN JUVENILE-ONSET OPEN ANGLE GLAUCOMA - TREATMENT OUTCOMES IN TERTIARY HOSPITALS IN MALAYSIA

AIM OF THE STUDY

To compare the intraocular pressure (IOP) lowering effect and postoperative complications between primary augmented trabeculectomy and glaucoma drainage device (GDD) implantation as primary surgical intervention in patients with juvenile-onset open angle glaucoma (JOAG).

PATIENTS AND METHODS

A retrospective review study involving 20 eyes that underwent primary augmented trabeculectomy with mitomycin (MMC) and 10 eyes GDD implantation in 3 tertiary centres in Malaysia between 1 January 2013 and 31 December 2019. They were followed up for at least 12 months postsurgical intervention. Intraocular pressure (IOP), number of topical IOP lowering medication and complications were evaluated at 1, 3, 6 and 12 months post-intervention. Based on the IOP, the success was divided into complete and partial success, and failure. IOP and postsurgical complications were compared using the Repetitive Measure Analysis of Variance (RM ANOVA) and the Pearson chi-square test.

RESULTS

Both methods were effective in lowering the IOP. Eyes with primary augmented trabeculectomy have significant lower IOP compared to GDD implantation (p = 0.037). There was a higher incidence of postoperative hypotony (30%) in the trabeculectomy group. There was also a significant reduction of mean number of topical pressure-lowering drugs required postoperatively (p = 0.015). Complete success was achieved in 100% of eyes with trabeculectomy and 67% in GDD implantation (p = 0.047).

CONCLUSIONS

Primary augmented trabeculectomy and GDD implantation are good surgical options for the treatment of JOAG. Both methods provide IOP lowering at 1 year. However, trabeculectomy provides better pressure lowering, compared to GDD implantation in patients with JOAG.

In Vitro Evaluation of Zinc Oxide Tetrapods as a New Material Component for Glaucoma Implants

In our previous study we were able to show that zinc oxide (ZnO) tetrapods inhibit wound healing processes. Therefore, the aim of this study was to test the antiproliferative effect of two types of porous polydimethylsiloxane (PDMS)/ tetrapodal zinc oxide (ZnO-T) materials, as well as their usability for glaucoma implants. To find the best implant material, two different porous PDMS/ZnO-T materials were examined. One consisted of 3D interconnected PDMS coarse-pored foams with protruding ZnO-T particles; the other consisted of fine-pored 3D interconnected ZnO-T networks homogeneously coated by a thin PDMS film in the nanometer range. Fibroblast cell viability was investigated for both materials via MTT dye, and some implant material samples were further processed for electron microscopy. Both PDMS/ZnO-T materials showed reduced cell viability in the MTT staining. Furthermore, the electron microscopy revealed barely any fibroblasts growing on the implant materials. At the surface of the fine-pored implant material, however, fibroblasts could not be observed in the etched control samples without ZnO-T. It was found that post-processing of the material to the final stent diameter was highly challenging and that the fabrication method, therefore, had to be adapted. In conclusion, we were able to demonstrate the antiproliferative potential of the two different PDMS/ZnO-T materials. Furthermore, smaller pore size (in the range of tens of micrometers) in the implant material seems to be preferable.

SALUS-a non-inferiority trial to compare self-tonometry in glaucoma patients with regular inpatient intraocular pressure controls: study design and set-up

Purpose

The SALUS study aims to improve the healthcare situation for glaucoma patients in Germany. In order to detect diurnal intraocular pressure (IOP) fluctuations, inpatient monitoring of IOP in an eye hospital for a minimum of 24 h is the current standard. SALUS assesses the benefits of a new form of outpatient care, where IOP can be measured by the patients themselves at home using a self-tonometer. This approach should promote the patient’s health competence and empowerment within the healthcare system while reducing treatment costs.

Methods

The SALUS study is a randomized controlled, open non-inferiority trial, alongside an economic analysis, determining whether outpatient monitoring of IOP with self-tonometry is at least as effective as current standard care and would reduce treatment costs. Participants (n = 1980) will be recruited by local ophthalmologists in the area of Westphalia-Lippe, Germany, and randomized to receive 7-day outpatient or 24-h inpatient monitoring. Participants in both study arms will also receive 24-h blood pressure monitoring. Furthermore, patient data from both study groups will be collected in an electronic case file (ECF), accessible to practitioners, hospitals, and the study participants. The primary endpoint is the percentage of patients with IOP peaks, defined as levels 30% above the patient-specific target pressure. Data will also be collected during initial and final examinations, and at 3, 6, and 9 months after the initial examination.

Results

The study implementation and trial management are represented below.

Conclusion

SALUS is a pioneering prospective clinical trial focused on the care of glaucoma patients in Germany. If SALUS is successful, it could improve the healthcare situation and health literacy of the patients through the introduction of various telemedical components. Furthermore, the approach would almost certainly reduce the treatment costs of glaucoma care.

Trial registration

ClinicalTrials.gov ID: NCT04698876, registration date: 11/25/2020.

DRKS-ID: DRKS00023676, registration date: 11/26/2020.

Predictors of Early Onset Glaucoma

Purpose/Relevance

To determine the influence of hypertension (HTN), type 2 diabetes (DM2), migraine, and obstructive sleep apnea (OSA) on the onset of primary open-angle glaucoma (POAG) to enhance predictive accuracy.

Methods

In this cross-sectional study, data for 389 eligible patients with POAG were collected through medical records review and phone surveys. All data were assessed collectively using stepwise multiple regression analysis to determine the relative contribution to age at POAG diagnosis. We used the following groups, based on age at diagnosis, HTN for patients with or without DM2 (model 1), HTN for patients with DM2 (model 2), DM2 for patients with or without HTN (model 3), and DM2 for patients with HTN (model 4).

Results

In model 1, age at HTN diagnosis was associated with age at POAG diagnosis (β = 0.14; 95% CI, 0.01–0.26, p = 0.04). In model 2, age at HTN diagnosis was not associated with age at POAG diagnosis (p > 0.05). In model 3, age at DM2 diagnosis was associated with age at POAG diagnosis (β = 0.37; 95% CI 0.16–0.58, p = 0.001). In model 4, age at DM2 diagnosis was associated with age at POAG diagnosis (β = 0.40; 95% CI 0.00–0.15, p = 0.003). Asian race/ethnicity was associated with early onset of POAG in model 3 (β = −6.44; 95% CI −12.34–0.54, p = 0.033). OSA and migraine did not influence the onset of POAG.

Conclusion

Our study found that the diagnosis of DM2 and HTN at an earlier age is associated with the early onset of POAG.

Statistical Analysis on Time to Blindness of Glaucoma Patients at Jimma University Specialized Hospital: Application of Accelerated Failure Time Model

Background. Glaucoma is one of the most frequent vision-threatening eye diseases. It is frequently associated with excessive intraocular pressure (IOP), which can cause vision loss and damaged optic nerves. The main objective of this study was to model time to blindness of glaucoma patients by using appropriate statistical models. Study Design. A Retrospective Community-Based Longitudinal Study design was applied. Materials and Procedures. The data were obtained from Ophthalmology Department of JUSH from the period of January 2016 to August 2020. The glaucoma patient’s information was extracted from the patient card and 321 samples were included in the study. To discover the factors that affect time to blindness of glaucoma patients’, researchers used the Accelerated Failure Time (AFT) model. Results. 81.3 percent of the 321 glaucoma patients were blind. Unilaterally and bilaterally blinded female and male glaucoma patients were 24.92 and 56.38%, respectively. After glaucoma disease was confirmed, the median time to the blindness of both eyes and one eye was 12 months. The multivariable log-logistic accelerated failure-time model fits the glaucoma patient’s time to blind dataset well. The result showed that the chance of blindness of glaucoma patients who have absolute stage of glaucoma, medium duration of diagnosis, long duration of diagnosis, and IOP greater than 21 mmHg were high with parameters (ϕ = 2.425, $p$ value = 0.049, 95% CI [2.249, 2.601]), (ϕ = 1.505, $p$ value = 0.001, 95% CI [0.228, 0.589]), (ϕ = 3.037, $p$ value = 0.001, 95% C.I [2.850, 3.22]) and (ϕ 0.851, $p$ value = 0.034, 95% C.I [0.702, 0.999]), respectively. Conclusion. The multivariable log-logistic accelerated failure time model evaluates the prognostic factors of time to blindness of glaucoma patients. Under this finding, duration of diagnosis, IOP, and stage of glaucoma were a key determinant factors of time to blindness of glaucoma patients’. Finally, the log-logistic accelerated failure-time model was the best-fitted parametric model based on AIC and BIC values.

From the PnTx2-6 Toxin to the PnPP-19 Engineered Peptide: Therapeutic Potential in Erectile Dysfunction, Nociception, and Glaucoma

The venom of the “armed” spider Phoneutria nigriventer comprises several potent toxins. One of the most toxic components from this venom is the neurotoxin PnTx2-6 (LD50 = ∼ 0.7 μg/mouse, 48 residues, five disulfide bridges, MW = 5,289.31 Da), which slows down the inactivation of various Na+ channels. In mice and rats, this toxin causes priapism, an involuntary and painful erection, similar to what is observed in humans bitten by P. nigriventer. While not completely elucidated, it is clear that PnTx2-6 potentiates erectile function via NO/cGMP signaling, but it has many off-target effects. Seeking to obtain a simpler and less toxic molecule able to retain the pharmacological properties of this toxin, we designed and synthesized the peptide PnPP-19 (19 residues, MW = 2,485.6 Da), representing a discontinuous epitope of PnTx2-6. This synthetic peptide also potentiates erectile function via NO/cGMP, but it does not target Na+ channels, and therefore, it displays nontoxic properties in animals even at high doses. PnPP-19 effectively potentiates erectile function not only after subcutaneous or intravenous administration but also following topical application. Surprisingly, PnPP-19 showed central and peripheral antinociceptive activity involving the opioid and cannabinoid systems, suggesting applicability in nociception. Furthermore, considering that PnPP-19 increases NO availability in the corpus cavernosum, this peptide was also tested in a model of induced intraocular hypertension, characterized by low NO levels, and it showed promising results by decreasing the intraocular pressure which prevents retinal damage. Herein, we discuss how was engineered this smaller active non-toxic peptide with promising results in the treatment of erectile dysfunction, nociception, and glaucoma from the noxious PnTx2-6, as well as the pitfalls of this ongoing journey.

Ambulatory and hospital care of glaucoma in Spain and associated medical costs

OBJECTIVES

This study aimed to analyze the impact of glaucoma in ambulatory centers and hospitals in Spain over the past decade, in terms of incidence and medical costs.

METHODS

Administrative data of glaucoma patients from ambulatory centers and hospitals in Spain and registered between 2011 and 2020 was obtained from a Spanish National discharge database. Medical costs obtained were based on the diagnosis-related group-based hospital payment systems, determined by the Spanish Ministry of Health.

RESULTS

Data from 100,734 ambulatory care visits and 11,408 hospital admissions related to glaucoma were obtained from the database. Most of the cases were registered in patients over 65 years of age. The incidence of glaucoma in ambulatory centers was 2.2 per 10,000 persons over the study period; in hospitals, the incidence was 0.2 per 10,000 persons. The incidence of glaucoma in ambulatory settings increased significantly over the study period, while the incidence in hospitals decreased over the same period. Most ambulatory visits and hospital admissions were programmed or non-urgent. The mean cost per ambulatory visit was €954, €5.5 million in total annually; the mean cost per hospital admission was €3,727, €4.1 million in total annually. The annual cost of ambulatory care increased significantly over the study period, while the annual cost of hospital care decreased significantly.

CONCLUSIONS

The medical costs of glaucoma in Spanish hospitals decreased over the study period, while the costs of ambulatory care increased. This shift in the management of glaucoma should be considered in future resource allocation decisions.

Handheld chromatic pupillometry can accurately and rapidly reveal functional loss in glaucoma

BACKGROUND/AIMS

Early detection and treatment of glaucoma can delay vision loss. In this study, we evaluate the performance of handheld chromatic pupillometry (HCP) for the objective and rapid detection of functional loss in glaucoma.

METHODS

In this clinic-based, prospective study, we enrolled 149 patients (median (IQR) years: 68.5 (13.6) years) with confirmed glaucoma and 173 healthy controls (55.2 (26.7) years). Changes in pupil size in response to 9 s of exponentially increasing blue (469 nm) and red (640 nm) light-stimuli were assessed monocularly using a custom-built handheld pupillometer. Pupillometric features were extracted from individual traces and compared between groups. Features with the highest classification potential, selected using a gradient boosting machine technique, were incorporated into a generalised linear model for glaucoma classification. Receiver operating characteristic curve analyses (ROC) were used to compare the performance of HCP, optical coherence tomography (OCT) and Humphrey Visual Field (HVF).

RESULTS

Pupillary light responses were altered in glaucoma compared with controls. For glaucoma classification, HCP yielded an area under the ROC curve (AUC) of 0.94 (95% CI 0.91 to 0.96), a sensitivity of 87.9% and specificity of 88.4%. The classification performance of HCP in early-moderate glaucoma (visual field mean deviation (VFMD) > -12 dB; AUC=0.91 (95% CI 0.87 to 0.95)) was similar to HVF (AUC=0.91) and reduced compared with OCT (AUC=0.97; p=0.01). For severe glaucoma (VFMD ≤ -12 dB), HCP had an excellent classification performance (AUC=0.98, 95% CI 0.97 to 1) that was similar to HVF and OCT.

CONCLUSION

HCP allows for an accurate, objective and rapid detection of functional loss in glaucomatous eyes of different severities.

Path to Diagnosis and Clinical Characteristics of Advanced Glaucoma at Initial Diagnosis: a Tertiary Single Center Experience

Purpose: As routine health examinations become more common, many patients first diagnosed with glaucoma have advanced glaucoma. We analyzed the routes to diagnosis and the characteristics of patients initially diagnosed with advanced glaucoma.Methods: We retrospectively retrieved the medical records of patients first diagnosed with advanced glaucoma in our tertiary care center. The inclusion criteria were a mean deviation (MD) less than -12 dB on the visual field test, accompanied by structural damage. All patients were classified in terms of unilateral/bilateral disease, the intraocular pressure before medication, and lens status. We divided patients into those with monocular or binocular advanced glaucoma, high- or normal-pressure glaucoma, and those who were pseudophakic or phakic.Results: We included 73 patients of mean age 69.3 years. The visual field test MD was -19.6 dB. In those with binocular advanced glaucoma, incidental ophthalmic examination was the most common means of diagnosis (52.2%). Central-island visual field defects were the most common defects (54.2%). In those with monocular advanced glaucoma, glaucoma-associated symptoms most commonly triggered diagnosis (46.9%). Both superior and inferiorvisual field defects were the most common defects (42.8%). Glaucoma-associated symptoms were present in 68.2 and 22.8% of patients with high- and normal-pressure glaucoma, respectively. Central-island visual field defects were present in 43.6 and 29.4% of those with high- and normal-pressure glaucoma, respectively.Conclusions: We analyzed the routes to diagnosis and the clinical characteristics of patients with advanced glaucoma. In those with binocular disease, glaucoma was most commonly diagnosed on incidental ophthalmic examination. Central-island visual field defects were the most common defects in patients with binocular and high-pressure glaucoma, and the pseudophakic group. A multi-center longitudinal study on risk factors for delayed glaucoma diagnosis is needed.

Correlation of Ocular Biometric Parameters and Macular Ganglion Cell Layer in Normal Eyes

PURPOSE

To determine the association between ocular biometric parameters and macular ganglion cell layer (MGCL) thickness in normal eyes.

METHODS

This observational cohort study was conducted with 76 eyes of 76 healthy subjects. Keratometry, pachymetry, corneal volume, iridocorneal angle were measured with Sirius (CSO, Florence, Italy); axial length, anterior chamber depth, anterior chamber volume, corneal diameter were measured with IOL Master (Carl Zeiss Meditec, Dublin, California). For all participants, serial horizontal Spectralis Domain Optical Coherence Tomography (SD-OCT, Heidelberg Engineering, GmbH, Dossenheim, Germany) scans of the macula and peripapillary retinal nerve fiber layer (RNFL) analysis were obtained using SD-OCT. The relationship between numerical variables was given by Pearson correlation coefficient.

RESULTS

The mean age of the subjects was 36.3 ± 11.9 years (between 19 and 70 y). Fifty-one patients were female (67.1%) and twenty-five patients were male (32.9%). MGCL was found to be correlated with anterior chamber depth, anterior chamber volume, iridocorneal angle, axial length and white to white (p = .015 r = 0.594, p = .002 r = 0.365, p = .013 r = 0.299, p = .004 r = 0.335, p = .013 r = 0.289, respectively). In addition, MGCL was correlated positively with the mean global and superotemporal RNFL (p ≤ 0.005). However, neither central corneal thickness nor keratometry values were found to be correlated with MGCL.

CONCLUSION

The results of this study showed that MGCL thickness is affected by ocular biometric parameters. Therefore, these parameters should be taken into consideration when interpreting MGCL thickness measurements in the diagnosis of glaucoma.

Comparison between Latanoprost, Travoprost, and Tafluprost in reducing intraocular pressure fluctuations in patients with glaucoma

PURPOSE

To compare the efficacies of latanoprost 0.005%, travoprost 0.004%, and tafluprost 0.0015% in reducing diurnal intraocular pressure (IOP) fluctuations in patients with newly diagnosed primary open-angle glaucoma (POAG).

METHODS

In this prospective randomized clinical trial, 60 patients who were newly diagnosed with POAG were divided into three equal groups. Patients were examined at presentation and at second and sixth weeks. Diurnal phasing of IOP was conducted using a calibrated Goldmann applanation tonometer. IOP measurements were recorded from 8:00 am to 9:00 am, from 3:00 pm to 4:00 pm, and from 7:00 pm to 8:00 pm.

RESULTS

The study groups were distributed similarly in terms of age and gender (p-values: 0.76) and the participants had a mean age of 52.98 ± 13.43 years. The IOP at the day of inclusion was not statistically significant among the three groups (p-values 0.27, 0.51, and 0.64 at 8 am, 2 pm, and 8 pm, respectively). Similar nonsignificant differences were noticed on the follow-up visits. However, the tafluprost group showed a significant reduction in IOP on the follow-up visit at the second week at 8 pm (30.5% reduction, p-value: 0.03). All three drugs showed a comparable and significant reduction in IOP and IOP fluctuations. The pattern of side effects was similar in all the groups.

CONCLUSION

Latanoprost, travoprost, and tafluprost show a similar effectiveness in reducing the mean IOP and the diurnal IOP fluctuation in POAG. Importantly, the three drugs have comparable tolerability with insignificant differences regarding the pattern of their side effects.

Comparison of adherence between fixed and unfixed topical combination glaucoma therapies using Japanese healthcare/pharmacy claims database: a retrospective non-interventional cohort study

Background

Adherence to chronic therapies is crucial to prevent the progression of disease, such as glaucoma. However, only a limited number of studies have investigated them using real-world data in Japan. This study aimed to evaluate Japanese patients’ adherence to fixed- and unfixed-combination eye drops as a second-line therapy for glaucoma in real-world practice.

Methods

This retrospective, non-interventional cohort study utilized a commercially available Japanese healthcare database (MinaCare database). Medical/pharmacy claims data were collected from 2011 to 2016. The primary endpoint was adherence to medications, assessed by proportion of days covered (PDC) with medication during a 12-month post-index period. Meanwhile, the secondary endpoints included the persistence rate.

Results

A total of 738 patients were included in this study: 309 and 329 in the fixed- and unfixed-combination cohorts, respectively. Prostaglandin analog (PG)/β-blocker (BB) was most commonly claimed in 241/309 (78.0%) patients in the fixed-combination cohort. In the unfixed-combination cohort, PG and BB were claimed in 130/329 (39.5%) patients, whereas PG and α2-agonist were claimed in 87/329 (26.4%) patients. Patients were more adherent to the fixed-combination than the unfixed-combinations (mean PDCs [SD], 79.1% [32.1] vs. 62.2% [38.0]; P < 0.0001). The proportion of patients with good adherence (PDC ≥ 80%) was also higher in the fixed-combination cohort (69.6%) than in the unfixed-combination cohort (48.6%) (P < 0.0001). During the 12-month post-index period, the persistence rate was higher in the fixed-combination cohort than in the unfixed-combination cohort (47.6% [95% confidence intervals (CI): 41.9–53.0] vs. 24.9% [95% CI: 20.4–29.7], P < 0.0001).

Conclusions

Japanese patients with glaucoma preferred the fixed-combination therapies over the unfixed-combination therapies. Hence, fixed-combination therapies would contribute to the improvement of adherence.

Cascade screening for glaucoma in high-risk family members of African-Caribbean glaucoma patients in an urban population in London

Background/aims

Cascade screening has been used successfully in relatives of patients with inherited cancers and other genetic diseases to identify presymptomatic disease. This study was designed to examine if this approach would be successful in a high-risk group: first-degree relatives (FDR) of African-Caribbean glaucoma patients resident in London.

Methods

African-Caribbean patients (probands) with glaucoma from an inner London hospital setting in a deprived area were asked to disseminate personalised information to their FDR over the age of 30 and to arrange a free hospital-based screening. Data collected, including optical coherence tomography imaging, were reviewed by a glaucoma specialist and if glaucoma was diagnosed or suspected, local specialist referral via family doctor was made.

Results

203 probands were recruited from glaucoma clinics. 248 suitable FDR were identified as potentially eligible to attend screening. 57 (23%) FDR made contact with the research team of whom 18 (7%) attended a subsequent screening visit. No patients were diagnosed with glaucoma; one participant was diagnosed as glaucoma suspect. Reasons for poor uptake included reluctance by probands to involve their family members, and retirees spending significant time abroad.

Conclusion

Cascade screening of FDR of African-Caribbean glaucoma patients in inner city London was unsuccessful. Research confidentiality guidance prohibiting research teams directly contacting family members was a barrier. Greater community engagement, community-based screening and permission to contact FDR directly might have improved uptake.

A Topical Formulation of Melatoninergic Compounds Exerts Strong Hypotensive and Neuroprotective Effects in a Rat Model of Hypertensive Glaucoma

Melatonin is of great importance for regulating several eye processes, including pressure homeostasis. Melatonin in combination with agomelatine has been recently reported to reduce intraocular pressure (IOP) with higher efficacy than each compound alone. Here, we used the methylcellulose (MCE) rat model of hypertensive glaucoma, an optic neuropathy characterized by the apoptotic death of retinal ganglion cells (RGCs), to evaluate the hypotensive and neuroprotective efficacy of an eye drop nanomicellar formulation containing melatonin/agomelatine. Eye tissue distribution of melatonin/agomelatine in healthy rats was evaluated by HPLC/MS/MS. In the MCE model, we assessed by tonometry the hypotensive efficacy of melatonin/agomelatine. Neuroprotection was revealed by electroretinography; by levels of inflammatory and apoptotic markers; and by RGC density. The effects of melatonin/agomelatine were compared with those of timolol (a beta blocker with prevalent hypotensive activity) or brimonidine (an alpha 2 adrenergic agonist with potential neuroprotective efficacy), two drugs commonly used to treat glaucoma. Both melatonin and agomelatine penetrate the posterior segment of the eye. In the MCE model, IOP elevation was drastically reduced by melatonin/agomelatine with higher efficacy than that of timolol or brimonidine. Concomitantly, gliosis-related inflammation and the Bax-associated apoptosis were partially prevented, thus leading to RGC survival and recovered retinal dysfunction. We suggest that topical melatoninergic compounds might be beneficial for ocular health.

Hypotensive Effect of Nanomicellar Formulation of Melatonin and Agomelatine in a Rat Model: Significance for Glaucoma Therapy

BACKGROUND

Melatoninergic agents are known to reduce intraocular pressure (IOP). The present study was performed to evaluate the effect of nanomicellar formulations of melatoninergic agents on IOP in the rat.

METHODS

Tonometry was used to measure IOP in eyes instilled with melatonin or agomelatine. Ocular hypertension was induced by the injection of methylcellulose in the anterior chamber.

RESULTS

Melatonin formulated in nanomicelles had a longer lasting hypotonizing effect on IOP with respect to melatonin in saline. Nanomicellar formulations of melatonin and agomelatine, either alone or in combination, had lowering effects that did not depend on their concentration or their combination, which, however, resulted in an increased duration of the hypotonizing effect. The duration of the lowering effect was further increased by the addition of lipoic acid.

CONCLUSIONS

We demonstrated the effective hypotonizing activity of melatonin and agomelatine in combination with lipoic acid. Although results in animals cannot be directly translated to humans, the possibility of developing novel therapeutical approaches for patients suffering from hypertensive glaucoma should be considered.