Primary glaucomas in adults: Epidemiology and public health-A review

Machine Learning Analysis Classifies Patients with Primary Angle-Closure Glaucoma Using Abnormal Brain White Matter Function

Objective

Primary angle-closure glaucoma (PACG) is a globally prevalent, irreversible eye disease leading to blindness. Previous neuroimaging studies demonstrated that PACG patients were associated with gray matter function changes. However, whether the white matter(WM) function changes in PACG patients remains unknown. The purpose of the study is to investigate WM function changes in the PACG patients.

Methods

In total, 40 PACG patients and 40 well-matched HCs participated in our study and underwent resting-state functional magnetic resonance imaging (rs-fMRI) scans. We compared between-group differences between PACG patients and HC in the WM function using amplitude of low-frequency fluctuations (ALFF). In addition, the SVM method was applied to the construction of the PACG classification model.

Results

Compared with the HC group, ALFF was attenuated in right posterior thalamic radiation (include optic radiation), splenium of corpus callosum, and left tapetum in the PACG group, the results are statistically significant (GRF correction, voxel-level P < 0.001, cluster-level P < 0.05). Furthermore, the SVM classification had an accuracy of 80.0% and an area under the curve (AUC) of 0.86 for distinguishing patients with PACG from HC.

Conclusion

The findings of our study uncover abnormal WM functional alterations in PACG patients and mainly involves vision-related regions. These findings provide new insights into widespread brain damage in PACG from an alternative WM functional perspective.

Neuroprotective Effects of Anti-diabetic Drugs in the Treatment of Patients with Diabetes and Glaucoma or at High Risk for Glaucoma

There is an association between glaucoma and several risk factors and metabolic diseases, such as type 2 diabetes mellitus. Diabetes mellitus leads to neurodegenerative changes, both peripherally and in the brain. This might be a shared pathophysiology and etiology for both glaucoma and diabetes. It is interesting that drugs for the treatment of diabetes seem to have neuroprotective properties independent of their blood sugar reduction. Although prospective, randomized, clinical studies are still missing, particularly metformin and glucagon-like peptide receptor agonists (GLP 1 RA) seem to have neuroprotective effects. Sulphonylureas (e.g., glibenclamide, glimepiride) are still used. They frequently potently reduce blood pressure but may be less neuroprotective. In the present review, the evidence for neuroprotective effects of the different antidiabetic drugs is presented and a possible differential therapy for patients with diabetes and glaucoma, or at high risk of glaucoma, will be discussed.

Altered functional connectivity between the default mode network in primary angle-closure glaucoma patients

Previous studies have recognized glaucoma as a neurodegenerative disease that causes extensive brain damage and is closely associated with cognitive function. In this study, we employed functional MRI to examine the intrinsic functional connectivity patterns of the default mode network (DMN) in patients diagnosed with primary angle-closure glaucoma (PACG), exploring its association with cognitive dysfunction. A total of 34 patients diagnosed with PACG and 34 healthy controls (HC), who were matched in terms of sex, age, and education, were included in the control group. The posterior cingulate cortex (PCC) was selected as the region of interest to examine functional connectivity alterations. Compared with the HC group, functional connectivity was attenuated in left anterior cingulum cortex and left paracentral lobule between with PCC in the PACG group, the results are statistically significant. Our study revealed that patients with PACG exhibit weakened functional connectivity within the DMN. This finding suggests the presence of a neurological mechanism that is associated with both visual dysfunction and cognitive impairments in PACG patients. Furthermore, our study provides neuroimaging evidence that can aid in the exploration of spontaneous neurological alterations and facilitate a deeper investigation of alterations in the visual conduction pathways of PACG patients.

Investigation into the usefulness of cynomolgus monkeys with spontaneously elevated intraocular pressure as a model for glaucoma treatment research

Many glaucoma treatments focus on lowering intraocular pressure (IOP), with novel drugs continuing to be developed. One widely used model involves raising IOP by applying a laser to the trabecular iris angle (TIA) of cynomolgus monkeys to damage the trabecular meshwork. This model, however, presents challenges such as varying IOP values, potential trabecular meshwork damage, and risk of animal distress. This study investigated whether animals with naturally high IOP (>25 mmHg) could be used to effectively evaluate IOP-lowering drugs, thereby possibly replacing laser-induced models. Relationships between TIA size, IOP, and pupil diameter were also examined. Three representative IOP-lowering drugs (latanoprost, timolol, ripasudil) were administered, followed by multiple IOP measurements and assessment of corneal thickness, TIA, and pupil diameter via anterior segment optical coherence tomography (AS-OCT). There was a positive correlation was noted between IOP and corneal thickness before instillation, and a negative correlation between IOP and TIA before instillation. Our findings suggest animals with naturally high IOP could be beneficial for glaucoma research and development as a viable replacement for the laser-induced model and that measuring TIA using AS-OCT along with IOP yields a more detailed evaluation.

Peripapillary vessel density in healthy people, primary open-angle glaucoma, and normal-tension glaucoma

OBJECTIVE

To compare peripapillary vessel density using optical coherence tomography angiography (OCT-A) in eyes of healthy people, primary open-angle glaucoma (POAG), and normal-tension glaucoma (NTG).

METHODS

Thirty patients with POAG, 27 patients with NTG, and 29 healthy individuals in the control group were assessed. Capillary vessels in peripapillary retinal nerve fiber layer (RNFL) represented by whole image RPC (radial peripapillary capillary) density in an AngioDisc scan 4.5 × 4.5 mm centered on the optic disc, and ONH morphological variables (disc area, rim area, cup to disc area ratio (CDR)), and average peripapillary RNFL thickness were measured.

RESULTS

Differences in mean RPC, RNFL, disc area, rim area, and CDR between the groups were statistically significant (P < 0.05). The difference in RNFL thickness and rim area was not significant between NTG and healthy groups, while RPC and CDR showed a statistically significant difference between all pairs. The vessel density in the POAG group was 8.25% and 11.7% lower compared to the NTG and healthy groups, respectively; while the mean difference was less (2.97%) for the NTG and healthy group. In the POAG group, 67.2% of the variation in RPC can be explained by a model containing CDR and RNFL thickness, and in normal eyes 38.8% of the changes using a model containing RNFL.

CONCLUSION

The peripapillary vessel density is reduced in both types of glaucoma. The vessel density in NTG was significantly lower than in the healthy eyes, despite the lack of significant difference in RNFL thickness and neuroretinal rim area between them.

The molecular aspect of anti-glaucomatous eye drops - are we harming our patients?

Glaucoma is one of the leading causes of irreversible blindness. Progression is halted with a reduction in intraocular pressure (IOP), which is most often achieved with eye drops. A major challenge in the topical treatment of glaucoma patients is the many side effects and the resulting reduced adherence. Side effects may of course be due to the molecular properties of the active pharmaceutical ingredients (APIs). There are currently six different APIs available: prostaglandin analogues, β-adrenergic inhibitors, α-adrenergic agonists, carbonic anhydrase inhibitors, rho-kinase inhibitors and muscarinic 3 agonists. But the additives used in eye drops are also known to cause damage to the ocular surface and to some extent also to the deeper tissues. Said additives are considered inactive molecular components and are added to secure for instance viscosity and pH value, and to prevent contamination. There has been an increasing focus on the harmful effects of preservatives, with the most commonly used preservative benzalkonium chloride (BAK) being particularly controversial. BAK has long been recognized as a toxin that increases the risk of ocular discomfort. This can affect the adherence and ultimately result in lack of disease control. Other issues include the addition of certain buffers, such as phosphates, and varying pH values. This review will address the different molecular components of the IOP-lowering eye drops and what to be aware of when prescribing topical glaucoma treatment.

Association between helicobacter pylori infection and primary open-angle glaucoma: a systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis summarize the evidence for the association between Helicobacter pylori infection and Primary Open-Angle Glaucoma.

METHODS

Eligible studies reporting an association between H. pylori infection and Glaucoma were identified through an extensive search of the Excerpta Medica (EMBASE), Web of Science, Scopus, and PubMed databases and an assessment of the reference list of the top articles until October 2022. Analysis was performed with random effects model using Stata 16.

RESULT

Twenty-four studies were included in the systematic review. This study involved 1602 glaucoma patients and 2800 control individuals. The combined RRs of cohort studies and overall combined ORs of case-control studies showed a significant correlation between H. pylori infection and Glaucoma. Subgroup analysis showed that glaucoma patients had a higher risk of having H. pylori infection if they were residents of Europe countries (Cohort: RR: 1.69; 95% CI: 1.3-2.19) and (Case-Control: RR: 3.71; 95% CI: 2.07-6.64), if they had POAG type (Cohort: RR: 1.76; 95% CI: 1.37-2.27) and (Case-Control: RR: 3.71; 95% CI: 2.934.70), if their diagnostic method of HP was histology (Cohort: RR: 1.95; 95% CI: 1.26-3.01) and (Case-Control: RR: 4.06; 95% CI: 2.28-7.22), and if they were over 60 years old (Cohort: RR: 1.63; 95% CI: 1.33-2.00) and (Case-Control: RR: 2.95; 95% CI: 2.27-3.83).

DISCUSSION

The results of this meta-analysis suggest a statistically significant association between Helicobacter pylori infection and Primary Open-Angle Glaucoma.

Use of a Cationic Emulsion of Latanoprost to Treat Glaucoma Patients with Ocular Surface Disease: A Preclinical Review

Prostaglandin analogue topical medications are one of the most effective therapeutic approaches for the chronic management of glaucoma and ocular hypertension, through the reduction of elevated intra ocular pressure (IOP). While many of the first generations of anti-glaucoma eye drops were preserved with benzalkonium chloride, their repeated use may induce chronic ocular surface toxicity that leads to ocular surface disease (OSD) signs and symptoms. As a result, soft-preservatives and preservative-free formulations have been developed with the goal to avoid the long-term iatrogenic toxicity of the preservative agents. In addition, it has been suggested that OSD and its associated inflammation may negatively impact the efficacy of the IOP-lowering medications, including treatment adherence and compliance. Hence, it may be particularly interesting that glaucoma medications can concomitantly protect and "heal" the ocular surface and its environment while lowering elevated IOP, for the greater benefit of glaucoma patients. The objective of the present review is to briefly present the preclinical data of the cationic oil-in-water emulsion of latanoprost (latanoprost-CE) to shed some light on its mechanisms of action. It overall supports the following hypothesis: the restoration of a healthy ocular surface environment and treatment of the OSD signs and symptoms will allow for an improved elevated IOP reduction and glaucoma management. This would be achieved with a once daily dosing regimen to preserve glaucoma patients' vision, ocular surface, and quality-of-life and wellness.

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.

Influence of the body positions adopted for resistance training on intraocular pressure: a comparison between the supine and seated positions

OBJECTIVES

A variety of factors are known to mediate on the intraocular pressure (IOP) response to resistance training. However, the influence of the body position adopted during resistance training on IOP remain unknown. The objective of this study was to determine the IOP response to the bench press exercise at three levels of intensity when performed in supine and seated positions.

METHODS

Twenty-three physically active healthy young adults (10 men and 13 women) performed 6 sets of 10 repetitions against the 10-RM (repetition maximum) load during the bench press exercise against three levels of intensity (high intensity: 10-RM load; medium intensity: 50% of the 10-RM load; and control: no external load) and while adopting two different body positions (supine and seated). A rebound tonometer was employed to measure IOP in baseline conditions (after 60 s in the corresponding body position), after each of the 10 repetitions, and after 10 s of recovery.

RESULTS

The body position adopted during the execution of the bench press exercise significantly affected the changes in IOP (p < 0.001, η_p² = 0.83), with the seated position providing lower increases in IOP levels compared to the supine position. There was an association between IOP and exercise intensity, with greater IOP values in the more physically demanding conditions (p < 0.001, η_p² = 0.80).

CONCLUSIONS

The use of seated positions, instead of supine positions, for the execution of resistance training should be prioritized for maintaining more stable IOP levels. This set of findings incorporates novel insights into the mediating factors on the IOP response to resistance training. In future studies, the inclusion of glaucoma patients would allow to assess the generalizability of these findings.

CO2 Laser-Assisted Sclerectomy Surgery Alone or Combined with Phacoemulsification in Primary Open-Angle Glaucoma: Comparison of 1-Year Outcomes

Introduction

To compare 1-year outcomes of CO₂ laser-assisted sclerectomy surgery (CLASS) alone or combined with phacoemulsification (CLASS + Phaco) in eyes with primary open-angle glaucoma (POAG).

Methods

This was a prospective, comparative, case series study. A total of 46 eyes with POAG underwent CLASS or CLASS + Phaco were followed up for 1 year. The primary outcomes included changes in intraocular pressure (IOP), medication and best corrected visual acuity (BCVA). The secondary outcomes were success rate, functional bleb, postoperative laser intervention and complications.

Results

CLASS alone resulted in a greater IOP reduction compared with CLASS + Phaco. BCVA improved remarkably in CLASS + Phaco group, but there was no difference in BCVA before and after CLASS. The number of antiglaucoma medications significantly decreased at 12 months postoperatively in both groups. Functional blebs were more commonly seen in the CLASS than combination group. The overall success rate was higher in the CLASS than CLASS + Phaco group at 1 year after surgery. The incidence of peripheral anterior synechiae (PAS) in CLASS + Phaco group was significantly lower than that of CLASS alone.

Conclusion

CLASS alone achieved a greater IOP reduction, more common functional bleb formation and a higher success rate compared to CLASS combined with Phaco, while combination surgery yielded a better BCVA improvement and a lower PAS incidence than CLASS alone. Both surgical strategies have favorable safety and efficacy among POAG patients. Combined surgery could be a viable option for patients with co-existing POAG and cataract.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40123-022-00539-2.