Has the EAGLE landed for the use of clear lens extraction in angle-closure glaucoma? And how should primary angle-closure suspects be treated?

Targeting cGAS-STING signaling protects retinal ganglion cells from DNA damage-induced cell loss and promotes visual recovery in glaucoma

BACKGROUND

Glaucoma is an optic neurodegenerative disease. Retinal ganglion cells (RGCs) are the fundamental neurons in the trabecular meshwork, and their loss is the main pathological reason for glaucoma. The present study was to investigate mechanisms that regulate RGCs survival.

METHODS

A mouse model of glaucoma was established by injecting hypertonic saline into the limbal veins. RGCs apoptosis was detected by using flow cytometry. Protein expressions in RGCs in response to DNA damage inducer cisplatin treatment were detected by immunofluorescence and western blot. The expressions of inflammatory cytokines were determined using ELISA and real-time PCR.

RESULTS

In the hypertonic saline-injected mice, we found visual function was impaired followed by the increased expression of γH2AX and activation of cGAS-STING signaling. We found that DNA damage inducer cisplatin treatment incurred significant DNA damage, cell apoptosis, and inflammatory response. Mechanistically, cisplatin treatment triggered activation of the cGAS-STING signaling by disrupting mitochondrial function. Suppression of cGAS-STING ameliorated inflammation and protected visual function in glaucoma mice.

CONCLUSIONS

The data demonstrated that cGAS-STING signaling is activated in the damaged retinal ganglion cells, which is associated with increased inflammatory responses, DNA damage, and mitochondrial dysfunction. Targeting the cGAS-STING signaling pathway represents a potential way to alleviate glaucoma-related visual function.

Xiaoqing: A Q&A model for glaucoma based on LLMs

Glaucoma is one of the leading cause of blindness worldwide. Individuals affected by glaucoma, including patients and their family members, frequently encounter a deficit in dependable support beyond the confines of clinical environments. Seeking advice via the internet can be a difficult task due to the vast amount of disorganized and unstructured material available on these sites, nevertheless. This research explores how Large Language Models (LLMs) can be leveraged to better serve medical research and benefit glaucoma patients. We introduce Xiaoqing, a Natural Language Processing (NLP) model specifically tailored for the glaucoma field, detailing its development and deployment. To evaluate its effectiveness, we conducted two forms of experiments: comparative and experiential. In the comparative analysis, we presented 22 glaucoma-related questions in simplified Chinese to three medical NLP models (Xiaoqing LLMs, HuaTuo, Ivy GPT) and two general models (ChatGPT-3.5 and ChatGPT-4), covering a range of topics from basic glaucoma knowledge to treatment, surgery, research, management standards, and patient lifestyle. Responses were assessed for informativeness and readability. The experiential experiment involved glaucoma patients and non-patients interacting with Xiaoqing, collecting and analyzing their questions and feedback on the same criteria. The findings demonstrated that Xiaoqing notably outperformed the other models in terms of informativeness and readability, suggesting that Xiaoqing is a significant advancement in the management and treatment of glaucoma in China. We also provide a Web-based version of Xiaoqing, allowing readers to directly experience its functionality. The Web-based Xiaoqing is available at https://qa.glaucoma-assistant.com//qa.

Outcomes of Filtering Surgery Versus Clear Lens Extraction in Young Patients With Angle-Closure Glaucoma

PURPOSE

To compare the effect of filtering surgery versus clear lens extraction in young patients with medically uncontrolled angle-closure glaucoma (ACG).

DESIGN

Retrospective, nonrandomized, comparative, interventional study.

METHODS

We reviewed the medical charts of patients with the following scenarios: (1) age ≤40 years; (2) diagnosis of ACG without cataract, including primary angle-closure glaucoma (PACG), nanophthalmic ACG, and ACG combined with retinal dystrophies; and (3) ACG undergoing filtering surgery or clear lens extraction. The main outcomes including intraocular pressure (IOP), number of medications, best-corrected visual acuity, and severe complications were extracted at the postoperative early (within 1 week) and late stage (>3 months) follow-up.

RESULTS

Data from 160 eyes of 130 young patients with ACG were available. Eyes with 76 PACG, 12 nanophthalmic ACG, and 26 ACG with retinal diseases underwent filtering surgery, whereas eyes with 22 PACG, 12 nanophthalmic ACG, and 12 ACG with retinal diseases received clear lens extraction. Overall, filtering surgery and clear lens extraction resulted in significant but comparable IOP and drug reductions at the postoperative late stage in each ACG subgroup, with similar complete success rates between 2 treatments (all P > .05). Regarding the safety, filtering surgery and patients with retinal diseases were independent factors associated with postoperative malignant glaucoma (P < .05 in both multivariable logistic regression models).

CONCLUSIONS

This study highlights that the efficacy of clear lens extraction is comparable to that of filtering surgery in medically uncontrolled ACG in young patients, but clear lens extraction is safer, especially for young patients with ACG comorbid with retinal diseases.

Inhibition of cGAS-STING pathway alleviates neuroinflammation-induced retinal ganglion cell death after ischemia/reperfusion injury

Acute glaucoma is a vision-threatening disease characterized by a sudden elevation in intraocular pressure (IOP), followed by retinal ganglion cell (RGC) death. Cytosolic double-stranded DNA (dsDNA)-a damage-associated molecular pattern (DAMP) that triggers inflammation and immune responses-has been implicated in the pathogenesis of IOP-induced RGC death, but the underlying mechanism is not entirely clear. In this study, we investigated the effect of the inflammatory cascade on dsDNA recognition and examined the neuroprotective effect of the cyclic GMP-AMP (cGAMP) synthase (cGAS) antagonist A151 on a retinal ischemia/reperfusion (RIR) mouse model. Our findings reveal a novel mechanism of microglia-induced neuroinflammation-mediated RGC death associated with glaucomatous vision loss. We found that RIR injury facilitated the release of dsDNA, which initiated inflammatory responses by activating cGAS-stimulator of interferon genes (STING) pathway. Correspondingly, elevated expressions of cGAS and STING were found in retinal samples from human glaucoma donors. Furthermore, we found that deletion or inhibition of cGAS or STING in microglia transfected with poly(dA:dT) specifically decreased microglia activation and inflammation response. We also observed that A151 treatment promoted poly(dA:dT)--stimulated changes in polarization from the M1 to the M2 phenotype in microglia. Subsequently, A151 administered to mice effectively inhibited the cGAS-STING pathway, absent in melanoma 2 (AIM2) inflammasome and pyroptosis-related molecules. Furthermore, A151 administration significantly reduced neuroinflammation, ameliorated RGC death and RGC-related reductions in visual function. These findings provide a unique perspective on glaucomatous neuropathogenesis and suggest cGAS as an underlying target of retinal inflammation to provide a potential therapeutic for acute glaucoma.

Cost-effectiveness of Prophylactic Laser Peripheral Iridotomy in Primary Angle-Closure Suspects

PURPOSE

To investigate the cost-effectiveness (CE) of prophylactic laser peripheral iridotomy (LPI) in primary angle-closure (PAC) suspects (PACSs).

DESIGN

Cost-effectiveness analysis utilizing Markov models.

SUBJECTS

Patients with narrow angles (PACSs).

METHODS

Progression from PACSs through 4 states (PAC, PAC glaucoma, blindness, and death) was simulated using Markov cycles. The cohort entered at 50 years and received either LPI or no treatment. Transition probabilities were calculated from published models, and risk reduction of LPI was calculated from the Zhongshan Angle Closure Prevention trial. We estimated costs of Medicare rates, and previously published utility values were used to calculate quality-adjusted life year (QALY). Incremental CE ratios (ICER) were evaluated at $50 000. Probabilistic sensitivity analyses (PSAs) addressed uncertainty.

MAIN OUTCOME MEASURES

Total cost, QALY, and ICER.

RESULTS

Over 2 years, the ICER for the LPI cohort was > $50 000. At 6 years, the LPI cohort was less expensive with more accrued QALY. In PSA, the LPI arm was cost-effective in 24.65% of iterations over 2 years and 92.69% over 6 years. The most sensitive parameters were probability of progressing to PAC and cost and number of annual office visits.

CONCLUSIONS

By 6 years, prophylactic LPI was cost-effective. The rate of progressing to PAC and differing practice patterns most impacted CE. With uncertainty of management of narrow angles, cost may be a decision management tool for providers.

FINANCIAL DISCLOSURE(S)

The authors have no proprietary or commercial interest in any materials discussed in this article.

Prevalence of zonulopathy in primary angle closure disease

Background

To determine the prevalence of zonulopathy in a large cohort of eyes with primary angle closure disease (PACD) that underwent cataract surgery.

Methods

Retrospective consecutive case series of PACD eyes (including primary angle closure suspect, primary angle closure, and primary angle closure glaucoma) that underwent phacoemulsification cataract surgery or clear lens extraction between 2009 and 2020 at a single ophthalmology centre. Those with risk factors for zonulopathy such as history of trauma, pseudoexfoliation syndrome, intraocular surgery, retinitis pigmentosa or connective tissue disorders were excluded. The primary outcomes included the prevalence of zonulopathy assessed intraoperatively and secondary pigment dispersion syndrome.

Results

In our cohort of 806 consecutive PACD eyes, the prevalence of zonulopathy was 7.3% (59 of 806 eyes) – significantly greater than the 0.46%–2.6% range reported for the general population (p < 0.001). Intraoperative signs of zonular weakness included floppy capsular bag (29 eyes, 3.6%), zonular laxity (25 eyes, 3.1%) and zonular dehiscence (11 eyes, 1.4%). Among these eyes, capsular tension ring was used in 23 eyes (39.0%), six eyes (10.2%) experienced vitreous prolapse intraoperatively and underwent anterior vitrectomy, and two eyes (3.4%) experienced posterior capsular rupture, one of which required a scleral‐fixated intraocular lens. Secondary pigment dispersion syndrome was observed in 141 eyes (17.5%).

Conclusions

This study evidenced a high prevalence of zonulopathy among a large cohort of PACD eyes and suggests zonulopathy as a possible under‐recognised cause of angle closure. Until more sophisticated imaging modalities become available, awareness about the prevalence of zonulopathy in angle closure disease coupled with careful preoperative examinations can help minimise or prevent the complications of zonulopathy.

Lessons From Management: Perioperative Phacoemulsification Planning Following Resolution of Acute Angle Closure

Patients with loose zonular apparatus after acute angle closure may require phacoemulsification cataract surgery. The authors' experience from management of such patients provides excellent instruction on the surgical intervention for their cataracts. This is because patients who have recovered from acute angle closure glaucoma may not have evident zonular laxity preoperatively, as the iris may be taut secondary to the effects of associated ischaemia. If the surgeon’s preoperative planning is directed to the possibility of loose zonular apparatus, then appropriate preoperative, intraoperative, and postoperative planning and management can be effected. This may permit preoperative patient counselling regarding the potentially increased complexity of the case. Intraoperatively, deliberately gentle capsulorrhexis, the use of iris hooks or a pupil expander to dilate the pupil, iris hooks to support the capsular bag, and the employment of a capsular tension ring may be helpful. Postoperatively, due to the previous ocular ischaemia, intraocular pressure elevation may ensue, and should be actively managed. The authors provide a summary of factors that require consideration in patients undergoing cataract surgery following acute angle closure.

A Rare Case of Acute Bilateral Endothelial Decompensation after Prophylactic Nd:YAG Laser Iridotomy Requiring Endothelial Keratoplasty

Aim

To describe a case of acute bilateral endothelial decompensation following prophylactic Nd:YAG laser iridotomy (LI) for occludable angles.

Background

Although regarded safe, LI can occasionally be a source of various ocular complications, including corneal endothelial damage. In the herein case, we describe the first case of acute bilateral endothelial decompensation after Nd:YAG LI.

Case description

A 63-year-old man was referred for consultation due to visual acuity deterioration in both eyes 2 weeks after undergoing an uneventful prophylactic LI for occludable angles. On examination, bilateral corneal edema with Descemet's membrane folds was observed. Direct corneal damage from the laser beam was not seen. Specular microscopy failed to count endothelial density. Anterior-segment optical coherence tomography (OCT), ultrasound biomicroscopy, and ocular biometry were performed. The patient was referred for bilateral endothelial keratoplasty.

Conclusion

Subacute endothelial dysfunction should be considered as a possible adverse event following Nd:YAG LI and patients should be advised accordingly.

Clinical relevance

Surgeons should be aware of the potentially devastating complication of bilateral corneal decompensation following routine Nd:YAG LI, even in patients without preexisting corneal injury. Patients should be advised accordingly.

How to cite this article

Weill Y, Abulafia A, Smadja D, et al. A Rare Case of Acute Bilateral Endothelial Decompensation after Prophylactic Nd:YAG Laser Iridotomy Requiring Endothelial Keratoplasty. J Curr Glaucoma Pract 2020;14(3):109–111.

Non-contact tests for identifying people at risk of primary angle closure glaucoma

BACKGROUND

Primary angle closure glaucoma (PACG) accounts for 50% of glaucoma blindness worldwide. More than three-quarters of individuals with PACG reside in Asia. In these populations, PACG often develops insidiously leading to chronically raised intraocular pressure and optic nerve damage, which is often asymptomatic. Non-contact tests to identify people at risk of angle closure are relatively quick and can be carried out by appropriately trained healthcare professionals or technicians as a triage test. If the test is positive, the person will be referred for further specialist assessment.

OBJECTIVES

To determine the diagnostic accuracy of non-contact tests (limbal anterior chamber depth (LACD) (van Herick test); oblique flashlight test; scanning peripheral anterior chamber depth analyser (SPAC), Scheimpflug photography; anterior segment optical coherence tomography (AS-OCT), for identifying people with an occludable angle.

SEARCH METHODS

We searched the following bibliographic databases 3 October 2019: CENTRAL; MEDLINE; Embase; BIOSIS; OpenGrey; ARIF and clinical trials registries. The searches were limited to remove case reports. There were no date or language restrictions in the searches.

SELECTION CRITERIA

We included prospective and retrospective cross-sectional, cohort and case-control studies conducted in any setting that evaluated the accuracy of one or more index tests for identifying people with an occludable angle compared to a gonioscopic reference standard.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed data extraction and quality assessment using QUADAS2 for each study. For each test, 2 x 2 tables were constructed and sensitivity and specificity were calculated. When four or more studies provided data at fixed thresholds for each test, we fitted a bivariate model using the METADAS macro in SAS to calculate pooled point estimates for sensitivity and specificity. For comparisons between index tests and subgroups, we performed a likelihood ratio test comparing the model with and without the covariate.

MAIN RESULTS

We included 47 studies involving 26,151 participants and analysing data from 23,440. Most studies were conducted in Asia (36, 76.6%). Twenty-seven studies assessed AS-OCT (analysing 15,580 participants), 17 studies LACD (7385 participants), nine studies Scheimpflug photography (1616 participants), six studies SPAC (5239 participants) and five studies evaluated the oblique flashlight test (998 participants). Regarding study quality, 36 of the included studies (76.6%) were judged to have a high risk of bias in at least one domain.The use of a case-control design (13 studies) or inappropriate exclusions (6 studies) raised patient selection concerns in 40.4% of studies and concerns in the index test domain in 59.6% of studies were due to lack of masking or post-hoc determination of optimal thresholds. Among studies that did not use a case-control design, 16 studies (20,599 participants) were conducted in a primary care/community setting and 18 studies (2590 participants) in secondary care settings, of which 15 investigated LACD. Summary estimates were calculated for commonly reported parameters and thresholds for each test; LACD ≤ 25% (16 studies, 7540 eyes): sensitivity 0.83 (95% confidence interval (CI) 0.74, 0.90), specificity 0.88 (95% CI 0.84, 0.92) (moderate-certainty); flashlight (grade1) (5 studies, 1188 eyes): sensitivity 0.51 (95% CI 0.25, 0.76), specificity 0.92 (95% CI 0.70, 0.98) (low-certainty); SPAC (≤ 5 and/or S or P) (4 studies, 4677 eyes): sensitivity 0.83 (95% CI 0.70, 0.91), specificity 0.78 (95% CI 0.70, 0.83) (moderate-certainty); Scheimpflug photography (central ACD) (9 studies, 1698 eyes): sensitivity 0.92 (95% CI 0.84, 0.96), specificity 0.86 (95% CI 0.76, 0.93) (moderate-certainty); AS-OCT (subjective opinion of occludability) (13 studies, 9242 eyes): sensitivity 0.85 (95% CI 0.76, 0.91); specificity 0.71 (95% CI 0.62, 0.78) (moderate-certainty). For comparisons of sensitivity and specificity between index tests we used LACD (≤ 25%) as the reference category. The flashlight test (grade 1 threshold) showed a statistically significant lower sensitivity than LACD (≤ 25%), whereas AS-OCT (subjective judgement) had a statistically significant lower specificity. There were no statistically significant differences for the other index test comparisons. A subgroup analysis was conducted for LACD (≤ 25%), comparing community (7 studies, 14.4% prevalence) vs secondary care (7 studies, 42% prevalence) settings. We found no evidence of a statistically significant difference in test performance according to setting. Performing LACD on 1000 people at risk of angle closure with a prevalence of occludable angles of 10%, LACD would miss about 17 cases out of the 100 with occludable angles and incorrectly classify 108 out of 900 without angle closure.

AUTHORS' CONCLUSIONS

The finding that LACD performed as well as index tests that use sophisticated imaging technologies, confirms the potential for this test for case-detection of occludable angles in high-risk populations. However, methodological issues across studies may have led to our estimates of test accuracy being higher than would be expected in standard clinical practice. There is still a need for high-quality studies to evaluate the performance of non-invasive tests for angle assessment in both community-based and secondary care settings.

NLRP12 collaborates with NLRP3 and NLRC4 to promote pyroptosis inducing ganglion cell death of acute glaucoma

BACKGROUND

Acute glaucoma, characterized by a sudden elevation in intraocular pressure (IOP) and retinal ganglion cells (RGCs) death, is a major cause of irreversible blindness worldwide that lacks approved effective therapies, validated treatment targets and clear molecular mechanisms. We sought to explore the potential molecular mechanisms underlying the causal link between high IOP and glaucomatous RGCs death.

METHODS

A murine retinal ischemia/ reperfusion (RIR) model and an in vitro oxygen and glucose deprivation/reoxygenation (OGDR) model were used to investigate the pathogenic mechanisms of acute glaucoma.

RESULTS

Our findings reveal a novel mechanism of microglia-induced pyroptosis-mediated RGCs death associated with glaucomatous vision loss. Genetic deletion of gasdermin D (GSDMD), the effector of pyroptosis, markedly ameliorated the RGCs death and retinal tissue damage in acute glaucoma. Moreover, GSDMD cleavage of microglial cells was dependent on caspase-8 (CASP8)-hypoxia-inducible factor-1α (HIF-1α) signaling. Mechanistically, the newly identified nucleotide-binding leucine-rich repeat-containing receptor (NLR) family pyrin domain-containing 12 (NLRP12) collaborated with NLR family pyrin domain-containing 3 (NLRP3) and NLR family CARD domain-containing protein 4 (NLRC4) downstream of the CASP8-HIF-1α axis, to elicit pyroptotic processes and interleukin-1β (IL-1β) maturation through caspase-1 activation, facilitating pyroptosis and neuroinflammation in acute glaucoma. Interestingly, processing of IL-1β in turn magnified the CASP8-HIF-1α-NLRP12/NLRP3/NLRC4-pyroptosis circuit to accelerate inflammatory cascades.

CONCLUSIONS

These data not only indicate that the collaborative effects of NLRP12, NLRP3 and NLRC4 on pyroptosis are responsible for RGCs death, but also shed novel mechanistic insights into microglial pyroptosis, paving novel therapeutic avenues for the treatment of glaucoma-induced irreversible vision loss through simultaneously targeting of pyroptosis.