Differences in Systemic Pulse Waveform Between Individuals With Glaucoma, Glaucoma Suspects, and Healthy Controls.

Purpose: It has been hypothesized that compromised ocular circulation in glaucoma may be concomitant of systemic changes. The purpose of this study is to test whether systemic blood flow pulse waveform patterns differ between individuals with glaucoma (GL), glaucoma suspects (GLS), and normal healthy controls (HC). Methods: The study included 35 bilateral GL, 67 bilateral GLS, 29 individuals with unilateral GL who were considered GLS in the other eye, and 44 healthy controls. Systemic pulsatile blood pressure waveforms were recorded using a finger cuff. A continuous 200 Hz plethysmography recording is made to obtain a pulse waveform. Waveform parameters were extracted using custom software from an average of eight pulse cycles. These were compared between GL, GLS, and HC groups on a per-eye basis, using generalized estimating equation models to account for intereye correlations; and plotted against disease severity by visual field linearized mean deviation (MDlin) and retinal nerve fiber layer thickness (RNFLT). Results: Averaged blood pressure was significantly lower in the HC group (mean ± standard deviation 91.7 ±11.7 mm Hg) than the GLS (102.4 ± 13.9) or GL (102.8 ± 13.7) groups, with P < 0.0001 (generalized estimating equation regression). Waveform parameters representing vascular resistance were higher in both GLS and GL groups than the HC group; and were correlated with RNFLT and MDlin (P ≤ 0.05). Conclusions: The shape of the systemic pulsatile waveform differs in individuals with GL/GLS suspects, compared to HC eyes. Blood pressure changes more rapidly in individuals with GL, which suggests higher arterial stiffness.

[Spontaneous rupture of the anterior lens capsule in Alport syndrome (case study)]. / Samoproizvol'noe vskrytie perednei kapsuly khrustalika pri sindrome Al'porta (klinicheskoe nablyudenie).

Alport syndrome is a hereditary disease characterized by glomerulopathy, manifested by hematuria and/or proteinuria, progressive decline in renal function, often combined with hearing and vision pathology. This article presents a clinical case of spontaneous opening of the anterior lens capsule in a patient with Alport syndrome, accompanied by uveitis and ophthalmic hypertension, and describes the features of the surgical aid and the postoperative period.

Effects of intraocular pressure change on intraocular lens power calculation in primary open-angle glaucoma and ocular hypertension.

This study aimed to assess the effect of intraocular pressure (IOP) changes on biometry and intraocular lens (IOL) power calculation in patients diagnosed with primary open-angle glaucoma (POAG) and ocular hypertension (OHT). This prospective non-randomized cohort study enrolled patients with diagnosed POAG and OHT, presenting with IOP levels exceeding 25 mmHg. Thai Clinical Trials Registry number was TCTR20180912007. Optical biometry, encompassing measurements such as corneal thickness (CCT), keratometry, anterior chamber depth (ACD), and axial length, was conducted before and after IOP reduction. The IOL power was also determined using the SRK/T formula. The main outcomes measured were alterations in biometry and IOL power. Correlations between IOP, biometric parameters, and IOL power were analyzed. In total, 28 eyes were included in the study, with a mean patient age of 65.71±10.2 years. After IOP reduction, all biometric parameters, except CCT and ACD, exhibited a decrease without reaching statistical significance (all p>0.05). Meanwhile, IOL power showed a slight increase of 0.214±0.42 diopters (P = 0.035). The correlation between IOP and biometric parameters was found to be weak. However, there was a moderate correlation between IOP and IOL power (r2 = 0.267). Notably, IOL power tended to increase by more than 0.5 diopters when IOP decreased by more than 10 mmHg (p < 0.001). In conclusion, changes in IOP among patients with POAG and OHT do not significantly impact biometry and IOL power calculations. Nonetheless, it may be prudent to consider a slight adjustment in IOL power when IOP is lowered by more than 10 mmHg.

Repeatability of a Virtual Reality Headset Perimeter in Glaucoma and Ocular Hypertensive Patients.

Purpose: The VisuALL S is an automated, static threshold, virtual reality-based perimeter for mobile evaluation of the visual field. We examined same-day and 3-month repeatability. Methods: Adult participants with a diagnosis of glaucoma or ocular hypertension underwent two VisuALL 24-2 Normal T- Full threshold strategy tests at baseline and one additional exam at 3 months for each eligible eye. Spearman, intraclass correlation coefficients (ICCs), and Bland-Altman plots were used to assess the correlation of individual point sensitivities and mean deviation (MD) among three tests. Results: Eighty-eight eyes (44 participants) were included. Average age was 68.1 ± 14.3 years, and 60.7% were male. VisuALL MD was highly correlated between tests (intravisit: r = 0.89, intervisit: r = 0.82; P < 0.001 for both). Bland-Altman analysis showed an average difference in intravisit MD of -0.67 dB (95% confidence interval [CI], -6.04 to 4.71 dB) and -0.15 dB (95% CI, -8.04 to 7.73 dB) for intervisit exams. Eight-five percent of pointwise intravisit ICCs were above 0.75 (range, 0.63 to 0.93), and 65% of pointwise intervisit ICCs were above 0.75 (range, 0.55 to 0.91). Conclusions: VisuALL demonstrated high correlation of MD between tests and good repeatability for individual point sensitivities among three tests in 3 months, except at the points around the blind spot and superiorly. Translational Relevance: The preliminary reproducibility results for VisuALL are encouraging. Its portable design makes it a potentially useful tool for patients with glaucoma, enabling more frequent assessments both at home and in clinical settings.

Development and characterization of a chronic high intraocular pressure model in New Zealand white rabbits for glaucoma research.

Glaucoma is a neurodegenerative disease characterized by visual field loss associated with optic nerve damage and ocular hypertension. The biological basis for the elevated intraocular pressure (IOP) is largely unknown, such that lowering the IOP is currently the only established treatment. Several animal models have been developed to elucidate the mechanism underlying the increased IOP and for use in drug discovery research, but their utility is often limited by the occurrence of severe intraocular inflammation and by technical challenges. In this study, we developed a rabbit glaucoma model that does not require experimental disease induction. Rabbits were chosen as the model because their eyeballs are similar in size to those of humans, and they are easy to breed. By crossing rabbit strains with inherited glaucoma, as indicated by obvious buphthalmos, we produced a strain that exhibits ocular hypertension. The IOP of the Ocular Hypertension (OH) rabbits was significantly higher than that of the wild type (WT; normal New Zealand white rabbits) from the age of 3 weeks to at least 22 weeks. The significantly larger corneal diameter of the OH rabbits indicated ocular enlargement, whereas there was no significant difference in corneal thickness compared with WT rabbits. Anterior segment ocular coherence tomography and gonioscopic observations revealed an open angle in the OH rabbits. Hematoxylin and eosin (HE) staining together with Masson's trichrome staining showed abnormal collagen accumulation in the angle of the OH rabbit's eyes. Furthermore, aqueous humor (AH) outflow imaging following an intravitreal injection of a fluorescent probe into the anterior chamber for tissue-section analysis revealed retention of the probe in the area of collagen deposition in the OH eyes. The OH rabbits also had a time-dependent increase in the cup/disc ratio. In conclusion, investigations using our newly developed rabbit model of open-angle ocular hypertension showed that abnormal accumulation of extracellular matrix at the angle increased AH outflow resistance in the conventional outflow pathway, leading to a high IOP. Furthermore, the OH rabbits exhibited glaucomatous optic disc cupping over time. These findings suggest the utility of the OH rabbits as a model for open-angle glaucoma (OAG).

Antioxidant effect of gallic acid on retinal ganglion cells in glaucoma model.

To evaluate the protective effect of gallic acid on the optic nerve by studying the inhibitory effect of gallic acid on oxidative stress in retinal ganglion cells. 100 male SD rats were randomly divided into four groups: normal control group, simple high IOP group, 0.5% gallic acid experimental group, and 1% gallic acid experimental group. HE staining, immunofluorescence, DHE staining, Western blot, and q-PCR were used to observe the antioxidant effect of gallic acid on the retina of acute ocular hypertension rats. HE staining of the retina of SD rats confirmed that the nucleus of RGCs was clear, the thickness of the RNFL was regular in the normal control group, and the nucleus of RGCs was ruptured and lysed in the simple high intraocular pressure (IOP) group and the gallic acid group, and the thickness of the RNFL was significantly thickened, but the thickness of the RNFL in the gallic acid group was significantly reduced compared with that in the simple high IOP group (p < 0.05). DHE staining showed that ROS content in the simple high IOP group was significantly increased compared with the normal control group, and ROS content was significantly decreased after the application of gallic acid (p < 0.05). Immunofluorescence staining with Brn-3a antibody confirmed that the number of RGCs was significantly reduced in the simple high IOP group compared with the normal control group, whereas after application of gallic acid, the number of RGCs was significantly more in the gallic acid group than in the simple high IOP group (p < 0.05). Western Blot and q-PCR confirmed that hypoxia-inducing factor 1α (HIF-1α) protein content and transcription level were significantly increased in the retinal tissue of the simple high IOP group, and gallic acid could inhibit HIF-1α protein content (p < 0.05) and reduce transcription factor level (p < 0.05). Gallic acid exerts a protective effect on RGC by inhibiting oxidative stress in rats with acute IOP elevation.

[Standardizing the diagnosis and treatment of ocular hypertension based on evidence-based medicine].

Ocular hypertension (OHT) refers to a condition in which the intraocular pressure increases without causing glaucomatous optic nerve changes or visual field damage. The incidence rate of OHT in people over 40 years old is as high as 4% to 10%. According to the OHT Treatment Study (OHTS), the incidence of primary open angle glaucoma (POAG) among OHT patients is increasing year by year, so it is necessary to conduct long-term follow-up. This article elaborates on five major risk factors for the progression of OHT to POAG: age, intraocular pressure, vertical cup-disc ratio, pattern standard deviation of visual field, and central corneal thickness. It also summarizes other potential risk factors, such as long-term fluctuations in intraocular pressure, asymmetry of intraocular pressure and visual field between the two eyes, structural phenotypes of the optic disk, and optic disk hemorrhage. Predicting the risk of OHT progression to POAG based on risk factors, patients with different risk levels require different timing for treatment initiation and follow-up intervals. Those with higher risks should start preventive treatment earlier and have shorter follow-up intervals. Both drug therapy and selective laser trabeculoplasty can serve as initial treatment options for OHT. Combining evidence-based medicine research and individualized evaluation of treatment can enhance the clinical diagnosis and treatment level of OHT.

[Minoxidil-induced ophthalmic hypertension (case report)]. / Indutsirovannaya minoksidilom oftal'mogipertenziya (klinicheskoe nablyudenie).

This article presents a case of a 31-year-old male patient who presented to the outpatient department of the Krasnov Research Institute of Eye Diseases with complaints of diplopia and increased intraocular pressure (IOP) up to 30 mm Hg. The patient had been using minoxidil topically for androgenic alopecia for 8 years. On examination, mild swelling of the bulbar conjunctiva in the upper fornix was revealed; optical coherence tomography showed thinning of the ganglion cell layer, most likely due to moderate myopia. The patient responded well to discontinuation of minoxidil and topical therapy with prostaglandin analogues. After 4 months, an attempt was made to replace topical hypotensive therapy with carbonic anhydrase inhibitors, but the previous hypotensive regimen had to be resumed due to an increase in IOP. During 10 months of observation, no signs of progression were detected according to optical coherence tomography and static perimetry.

The Robust Lamina Cribrosa Vasculature: Perfusion and Oxygenation Under Elevated Intraocular Pressure.

Purpose: Elevated intraocular pressure (IOP) is thought to cause lamina cribrosa (LC) blood vessel distortions and potentially collapse, adversely affecting LC hemodynamics, reducing oxygenation, and triggering, or contributing to, glaucomatous neuropathy. We assessed the robustness of LC perfusion and oxygenation to vessel collapses. Methods: From histology, we reconstructed three-dimensional eye-specific LC vessel networks of two healthy monkey eyes. We used numerical simulations to estimate LC perfusion and from this the oxygenation. We then evaluated the effects of collapsing a fraction of LC vessels (0%-36%). The collapsed vessels were selected through three scenarios: stochastic (collapse randomly), systematic (collapse strictly by the magnitude of local experimentally determined IOP-induced compression), and mixed (a combination of stochastic and systematic). Results: LC blood flow decreased linearly as vessels collapsed-faster for stochastic and mixed scenarios and slower for the systematic one. LC regions suffering severe hypoxia (oxygen <8 mm Hg) increased proportionally to the collapsed vessels in the systematic scenario. For the stochastic and mixed scenarios, severe hypoxia did not occur until 15% of vessels collapsed. Some LC regions had higher perfusion and oxygenation as vessels collapsed elsewhere. Some severely hypoxic regions maintained normal blood flow. Results were equivalent for both networks and patterns of experimental IOP-induced compression. Conclusions: LC blood flow was sensitive to distributed vessel collapses (stochastic and mixed) and moderately vulnerable to clustered collapses (systematic). Conversely, LC oxygenation was robust to distributed vessel collapses and sensitive to clustered collapses. Locally normal flow does not imply adequate oxygenation. The actual nature of IOP-induced vessel collapse remains unknown.

Reverse pupillary block with pigment dispersion and elevated intraocular pressure following bilateral phakic intraocular lens implantation.

The authors describe a case of reverse pupillary block with pigment dispersion following sequential phakic intraocular lens (pIOL) implantation for high myopia, in a young female patient. The intraocular pressure (IOP) elevation began 3 weeks postoperatively, for which Nd-YAG laser peripheral iridotomies (PIs) were attempted elsewhere. Despite maximum medical therapy, the IOP was uncontrolled. She was referred to our institute for further management. Examination showed anteriorly displaced iris-pIOL diaphragm, iris pigment dispersion and raised IOP. The PIs were incomplete. Based on clinical evaluation and investigations, we concluded that the excess area of contact of the posterior iris over the pIOL caused a reverse pupillary block and pigment dispersion. The IOPs were controlled by repeating laser iridotomies and with medical therapy. Subsequently, the patient developed a low lens vault leading to bilateral cataract. Sequential explantation of the pIOL along with cataract extraction was performed and her vision was restored.

Priorities for health outcomes in glaucoma in an ethnically diverse UK cohort: an observational study.

OBJECTIVES: To assess whether patients from minority ethnic groups have different perceptions about the quality-of-life outcomes that matter most to them. DESIGN: Cross-sectional observational study. SETTING: High volume eye centres serving the most ethnically diverse region in the UK, recruiting from July 2021 to February 2022. PARTICIPANTS: 511 patients with primary open-angle glaucoma and the predisease state of ocular hypertension. MAIN OUTCOME MEASURES: The main outcome was participants' self-reported priorities for health outcomes. RESULTS: Participants fell into one of four clusters with differing priorities for health outcomes, namely: (1) vision, (2) drop freedom, (3) intraocular pressure and (4) one-time treatment. Ethnicity was the strongest determinant of cluster membership after adjusting for potential confounders. Compared with white patients prioritising vision alone, the OR for black/black British patients was 7.31 (95% CI 3.43 to 15.57, p<0.001) for prioritising drop freedom; 5.95 (2.91 to 12.16, p<0.001) for intraocular pressure; and 2.99 (1.44 to 6.18, p=0.003) for one-time treatment. For Asian/Asian British patients, the OR was 3.17 (1.12 to 8.96, p=0.030) for prioritising intraocular pressure as highly as vision. Other ethnic minority groups also had higher ORs for prioritising health outcomes other than vision alone: 4.50 (1.03 to 19.63, p=0.045) for drop freedom and 5.37 (1.47 to 19.60, p=0.011) for intraocular pressure. CONCLUSIONS: Ethnicity is strongly associated with differing perceptions about the health outcomes that matter. An individualised and ethnically inclusive approach is needed when selecting and evaluating treatments in clinical and research settings.

[Topical application of hypotensive drugs for the prevention of intraocular pressure elevation after intravitreal injections of anti-VEGF drugs]. / Mestnoe primenenie gipotenzivnykh preparatov s tsel'yu profilaktiki povysheniya urovnya vnutriglaznogo davleniya posle intravitreal'nykh in"ektsii anti-VEGF-preparatov.

The management protocol for patients with neovascular age-related macular degeneration (nAMD) involves multiple intravitreal injections (IVI) of anti-VEGF drugs. The ability to reduce the peak intraocular pressure (IOP) rise is greatly important in clinical practice. PURPOSE: This study evaluates the effect of topical hypotensive drugs on the short-term IOP rise after IVI of anti-VEGF drugs in patients with nAMD. MATERIAL AND METHODS: The prospective study included 80 patients with newly diagnosed nAMD. Before the start of treatment, the patients were divided into 4 groups of 20 people each: 1st - controls, who received no prophylactic drugs, in the 2nd, 3rd and 4th groups local instillations of one drop of hypotensive drugs brinzolamide 1%, brinzolamide-timolol, brimonidine-timolol were performed in the conjunctival sac twice: 1 day before the injection (at 20:00) and on the day of the injection 2 hours before the manipulation (at 08:00), respectively. IOP was measured in each patient using ICare Pro non-contact tonometer before injection, as well as 1 min, 30 and 60 min after injection. RESULTS: Prophylactic use of hypotensive drugs was associated with a significant decrease in IOP immediately after IVI compared to the same parameter in the 1st group (p<0.001), the maximum decrease in IOP values was observed when using a fixed combination of brimonidine-timolol by 12.1 mm Hg compared to the controls (p<0.001), the combination of brinzolamide-timolol reduced IOP by 8.5 mm Hg (p<0.001), brinzolamide 1% led to the smallest decrease in IOP - by 5.1 mm Hg (p<0.001). CONCLUSION: Study patients that received instillations of brimonidine-timolol combination of one drop into the conjunctival sac 1 day before the injection and on the day of the injection showed the maximum decrease in IOP compared to patients of the other groups.

Pilot study comparing a new virtual reality-based visual field test to standard perimetry in children.

PURPOSE: To assess the feasibility and performance of Vivid Vision Perimetry (VVP), a new virtual reality (VR)-based visual field platform. METHODS: Children 7-18 years of age with visual acuity of 20/80 or better undergoing Humphrey visual field (HVF) testing were recruited to perform VVP, a VR-based test that uses suprathreshold stimuli to test 54 field locations and calculates a fraction seen score. Pearson correlation coefficients were calculated to evaluate correlation between HVF mean sensitivity and VVP mean fraction seen scores. Participants were surveyed regarding their experience. RESULTS: A total of 37 eyes of 23 participants (average age, 12.9 ± 3.1 years; 48% female) were included. All participants successfully completed VVP testing. Diagnoses included glaucoma (12), glaucoma suspect (7), steroid-induced ocular hypertension (3), and craniopharyngioma (1). Sixteen participants had prior HVF experience, and none had prior VVP experience, although 7 had previously used VR. Of the 23 HVF tests performed, 9 (39%) were unreliable due to fixation losses, false positives, or false negatives. Similarly, 35% of VVP tests were unreliable (as defined by accuracy of blind spot detection). Excluding unreliable HVF tests, the correlation between HVF average mean sensitivity and VVP mean fraction seen score was 0.48 (P = 0.02; 95% CI, 0.09-0.74). When asked about preference for the VVP or HVF examination, all participants favored the VVP, and 70% were "very satisfied" with VVP. CONCLUSIONS: In our cohort of 23 pediatric subjects, VVP proved to be a clinically feasible VR-based visual field testing, which was uniformly preferred over HVF.

Rate of Initial Optic Nerve Head Capillary Density Loss and Risk of Visual Field Progression.

Importance: Rapid initial optic nerve head capillary density loss may be used to assess the risk of glaucoma visual field progression. Objective: To investigate the association between the rate of initial optic nerve head capillary density loss from optical coherence tomography angiography (OCTA) and visual field progression. Design, Setting, Participants: This was a retrospective study of a longitudinal cohort at a glaucoma referral center. A total of 167 eyes (96 with primary open-angle glaucoma and 71 with glaucoma suspect) of 109 patients were monitored for a mean (SD) of 5.7 (1.4) years from January 2015 to December 2022. Data analysis was undertaken in April 2023. Main Outcomes and Measures: The rates of initial capillary density and average retinal nerve fiber layer loss were calculated from the first 3 optic nerve head OCTA and OCT scans, respectively, during the initial follow-up (mean [SD], 2.0 [1.0] years). Based on the median rate, eyes were categorized into fast and slow progressor groups. The association between initial capillary density change or retinal nerve fiber layer thinning and visual field progression was evaluated using linear-mixed and time-varying Cox models. Results: A total of 167 eyes of 109 patients (mean [SD] age, 69.0 [11.1] years; 56 [51.4%] female and 53 [48.6%] male) were assessed. Eighty-three eyes were slow OCTA progressors, while 84 eyes were fast with mean capillary density loss of -0.45% per year and -1.17% per year, respectively (mean difference, -0.72%/year; 95% CI,-0.84 to -0.60; P < .001). Similarly, 83 eyes were slow OCT progressors, while 84 eyes were fast with mean retinal nerve fiber layer thinning of -0.09 µm per year and -0.60 µm per year, respectively (mean difference, -0.51 µm/year; 95% CI,-0.59 to -0.43; P < .001). The fast OCTA and OCT progressors were associated with more rapid visual field loss (mean difference, -0.18 dB/year; 95% CI,-0.30 to -0.06; P = .004 and -0.17 dB/year; 95% CI,-0.29 to -0.06; P = .002, respectively). Fast OCTA progressing eyes were more likely to have visual field progression (hazard ratio, 1.96; 95% CI, 1.04-3.69; P = .04). Seventeen of 52 eyes (32.7%; 95% CI, 32.5-32.8) with fast OCTA and OCT progression developed subsequent visual field likely progression. Conclusion and Relevance: Rapid initial optic nerve head capillary density loss from OCTA was associated with a faster rate of visual field progression and a doubling of the risk of developing event progression in this study. These findings may support clinical use of OCTA and OCT optic nerve head measurements for risk assessment of glaucoma progression.

NADPH and NAC synergistically inhibits chronic ocular hypertension-induced neurodegeneration and neuroinflammation through regulating p38/MAPK pathway and peroxidation.

Glaucoma, the leading cause of irreversible blindness worldwide, is characterized by neurodegeneration and neuroinflammation with retinal NAD/NADP and GSH decline. Nicotinamide adenine dinucleotide (NAD)/NAD phosphate (NADP) and glutathione (GSH) are two redox reducers in neuronal and glial metabolism. However, therapeutic strategies targeting NAD/NADP or GSH do not exert ideal effects, and the underlying mechanisms are still poorly understood. We assessed morphological changes in retinal ganglion cells (RGCs), the affected neurons in glaucoma, and Müller cells, the major glial cells in the retina, as well as the levels of phosphorylated p38 (p-p38) and Caspase-3 in glaucoma patients. We constructed a modified chronic ocular hypertensive rat model and an oxygen-glucose deprivation (OGD) cell model. After applying NADPH and N-acetylcysteine (NAC), a precursor to cysteine, the rate-limiting substrate in GSH biosynthesis, to cells, apoptosis, axonal damage and peroxidation were reduced in the RGCs of the NAC group and p-p38 levels were decreased in the RGCs of the NADPH group, while in stimulated Müller cells cultured individually or cocultured with RGCs, gliosis and p38/MAPK, rather than JNK/MAPK, activation were inhibited. The results were more synergistic in the rat model, where either NADPH or NAC showed crossover effects on inhibiting peroxidation and p38/MAPK pathway activation. Moreover, the combination of NADPH and NAC ameliorated RGC electrophysiological function and prevented Müller cell gliosis to the greatest extent. These data illustrated conjoined mechanisms in glaucomatous RGC injury and Müller cell gliosis and suggested that NADPH and NAC collaborate as a neuroprotective and anti-inflammatory combination treatment for glaucoma and other underlying human neurodegenerative diseases.

Profiling IOP-Responsive Genes in the Trabecular Meshwork and Optic Nerve Head in a Rat Model of Controlled Elevation of Intraocular Pressure.

Purpose: The rat controlled elevation of intraocular pressure (CEI) model allows study of in vivo responses to short-term exposure to defined intraocular pressures (IOP). In this study, we used NanoString technology to investigate in vivo IOP-related gene responses in the trabecular meshwork (TM) and optic nerve head (ONH) simultaneously from the same animals. Methods: Male and female rats (N = 35) were subjected to CEI for 8 hours at pressures simulating mean, daytime normotensive rat IOP (CEI-20), or 2.5× IOP (CEI-50). Naïve animals that received no anesthesia or surgical interventions served as controls. Immediately after CEI, TM and ONH tissues were dissected, RNA was isolated, and samples were analyzed with a NanoString panel containing 770 genes. Postprocessing, raw count data were uploaded to ROSALIND for differential gene expression analyses. Results: For the TM, 45 IOP-related genes were significant in the CEI-50 versus CEI-20 and CEI-50 versus naïve comparisons, with 15 genes common to both comparisons. Bioinformatics analysis identified Notch and transforming growth factor beta (TGFß) pathways to be the most up- and downregulated Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, respectively. For ONH, 22 significantly differentially regulated genes were identified in the CEI-50 versus naïve comparison. Pathway analysis identified defense response and immune response as two significantly upregulated biological process pathways. Conclusions: This study demonstrated the ability to assay short-term IOP-responsive genes in both TM and ONH tissues simultaneously. In the TM, downregulation of TGFß pathway genes suggests that TM responses may reduce TGFß-induced extracellular matrix synthesis. For ONH, the initial response to short-term elevated IOP may be protective.

Dysregulation of neuroprotective lipoxin pathway in astrocytes in response to cytokines and ocular hypertension​.

Glaucoma leads to vision loss due to retinal ganglion cell death. Astrocyte reactivity contributes to neurodegeneration. Our recent study found that lipoxin B4 (LXB4), produced by retinal astrocytes, has direct neuroprotective actions on retinal ganglion cells. In this study, we aimed to investigate how the autacoid LXB4 influences astrocyte reactivity in the retina under inflammatory cytokine-induced activation and during ocular hypertension. The protective activity of LXB4 was investigated in vivo using the mouse silicone-oil model of chronic ocular hypertension. By employing a range of analytical techniques, including bulk RNA-seq, RNAscope in-situ hybridization, qPCR, and lipidomic analyses, we discovered the formation of lipoxins and expression of the lipoxin pathway in rodents (including the retina and optic nerve), primates (optic nerve), and human brain astrocytes, indicating the presence of this neuroprotective pathway across various species. Findings in the mouse retina identified significant dysregulation of the lipoxin pathway in response to chronic ocular hypertension, leading to an increase in 5-lipoxygenase (5-LOX) activity and a decrease in 15-LOX activity. This dysregulation was coincident with a marked upregulation of astrocyte reactivity. Reactive human brain astrocytes also showed a significant increase in 5-LOX. Treatment with LXB4 amplified the lipoxin biosynthetic pathway by restoring and amplifying the generation of another member of the lipoxin family, LXA4, and mitigated astrocyte reactivity in mouse retinas and human brain astrocytes. In conclusion, the lipoxin pathway is functionally expressed in rodents, primates, and human astrocytes, and is a resident neuroprotective pathway that is downregulated in reactive astrocytes. Novel cellular targets for LXB4's neuroprotective action are inhibition of astrocyte reactivity and restoration of lipoxin generation. Amplifying the lipoxin pathway is a potential target to disrupt or prevent astrocyte reactivity in neurodegenerative diseases, including retinal ganglion cell death in glaucoma.

Circumlimbal suture and laser burns: Comparison between two different chronic glaucoma models. / çŽ¯è§’è†œç¼˜ç¼åˆä¸Žæ¿€å ‰å ‰å‡æ¨¡åž‹ï¼šä¸¤ç§æ ¢æ€§é«˜çœ¼åŽ‹æ¨¡åž‹çš„æ¯”è¾ƒï¼ˆè‹±æ–‡ï¼‰.

OBJECTIVES: Glaucoma is a multifactorial optic neuropathy with a high rate of irreversible visual loss, and its pathogenesis is complex and still unclear. Elevated intraocular pressure (IOP) is well recognized as the sole modifiable risk factor for the development of glaucoma in the majority of cases. This study aims to compare 2 different methods of inducing chronic ocular hypertension by circumlimbal suture or by laser burns in degree and lasting time of the IOP, different status of the retina and retinal ganglion cells (RGCs), and changes of the microstructure of neurons. METHODS: The chronic ocular hypertension models were induced by 2 different ways. One kind of the models was built by unilateral circumlimbal suture (10/0) implantation (suture group), another kind of model was built by laser burns at trabecular meshwork and episcleral veins (laser group). The untreated contralateral eye served as the control group. Changes in IOP were observed and regularly monitored in the 2 groups of rats. HE staining was applied to observe the retinal and optic nerve pathology. Transmission electron microscope (TEM) was used to observe the mitochondrial morphology. RGCs were specifically labeled with Brn3b antibody and counted. The expression of caspase-3 was detected by Western blotting to clarify the apoptosis of RGCs. RESULTS: Compared with the control group, IOP were significantly increased in the suture group and the laser group (both P<0.05). The suture group induced a 1.5-fold elevation of IOP, and sustained for 8 weeks. The laser group induced a 2-fold elevation of IOP for 12 weeks. Both methods could cause RGCs loss (both P<0.05), which were verified by pathology and immune staining of Brn3b. The expressions of caspase-3 were also increased (both P<0.05). The mitochondrial morphology became more fragment, which changed from long shape to round and small one under TEM in 2 models. For comparison, the pathology changes of retinal structure in suture group were not obviously than those in the laser group. CONCLUSIONS: Circumlimbal suture can build an effective model of chronic elevated IOP and induce glaucomatous pathologic changes similar to those in the laser photocoagulation, but the pathologic changes are milder than those in laser photocoagulation. Compare with translimbal laser photocoagulation, equipment and skill demand for circumlimbal suture is less.

Pathological high intraocular pressure induces glial cell reactive proliferation contributing to neuroinflammation of the blood-retinal barrier via the NOX2/ET-1 axis-controlled ERK1/2 pathway.

BACKGROUND: NADPH oxidase (NOX), a primary source of endothelial reactive oxygen species (ROS), is considered a key event in disrupting the integrity of the blood-retinal barrier. Abnormalities in neurovascular-coupled immune signaling herald the loss of ganglion cells in glaucoma. Persistent microglia-driven inflammation and cellular innate immune system dysregulation often lead to deteriorating retinal degeneration. However, the crosstalk between NOX and the retinal immune environment remains unresolved. Here, we investigate the interaction between oxidative stress and neuroinflammation in glaucoma by genetic defects of NOX2 or its regulation via gp91ds-tat. METHODS: Ex vivo cultures of retinal explants from wildtype C57BL/6J and Nox2 -/- mice were subjected to normal and high hydrostatic pressure (Pressure 60 mmHg) for 24 h. In vivo, high intraocular pressure (H-IOP) was induced in C57BL/6J mice for two weeks. Both Pressure 60 mmHg retinas and H-IOP mice were treated with either gp91ds-tat (a NOX2-specific inhibitor). Proteomic analysis was performed on control, H-IOP, and treatment with gp91ds-tat retinas to identify differentially expressed proteins (DEPs). The study also evaluated various glaucoma phenotypes, including IOP, retinal ganglion cell (RGC) functionality, and optic nerve (ON) degeneration. The superoxide (O2-) levels assay, blood-retinal barrier degradation, gliosis, neuroinflammation, enzyme-linked immunosorbent assay (ELISA), western blotting, and quantitative PCR were performed in this study. RESULTS: We found that NOX2-specific deletion or activity inhibition effectively attenuated retinal oxidative stress, immune dysregulation, the internal blood-retinal barrier (iBRB) injury, neurovascular unit (NVU) dysfunction, RGC loss, and ON axonal degeneration following H-IOP. Mechanistically, we unveiled for the first time that NOX2-dependent ROS-driven pro-inflammatory signaling, where NOX2/ROS induces endothelium-derived endothelin-1 (ET-1) overexpression, which activates the ERK1/2 signaling pathway and mediates the shift of microglia activation to a pro-inflammatory M1 phenotype, thereby triggering a neuroinflammatory outburst. CONCLUSIONS: Collectively, we demonstrate for the first time that NOX2 deletion or gp91ds-tat inhibition attenuates iBRB injury and NVU dysfunction to rescue glaucomatous RGC loss and ON axon degeneration, which is associated with inhibition of the ET-1/ERK1/2-transduced shift of microglial cell activation toward a pro-inflammatory M1 phenotype, highlighting NOX2 as a potential target for novel neuroprotective therapies in glaucoma management.

Smoking Intensity is Associated With Progressive Optic Nerve Head Vessel Density Loss in Glaucoma.

PRCIS: A lifetime history of greater smoking consumption was associated with faster vessel density loss over time. Smoking intensity should be considered when assessing the risk of glaucoma progression, as well as its management. PURPOSE: To investigate the relationship of smoking and smoking intensity, with the rate of optic nerve head (ONH) whole image capillary density (wiCD) loss in primary open angle glaucoma (POAG) and glaucoma suspect patients. METHODS: In this longitudinal study, patients with POAG who had at least 2 years of follow-up and optical coherence tomography angiography (OCTA) performed at a minimum of 4 visits were selected for study. The smoking intensity was calculated as the pack-year at the baseline OCTA. Univariable and multivariable linear mixed models were used to determine the effect of each parameter on the rates of wiCD loss over time. Nonlinear least-squares estimation with piecewise regression model was used to investigate the cutoff point for the relationship between wiCD loss and smoking intensity. RESULTS: One hundred sixty-four eyes (69 glaucoma suspect and 95 POAG) of 110 patients were included with a mean (95% CI) follow-up of 4.0 (3.9 to 4.1) years. Of the 110 patients, 50 (45.5%) had a reported history of smoking. Greater smoking intensity was associated with faster wiCD loss [-0.11 (-0.23 to 0.00)] %/year per 10 pack-year higher; P =0.048) after adjusting for covariates. The wiCD thinning became significantly faster when smoking intensity was greater than 22.2 pack-years. Smoking had no effect on the rate of wiCD thinning in patients who smoked <22.2 pack-years during their lifetime. CONCLUSIONS: A history of greater smoking consumption was associated with faster vessel density loss, suggesting smoking intensity as a potential risk factor for glaucoma.