Severe Primary Open-angle Glaucoma Research Articles

A parafoveal retinal cones analysis using adaptive-optics retinal camera in patients with primary open angle glaucoma.

To study the density, spacing, and regularity of retinal cone photoreceptors using an Adaptive Optics (AO) retinal camera (Rtx1TM, Imagine Eyes, Orsay, France) in patients with Primary Open Angle Glaucoma (POAG) and to compare the outcomes with those of healthy age-matched control subjects. The study included 43 eyes with POAG and 31 eyes of normal subjects. POAG patients were divided into three groups according to the severity of the visual field defect. The AO Rtx1TM was used to obtain images of the parafoveal cone mosaic to calculate cone values. Analysis was performed at two and four degrees of eccentricity from the fovea along the four meridians (nasal, temporal, superior, inferior). In POAG eyes, the mean ± standard deviation (SD) cone density at 2° considering all meridians was significantly lower than in normal controls (23,058.6 ± 3532.0 cones/mm2, and 25,511.7 ± 3157.5 cones/mm2, respectively; p = 0.003). Cone spacing was 7.3 ± 0.5 µm in POAG and 7.0 ± 0.4 µm in normal controls (p = 0.005), and cone regularity was 90.5 ± 4.9% and 93.5 ± 1.9% in POAG and normal controls, respectively (p < 0.001). At 4° similar trends were observed. However, no significant differences were found among patients with different severity of POAG (p > 0.05). Using AO Rtx1TM, significant differences in retinal photoreceptors mosaic pattern were found between POAG eyes and age-matched controls, indicating a reduction in photoreceptors in POAG. No significant differences in retinal photoreceptor values were found among the three POAG groups.

No Evidence That Vitamin D Levels or Deficiency Are Associated with the Risk of Open-Angle Glaucoma in Individuals of European Ancestry: A Mendelian Randomisation Analysis.

Glaucoma is the second leading cause of blindness worldwide, with intraocular pressure as the only known modifiable risk factor. Vitamin D has been proposed to influence intraocular pressure and decrease retinal ganglion cell degeneration. Based on these findings, vitamin D has been suggested to prevent or reduce the severity of primary open-angle glaucoma (POAG), which is the most common form. We applied two-sample Mendelian randomisation (MR) analyses to data from the SUNLIGHT consortium and the UK Biobank to assess the causal effect of vitamin D levels and vitamin D deficiency on primary open-angle glaucoma (POAG). MR analysis, including sensitivity tests using other GWAS summary statistics from FinnGen, was also performed. We also investigated the association between single nucleotide polymorphisms (SNPs) on genes involved in vitamin D metabolic pathways and POAG. We found no statistical evidence that vitamin D levels (OR = 1.146, 95% CI 0.873 to 1.504, p = 0.326) or vitamin D deficiency (OR = 0.980 (95% CI 0.928 to 1.036, p = 0.471) causally affect the risk of developing POAG. Sensitivity analyses, including the use of a more relaxed p-value threshold, and use of winter-measured samples only, replication in the FinnGen dataset, and exploration of specific genetic markers also showed no evidence of association between SNPs for genes involved in key steps of vitamin D metabolism and POAG. These results indicate that vitamin D may not be a significant factor in modifying POAG risk, challenging the hypothesis that vitamin D supplementation could be effective in reducing POAG risk. Further research should focus on identifying other potential risk factors for POAG prevention strategies.

The association between airborne particulate matter (PM2.5) exposure level and primary open-angle glaucoma

The eye is vulnerable to the adverse effects of air pollution. Previous experimental study found that fine particulate matter (PM2.5) had a direct toxic effect on intraocular tissues. However, clinical evidence for the impact of air pollutants exposure on functional and structural changes in glaucoma remains scarce. A total of 120 patients with primary open-angle glaucoma (POAG) who met the inclusion criteria were included in this retrospective study. The standardized ophthalmic examination, such as intraocular pressure (IOP), visual field, optical coherence tomography, and comprehensive physical examination, were performed. The air pollution data, including PM2.5 concentration and air quality index (AQI), were collected. PM2.5 and AQI for the day of the medical examination, as well as one month, and three months before the medical examination date, were investigated. In our results, higher average exposure levels for one-month and three-month, were associated with increased IOP (r=0.229, P=0.013; r=0.204, P=0.028, respectively) and decreased visual field mean sensitivity (MS) (r=-0.212, P=0.037; r=-0.305, P=0.002, respectively). PM2.5 concentrations for the day of the medical examination was not significantly associated with ocular parameters. In multiple linear regression analysis adjusted for demographic and clinical factors, higher PM2.5 exposure for one month was associated with elevated IOP (P=0.040, β=0.173, 95 %CI=0.008–0.337). We also found an association between PM2.5 and MS (one-month exposure: β=-0.160, P=0.029; three-month exposure: β=-0.238, P=0.002). The logistic regression analysis found that three-month average PM2.5 exposure level was significantly associated with the disease severity (β=0.043, P=0.025, 95 %CI=1.005–1.084). In conclusion, this study is the first to investigate the relationship between air pollution and detailed ocular parameters of POAG patients in Shanghai over a three-year period, and to explore the effects of different exposure times of PM2.5 on glaucoma. This study found that PM2.5 exposure was correlated with elevated IOP and decreased MS. The one-month PM2.5 exposure level had the most significant effects on IOP. The three-month PM2.5 exposure level was an independent risk factor for POAG severity. Current evidence suggests there may be an association between PM2.5 exposure and POAG.

Outcomes of bent ab interno needle goniectomy with phacoemulsification in moderate to severe primary open angle glaucoma.

To assess the safety and efficacy of bent ab interno needle goniectomy (BANG) in moderate to severe primary open angle glaucoma (POAG) eyes undergoing phacoemulsification (phaco). Single-arm, prospective, interventional study. POAG patients with medically uncontrolled intraocular pressure (IOP), >15 mmHg for moderate and >12 mmHg for severe POAG, with visually significant cataract were recruited. All patients underwent BANG using a 26-gauge needle to excise 30° of the trabecular meshwork, along with phaco. Primary outcome was IOP. Secondary outcomes were success rate, percentage reduction in IOP/antiglaucoma medications (AGMs), and intraoperative complications. Success at 12 months was defined as: criterion A: IOP <15 mmHg for moderate glaucoma or <12 mm Hg for severe glaucoma with or without AGMs OR criterion B reduction in number of AGMs by >1. Thirty-two eyes of 32 patients underwent BANG + phaco. Mean age of the participants was 62.7 ± 8.4 years and there were 25 males and seven females. At 12 months, a significant decrease was noted in both IOP (from 17.6 ± 3.6 to 12 ± 1.6 mmHg, 31.8%; P < 0.001) and AGMs (from 3.7 ± 0.9 to 2.8 ± 0.8, 24.3%; P < 0.001). Twenty percent or more reduction in IOP was achieved in 62.5% (20/32) of eyes. Overall success (meeting either of the criteria A or B) at 12 months was achieved in 87.5% eyes. Mild postoperative hyphema was noted in 10 (31.2%) eyes, and two eyes (6.2%) required additional filtration surgery at 7 months. A 30-degree BANG with phaco in patients of POAG appears to be a safe, effective and affordable MIGS for developing countries.

Factors Associated with Nonreturn after Loss to Follow-Up from Glaucoma Care: An IRIS® Registry Retrospective Analysis

PurposeLoss to follow-up (LTFU) in primary open-angle glaucoma (POAG) can lead to undertreatment, disease progression, and irreversible vision loss. Patients who become LTFU either eventually re-establish glaucoma care after a lapse or never return to the clinic. The purpose of this study is to examine a large population of POAG patients who became LTFU to determine the proportion that return to care and to identify demographic and clinical factors associated with non-return after LTFU. DesignRetrospective longitudinal cohort study ParticipantsPatients with a diagnosis of POAG with a clinical encounter in 2014 in the IRIS® Registry (Intelligent Research in Sight) MethodsWe examined follow-up patterns for 553,663 patients with POAG who had an encounter in the IRIS Registry in 2014 by following their documented clinic visits through 2019. LTFU was defined as exceeding one calendar year without an encounter. Within the LTFU group, patients were classified as returning after a lapse in care (return after LTFU) or not (non-return after LTFU). Main Outcome MeasuresProportion of patients with non-return after LTFU and baseline demographic and clinical characteristics associated with non-return among LTFU POAG patients. ResultsAmong 553,663 POAG patients, 277,019 (50%) had at least one episode of LTFU over the 6-year study period. Within the LTFU group, 33% (92,471) returned to care and 67% (184,548) did not return to care. Compared to those who returned to care, LTFU patients with non-return were more likely to be older (age >80 years; RR=1.48; 95% CI: 1.47-1.50), to have unknown/missing insurance (RR=1.31; 95% CI: 1.30-1.33), and to have severe-stage POAG (RR=1.13; 95% CI: 1.11-1.15). Greater POAG severity and visual impairment were associated with non-return with a dose-dependent relationship in the adjusted model that accounted for demographic characteristics. Among those with return after LTFU, almost all returned within 2 years of last appointment (82,201; 89%) rather than 2 or more years later. ConclusionHalf of POAG patients in the IRIS Registry had at least one period of LTFU, and two-thirds of LTFU POAG patients did not return to care. More effort is warranted to re-engage the vulnerable POAG patients who become LTFU.

36-Month Outcomes of Ahmed ClearPath® Glaucoma Drainage Device in Severe Primary Open Angle Glaucoma.

To evaluate the safety and effectiveness of the Ahmed ClearPath® (ACP) 250 mm2 glaucoma drainage device (GDD) in managing refractory primary open-angle glaucoma (POAG). This was a retrospective case series focused on adult patients diagnosed with severe POAG who underwent implantation of an ACP GDD. Over a 36-month follow-up period, data on intraocular pressure (IOP), the number of glaucoma medications, and complications were recorded. The primary objectives were to assess the reductions from baseline in both IOP and medication usage, through 36 months. Secondary objectives included the proportion of eyes achieving an IOP reduction of ≥ 20% from baseline at 36 months. Intraoperative and postoperative complications were also assessed. Twelve eyes from 11 patients (mean age: 71.3 ± 14.1 years) met the inclusion criteria and were included in the study. All patients had severe POAG (n=11), with the majority being Caucasian (n=8) and female (n=10). The mean (standard deviation) IOP and number of glaucoma medications at baseline were 29 (7.6) mmHg and 3 (0.9), respectively. At 36 months, mean IOP was reduced to 10.6 (5.5) mmHg (-61.8%; p= 0.0008) and mean number of medications was reduced to 0.9 (0.9) (-71.4%; p=0.0005), with 88.9% of eyes achieving an IOP reduction by ≥20%. No vision threatening complications were observed. To our knowledge this is the first study to report 36-month outcomes of the novel ACP device in the treatment of refractory POAG. The safety profile and efficacy of the ACP was found to be comparable to that of other commonly utilized GDD models.

Micropulse Transscleral Cyclophotocoagulation in Non-Incisional Eyes with Ocular Hypertension and Primary Open-Angle Glaucoma.

To investigate the safety and effectiveness of micropulse transscleral cyclophotocoagulation (MPTSCPC) in non-incisional eyes with ocular hypertension (OHT) and early, moderate, and severe primary open-angle glaucoma (POAG). Retrospective cohort study of eyes that underwent MPTSCPC from 2016 to 2019 at an outpatient clinic in Canada. Eyes were excluded if any incisional procedures, except cataract surgery, were performed prior to MPTSCPC treatment. Laser power ranged from 900 to 2500mW. A total of 153 eyes from 93 patients were included (OHT n=22; early POAG n=46; moderate POAG n=35; severe POAG n=50). The baseline IOP was 18.37 ± 4.76mmHg in the total cohort. All cohorts experienced a significant mean IOP reduction by final follow-up (total p<0.001; OHT p=0.003; early POAG p<0.001; moderate POAG p=0.022; severe POAG p=0.015). Overall, 52.9% of eyes achieved an IOP reduction of ≥20% from baseline to final follow-up (OHT 59.1%; early POAG 58.7%; moderate POAG 45.7%; severe POAG 50.0%). There was worsening in best-corrected visual acuity in the total cohort (mean difference=0.11 ± 0.36 logMAR, p=0.11), mostly attributable to cataract progression (34.1% of phakic eyes) and ocular surface disease (7.2%). The number of topical medications and drug classes remained unchanged in the total cohort (p=0.425 and p=0.791, respectively). Twenty-two eyes (14.4%) required retreatment, which provided an additional IOP reduction of 1.26mmHg (p=0.344). By final follow-up, 8 eyes (5.2%) required escalation to incisional procedures. MPTSCPC is a safe and effective adjunct IOP-lowering treatment in non-incisional eyes with OHT and POAG.

Aqueous humour protein dysregulation in Asian eyes with primary open angle glaucoma

The pathophysiology of Primary Open Angle Glaucoma (POAG) remains poorly understood. Through proteomic analysis of aqueous humour (AH) from POAG patients, we aim to identify changes in protein composition of these samples compared to control samples.High resolution mass spectrometry-based TMT6plex quantitative proteomics analysis is performed on AH samples collected from POAG patients, and compared against a control group of patients with cataracts. Data are available via ProteomeXchange with identifier PXD033153.1589 proteins were quantified from the aqueous samples using Proteome Discoverer version 2.2 software. Among these proteins, 210 were identified as unique master proteins. The proteins which were up or down-regulated by ±3 fold-change were considered significant. Human neuroblastoma full-length cDNA clone CS0DD006YL02 was significantly upregulated in patients with severe POAG on >2 medications, while actin, cytoplasmic 1, V2-7 protein (fragment), immunoglobulin-like polypeptide 1 and phosphatidylethanolamine-binding protein 4 were only present in these patients with severe POAG on >2 medications.Beta-crystallin B1 and B2, Gamma-crystallin C, D and S were significantly downregulated in the severe POAG ≤2 glaucoma medications group.Beta-crystallin B2, Gamma-crystallin D and GCT-A9 light chain variable region (fragment) were significantly downregulated in the non-severe POAG group.Actin, cytoplasmic 1 was significantly upregulated in subjects with severe POAG who required more than 2 glaucoma medications. Crystallins (Beta-crystallin B1 and B2, Gamma-crystallin C, D and S) were significantly downregulated in subjects with severe POAG who required less than 2 glaucoma medications.

Evaluation of glaucomatous macular and optic nerve vascular damage by optical coherence tomography angiography

Purpose The aim of this study was to compare the macular and optic nerve head vessel perfusion density in mild primary open-angle glaucoma (POAG) and moderate–severe POAG patients to normal eyes as a control cohort. Patients and methods This is a retrospective comparative case–control study that included 80 eyes of 46 participants. The study included 60 eyes of 36 POAG patients and 20 eyes of 10 healthy participants (control group). The patients underwent 3.0×3.0 mm optical coherence tomography angiography (OCTA) scans centered on the macula and 4.5×4.5 mm scans on the optic disc. Results The OCTA scans of the glaucomatous eyes revealed a reduction in microvasculature in the peripapillary area, which was absent in the control cohort. The whole disc vessel density (VD) was significantly less in the glaucomatous eyes (mean=38.02±8.74) compared to the control cohort (mean=50.41±2.58, P&lt;0.001). The severity of glaucoma was linked to a decrease in macular VD percentage, with a mean superficial VD of 36.09±5.67 in the glaucoma cohorts and 46.64±5.53 in the control cohort (P&lt;0.001), which was more pronounced than in the deep layer (P&lt;0.008). There was no statistically significant difference in the foveal avascular zone size between the control and glaucoma cohorts at any stage (P=0.999). Conclusion The OCTA vascular density accurately distinguished the glaucoma from healthy eyes, with superior performance in the peripapillary region. The foveal avascular zone size did not indicate glaucoma severity. The OCTA noninvasive assessment of the capillary networks showed a potential for managing the glaucoma patients by characterizing the retinal vascular changes.

Association of the Severity of Primary Open-Angle Glaucoma with Serum Vitamin D Levels

Association of the Severity of Primary Open-Angle Glaucoma with Serum Vitamin D Levels

Relative Flow Index as a Novel Optical Coherence Tomography Angiography Biomarker in Primary Open Angle Glaucoma.

Relative flow indices as novel optical coherence tomography angiography (OCTA) biomarkers demonstrated reduced optic nerve head and peripapillary large vessel and capillary perfusion in primary open angle glaucoma (POAG). Large vessel perfusion correlated with disease severity and progression. To introduce relative flow indices as novel OCTA biomarkers and their pathologic insights in POAG. This is a retrospective case-control study where 57 POAG and 57 control eyes were included. OCTA 4.5×4.5mm optic nerve head (ONH) were analyzed using ImageJ 1.53t to calculate global flow indices (GFIs) and relative flow indices (RFIs) for whole image optic nerve head, isolated radial peripapillary capillary plexus, and isolated large vessel angiograms. Retinal nerve fiber layer thickness (RNFLT), ONH vascular density (VD), except inside disc and large vessel VD, GFIs, and RFIs were lower in POAG than control. There was a positive correlation between RNFLT and both VD and GFIs. Among RFIs, only large vessel RFI (ONHLVRFI) demonstrated a positive correlation with average RNFLT. Linear regression demonstrated a significant positive coefficient for ONHLVRFI with RNFLT as the dependent variable. The area under receiver operating characteristic curve showed diagnostic accuracy ranging fair, good, and excellent for all biomarkers. Inferior RNFLT had the highest area under the curve (0.922) while optic nerve head large vessel density had the lowest (0.523). POAG showed structural loss of RNFL neurovascular unit manifesting as positively correlated reduction of VD and RNFLT. Also, POAG had lower global perfusion of the optic nerve head and peripapillary area, resulting in the positively correlated reduction of GFIs and RNFLT. Although RFIs were lower in POAG, only ONHLVRFI demonstrated a positive correlation and regression with RNFLT, implying that large vessel hypoperfusion was associated with POAG severity and progression.

Ab-Externo MicroShunt versus Trabeculectomy in Primary Open-Angle Glaucoma: Two-Year Results from a Randomized, Multicenter Study

PurposeTo compare the effectiveness and safety of the MicroShunt (Santen Inc., Emeryville, CA, USA) versus trabeculectomy in patients with primary open-angle glaucoma (POAG). DesignProspective, randomized, multicenter trial conducted in the United States and Europe. ParticipantsAdult patients (aged 40-85 years) with mild to severe POAG inadequately controlled on maximum tolerated medical therapy and intraocular pressure (IOP) ≥15 mmHg and ≤40 mmHg. MethodsPatients were randomized 3:1 to standalone MicroShunt implantation (n=395) or trabeculectomy (n=132), both augmented with mitomycin C (MMC) 0.2 mg/mL for 2 minutes. Main Outcome MeasuresThe primary effectiveness endpoint was surgical success, defined as ≥20% reduction in mean diurnal IOP from baseline with no increase in glaucoma medications. Secondary endpoints included changes in mean IOP and medication use from baseline and the need for postoperative interventions. ResultsAt 2 years, the rate of surgical success was lower in the MicroShunt than in the trabeculectomy group (50.6% versus 64.4%, p=0.005). Mean diurnal IOP was reduced from 21.1 ± 4.9 mmHg at baseline to 13.9 ± 3.9 mmHg at 24 months in the MicroShunt group and from 21.1 ± 5.0 mmHg at baseline to 10.7 ± 3.7 mmHg at 24 months in the trabeculectomy group (p<0.001 compared with baseline in both groups). Mean medication use decreased from 3.1 to 0.9 in the MicroShunt group and from 2.9 to 0.4 in the trabeculectomy group (p<0.001 compared with baseline in both groups). Adverse events at 2 years were generally similar in the two groups, except that hypotony was more common in eyes undergoing trabeculectomy (51.1% versus 30.9%, p<0.001). Repositioning or explantation of the implant occurred in 6.8% of MicroShunt patients. The majority of these patients had device removal at the time of subsequent glaucoma surgery. Vision-threatening complications were uncommon in both groups. ConclusionAt 2 years, both the MicroShunt and trabeculectomy provided significant reductions in IOP and medication use, with trabeculectomy continuing to have greater surgical success.

Peripapillary Retinoschisis in a Patient with Severe Primary Open Angle Glaucoma

Peripapillary retinoschisis is a rare finding that may be associated with the progression of primary open angle glaucoma (POAG). Potential pathophysiological mechanisms have been proposed to explain this association, such as acute and chronic increase in intraocular pressure, vitreopapillary traction, and Müller cell dysfunction from optic nerve head deformation. OCT imaging has revealed hyper-reflective strut-like pillars within the schisis cavity described as “bridging structures.” While peripapillary retinoschisis may spontaneously resolve, other strategies may include lowering intraocular pressure, intraocular injections, or pars plana vitrectomy.present a patient with peripapillary retinoschisis incidentally found during a workup for primary open angle glaucoma.

Evaluation of systemic IL-6 trans-signalling in patients with primary open-angle glaucoma

To evaluate systemic trans-signalling of interleukin (IL)-6 in patients with primary open-angle glaucoma (POAG). Fifty-one POAG patients and 47 matched healthy controls were enrolled. Serum concentrations of IL-6, sIL-6R, and sgp130 were quantified. Serum levels of IL-6, sIL-6R, and IL-6/sIL-6R ratios in the POAG group were significantly higher than those in control group, while only the sgp130/sIL-6R/IL-6 ratio was decreased. Among POAG subjects, advanced-stage patients exhibited significantly higher intraocular pressure (IOP), serum IL-6 and sgp130 levels, and IL-6/sIL-6R ratio than those in the early to moderate stage. The ROC curve analysis revealed that the IL-6 level and IL-6/sIL-6R ratio performed better than other parameters in diagnosing POAG and discriminating POAG severity. Serum IL-6 level was moderately correlated with IOP and C/D ratio, while a weak correlation was observed between sIL-6R levels with C/D ratio. IL-6 and sIL-6R levels were correlated with each other in POAG patients but not in healthy controls. Overstimulation of systemic IL-6 trans-signalling has been implicated in POAG.

Effect of Phacoemulsification on Intraocular Pressure in Eyes with Functioning Tube Shunts.

To evaluate the effect of phacoemulsification on intraocular pressure (IOP) in eyes with functioning tube shunts. This was a retrospective chart review of primary open-angle glaucoma (POAG) patients with a functioning tube who underwent phacoemulsification and had 24 months of follow-up. The primary end point was defined as surgical failure (IOP 21 mmHg) at month 24, progression to no light perception (NLP) vision, glaucoma reoperation, or implant removal. Surgical failure defined as IOP 18 and 15 mmHg, changes in visual acuity (VA), IOP, and number of medications were assessed. Twenty-seven eyes of 27 patients with moderate or severe POAG were included. The mean age of the patients was 64.2 10.8 years. The interval between the tube shunt and phacoemulsification was 28.8 25.0 months. At the end of the study, four (14.8%) eyes met the failure criteria; the average time to failure was 9.3 3.8 months. The causes of failure were high IOP in two (50.0%) and glaucoma reoperation in two (50.0%) eyes; however, no eyes progressed to NLP vision. Surgical failure defined as IOP 18 and 15 mmHg showed an increasing failure rate (18.5% and 48.5%, respectively).Themean IOP and medications number remained stable at month 24 compared to baseline (P = 0.131 and P = 0.302, respectively). Initially, VA showed improvement, with the greatest improvement at 6 months (P = 0.001), but at 24 months the improvement was no longer significant (P = 0.430). Phacoemulsification in patients with functioning tubes did not change the mean IOP in most of the patients (86.2%); the number of medications also did not increase.

A Rare Case of Abiotrophia defectiva Bleb Associated Endophthalmitis.

To report a rare case of Abiotrophia defectiva bleb associated endophthalmitis (BAE). In this case report of a patient with BAE, the authors describe the features of severe and rapid onset, associated retinitis, and a favorable outcome after aggressive early intervention. A 75-year old female presented that decreased visual acuity of hand motions with elevated intraocular pressure of 39 mm Hg in the left eye. Her past ocular history was notable for severe primary open angle glaucoma with uneventful trabeculectomy and cataract surgery in both eyes 7 years prior. Examination revealed conjunctival injection and an opaque avascular cystic bleb along with anterior chamber cellular reaction with a B-scan ultrasound concerning for vitritis. Abiotrophia defectiva was isolated from the vitreous tap within 48 hours and confirmed later with 16S ribosomal RNA sequencing. After initial vitreous tap and inject and subsequent PPV, her BCVA had improved to 20/500 at post operative week 1 and then improved to 20/40 at post-operative month 2. Her exam was notable for resolved corneal edema, a deep and quiet anterior chamber, and resolved intraretinal hemorrhages. This is one of the first BAE cases with rapid identification of Abiotrophia defectiva. Abiotrophia defectiva was isolated from the initial vitreous tap within 48 hours and confirmed with 16S ribosomal RNA sequencing. This case highlights that rapid identification of Abiotrophia defectiva may be indicative of a greater bacterial load and should prompt aggressive intervention and that the visual prognosis can be favorable.

Amsler Grid Versus 10-2 Test in Primary Open Angle Glaucoma.

Glaucoma is the leading cause of global irreversible blindness. The goal of management in glaucoma lies in its early detection and treatment to prevent further optic neuropathy. Available equipment for early glaucoma detection is not cost-effective or readily available in resource-scarce settings such as Nigeria. Thus, there is a need for a simple cost-effective tool to detect glaucomatous central visual field (CVF) defects in all the stages of glaucoma within the community in resource scarce-settings. The aim of this article is to determine the validity of the Amsler grid in detecting central glaucomatous visual field defects in primary open angle glaucoma (POAG). This was a cross-sectional study of follow-up glaucoma patients at a secondary eye care hospital in Nigeria. All patients had detailed ophthalmic examination in addition to 24-2 and 10-2 CVF tests and Amsler grid test. POAG was classified using the Hodapp-Parrish-Anderson criteria into mild, moderate, and severe on 24-2 CVF. The diagnostic validity of the Amsler grid was calculated using the 10-2 CVF as a reference standard. Regression analyses were performed between the Amsler grid scotoma area and 10-2 CVF parameters [mean deviation (MD), scotoma extent (SE), and scotoma mean depth (SMD)]. A total of 150 eyes of 150 patients were enrolled. The sensitivity, specificity, and positive predictive value and negative predictive value of the Amsler grid compared with the 10-2 CVF was 49.5%, 95.9%, 96.2%, and 47.9%, respectively, with an area under curve of 0.7. Sensitivity increased with increasing severity (P < 0.001) from 20.0%, 31.0%, and 76.6% in mild, moderate, and severe POAG, respectively. The Amsler grid scotoma area had the strongest relationship with the 10-2 MD, followed by 10-2 SE and 10-2 SMD with a quadratic R2 of 0.579, 0.370, and 0.307, respectively. The Amsler grid has a low sensitivity in mild-to-moderate POAG. However, it may serve as an adjunctive tool in resource-scarce settings for detection of severe POAG in the community by primary eye care providers.

Association between Serum Uric Acid Levels and Primary Open-angle Glaucoma: A Cross-sectional Study

Introduction: There is an intricate association between serum Uric Acid (UA) levels and Primary Open Angle Glaucoma (POAG). UA levels in the blood are known to be a good indicator of antioxidant function, and a decrease in UA plays a key role in the pathogenesis of POAG. However, the association of serum UA and Uric Acid Creatinine Ratio (UACR) in POAG cases in the Indian population remains unexplored. Aim: To investigate the association of serum UA levels and serum UACR with POAG. Materials and Methods: This cross-sectional study was conducted among patients who attended the Outpatient Department (OPD) of Opthalmology at Maharajah’s Institute of Medical Sciences, Vizianagaram, Andhra Pradesh, India. The duration of the study was one year and six months, from January 15, 2021 to July 15, 2022. The study included 200 recently diagnosed patients with POAG, who were divided into three groups based on Intraocular Pressure (IOP): Group 1 (mild) with an IOP of 21-30 mmHg, group 2 (moderate) with an IOP of 31-50 mmHg, and group 3 (severe) with an IOP greater than 51 mmHg. Age and gender-matched 199 healthy subjects were included as the control group. Blood samples were collected from the study subjects after obtaining informed consent and were tested for serum UA (using the modified Trinder method) and serum creatinine (using Jaffe’s method) in a semiautomatic analyser (Erba chem 7). The data were analysed using Statistical Package for Social Sciences (SPSS) version 21.0 software and MS Excel 2007. Results: The mean age of the study participants of all three groups was found to be 51.19±5.06 years with 46.7% male and 53.3% female subjects. The serum UA levels were 5.55±0.74 mg/dL in the mild POAG group, 4.1±0.5 mg/dL in the moderate POAG group, and 2.67±0.6 mg/dL in the severe POAG group (p-value &lt;0.001). The present study also found that among the three study groups of POAG, UA levels were the lowest in the severe POAG group, followed by the moderate POAG group, and then the mild POAG group. This pattern was observed in both the males and females population. Conclusion: The present study found that serum UA levels were decreased in POAG patients compared to the normal healthy control group. Furthermore, the study revealed a significant negative association between serum UA levels and serum UACR levels with the severity of POAG.

Effects of Arterial Stiffness on Visual Field Severity and Progression in Malay Patients with Primary Open Angle Glaucoma

Introduction: Vascular dysregulation is postulated to be involved in the pathogenesis of primary open angle glaucoma (POAG). Systemic arterial stiffness may accelerate the pre-existing damage. The purpose of this study was to determine the association of arterial stiffness with severity and progression of visual field in Malay patients with POAG. Methods: A cross-sectional study was conducted with 55 patients with POAG and 55 age- and sex-matched control subjects. The patients with POAG were further divided in accordance with their Advanced Glaucoma Intervention Study (AGIS) scores on their visual fields (VFs) (mild in 23 patients, moderate in 18, and severe in 14). Progression was defined as the worsening of the VF defect quantified as an increase in AGIS score of 4 points from the baseline. Arterial stiffness was measured using SphygmoCor and quantified as pulse wave analysis (PWA) and pulse wave velocity (PWV). Results: No significant differences in PWA and PWV were found between the patients with POAG and the control subjects (p=0.333 and p=0.443, respectively). The mean follow-up duration for the patients with POAG was 4.7±3.1 years. PWA and PWV showed no significant association with POAG severity after the confounding factors were controlled for. Ten patients with progression of VF were identified. In the analysis of covariance, a significantly higher PWV was found in the patients with disease progression (p=0.036). Conclusion: VF severity and progression were not associated with systemic arterial stiffness. The probable reason is that other factors affecting retinal microcirculation may play a larger role in the severity and progression of POAG.

Structure-Function Relationship between Cluster Mean Defect and Sector Peripapillary Retinal Nerve Fiber Layer Thickness in Primary Open Angle Glaucoma.

Purpose To determine the structure–function relationship between cluster mean defect (MD) offered by standard automated perimetry and corresponding sector peripapillary retinal nerve fiber layer thickness (pRNFLT) measured with optical coherence tomography (OCT) in primary open angle glaucoma (POAG). Method 39 healthy eyes (control group), 43 early POAG eyes (global MD ≤ 6 dB, early group), 30 moderate POAG eyes (global MD between 6 and 12 dB, moderate group), and 53 advanced POAG eyes (global MD > 12 dB, advanced group) underwent visual field (VF) examination with Octopus perimeter (dynamic strategy/G2 pattern) and peripapillary retinal nerve fiber layer thickness measurements with RTVue-100 FD-OCT. Spearman analysis was used to investigate the correlation between cluster MDs provided by Octopus perimeter and corresponding sector pRNFLT for the total sample and each subgroup, respectively. Then, linear (y = a+ bx) and curvilinear (quadratic, y = a+bx + cx2) regression analyses were employed to investigate the model for the cluster MD-sector pRNFLT pair with significant correlation. The strength of the relationship was characterized with correlation coefficient (ρ) and coefficient of determination (R2). For the cluster–sector pair that could be fitted by both models, Wilcoxon signed rank test of absolute residuals was used to compare the goodness of fit. Results Correlation between cluster MDs and corresponding sector pRNFLT was significant for all clusters in the total sample (ρ values: −0.572 to 0.832, P < 0.001) and in the POAG group (ρ values: −0.551 to −0.777, P < 0.001). The highest ρ values were found for cluster-sector pair 9 and pair 3, respectively. The curvilinear (quadratic) model provided better fit for all 10 cluster-sector pairs in the total sample (R2 values: 0.431–0.687, P < 0.001) and in the POAG group (R2 values: 0.364–0.594, P < 0.01). The highest R2 values were found also for cluster–sector pair 9 and pair 3, respectively. In the control group, no significant correlation was found for any cluster–sector pair (P > 0.01). In the early group, correlation was significant for cluster–sector pairs 3, 8, and 9 (ρ values: −0.449, −0.627, and −0.815, resp., P < 0.01). In the moderate group, correlation was significant for pairs 2, 3, 8, and 9 (ρ values: −0.703, −0.556, −0.680, and −0.637, resp., P < 0.01). In the advanced group, correlation was significant (P < 0.01) for all 10 pairs (ρ values: −0.395 to −0.699, P < 0.001) except for pairs 2, 3, and 8, and the highest ρ value was found for pair 1. For all cluster–sector pairs with significant correlation in the early, moderate, and advanced groups, only linear model could be fitted (P < 0.01), except for pair 9 in the early group and pair 5 in the advanced group. Conclusions Cluster MD of the Octopus visual field showed significant moderate-to-strong negative correlation and curvilinear (quadratic) relationship with the corresponding sector pRNFLT for POAG. This type of regional structure–function relationship varied according to the severity of POAG, and at each stage, the significantly correlated cluster–sector pairs mainly showed linear relationship. The results could provide guidance for better utilization of this regional structure–function method in the management of different stages of POAG.