Primary Open-angle Glaucoma Eyes Research Articles

Is Primary Open-Angle Glaucoma a Vascular Disease? Assessment of the Relationship between Retinal Arteriolar Morphology and Glaucoma Severity Using Adaptive Optics.

Retinal vascular abnormalities may be associated with glaucomatous damage. Adaptive optics (AO) is a new technology that enables the analysis of retinal vasculature at the cellular level in vivo. The purpose of this study was to evaluate retinal arteriolar parameters using the rtx1 adaptive optics fundus camera (AO-FC) in patients with primary open-angle glaucoma (POAG) at different stages and to investigate the relationship between these parameters and changes in spectral-domain optical coherence tomography (SD-OCT) and perimetry. Parameters of the retinal supratemporal and infratemporal arterioles (wall thickness (WT), lumen diameter (LD), total diameter (TD), wall-to-lumen ratio (WLR), and cross-sectional area of the vascular wall (WCSA)) were analysed with the rtx1 in 111 POAG eyes, which were divided into three groups according to the severity of the disease, and 70 healthy eyes. The associations between RTX1 values and the cup-to-disk ratio, SD-OCT parameters, and visual field parameters were assessed. Compared with the control group, the POAG groups showed significantly smaller TD and LD values (p < 0.05) and significantly higher WLR and WT values (p < 0.05) for the supratemporal and infratemporal arterioles. TD was significantly positively correlated with the retinal nerve fibre layer (RNFL) and ganglion cell complex (GCC) (p < 0.05). LD was significantly positively correlated with the RNFL, GCC, and rim area (p < 0.05). The WLR was significantly negatively correlated with the RNFL, GCC, rim area, and MD (p < 0.05), while it was significantly positively correlated with the cup-to-disc ratio and PSD (p < 0.05). The results suggest that vascular dysfunction is present in POAG, even at a very early stage of glaucoma, and increases with the severity of the disease.

Changes in Optic Nerve Head Blood Flow During Horizontal Ocular Duction.

In this study, we aimed to compare blood flow changes in the optic nerve head (ONH) during horizontal ocular duction among normal, primary open-angle glaucoma (POAG), and normal-tension glaucoma (NTG) eyes. In this cross-sectional study, we included 90 eyes from 90 participants (30 control eyes, 30 POAG eyes, and 30 NTG eyes). ONH blood flow was measured with laser speckle flowgraphy using an external fixation light to induce central gaze, abduction, and adduction at 30 degrees for each eye. The mean blur rate (MBR) of the entire ONH area (MA), vascular region (MV), and tissue region (MT), and the change ratio were analyzed. The change ratio was defined as abduction or adduction value/central gaze value. In the control group, MA significantly decreased during adduction (22.9 ± 3.7) compared with that during central gaze (23.6 ± 3.9, P < 0.05). In the POAG group, MA (adduction = 17.4 ± 3.8 and abduction = 17.3 ± 3.6) and MV (adduction = 37.9 ± 5.6 and abduction = 38.0 ± 5.6) significantly decreased during adduction and abduction compared with those during central gaze (18.0 ± 4.1 and 39.5 ± 6.3, respectively, P < 0.05). In the NTG group, MA significantly decreased during adduction (17.4 ± 4.2) compared with that during central gaze (18.1 ± 4.6) and abduction (18.1 ± 4.8, P < 0.05). The change ratio did not differ between the glaucoma and control groups. ONH blood flow decreased during horizontal ocular duction regardless of normal or glaucoma states; however, the change ratio was comparable between the normal and glaucoma groups.

The anterior scleral thickness in primary open-angle glaucoma with high myopia.

This study aimed to investigate and compare the anterior scleral thickness (AST) among high myopia (HM), primary open-angle glaucoma (POAG), and POAG with HM (HMPOAG) groups. Thirty-two HM eyes, 30 POAG eyes, and 31 HMPOAG eyes were included. The Schlemm's canal (SC) area, trabecular meshwork (TM) thickness, scleral spur (SS) length, and AST were measured using swept-source optical coherence tomography. AST was measured at 0 mm (AST0), 1 mm (AST1), 2 mm (AST2), and 3 mm (AST3) from SS. The HMPOAG group had significantly thinner AST, SS length, and TM thickness than the HM and POAG groups (all p < 0.05). In addition, the SC area of the HMPOAG group was also significantly smaller than that of the HM group (p < 0.001). The HMPOAG group had the thinnest AST, shortest SS, thinnest TM, and smallest SC. The thinnest AST might contribute to the shortest SS, and further to the thinnest TM and smallest SC in the HMPOAG group. AST might be a novel clinical indicator in the prediction and evaluation of POAG.

Early impairment of magnocellular visual pathways mediated by isolated-check visual evoked potentials in primary open-angle glaucoma: a cross-sectional study

ObjectiveTo explore different performances in the magnocellular (MC) and parvocellular (PC) visual pathways in patients with primary open-angle glaucoma (POAG) and to objectively assess impairment in early stage of POAG.Methods...

Assessing the Efficacy of the PAUL Glaucoma Implant in Pseudoexfoliative Glaucoma.

The aim of the study was to evaluate the outcomes and complications associated with PAUL glaucoma implant (PGI) surgery in pseudoexfoliation glaucoma (PXG) patients, comparing them with a primary open-angle glaucoma (POAG) control group. A retrospective analysis included 39 PXG and 29 POAG eyes undergoing PGI surgery between January 2020 and December 2022. Surgical success was defined as intraocular pressure (IOP) between ≤21 and ≥6 mmHg at 12 months and no loss of light perception. Demographic data, ocular examinations, and complications were recorded. PXG patients (68.5±9.9 years) differed significantly in age from POAG patients (54.1±10.6 years) (p<0.05). Surgical success rates at 12 months were 97.4% (PXG) and 86.2% (POAG). No significant inter-group differences in gender, laterality, lens status, vertical cup/disc ratio, or pre-operative best-corrected visual acuity were observed. Mean IOP comparisons showed significant differences within both groups (p<0.001). Ripcord suture removal occurred at mean 30.3±7.43 days (PXG) and 30.6±9.89 days (POAG). Median pre-operative AGM use was 4 (PXG) and 3 (POAG). No significant differences were noted postoperatively. To the best of our knowledge, this is the first study to evaluate the results of PGI in PXG and POAG, demonstrating a remarkable success rate and limited complications. Encouragingly, PXG patients with a history of unsuccessful filtration surgery demonstrated positive outcomes. The findings affirm PGI as a promising surgical intervention for PXG and POAG, exhibiting high success rates and manageable complications.

Optical Coherence Tomography Angiography Vessel Density in Healthy, Glaucoma Suspect, and Glaucoma Eyes

Abstract Purpose: To evaluate and compare optical coherence tomography angiography (OCTA) retinal vasculature measurements in healthy, glaucoma suspect (GS), and glaucoma patients. Methods: One hundred fourteen eyes with good quality OCTA pictures were included from 38 healthy, 38 GS, 38 and primary open-angle glaucoma (POAG) participants. The information on retinal vasculature was summarized as a vessel density map and as vessel density (%), which is the fraction of the flowing vessel area over the total area examined. The superior, inferior, nasal, and temporal quadrants, as well as whole vessel density (wVD) and peripapillary vessel density (ppVD) data taken from the retinal nerve fiber layer, were studied. Global indices of the visual field were correlated with vessel density measurement. Results: Mean vessel density was significantly lower in POAG eyes compared with GSs and healthy eyes (wVD) 45.34% ± 6.64%, 50.06% ± 1.97% and 53.06% ± 2.12%, respectively (P &lt; 0.001), and ppVD 47.42% ± 7.73%, 47.42% ± 7.73% and 56.074% ± 2.71%, respectively (P &lt; 0.001). A linear relationship between vessel density (wVD and ppVD) and global indices of the visual field (mean deviation [MD] and pattern standard deviation [PSD]) shows a significant (P &lt; 0.001) relation. R 2 is 0.35, 0.36, 0.36, and 0.33 for MD and wVD, PSD and wVD, PSD and ppVD, and MD and ppVD, respectively. Conclusions: For distinguishing between healthy and glaucoma eyes, OCTA vessel density demonstrated near similar diagnostic accuracy to visual field tests. These findings imply that OCTA measurements reflect damage to tissues important in the pathogenesis of POAG.

Possibilities of Preservative-Free Therapy for Primary Open-Angle Glaucoma

Purpose: to evaluate the efficacy and safety of preservative free travoprost generic in primary open-angle glaucoma patients. Patients and methods. 40 patients with compensated primary open-angle glaucoma (POG) and dry eye (DE) were examined: 1st group (20 patients) with the initial stage of POG (travoprost with a preservative monotherapy), 2nd group with an advanced stage of POG (travoprost with a preservative in combination therapy). In all patients, travoprost with a preservative was replaced with preservative free travoprost (Traviolan, 1 time per day, in the evening). Control: 1 — when included in the study; 2 — 4 weeks after replacing travoprost with a preservative for preservative free travoprost. Efficiency criteria: absence of negative dynamics of intraocular pressure (IOP) and MD and PSD perimetric indices (dB; Optos). Safety criteria: absence of OSDI (scores), tear film brake up time (TBUT; Norn’s test, s), lower tear meniscus height (LTMH, µm; OptoVue) and Bijsterveld’s xerosis index (XI, scores) negative dynamics. Results. At the 2nd control point, all observed did not have a statistically significant dynamics of IOP, MD, PSD. In patients of both groups, at the 2nd control point, there was the OSDI and TBUT statistically significant positive dynamics, and in patients of the 1st group — XI statistically significant positive dynamics. The trend towards to XI decreasing in 2nd group patients and the LTMH dynamics in both groups turned out to be statistically insignificant. Conclusion. Preservative free travoprost has shown efficacy comparable to that of travoprost with preservative in both monotherapy and combination therapy. Significant positive dynamics of OSDI and TBUT in patients of both groups and XI in 1st group patients after switching to preservative free travoprost indicates a good “safety profile” of therapy in terms of its effect on the ocular surface state in DE conditions, which, from our point of view, may contribute to maintaining the “quality of life” and patients compliance.

Comparison of Patterns of Structural Progression in Primary Open Angle Glaucoma and Pseudoexfoliation Glaucoma.

Primary open angle glaucoma and pseudoexfoliation glaucoma showed different progression patterns of the retinal nerve fiber layer and ganglion cell-inner plexiform layer thinning in OCT-guided progression analysis. To compare the patterns of progression of retinal nerve fiber layer (RNFL) and macular ganglion cell-inner plexiform layer (GCIPL) thinning by guided progression analysis (GPA) of optical coherence tomography (OCT) in primary open angle glaucoma (POAG) and pseudoexfoliation glaucoma (PXG). The progression of RNFL and GCIPL thinning was assessed by the GPA of Cirrus HD-OCT (Carl Zeiss Meditec, Dublin, CA). By overlaying the acquired images of the RNFL and GCIPL thickness-change maps, the topographic patterns of progressive RNFL and GCIPL thinning were evaluated. The rates of progression of RNFL and GCIPL thinning were analyzed and compared between patients with POAG and those with PXG. Of the 248 eyes of 248 patients with POAG (175 eyes of 175 patients) or PXG (73 eyes of 73 patients) enrolled, 156 POAG eyes and 48 PXG eyes were included. Progressive RNFL thinning was significantly more common in PXG than in POAG ( P =0.005). According to the RNFL progression-frequency maps, progression appeared mainly in the superotemporal and inferotemporal areas in POAG, whereas it had invaded more into the temporal area in PXG. According to the GCIPL maps, progression was most common in the inferotemporal area in both POAG and PXG. The average progression rate of GCIPL thinning was faster in PXG than in POAG ( P =0.013), and when analyzed in 2 halves (superior/inferior), the progression rate of the inferior half was faster in PXG than in POAG ( P =0.011). OCT GPA showed progression patterns of RNFL and GCIPL thinning in POAG and PXG. Understanding the specific patterns of progressive RNFL and GCIPL thinning according to glaucoma type may prove helpful to glaucoma-patient treatment and monitoring.

Macula vessel density and its relationship with the central visual field mean sensitivity across different stages of exfoliation glaucoma

ABSTRACT Clinical relevance Alterations in ocular microvasculature may contribute to pathogenesis of exfoliation glaucoma (XFG) and may improve monitoring this aggressive type of open angle glaucoma. Background This work aims to compare the macula vessel density and the relationship between macula vessel density and central visual field mean sensitivity between eyes with XFG and eyes with primary open-angle glaucoma (POAG) of different stages. Methods In this cross-sectional observational study, the macula vessel density values were compared among 52 POAG cases (26 early stage, 26 moderate to advanced stage) and 53 XFG cases (27 early stage, 26 moderate to advanced stage). The vessel density values were evaluated with optical coherence tomography angiography. Vasculature–function and structure–function relationships were analysed by comparing macula vessel density, inner macula thickness and visual field mean sensitivity in early and moderate to advanced stages of XFG and POAG eyes separately. Results The early stage XFG eyes had a significantly lower global macula vessel density compared with early stage POAG eyes (42.81 ± 3.85% and 46.56 ± 3.90%, respectively; p = 0.02). However, the tendency of XFG eyes for a lower vessel density compared with the POAG eyes did not exhibit any significance in moderate to advanced stages of glaucoma (37.39 ± 5.65% and 38.35 ± 4.67%, respectively; p = 0.9). The macula vessel density (%)–visual field mean sensitivity (1/Lambert) correlation was statistically significant in early stage XFG eyes (r = 0.464 p = 0.01), while no such correlation was notable for the early stage POAG eyes (r = –0.029 p = 0.89). Conclusion The macula vessel density appears to be more severely affected in early stage XFG than POAG of similar severity, suggesting a relatively greater value of vascular insufficiency in XFG. The significant vasculature-function association in early stage XFG, which was absent in early stage POAG, may infer the importance of macula vessel density in monitoring functional loss in early stages of XFG.

Role of Glucocorticoids and Glucocorticoid Receptors in Glaucoma Pathogenesis.

The glucocorticoid receptor (GR), including both alternative spliced isoforms (GRα and GRβ), has been implicated in the development of primary open-angle glaucoma (POAG) and iatrogenic glucocorticoid-induced glaucoma (GIG). POAG is the most common form of glaucoma, which is the leading cause of irreversible vision loss and blindness in the world. Glucocorticoids (GCs) are commonly used therapeutically for ocular and numerous other diseases/conditions. One serious side effect of prolonged GC therapy is the development of iatrogenic secondary ocular hypertension (OHT) and OAG (i.e., GC-induced glaucoma (GIG)) that clinically and pathologically mimics POAG. GC-induced OHT is caused by pathogenic damage to the trabecular meshwork (TM), a tissue involved in regulating aqueous humor outflow and intraocular pressure. TM cells derived from POAG eyes (GTM cells) have a lower expression of GRβ, a dominant negative regulator of GC activity, compared to TM cells from age-matched control eyes. Therefore, GTM cells have a greater pathogenic response to GCs. Almost all POAG patients develop GC-OHT when treated with GCs, in contrast to a GC responder rate of 40% in the normal population. An increased expression of GRβ can block GC-induced pathogenic changes in TM cells and reverse GC-OHT in mice. The endogenous expression of GRβ in the TM may relate to differences in the development of GC-OHT in the normal population. A number of studies have suggested increased levels of endogenous cortisol in POAG patients as well as differences in cortisol metabolism, suggesting that GCs may be involved in the development of POAG. Additional studies are warranted to better understand the molecular mechanisms involved in POAG and GIG in order to develop new disease-modifying therapies to better treat these two sight threatening forms of glaucoma. The purpose of this timely review is to highlight the pathological and clinical features of GC-OHT and GIG, mechanisms responsible for GC responsiveness, potential therapeutic options, as well as to compare the similar features of GIG with POAG.

Comparison of the Choroid in Primary Open-angle and Angle-Closure Glaucoma Using Optical Coherence Tomography.

The current study highlights distinct choroidal alterations in primary open-angle and angle-closure glaucoma, underscoring the potential of choroidal vascularity index as a valuable indicator for understanding glaucoma pathogenesis. To evaluate choroidal structural changes in patients with primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG) and healthy controls utilizing the choroidal vascularity index (CVI) and subfoveal choroidal thickness (SFCT) by enhanced depth imaging optical coherence tomography (EDI-OCT). This study was cross-sectional. A total of 171 eyes of 171 subjects, comprising 69 eyes with untreated POAG, 58 eyes with untreated PACG and 44 healthy eyes, were enrolled in this study. SFCT, luminal area (LA), stromal area (SA) and total choroidal area (TCA) were measured on EDI-OCT scans. The CVI parameter is calculated as the proportion of LA to TCA. This study included 69 POAG patients with a mean age of 51.4±13.3 years, 58 PACG patients with a mean age of 57.0±7.3 years, and 44 healthy subjects with a mean age of 51.11±10.7 years. The CVI in the POAG and PACG groups was significantly lower than that in the control group (P = 0.001 and P = 0.005, respectively), however not significantly different between the two glaucoma groups (P = 1.000). POAG eyes had significantly lower LA than PACG and controls (P = 0.014 and P = 0.049, respectively), while PACG eyes had significantly greater SA than controls (P = 0.041). The CVI of POAG and PACG eyes was significantly lower than that of normal eyes. A reduced LA was observed mainly in eyes with POAG, and an increased SA was observed mainly in eyes with PACG. The role of the choroid may differ between POAG and PACG eyes.

Comparison of Goldmann and ORA tonometers in newly diagnosed, untreated, POAG and OHT eyes

Background and objectiveThe corneal biomechanical properties in naïve, untreated glaucoma and ocular hypertension (OHT) eyes is interesting, because it may be a source of error in intraocular pressure (IOP) measurements by Goldmann applanation tonometer (GAT) and Ocular Response Analyzer (ORA)The main objective of this study was to evaluate the IOP values obtained using GAT and the ORA, in primary open angle glaucoma (POAG) and in OHT untreated eyes. Material and MethodsObservational, masked, cross sectional observational study. Newly diagnosed, untreated POAG and OHT eyes were included. Results51 POAG and 34 OHT eyes were analyzed. We found that IOPcc (IOP corneal-compensated) was significantly higher than GAT IOP in POAG (p = 0.0002) while we did not find any significant difference between both tonometers in OHT (p = 0.1). ConclusionsGAT seems to underestimate the real IOP in untreated POAG eyes and it seems to be quite accurate in OHT eyes.

Estudio comparativo entre tonómetros Goldmann y ORA en pacientes recién diagnosticados de GPAA o HTO, sin tratamiento

Background and objectiveThe corneal biomechanical properties in naïve, untreated glaucoma and ocular hypertension (OHT) eyes is interesting, because it may be a source of error in intraocular pressure (IOP) measurements by Goldmann applanation tonometer (GAT) and ocular response analyzer (ORA).The main objective of this study was to evaluate the IOP values obtained using GAT and the ORA, in primary open angle glaucoma (POAG) and in OHT untreated eyes. Material and methodsObservational, masked, cross sectional observational study. Newly diagnosed, untreated POAG and OHT eyes were included. ResultsFifty-one POAG and 34 OHT eyes were analyzed. We found that IOPcc (IOP corneal-compensated) was significantly higher than GAT IOP in POAG (P=.0002) while we did not find any significant difference between both tonometers in OHT (P=.1). ConclusionsGAT seems to underestimate the real IOP in untreated POAG eyes and it seems to be quite accurate in OHT eyes.

Association Between Optic Disc Perfusion Determined by Swept-Source Optical Coherence Tomography Angiography and Visual Field Progression in Glaucoma.

Reduced optic disc vessel density determined by swept-source optical coherence tomography angiography (SS-OCTA) was associated with visual field (VF) deterioration in glaucomatous eyes, which suggested that this parameter can be a potential biomarker that correlates well with functional deterioration. The purpose of this study was to identify the association between optic disc perfusion evaluated by SS-OCTA and VF progression in primary open angle glaucoma (POAG) eyes. A total of 266 POAG eyes of 266 patients (5.4y of mean follow-up) were included. Optic nerve head SS-OCTA was performed to evaluate the optic disc vessel density (dVD), parapapillary choroidal vessel density (pcVD), choroidal microvascular dropout (cMvD), and optic disc microvascular dropout (dMvD). VF progression was defined using Early Manifest Glaucoma Trial criteria. Factors associated with VF worsening were assessed by Cox proportional hazard analysis. Eighty (30.1%) out of the 266 POAG eyes showed VF progression. The progression group showed a significantly higher proportion of disc hemorrhage, cMvD, and dMvD but lower dVD and pcVD than the stable group (all P <0.05). Considering the strong association between the parameters [dMvD vs. dVD ( r = -0.757, P =0.010], cMvD vs. pcVD ( r = -0.745, P =0.012), dMvD vs. cMvD ( r = 0.802, P <0.001], dVD vs. pcVD ( r = 0.862, P <0.001), CMvD vs. dVD ( r = -0.698, P =0.031), and dMvD vs. pcVD ( r = -0.688, P =0.034)], 6 models with different combinations of covariates compensating for multicollinearity were developed. Younger age, presence of disc hemorrhage, and lower dVD were consistently associated with progression in all models that included these parameters. Optic disc perfusion, represented as dVD, may be a useful biomarker that correlates well with functional deterioration in POAG eyes.

Multimodal Deep Learning Classifier for Primary Open-angle Glaucoma Diagnosis Using Wide-field Optic Nerve Head Cube Scans in Eyes With and Without High Myopia.

An OCT-based multimodal deep learning classification model including texture information is introduced that outperforms single-modal models and multimodal models without texture information for glaucoma diagnosis in eyes with and without high myopia. To evaluate the diagnostic accuracy of a multimodal deep learning (DL) classifier using wide optical coherence tomography (OCT) optic nerve head cube scans in eyes with and without axial high myopia. 371 primary open-angle glaucoma (POAG) eyes and 86 healthy eyes, all without axial high myopia (axial length AL≤26mm) and 92 POAG eyes and 44 healthy eyes, all with axial high myopia (AL>26mm) were included. The multimodal DL classifier combined features of 3 individual VGG-16 models: 1) texture-based en face image, 2) retinal nerve fiber layer (RNFL) thickness map image and 3) confocal scanning laser ophthalmoscope (cSLO) image. Age, AL, and disc area adjusted area under the receiver operating curves (AUROC) were used to compare model accuracy. Adjusted AUROC for the multimodal DL model was 0.91 (95% CI = 0.87, 0.95). This value was significantly higher than the values of individual models (0.83 [0.79, 0.86] for texture based en face image; 0.84 [0.81, 0.87] for RNFL thickness map; and 0.68 [0.61, 0.74] for cSLO image; all P≤0.05). Using only highly myopic eyes, the multimodal DL model showed significantly higher diagnostic accuracy (0.89 [0.86 , 0.92]) compared to texture en face image (0.83 [0.78 , 0.85]), RNFL (0.85 [0.81 , 0.86]) and cSLO image models (0.69 [0.63 , 0.76]) (all P≤0.05). Combining OCT-based RNFL thickness maps with texture based en face images showed better ability to discriminate between healthy and POAG than thickness maps alone, particularly in high axial myopic eyes.

Evaluation of microvascular changes in the retina and choriocapillaris in primary glaucoma and neuromyelitis optica spectrum disorder with optical coherence tomography angiography

BackgroundTo assess quantitatively the microvascular changes in the retina and choroid of healthy eyes, eyes of subjects with primary angle-closure glaucoma (PACG), primary open-angle glaucoma (POAG) and neuromyelitis optica spectrum disorder (NMOSD) using optical coherence tomography angiography (OCTA). MethodsA series of healthy individuals and subjects with PACG, POAG and NMOSD were recruited in this cross-sectional study. OCTA was performed to capture the optic nerve head and macula images and the vessel density (VD) and retinal nerve fiber layer (RNFL) thickness were quantified. The choriocapillary flow density (CFD) was calculated as the percentage of flow area to the whole selected area. ResultsA total of 68 PACG subjects, 25 POAG subjects, 51 NMOSD subjects and 37 healthy controls were enrolled. Significant decreases in peripapillary VD and RNFL thickness were observed in PACG (p < 0.001) and POAG (p < 0.001) eyes and also in NMOSD subjects with an optic neuritis history (p < 0.001) compared with healthy controls. Unaffected eyes in PACG and POAG subjects had lower baseline peripapillary VD than healthy controls (p = 0.002 and p = 0.011, respectively). PACG eyes showed a lower baseline CFD than POAG (p = 0.0027) and the CFD in early and advanced PACG eyes showed a significantly much more decrease than POAG (p = 0.002 and p < 0.001, respectively). ConclusionsThe peripapillary vessel density and RNFL thickness was reduced in glaucomatous and NMOSD eyes compared with healthy controls. PACG eyes showed a lower CFD than POAG and the distinct peripapillary and choriocapillaris microvasculature changes may be correlated to different PACG and POAG pathogenesis.

Discrepancy between peripapillary retinal and choroidal microvasculature and the rate of localized retinal nerve fiber layer thinning in glaucoma

This observational case series study is conducted to compare the extent of microvasculature impairment in the peripapillary retina and choroid in eyes with primary open-angle glaucoma (POAG), and to investigate the association of the discrepancy between the microvasculature impairments of each layer with the rate of progressive retinal nerve fiber layer (RNFL) thinning. A total of 88 POAG eyes with a localized RNFL defect were enrolled, including 67 eyes with and 21 eyes without choroidal microvasculature dropout (CMvD). Circumferential widths of retinal microvascular impairment (RMvI) and CMvD were measured, and eyes were classified based on the relative width of CMvD to RMvI (CMvD/RMvI ratio). The rate of RNFL thinning was determined by linear regression based on ≥ 5 serial OCT examinations. Thinner global RNFL and worse visual field mean deviation at baseline were associated with a larger circumferential width of the RMvI, whereas the presence of cold extremities, lower mean arterial pressure and thinner juxtapapillary choroid were associated with a larger circumferential width of the CMvD. The rate of global RNFL thinning was faster in eyes with larger relative CMvD width than in eyes with equal CMvD and RMvI widths and in eyes without CMvD (P = 0.001). Lower mean arterial pressure (P = 0.041), larger CMvD width (P = 0.046), larger CMvD/RMvI ratio (P = 0.041), and detection of disc hemorrhage during the follow-up (P = 0.013) were significant factors associated with faster global RNFL thinning. Larger CMvD width relative to RMvI width may be indicative of an increased risk of faster RNFL thinning in POAG with localized RNFL defect. Comparing the microvasculature impairment in individual layers may help predict more rapid glaucoma progression.

Change of Choroidal Microvasculature Dropout After Trabeculectomy as Assessed by Optical Coherence Tomography Angiography.

Reduction in the angular circumference of choroidal microvascular dropout (CMvD AC) was found in POAG patients after trabeculectomy. Greater percentage of IOP reduction was significantly associated with decreased CMvD AC. The purpose of this study was to investigate the change of choroidal microvasculature dropout (CMvD) after trabeculectomy and its associated factors in primary open angle glaucoma (POAG) eyes using optical coherence tomography angiography. Fifty eyes of 50 POAG participants who had preoperative CMvD and underwent trabeculectomy were prospectively enrolled. Angular circumference (AC) of CMvD was determined from choroidal layer images by optical coherence tomography angiography preoperatively and at postoperative 1 year. The cutoff for significant AC of CMvD decrease was determined by the Bland-Altman method, and accordingly, patients were divided into 2, decreased and stable/increased CMvD AC groups. Changes in intraocular pressure (IOP) and CMvD AC were compared between the groups preoperatively and at postoperative 1 year. Factors associated with CMvD AC decrease were assessed by linear regression analysis. The cutoff for significant CMvD AC decrease was 3.58 degrees; accordingly, 26 eyes (52.0%) were categorized as decreased CMvD AC group. No significant intergroup differences in baseline characteristics were found. However, the decreased CMvD AC group presented significantly lower IOP (10.7±3.7 vs. 12.9±2.6mmHg, P =0.022), lower CMvD AC (32.03±33.95% vs. 53.44±39.33%, P =0.044), and higher parapapillary choroidal vessel density ( P =0.014) compared with the increased/stable CMvD AC group at postoperative 1 year. The greater percentage of IOP reduction was significantly associated with decreased CMvD AC ( P =0.046). CMvD AC reduction associated with IOP lowering was found after trabeculectomy. The long-term clinical relevance of postoperative CMvD reduction should be further investigated.

VEGF levels in the aqueous humor of patients with primary open angle glaucoma: A systematic review and a meta-analysis.

To compare the VEGF levels in the aqueous humor of patients with Primary Open Angle Glaucoma (POAG) and non-glaucomatous eyes and reveal any potential statistically significant correlations. We searched PubMed, from inception to December 31, 2021. Key search terms included VEGF and Glaucoma. All relevant studies that evaluated the VEGF levels in patients with POAG and in the control group were included in this systematic review. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis of Diagnostic Test Accuracy Studies (PRISMA-DTA) guidelines were followed. Data were extracted independently by 2 authors. Heterogeneity was statistically quantified by Q, H, and I2 statistics, and a meta-analysis was performed using the random-effects model. Seven cross-sectional studies were included in the meta-analysis. 144 eyes were enrolled in the POAG group and 162 eyes in the control group. The random effect model showed no statistically significant difference between the two groups (SMD =0.284, 95% CI = -0.173 to 0.741; P = 0.223), but we noticed a trend towards elevated VEGF levels in the aqueous humor of POAG patients. Significant heterogeneity was detected (I2 = 74.1%, P = 0.001). This systematic review and meta-analysis indicates a trend towards elevated VEGF-A levels in the aqueous humor of patients with POAG and suggests a potential neuroprotective role of VEGF in patients with POAG. Future studies are required to evaluate the exact role of VEGF in POAG.

Progressive Macular Vessel Density Loss Observed on Optical Coherence Tomography Angiography in Glaucoma Patients With Single-Hemifield Visual Field Defects.

Faster hemispheric mVD loss was found in the affected hemifield of POAG patients without significant changes in hemispheric thickness. The progression of mVD loss was associated with the severity of VF damage. To evaluate the changes in macular vessel density (mVD) loss in primary open angle glaucoma (POAG) patients with visual field (VF) defects confined to 1 hemifield. This longitudinal cohort study used linear mixed models to evaluate the changes in the hemispheric mean total deviation (mTD), mVD, macular ganglion cell complex, macular ganglion cell-inner plexiform layer, and retinal nerve fiber layer between affected hemifields, unaffected hemifields, and healthy controls. Twenty-nine POAG eyes and 25 healthy eyes were followed for an average of 29 months. In POAG eyes, the rates of decline in hemispheric mTD and hemispheric mVD in the affected hemifields were significantly faster than those in the unaffected hemifields (-0.42±1.24 vs. 0.02±0.69dB/year, P =0.018 and -2.16±1.01 vs. -1.77±0.90% / year, P =0.031, respectively). There were no differences in the rate of hemispheric thickness change between the 2 hemifields. The rate of hemispheric mVD decline in both hemifields of POAG eyes was significantly faster than that of the healthy controls (All P <0.05). An association between the reduced mTD of the VF and the rate of hemispheric mVD loss in the affected hemifield was observed (r=0.484, P =0.008). Faster rates of mVD loss (β=-1.72±0.80, P =0.050) were significantly related to reduced hemispheric mTD in the multivariate analysis. Faster hemispheric mVD loss was found in the affected hemifield of POAG patients without significant changes in hemispheric thickness. The progression of mVD loss was associated with the severity of VF damage.