Retinal Ganglion Cell Layer Change in Patients Treated With Anti-Vascular Endothelial Growth Factor for Neovascular Age-related Macular Degeneration

Impact of Intra-Retinal Fluids on Changes in Retinal Ganglion Cell and Nerve Fiber Layers in Neovascular AMD under Anti-VEGF Therapy

Purpose: To investigate the influence of intraretinal fluid (IRF) on change in retinal nerve fiber layer (RNFL) and retinal ganglion cell layer (RGCL) and thickness in patients with naive neovascular AMD under anti-VEGF treatment. Design: post hoc analysis. Methods: 97 eyes of 83 patients on continuous therapy with intravitreal anti-vascular endothelial growth factors (anti-VEGF) and a follow-up of 24 months were included. RGCL and RNFL thickness in the perifoveal (-O), parafoveal (PF), and nasal areas and number of injections (IVI) were recorded before the first IVI as well as 1 and 2 years after initiating treatment and compared longitudinally and between groups with and without IRF. Results: The group with IRF at baseline had a higher RNFL thickness at baseline and showed a significant reduction in RNFL-PF between baseline and first and second follow-ups (p < 0.001) but not between first and second follow-ups. The group without IRF showed no significant reduction in RNFL over time. The presence of IRF was not associated with a reduction in RNFL-O or RNFL-nasal. RGCL thickness decreased significantly in both groups with and without IRF after 2 years. Number of IVIs showed no significant correlation to RNFL or RGCL after stratification for the presence of IRF. Conclusions: The presence of IRF has a significant influence on RNFL thickness at baseline as well as on its changes over time during anti-VEGF therapy. The preoperative presence of IRF should be considered when comparing changes in RNFL thickness after IVI.

Ganglion cell complex changes in wet AMD patients treated with anti-VEGF intravitreal injections according to a treat-and-extend protocol

OBJECTIVE

To analyze changes in ganglion cell complex (GCC) thickness in wet age-related macular degeneration (AMD) patients receiving intravitreal injections.

DESIGN

Retrospective cohort study involving 46 eyes at a single tertiary ophthalmology practice.

PARTICIPANTS

The injection group consisted of wet AMD patients who received intravitreal injections for at least 3 years following a treat-and-extend protocol. Twenty-two patients received ranibizumab, and 1 patient received aflibercept. The control group consisted of dry AMD patients who were observed only and did not receive medical treatment over the same period. GCC thickness and visual acuity were recorded at baseline and at 1-, 2-, and 3-year follow-up visits.

RESULTS

In the injection group, there was a nonsignificant trend toward reduction in GCC thickness over 3 years (-4.09 ± 8.47 µm; p = 0.09). Within the injection group, correlation analysis between the number of intravitreal injections and GCC thickness was nonsignificant but trended toward a direct relationship, with more injections correlated with a relatively thicker GCC at 3 years. There was no significant change in GCC thickness between baseline and year 3 for the control group.

CONCLUSIONS

Study results suggest that that there is no significant GCC thinning in wet AMD patients following a treat-and-extend regimen over 3 years.

A prospective observation of influence of anti-VEGF on optic disc vasculature in nAMD patients

BACKGROUND

This study aims to investigate the short-term changes in relatively normal retinal vessels following anti-vascular endothelial growth factor (anti-VEGF) therapy in nAMD patients, an area that currently represents a research gap.

METHODS

In this prospective study, we enrolled patients newly diagnosed with neovascular age-related macular degeneration (nAMD) and received standardized monthly anti-VEGF therapy for three months. Follow-ups were conducted at baseline and 1-week, 1-month, 2-months and 3-months post first injection. Assessment indicators included radial peripapillary capillary vascular density (RPC-VD) and retinal nerve fiber layer (RNFL) thickness in different optic disk regions using optical coherence tomography angiography, as well as intraocular pressure (IOP).

RESULTS

68 nAMD patients (68 eyes) were included in this study. Significant reductions of RPC-VD and increases of RNFL thickness primarily in the nasal regions were observed 1-week post anti-VEGF (adjusted P < 0.05). Significant negative correlations were found between 1-week changes in RPC-VD and RNFL thickness in the nasal sectors (P < 0.05). From 1 to 3 months post-injection, RPC-VD and RNFL thickness essentially returned to baseline levels. Throughout the follow-up periods, IOP remained stable (P > 0.05).

CONCLUSION

Anti-VEGF treatments transiently influence the relatively normal retinal vessels, which might lead to nerve fiber edema, predominantly on the nasal side of the optic disk.

Effect of Repeated Intravitreal Injections in Glaucoma Spectrum Diseases

Purpose

To evaluate whether repeated intravitreal injections (IVI) with an anti-vascular endothelial growth factor (anti-VEGF) agent are associated with glaucomatous progression in eyes with glaucoma spectrum diseases (GSD).

Methods

Single-center, retrospective, longitudinal study of patients with bilateral and similar GSD who: (1) received ≥8 IVI in only one eye during the study period; (2) had ≥2 retinal nerve fiber layer thickness (RNFL) measurements obtained by spectral-domain optical coherence tomography (SD-OCT) at least 12 months apart. The primary outcome was the absolute RNFL thickness change, comparing injected and fellow uninjected eyes. Linear mixed effects models were constructed, including a multivariable model.

Results

Sixty-eight eyes from 34 patients were included, 34 injected and 34 fellow uninjected eyes. Average baseline age was 67.68±21.77 years with a follow-up of 3.66±1.89 years and 25.12±14.49 IVI. RNFL thickness decreased significantly from 80.92±15.78 to 77.20±17.35 μm (p<0.001; -1.18±1.93 μm/year) in injected eyes and from 79.95±17.91 to 76.61±17.97 μm (p<0.001; -1.07±0.98 μm/year) in uninjected eyes. In a multivariable linear mixed model of injected eyes, only higher baseline RNFL thickness (p < 0.001) significantly predicted higher absolute RNFL thickness loss. Neither absolute RNFL thickness variation (p=0.716) nor RNFL rate (p=0.779) was significantly different between paired injected and uninjected eyes. Absolute IOP variation was not significantly different between groups (16.62±4.77 to 15.09±4.34 mmHg in injected eyes and 17.68±5.01 to 14.50±3.39 mmHg in fellow uninjected eyes; p=0.248). The proportion of eyes receiving glaucoma medical treatment increased significantly in both groups (55.9% to 76.5% in injected eyes; p=0.039; 58.8% to 76.5% in uninjected eyes; p = 0.031). The number of glaucoma medications also increased significantly in both groups (1.03±1.11 to 1.59±1.18 glaucoma medications in injected eyes; p=0.003; 1.09±1.11 to 1.56±1.19 glaucoma medications in uninjected eyes; p=0.003).

Conclusion

Repeated IVI do not seem to accelerate glaucomatous progression. Future studies with a longer follow-up are needed.

CRISPR/Cas9 mediated specific ablation of vegfa in retinal pigment epithelium efficiently regresses choroidal neovascularization

The CRISPR/Cas9 system easily edits target genes in various organisms and is used to treat human diseases. In most therapeutic CRISPR studies, ubiquitously expressed promoters, such as CMV, CAG, and EF1α, are used; however, gene editing is sometimes necessary only in specific cell types relevant to the disease. Therefore, we aimed to develop a retinal pigment epithelium (RPE)-specific CRISPR/Cas9 system. We developed a CRISPR/Cas9 system that operates only in retinal pigment epithelium (RPE) by expressing Cas9 under the RPE-specific vitelliform macular dystrophy 2 promoter (pVMD2). This RPE-specific CRISPR/pVMD2-Cas9 system was tested in human retinal organoid and mouse model. We confirmed that this system works specifically in the RPE of human retinal organoids and mouse retina. In addition, the RPE-specific Vegfa ablation using the novel CRISPR-pVMD2-Cas9 system caused regression of choroidal neovascularization (CNV) without unwanted knock-out in the neural retina in laser-induced CNV mice, which is a widely used animal model of neovascular age-related macular degeneration. RPE-specific Vegfa knock-out (KO) and ubiquitous Vegfa KO were comparable in the efficient regression of CNV. The promoter substituted, cell type-specific CRISPR/Cas9 systems can be used in specific 'target cell' therapy, which edits genes while reducing unwanted off- 'target cell' effects.

Analysis of ganglion cell-inner plexiform layer thickness in retinal vein occlusion with resolved macular edema

PURPOSE

To analyze the retinal ganglion cell-inner plexiform layer (GCIPL) changes in retinal vein occlusion (RVO) eyes with resolved macular edema using optical coherence tomography.

METHODS

We compared the average and minimum GCIPL thickness in RVO eyes with fellow eyes and healthy controls including 40 unilateral RVO patients and 48 healthy subjects. The average GCIPL thickness in BRVO eyes was segmented into the affected and opposite area according to the site of lesion, comparing them with corresponding areas in fellow eyes. Furthermore, maximum central macular thickness (CMT), visual acuity (VA), and intravitreal injection times were recorded to investigate their relationship with the GCIPL thickness.

RESULTS

Despite no significant difference in CMT (P = 0.96), the average (P = 0.02 and P < 0.001, respectively) and minimum (both P < 0.001) GCIPL thicknesses were decreased in RVO eyes with resolved macular edema after treatment in comparison to fellow eyes and healthy eyes. Maximum CMT thickness was negatively correlated with the minimum GCIPL thickness (r = - 0.47, P = 0.003). VA and average GCIPL thickness were associated (r_s = - 0.49, P = 0.002). In a subgroup analysis that only included BRVO patients, the opposite area revealed no significant difference between two eyes (P = 0.91) although the affected area in BRVO eyes was decreased (P < 0.001).

CONCLUSIONS

A decrease of GCIPL thickness in RVO was observed even after anatomic restoration and associated with VA prognosis. These GCIPL defects could be attributable to systemic risks and RVO itself, not anti-VEGF effects.

Influence of Multiple Anti-VEGF Injections on Retinal Nerve Fiber Layer and Ganglion Cell-Inner Plexiform Layer Thickness in Patients with Exudative Age-Related Macular Degeneration

Backgrounds and Objectives: To analyze the influence of multiple anti-VEGF intravitreal injections for exudative age-related macular degeneration on the thickness of peripapillary retinal nerve fiber layer (RNFL) and macular ganglion cell-inner plexiform layer (GC + IPL) using spectral domain optical coherence tomography (SD-OCT). Materials and Methods: A prospective interventional study of consecutive patients treated with intravitreal bevacizumab (IVB) was performed. Average and sectorial values of RNFL and GC + IPL thickness were recorded using Cirrus SD-OCT at 0, 6, 12, and 24 months. Patients suffering from any ocular disease that could affect RNFL or GC + IPL thickness were excluded. Results: A total of 135 patients (70 women and 65 men, aged 65 ± 15 years) were included. The average number of injections per patient was 12.4 ± 2.4. Average RNFL and GC + IPL thickness prior to the first injection (87.6 ± 12.2 and 47.2 ± 15.5 respectively), and after 24-month follow-up (86.2 ± 12.6 and 46.7 ± 11.9 respectively) did not differ significantly (p > 0.05). There was a significant decrease in GC2, GC5 segments, and minimum GC + IPL thickness. Conclusion: Repeated anti-VEGF treatment did not cause significant changes in the thickness of RNFL and GC + IPL layers over a period of 24 months. The detected decrease in GC2 and GC5 sectors, as well as in minimum GC + IPL thickness, could be a sign of ganglion cell damage induced by the treatment or could occur during the natural course of the disease.

Relationship between ganglion cell complex thickness and vision in age-related macular degeneration treated with aflibercept

PURPOSE

This study aimed to analyze the correlation between ganglion cell complex thickness (GCCT) and vision compared with the choroidal thickness (CT) and central retinal thickness (CRT) in relation to the outcomes of intravitreal aflibercept treatment for choroidal neovascular membranes secondary to age-related macular degeneration (AMD).

METHODS

This was a prospective, observational study. Forty-three eyes of 38 patients with wet AMD received a monthly loading dose of 2 mg aflibercept by intravitreal injection (IVI) during the first 3 months and were then followed at regular monthly intervals for an average of 10 months by a pro re nata regimen. All patients were examined using spectral domain-optic coherence tomography (OCT) and enhanced depth imaging OCT. According to their response to IVI treatment in the third month, patients were divided into 2 groups, both functionally and anatomically.

RESULTS

Three-month GCCT and optic disc retinal nerve fiber layer thickness (ODRNFLT) had the most correlation with the 10-month vision (p  =  0.002, p  =  0.02, respectively). While baseline GCCT was most correlated with the functional response, baseline CRT was most correlated with the anatomical response (p  =  0.01, p  =  0.004, respectively).

CONCLUSIONS

The results suggest that a reduction in 3-month GCCT indicates a good long-term vision outcome, while a reduction in 3-month ODRNFLT shows a poor long-term vision outcome. The literature suggests that this study is the first to demonstrate that baseline GCCT is more strongly correlated with the functional response than it is with CT and CRT. Hence, GCCT has a prognostic value for vision impairment.

Examination of Inner Retinal Layers in Unilateral Wet Age-Related Macular Degeneration Treated with Anti-VEGF, Compared to Fellow Untreated Eyes

The main aim of this study was to characterize the retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) thickness in the macular area eyes affected by wet age-related macular degeneration (wAMD) treated with anti-VEGF and compare the results with the control of fellow untreated eyes affected by early stages of dry age-related macular degeneration (dAMD). Additionally, we aimed to estimate if the number of injections received and other factors, including age, best-corrected visual acuity (BCVA), or sex, may affect the differences in the obtained measurements of retinal nerve fiber layer thickness. We prospectively included 106 eyes of 53 patients with unilateral wet age-related macular degeneration. The fellow eyes with non-advanced dry age-related macular degeneration served as a control group in a cross-sectional study. RNFL and GCL in the macular region were evaluated using optical coherence tomography, with outcomes expressed as differences in the thickness of both examined layers between the study and control groups. We found thinner GCL in wAMD vs. dAMD (p < 0.001). In turn, the RNFL layer did not show any statistically significant differences between the two groups (p = 0.409). Similarly, we found a statistically significant correlation between the number of injections and the layer thickness (p = 0.106). Among all assessed parameters, age over 73 was the only factor significantly affecting the thickness of the retinal nerve fiber layer in both groups (p = 0.042). The morphology of the inner layers of the retina in dry and wet AMD seems to differ, possibly due to differences in the etiopathogenesis of these two forms of the disease. In our study, the retinal ganglion cell layer was thinner in the treated vs. fellow eye (with dry AMD), while the nerve fiber layer was not significantly different between the groups. The number of anti-VEGF injections had no effect on the thickness of the macular nerve fiber layer.

Glaucoma progression in patients receiving intravitreal anti‐VEGF treatment for neovascular age‐related macular degeneration

PURPOSE

The purpose of this study was to investigate how often glaucoma and neovascular age-related macular degeneration (nAMD) occur in the same patient and to evaluate whether glaucoma progression is faster in eyes treated with intravitreal anti-VEGF medications for nAMD.

METHODS

This single-centre retrospective real-world data (RWD) consists of medical records of 6314 glaucoma and 2166 nAMD patients treated in 2008-2017 in Tays Eye Centre, Finland. To study glaucoma progression, changes in visual fields (mean deviation [MD], dB/year), IOP (mmHg/year) and fundus photographs (progression, yes/no) were compared in glaucoma eyes with and without anti-VEGF treatment for nAMD and ≥1 year follow-up.

RESULTS

During the 10-year period, 147 patients with glaucoma received intravitreal anti-VEGF treatment for nAMD corresponding to 2% of glaucoma and 7% of nAMD patients. The mean change in MD was -0.70 dB/year (SD 1.8) vs. -0.27 dB/year (SD 1.7) (p = 0.027) in glaucoma eyes with (n = 37) and without (n = 4304) anti-VEGF injections, respectively. In patients with bilateral glaucoma and unilateral nAMD treated with anti-VEGF injections (n = 20), MD declined at -0.62 dB/year (SD 1.9) vs 0.33 dB/year (SD 1.5) (p = 0.654), and glaucoma progression was detected in 14/20 vs 10/20 (p = 0.219) fundus photographs in eyes with anti-VEGF treatment compared with their untreated fellow eyes.

CONCLUSION

nAMD and glaucoma were found co-existing in the same eye at rates that were similar to the age-corrected prevalence of the two diseases in the general population. Our results suggest that intravitreal anti-VEGF treatment for nAMD may accelerate glaucoma progression.

Impact of intravitreal ranibizumab, aflibercept and bevacizumab on retinal ganglion cell and nerve fibre layer thickness in Neovascular age‐related macular degeneration

PURPOSE

To compare the effects of monotherapy with intravitreal ranibizumab, aflibercept and bevacizumab on retinal ganglion cell layer (RGCL) and retinal nerve fibre layer (RNFL) in patients with naïve neovascular age-related macular degeneration (nAMD).

METHODS

This is a retrospective cohort study with three-groups comparison. 83 patients and 97 eyes on continuous monotherapy with an intravitreal anti-vascular endothelial growth factor (anti-VEGF) were followed for 24 months and divided into three groups according to anti-VEGF (aflibercept: 25 eyes, ranibizumab: 34 eyes, bevacizumab: 38 eyes). Main outcome measures included: RGCL and RNFL thickness, best corrected visual acuity (BCVA), central macular thickness (CMT), macular volume (MV) and the presence of intraretinal fluids (IRF), subretinal fluids (SRF) and retinal pigment epithelial atrophy (RPE-atrophy). All outcome measures were recorded at the time of the first injection, 1 and 2 years after treatment and compared longitudinally and between groups.

RESULTS

The mean age was 79 ± 7 years. The RGCL thickness, MV, CMT and the presence of IRF and SRF decreased significantly within all three medication groups (p < 0.05 for all) with no significant difference between groups over the 2-year follow-up period (p > 0.10 for all). The decrease in RNFL thickness was not significant within or between the groups after a 2-year follow-up (p > 0.055 for all). RPE-atrophy increased significantly after 2 years in all three groups (p < 0.028 for all) with no significant difference between groups at all three time points (p > 0.307 for all). BCVA was comparable between the three groups over the 2-year follow-up period (p > 0.22 for all).

CONCLUSIONS

Monotherapy with intravitreal aflibercept, bevacizumab and ranibizumab was associated with comparable significant decreases in RGCL thickness, CMT, MV, IRF and SRF in naïve nAMD patients during the first 2 years of treatment. Furthermore, no significant differences either in BCVA or RNFL thickness were observed between the three intravitreal anti-VEFGs during the first 2 years of treatment.

Risk, Prevalence, and Progression of Glaucoma in Eyes With Age-Related Macular Degeneration Treated With Intravitreal Anti-Vascular Endothelial Growth Factor Injections

PURPOSE

To examine the risk, prevalence, and progression of glaucoma development in age-related macular degeneration (AMD) eyes receiving intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections compared to controls.

DESIGN

Retrospective clinical cohort study.

METHODS

Retrospective review of eyes receiving intravitreal anti-VEGF injections from January 1, 2004, to December 31, 2013, for exudative AMD. Age- and sex-matched control groups of eyes included eyes with nonexudative AMD (NEAMD) and no AMD. Eyes with a diagnosis of glaucoma or glaucoma suspect were reviewed for injection details, type and date of glaucoma diagnosis, glaucoma treatments, standard automated perimetry (SAP), and spectral domain optical coherence tomography (SD-OCT). Qualitative progression was determined by indication of glaucoma progression in provider notes. Quantitative progression was assessed based on change in mean deviation (MD) on SAP, retinal nerve fiber layer thickness on SD-OCT, and intraocular pressure (IOP).

RESULTS

There were 707 eyes of 504 patients treated with anti-VEGF injections and 1008 eyes in the NEAMD and no-AMD cohorts. There was no difference in glaucoma or suspect prevalence at initial presentation between eyes treated with injections and NEAMD (6.9% vs 9.7%, P = .22) or no-AMD controls (vs 8.5%, P = .55). There was no difference in cumulative 5-year probability of new glaucoma diagnosis after anti-VEGF injections compared to NEAMD (1.9% vs 1.0%, P = .69) or no-AMD controls (vs 1.6%, P = .88). There was no difference in qualitative progression of glaucoma in the injection cohort vs NEAMD (P = .19) or no-AMD controls (P = .61). The rate of MD change in injection eyes was similar to NEAMD eyes (P = .74) but greater than no-AMD eyes (P = .02). Eyes receiving injections required more topical glaucoma medications compared with NEAMD (P = .03) and more glaucoma laser treatments compared with no-AMD controls (P = .009). Eyes receiving injections did not require more frequent incisional glaucoma surgery compared with NEAMD (21.0% vs 15.0%, P = .95) or no-AMD controls (vs 10.0%, P = .10).

CONCLUSION

Eyes treated with intravitreal anti-VEGF injections for exudative AMD did not have increased risk of developing glaucoma compared with controls. Of those with a glaucoma diagnosis, exudative AMD eyes receiving injections required a greater number of topical glaucoma medications compared with NEAMD eyes and had a greater rate of MD loss than no-AMD controls.

The Correlation Between MicroRNAs and Diabetic Retinopathy

Micro ribonucleic acids (miRNAs), as a category of post-transcriptional gene inhibitors, have a wide range of biological functions, are involved in many pathological processes, and are attractive therapeutic targets. Considerable evidence in ophthalmology indicates that miRNAs play an important role in diabetic retinopathy (DR), especially in inflammation, oxidative stress, and neurodegeneration. Targeting specific miRNAs for the treatment of DR has attracted much attention. This is a review focusing on the pathophysiological roles of miRNAs in DR, diabetic macular edema, and proliferative DR complex multifactorial retinal diseases, with particular emphasis on how miRNAs regulate complex molecular pathways and underlying pathomechanisms. Moreover, the future development potential and application limitations of therapy that targets specific miRNAs for DR are discussed.

Morphological and Functional Assessment of the Optic Nerve Head and Retinal Ganglion Cells in Dry vs Chronically Treated Wet Age-Related Macular Degeneration

Purpose

The aim of the study comprised the anatomical and functional assessment of the optic nerves and macular ganglion cells in the population of patients with unilateral wet age-related macular degeneration (wAMD) and comparison of its results to those obtained from the fellow eye with non-advanced dry age-related macular degeneration (dAMD). Furthermore, we aimed to determine if the number of administered injections contributed to the potential differences between the examined eyes.

Methods

The study was based on 104 eyes of 52 patients in a cross-sectional study. The eyes with chronically treated wAMD were the main subject of the study, while fellow eyes affected with non-advanced dAMD served as the control group. Primary morphological outcomes comprised differences in peripapillary retinal nerve fiber layer (RNFL) and GCC layers between the studied groups (treated and control). In turn, primary functional outcomes included differences in implicit times and amplitudes of the P100 wave of pattern visual evoked potentials (PVEP) and N95 wave of pattern electroretinogram (PERG) between treated and control groups.

Results

We did not find any differences in total RNFL thickness between wAMD and dAMD groups. The number of injections only affected the RNFL in the nasal quadrant of the optic disc (p = 0.023). We did not find any differences regarding GCL thickness in both groups. In the study group, a longer implicit time of the P100 of PVEP (p = 0.014) and a shorter amplitude of the P50-N95 wave of PERG (p = 0.005) were detected. The total number of injections had no significant effect on these two values.

Conclusion

We detected worse functional parameters of the optic nerve and retinal ganglion cells in eyes with wAMD, with lack of significant differences in anatomical (RNFL, GCL) parameters compared to the control group. However, the number of injections did not contribute to the differences found.

Cortical Atrophy Predicts Visual Performance in Long-Term Central Retinal Disease; GCL, pRNFL and Cortical Thickness Are Key Biomarkers

Purpose

The aim of this study was to assess both retinal and cortical structure in a cohort of patients with long-term acquired central retinal disease in order to identify potential disease biomarkers and to explore the relationship between the anterior and posterior visual pathways.

Methods

Fourteen participants diagnosed with long-term central retinal disease underwent structural assessments of the retina using spectral-domain optical coherence tomography, including macular ganglion cell layer (GCL) and peripapillary retinal nerve fiber layer (pRNFL) thickness. Structural magnetic resonance imaging was used to measure visual cortex, including cortical volume of the entire occipital lobe and cortical thickness of the occipital pole and calcarine sulcus, representing the central and peripheral retina, respectively.

Results

Mean thickness was significantly reduced in both the macular GCL and the inferior temporal pRNFL across patients. Cortical thickness was significantly reduced in both the occipital pole and calcarine sulcus, representing the central and peripheral retina, respectively. Disease duration significantly correlated with GCL thickness with a large effect size, whereas a medium effect size suggests the possibility that cortical thickness in the occipital pole may correlate with visual acuity.

Conclusions

Long-term central retinal disease is associated with significant structural changes to both the retina and the brain. Exploratory analysis suggests that monitoring GCL thickness may be a sensitive biomarker of disease progression and reductions in visual cortical thickness may be associated with reduced visual acuity. Although this study is limited by its heterogeneous population, larger cohort studies would be needed to better establish some of the relationships detected between disease dependent structural properties of the anterior and posterior visual pathway given the effect sizes reported in our exploratory analysis.

Retinal Vessel Density in Age-Related Macular Degeneration Patients with Geographic Atrophy

We compared the retinal vessel density and inner retinal thickness in patients who had one eye with geographic atrophy (GA) and a fellow eye with intermediate age-related macular degeneration (iAMD). The vessel density from the superficial vascular complex (SVC) and deep vascular complex (DVC) through optical coherence tomography angiography and the thickness of the nerve fiber layer, ganglion cell-inner plexiform layer (GCIPL), inner nuclear layer (INL), outer nuclear layer (ONL) on a structural optical coherence tomography thickness map were measured in 28 eyes of 14 GA patients with iAMD in the fellow eye. GA eyes had significantly lower vessel density in the SVC (26.2 ± 3.9% vs. 28.3 ± 4.4%; p = 0.015) and DVC (24.2 ± 2.6% vs. 26.8 ± 1.9%; p = 0.003) than fellow eyes (iAMD). GCIPL and ONL were significantly thinner in GA eyes than in the fellow eyes (p = 0.032 and 0.024 in the foveal areas, p = 0.029 and 0.065 in the parafovea areas, respectively). Twenty-four eyes of 12 patients were followed up for 2 years and seven of the fellow eyes (58.3%) developed GA during the follow-up period and showed reduced vessel density in the SVC (26.4 ± 3.0% vs. 23.8 ± 2.9%; p = 0.087) and DVC (25.8 ± 2.2% vs. 22.4 ± 4.4%; p = 0.047) compared to baseline. Vessel density and GCIPL thickness map measurements are potential GA markers in non-neovascular AMD.

Ganglion Cell Layer Thickness Change in Neovascular Age-Related Macular Degeneration Treated With Anti-VEGF Injections

Purpose:

This work assesses bilateral ganglion cell layer–inner plexiform layer (GCL-IPL) thickness changes in patients with unilateral neovascular age-related macular degeneration (nAMD) treated with antivascular endothelial growth factor (anti-VEGF).

Methods:

In this single-center, retrospective, cohort study, the medical records of patients with unilateral nAMD treated with anti-VEGF were reviewed. The treated group included eyes with newly diagnosed nAMD that subsequently underwent treatment with intravitreal anti-VEGF injections. The control group was the fellow eye with dry AMD. Eyes receiving at least 10 intravitreal injections were included. Measurement of GCL-IPL thickness was performed at different time points using spectral domain–optical coherence tomography.

Results:

A total of 216 eyes of 108 patients met the inclusion criteria. The mean age ± SD was 80.1 ± 10.7 years. Eyes in the treated group underwent a mean ± SD of 20.2 ± 7.2 injections in 21.3 ± 6.8 months. At baseline, average mean ± SD of GCL-IPL thickness was 73.71 ± 8.81 µm and 73.84 ± 8.26 µm in the treated and fellow eye, respectively ( P = .795). After 10 injections the average thickness was 65.41 ± 14.08 µm and 68.77 ± 13.24 µm in the treated and fellow eye, respectively ( P = .007). The absolute decrease in thickness was significantly greater in the treated eye than the fellow eye (mean ± SD, 8.31 ± 11.19 µm vs 5.07 ± 10.83 µm, respectively; P = .002).

Conclusions:

GCL-IPL thickness decreased significantly in the treated group more than in the control group after 10 anti-VEGF injections. The mechanism and clinical significance of this observation warrants further study.

Retinal nerve fibre layer and ganglion cell layer thickness changes following intravitreal aflibercept for age-related macular degeneration

PURPOSE

To evaluate the effect of intravitreal aflibercept (IVA) injections on peripapillary retinal nerve fibre layer thickness (RNFLT) and macular ganglion cell layer thickness (GCLT) in neovascular age-related macular degeneration (nAMD) patients during a 1-year follow-up.

METHODS

This is a prospective study including 34 patients who were treated with aflibercept for treatment-naive nAMD. Following a loading phase of 3-monthly aflibercept, re-injections were performed on a pro re nata regimen for 12 months. Best-corrected visual acuity, intraocular pressure, and spectral-domain-optical coherence tomography analysis were performed at baseline and 1 month, 3 months, 6 months, and 12 months following treatment. Peripapillary RNFLT and macular GCLT along with the central macular thickness (CMT) and subfoveal choroidal thickness (SFCT) were evaluated at each visit.

RESULTS

Mean number of aflibercept injections was 6.0 ± 1.8. Significant thinning was observed at the central macular ganglion cell layer and at 1 mm superior, temporal, and nasal ganglion cell layer compared to baseline at 1-year (p < 0.05). No significant change of RNFLT was shown (p > 0.05). Mean CMT and SFCT were significantly reduced after IVA therapy (p < 0.05, for both). No correlation was found between injection number and GCLT change.

CONCLUSIONS

Intravitreal aflibercept caused significant ganglion cell layer thinning during a 1-year follow-up without any changes in RNFLT. Intravitreal aflibercept itself may have a chance to induce decreased GCLT in nAMD patients.

AS1411 Nucleolin-Specific Binding Aptamers Reduce Pathological Angiogenesis through Inhibition of Nucleolin Phosphorylation

Proliferative retinopathies produces an irreversible type of blindness affecting working age and pediatric population of industrialized countries. Despite the good results of anti-VEGF therapy, intraocular and systemic complications are often associated after its intravitreal use, hence novel therapeutic approaches are needed. The aim of the present study is to test the effect of the AS1411, an antiangiogenic nucleolin-binding aptamer, using in vivo, ex vivo and in vitro models of angiogenesis and propose a mechanistic insight. Our results showed that AS1411 significantly inhibited retinal neovascularization in the oxygen induced retinopathy (OIR) in vivo model, as well as inhibited branch formation in the rat aortic ex vivo assay, and, significantly reduced proliferation, cell migration and tube formation in the HUVEC in vitro model. Importantly, phosphorylated NCL protein was significantly abolished in HUVEC in the presence of AS1411 without affecting NFκB phosphorylation and -21 and 221-angiomiRs, suggesting that the antiangiogenic properties of this molecule are partially mediated by a down regulation in NCL phosphorylation. In sum, this new research further supports the NCL role in the molecular etiology of pathological angiogenesis and identifies AS1411 as a novel anti-angiogenic treatment.

Neuroprotective effects of glial mediators in interactions between retinal neurons and Müller cells

Progressive retinal ganglion cell (RGC) loss underlies a number of retinal neurodegenerative disorders, which may lead to permanent vision loss. However, secreted neuroprotective factors, such as PEDF, VEGF and IL-6, which are produced by Müller cells, have been shown to promote RGC survival. Assuming that the communication of RGCs with Müller cells involves a release of glioactive substances we sought to determine whether retinal neurons are able to modulate expression levels of Müller cell-derived PEDF, VEGF and IL-6. We demonstrate elevated mRNA levels of these factors in Müller cells in co-cultures with RGCs or R28 cells when compared to homotypic Müller cell cultures. Furthermore, R28 cells were more protected from apoptosis when co-cultured with Müller cells. IL-6 and VEGF were upregulated in Müller cells under hypoxia. Both cytokines, as well as PEDF, induced an altered neuronal expression of members of the Bcl-2 family, which are central molecules in the regulation of apoptosis. These results suggest that in retinal ischemia, via own secreted mediators, RGCs can resist a potential demise by stimulating Müller cells to increase production of neuroprotective factors, which counteract RGC apoptosis.

Macular ganglion cell complex changes in eyes treated with aflibercept for neovascular age-related macular degeneration

BACKGROUND

To evaluate the effect of intravitreal aflibercept injection on macular ganglion cell complex (GCC) in patients with neovascular age-related macular degeneration (nAMD).

METHODS

In total, 36 eyes of 36 treatment-naïve patients with nAMD (18 female and 18 male) and 36 eyes of 36 healthy subjects (20 female and 16 male) as controls were included in this retrospective study. Spectral-domain optical coherence tomography images were evaluated after each injection for 3 months and at 12 months. Mean GCC thickness of the center, inner ring, and outer ring of the ETDRS grid was automatically quantified.

RESULTS

Mean foveal thickness was statistically significantly decreased at 3 months and at 12 months compared with baseline in the patient group. Ganglion cell layer thickness in the center was statistically significantly decreased in eyes with nAMD at baseline. There was a statistically significant decrease for mean retinal nerve fiber layer, ganglion cell layer, and inner plexiform layer thickness at 12 months compared with baseline.

CONCLUSIONS

Macular GCC thickness was decreased after intravitreal aflibercept injection in patients with nAMD, in particular at 12 months.

Progression of macular atrophy in patients undergoing anti-vascular endothelial growth factor therapy for neovascular age-related macular degeneration

PURPOSE

To assess differences in the progression of macular atrophy (MA) between neovascular age-related macular degeneration (AMD) subtypes and to identify the risk factors associated with the foveal involvement among patients with MA undergoing long-term anti-vascular endothelial growth factor (VEGF) treatment.

METHODS

Eighty eyes of 80 patients with neovascular AMD who developed incident MA following anti-VEGF therapy were retrospectively included. Macular atrophy (MA) was quantified using autofluoresence (AF) images within 24 months after the onset of MA, and the enlargement rate was compared between neovascular AMD subtypes. Regression models were constructed to explore relationships between foveal involvement in MA and baseline characteristics.

RESULTS

The growth rate of MA was 0.18 mm² /year for type 1 neovascularization (NV), 0.24 mm² /year for type 2 NV, and 1.21 mm² /year for type 3 NV; differences between groups were significant (p = 0.022). Multivariate logistic regression analysis revealed that thin subfoveal choroidal thickness (p = 0.028), presence of subretinal drusenoid deposit (p = 0.005), type 2 or 3 NV (p = 0.023), and geographic atrophy in the fellow eye (p = 0.035) were significant risk factors for MA with foveal involvement. The number of injections showed no significant association with the progression or the foveal involvement in MA.

CONCLUSIONS

The progression of MA in patients with neovascular AMD undergoing anti-VEGF treatment differed significantly depending on the subtype of neovascularization. The risk of foveal involvement in MA was associated with the baseline factors or phenotype of neovascular AMD rather than with injection frequency of anti-VEGF.

Rates of RNFL Thinning in Patients with Suspected or Confirmed Glaucoma Receiving Unilateral Intravitreal Injections for Exudative AMD

PURPOSE

This study evaluated whether the rate of retinal nerve fiber layer (RNFL) thinning is faster in eyes receiving intravitreal injections than in fellow uninjected eyes among patients suspected of having or confirmed to have glaucoma and exudative age-related macular degeneration (AMD).

DESIGN

Retrospective comparative cohort study.

METHODS

Patients with a diagnosis of unilateral exudative AMD and confirmed to have or suspected of having glaucoma in both eyes receiving unilateral intravitreal injections were identified. Those with ≥3 RNFL optical coherence tomography scans and ≥6 injections were included in the study. Rates of RNFL thinning in the injected eye versus the uninjected eye were estimated using linear mixed models. The main outcome measurement was the differences in rates of RNFL thinning in the injected versus the fellow uninjected eye. The effects of postinjection elevation of intraocular pressure (IOP), injection frequency, and number of injections were also evaluated.

RESULTS

A total of 53 patients met the inclusion criteria, receiving 26.4 ± 15.9 intravitreal injections. The average rate of RNFL thinning in uninjected eyes was -0.620 μm/year (P = .029). Injected eyes had an additional incremental loss of -0.385 μm/year, but this value was not statistically significant (95% confidence interval [CI]: -1.147 to 0.379 μm/year; P = .324). Subgroup analysis with only glaucoma patients (n = 33) also demonstrated a nonsignificant effect of injections (-0.568 μm/year; 95% CI: -1.454 to 0.319 μm/year; P = .212). Postinjection IOP elevation, injection frequency, and total number of injections were not associated with faster RNFL loss.

CONCLUSIONS

Among exudative AMD patients with glaucoma or suspected of having glaucoma, the rate of RNFL thinning in eyes receiving intravitreal injections did not significantly differ from that of fellow uninjected eyes.

Changes in the Ganglion Cell-inner Plexiform Layer after Consecutive Intravitreal Injections of Anti-vascular Endothelial Growth Factor in Age-related Macular Degeneration Patients

Purpose

To investigate the effect of intravitreal anti-vascular endothelial growth factor (VEGF) injections on ganglion cell-inner plexiform layer (GCIPL) thickness in patients with age-related macular degeneration (AMD).

Methods

This retrospective study included patients with continuous anti-VEGF treatment who were administered at least three consecutive injections for unilateral neovascular AMD. The GCIPL thickness of the study eyes was compared before and after treatment and with healthy fellow eyes using spectral-domain optical coherence tomography. We also evaluated best-corrected visual acuity, age, and intraocular pressure.

Results

In total, 96 eyes of 48 patients (14 females and 34 males; mean ± standard deviation [SD] age, 70.10 ± 8.89 years) with mean number of 6.29 (SD ± 3.76) anti-VEGF injections and a mean follow-up period of 24.93 months (SD ± 19.86) were included in the study. After three consecutive intravitreal injections of anti-VEGF, the mean GCIPL thickness was significantly reduced from 70.50 (SD ± 14.06) to 65.97 (SD ± 13.91) µm. Borderline or nonsignificant decrease was also observed in GCIPL thickness for each sector. At the end of the study, the mean GCIPL thickness was further reduced to 62.56 (SD ± 16.30) µm, and significant decreases were also observed in all other sectors compared with baseline.

Conclusions

It has been observed that GCIPL thickness can decrease with only three consecutive anti-VEGF injections as well as with long-term treatment in AMD patients.

Anatomical effects of intravitreal anti-vascular endothelial growth factor injections on inner layers of the lesion-free retina

PURPOSE

The primary aim of the study was to investigate the effects of anti-vascular endothelial growth factor (VEGF) injections on the inner retinal layer anatomy of the lesion-free retina in eyes treated for neovascular age-related macular degeneration (nAMD). The secondary aim was to compare the changes of inner retinal layers in the lesion-free region of treated eyes with the same region of the untreated, fellow eyes and, thus, to elucidate any adverse effect of anti-VEGF treatments independently of 1-year aging changes.

METHODS

This was a retrospective, longitudinal, case-control study of 50 eyes of 25 patients. Twenty-five eyes with nAMD comprised the study group (16 eyes treated with aflibercept and 9 eyes treated with ranibizumab) and 25 fellow eyes with dry AMD (16 eyes in AREDS 2 and 9 eyes in AREDS 3) comprised the fellow eye group. Spectral-domain optical coherence tomography (SD-OCT) measurements were done at pre-treatment, 1 month after three loading anti-VEGF injections and at the end of 1 year. The retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL) thicknesses and total retinal thickness in the macula were measured. Thicknesses of inner retinal layers which were lesion-free in the outer nasal subfield of ETDRS grid were analysed and the changes in thicknesses during the follow-up period were compared between study and fellow eye groups. Paired t-test for normally distributed variables was applied for analyses of differences for the comparison of the results across the pre-and the post-. A p value of less than 0.05 was considered statistically significant.

RESULTS

The mean number of injections was 5.76 ± 1.26 in the study group in 1 year. The mean decrease in total retinal thickness was significant with 6.08 ± 9.05 µm (p= 0.003) in nAMD group and was insignificant with 0.32 ± 1.03 µm (p> 0.05) in fellow eye group with dry AMD. Most of the retinal thickness decrease was during first three injections in nAMD group. Total retinal thickness and GCL thickness were thinner in the study group at every follow-up examination, but the difference between groups was not statistically significant (p> 0.05). RNFL, GCL, IPL, and INL thicknesses did not demonstrate a statistically significant change in both study and fellow eye groups during 1 year follow-up period (p> 0.05).

CONCLUSIONS

Repeated anti-VEGF injections in nAMD appear to have no significant effect on the RNFL, GCL, IPL, and INL thicknesses of the lesion-free retina. Additionally, there was no significant difference in inner retinal layer changes between in eyes treated with anti-VEGF injections for nAMD and fellow eye group during 1-year follow-up.

Targeting RGD-binding integrins as an integrative therapy for diabetic retinopathy and neovascular age-related macular degeneration

Integrins are a class of transmembrane receptors that are involved in a wide range of biological functions. Dysregulation of integrins has been implicated in many pathological processes and consequently, they are attractive therapeutic targets. In the ophthalmology arena, there is extensive evidence suggesting that integrins play an important role in diabetic retinopathy (DR), age-related macular degeneration (AMD), glaucoma, dry eye disease and retinal vein occlusion. For example, there is extensive evidence that arginyl-glycyl-aspartic acid (Arg-Gly-Asp; RGD)-binding integrins are involved in key disease hallmarks of DR and neovascular AMD (nvAMD), specifically inflammation, vascular leakage, angiogenesis and fibrosis. Based on such evidence, drugs that engage integrin-linked pathways have received attention for their potential to block all these vision-threatening pathways. This review focuses on the pathophysiological role that RGD-binding integrins can have in complex multifactorial retinal disorders like DR, diabetic macular edema (DME) and nvAMD, which are leading causes of blindness in developed countries. Special emphasis will be given on how RGD-binding integrins can modulate the intricate molecular pathways and regulate the underlying pathological mechanisms. For instance, the interplay between integrins and key molecular players such as growth factors, cytokines and enzymes will be summarized. In addition, recent clinical advances linked to targeting RGD-binding integrins in the context of DME and nvAMD will be discussed alongside future potential for limiting progression of these diseases.

Tonabersat Inhibits Connexin43 Hemichannel Opening and Inflammasome Activation in an In Vitro Retinal Epithelial Cell Model of Diabetic Retinopathy

This study was undertaken to evaluate the connexin hemichannel blocker tonabersat for the inhibition of inflammasome activation and use as a potential treatment for diabetic retinopathy. Human retinal pigment epithelial cells (ARPE-19) were stimulated with hyperglycemia and the inflammatory cytokines IL-1β and TNFα in order to mimic diabetic retinopathy molecular signs in vitro. Immunohistochemistry was used to evaluate the effect of tonabersat treatment on NLRP3, NLRP1, and cleaved caspase-1 expression and distribution. A Luminex cytokine release assay was performed to determine whether tonabersat affected proinflammatory cytokine release. NLRP1 was not activated in ARPE-19 cells, and IL-18 was not produced under disease conditions. However, NLRP3 and cleaved caspase-1 complex formation increased with hyperglycemia and cytokine challenge but was inhibited by tonabersat treatment. It also prevented the release of proinflammatory cytokines IL-1β, VEGF, and IL-6. Tonabersat therefore has the potential to reduce inflammasome-mediated inflammation in diabetic retinopathy.

Dose-Response Relationship between Intravitreal Injections and Retinal Nerve Fiber Layer Thinning in Age-Related Macular Degeneration

PURPOSE

To determine if multiple intravitreal injections of vascular endothelial growth factor (VEGF) inhibitors for unilateral exudative age-related macular degeneration (eAMD) are associated with thinning of the retinal nerve fiber layer (RNFL), we compared RNFL thickness measurements from the injected eye with that of the fellow eye with nonexudative age-related macular degeneration (neAMD).

DESIGN

Retrospective, cross-sectional study.

PARTICIPANTS

Patients undergoing anti-VEGF therapy for unilateral eAMD.

METHODS

Patients receiving anti-VEGF therapy secondary to eAMD in 1 eye with neAMD in their fellow eye were identified. Patients with a known diagnosis of glaucoma were excluded. Spectral domain OCT measurements of the peripapillary RNFL thickness from both eyes were performed and compared. The differences in the RNFL thickness measurements between eyes were correlated with the number of injections and the duration of therapy.

MAIN OUTCOME MEASURES

Correlation between the number of anti-VEGF injections and peripapillary RNFL thinning.

RESULTS

A total of 108 eyes of 54 patients were evaluated in this study. The average peripapillary RNFL thickness measurements of the injected eye and fellow eye were 87.3 ± 9.6 μm and 89.0 ± 7.5 μm, respectively (P = 0.055). The RNFL thickness difference (fellow eye minus injected eye) was significantly correlated with the number of injections (r = 0.40, P = 0.002) and months of injections (r = 0.38, P = 0.005). The relationship between the difference in the RNFL thickness and the number of injections had a nonlinear dose-response relationship that became apparent after approximately 30 injections and 50 months of injections.

CONCLUSIONS

The difference in RNFL thickness measurements between injected eyes and uninjected fellow eyes was largely within the reported normal limits for interocular differences between healthy eyes. Nevertheless, there was a dose-response relationship between RNFL thinning and number of injections among patients receiving a greater number of injections, suggesting that anti-VEGF injections may have a modest effect on the RNFL thickness after several years of therapy in eyes requiring more anti-VEGF injections; however, we cannot exclude that the RNFL thinning may be secondary to active age-related macular degeneration (AMD) disease progression in both eyes.

VEGF is an autocrine/paracrine neuroprotective factor for injured retinal ganglion neurons

Vascular endothelial growth factor-A (VEGF) is the angiogenic factor promoting the pathological neovascularization in age-related macular degeneration (AMD) or diabetic macular edema (DME). Evidences have suggested a neurotrophic and neuroprotective role of VEGF, albeit in retina, cellular mechanisms underlying the VEGF neuroprotection remain elusive. Using purified adult retinal ganglion cells (RGCs) in culture, we demonstrated here that VEGF is released by RGCs themselves to promote their own survival, while VEGF neutralization by specific antibodies or traps drastically reduced the RGC survival. These results indicate an autocrine VEGF neuroprotection on RGCs. In parallel, VEGF produced by mixed retinal cells or by mesenchymal stem cells exerted a paracrine neuroprotection on RGCs. Such neuroprotective effect was obtained using the recombinant VEGF-B, suggesting the involvement of VEGF-R1 pathway in VEGF-elicited RGC survival. Finally, glaucomatous patients injected with VEGF traps (ranibizumab or aflibercept) due to either AMD or DME comorbidity, showed a significant reduction of RGC axon fiber layer thickness, consistent with the plausible reduction of the VEGF autocrine stimulation of RGCs. Our results provide evidence of the autocrine neuroprotective function of VEGF on RGCs is crucially involved to preserve injured RGCs such as in glaucomatous patients.

Periostin and tenascin-C interaction promotes angiogenesis in ischemic proliferative retinopathy

Ischemic proliferative retinopathy (IPR), such as proliferative diabetic retinopathy (PDR), retinal vein occlusion and retinopathy of prematurity is a major cause of vision loss. Our previous studies demonstrated that periostin (PN) and tenascin-C (TNC) are involved in the pathogenesis of IPR. However, the interactive role of PN and TNC in angiogenesis associated with IPR remain unknown. We found significant correlation between concentrations of PN and TNC in PDR vitreous humor. mRNA and protein expression of PN and TNC were found in pre-retinal fibrovascular membranes excised from PDR patients. Interleukin-13 (IL-13) promoted mRNA and protein expression of PN and TNC, and co-immunoprecipitation assay revealed binding between PN and TNC in human microvascular endothelial cells (HRECs). IL-13 promoted angiogenic functions of HRECs. Single inhibition of PN or TNC and their dual inhibition by siRNA suppressed the up-regulated angiogenic functions. Pathological pre-retinal neovessels of oxygen-induced retinopathy (OIR) mice were attenuated in PN knock-out, TNC knock-out and dual knock-out mice compared to wild-type mice. Both in vitro and in vivo, PN inhibition had a stronger inhibitory effect on angiogenesis compared to TNC inhibition, and had a similar effect to dual inhibition of PN and TNC. Furthermore, PN knock-out mice showed scant TNC expression in pre-retinal neovessels of OIR retinas. Our findings suggest that interaction of PN and TNC facilitates pre-retinal angiogenesis, and PN is an effective therapeutic target for IPR such as PDR.

Effect of Intravitreal Injections on Retinal Imaging Metrics in Glaucomatous and Non-Glaucomatous Eyes

Purpose of Review

To summarize the available literature on retinal imaging metrics in the context of intravitreal injections in glaucomatous and non-glaucomatous eyes.

Recent Findings

The retinal nerve fiber layer (RNFL) in injected non-glaucomatous eyes appears to thin at a similar rate to uninjected fellow eyes. A total of four studies evaluating RNFL thinning in injected glaucomatous eyes yielded mixed results, with more recent longitudinal investigations suggesting a potential association. The ganglion cell-inner plexiform layer is also being studied as a potential endpoint in both glaucomatous and non-glaucomatous eyes following intravitreal injections.

Role of IL-4 in bone marrow driven dysregulated angiogenesis and age-related macular degeneration

Age-associated sterile inflammation can cause dysregulated choroidal neovascularization (CNV) as age-related macular degeneration (AMD). Intraocular fluid screening of 234 AMD patients identified high levels of IL-4. The purpose of this study was to determine the functional role of IL-4 in CNV formation using murine CNV model. Our results indicate that the IL-4/IL-4 receptors (IL4Rs) controlled tube formation and global proangiogenic responses of bone marrow cells. CCR2⁺ bone marrow cells were recruited to form very early CNV lesions. IL-4 rapidly induces CCL2, which enhances recruitment of CCR2⁺ bone marrow cells. This in vivo communication, like quorum-sensing, was followed by the induction of IL-4 by the bone marrow cells during the formation of mature CNVs. For CNV development, IL-4 in bone marrow cells are critically required, and IL-4 directly promotes CNV formation mainly by IL-4R. The IL-4/IL-4Rα axis contributes to pathological angiogenesis through communications with bone marrow cells leading to retinal degeneration.

Changes in inner retinal layer thickness in patients with exudative age-related macular degeneration during treatment with anti-vascular endothelial growth factor

The aim of this study was to identify any changes that occur in the retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GC-IPL) in patients with exudative age-related macular degeneration (AMD) during treatment with anti-vascular endothelial growth factor (VEGF) injections.Patients were enrolled in this retrospective study if they had exudative AMD, had received at least 3 injections of ranibizumab or aflibercept, and had a minimum of 12 months of follow-up. We analyzed the changes in the RNFL and GC-IPL using spectral-domain optical coherence tomography in rescan mode.Fifty-two eyes of 52 patients who had been treated with repeated anti-VEGF injections for exudative AMD were included. At the final visit, there was no significant between-group difference in best-corrected visual acuity or intraocular pressure. There was a significant decrease in central macular thickness in all groups (P < .05). There was a decrease in RNFL thickness that was only statistically significant in the ranibizumab group and when the ranibizumab or aflibercept groups were combined (P = .036 and .044, respectively). The thickness of the GC-IPL layer was significantly decreased in the aflibercept and total group (P = .035 and P = .048, respectively).The thicknesses of the RNFL and GC-IPL decreased in patients with exudative AMD who underwent repeated anti-VEGF injections.

Retinal and Choroidal Changes after Anti Vascular Endothelial Growth Factor Therapy for Neovascular Age-related Macular Degeneration

OBJECTIVE

To investigate changes in retinal nerve fiber layer, ganglion cell-inner plexiform layer, and choroidal thickness in the macular area in patients with neovascular age-related macular degeneration who received repeated intravitreal ranibizumab and aflibercept treatments.

METHODS

This retrospective study included 90 eyes of 90 treatment-naive patients. Fifty eyes were treated with intravitreal injections of aflibercept, and 40 were treated with intravitreal injections of ranibizumab. Unaffected fellow eyes (71 eyes) were used as controls. The dosage was one injection per month for 3 consecutive months as an initial treatment. The patients were examined monthly for 6 months following the initial injection. Additional intravitreal injections were given reactively in an optical coherence tomography-guided "pro re nata" protocol. Measurements of the retinal nerve fiber layer, ganglion cell-inner plexiform layer, full retina, and choroidal thickness were simultaneously obtained via swept-source optical coherence tomography in the nine Early Treatment Diabetic Retinopathy Study subfields.

RESULTS

The retinal nerve fiber layer thickness in the nine Early Treatment Diabetic Retinopathy Study subfields did not differ significantly among the three study groups (aflibercept vs. ranibizumab vs. control). The ganglion cell-inner plexiform layer thickness was significantly reduced in the aflibercept group, while the choroidal thickness was reduced in both the aflibercept and ranibizumab groups.

CONCLUSION

Excessive long-term vascular endothelial growth factor inhibition by an anti-vascular endothelial growth factor agent that is trapped by neuronal and retinal pigment epithelium cells may adversely affect the function of physiological vascular endothelial growth factor and harm retinal cells and vessels.

AUTOMATED RETINAL LAYER SEGMENTATION AND THEIR THICKNESS PROFILES IN HEALTHY SUBJECTS: A Comparison of 55° Wide-field and Conventional 30° Spectral Domain-Optical Coherence Tomography

Fifty-five degree wide-field spectral domain optical coherence tomography provides an alternative to standard 30° optical coherence tomography lens with comparable thickness values with a greater field of view.

Purpose:

To assess whether retinal thickness measurements with a standard 30° spectral domain optical coherence tomography (SD-OCT) are comparable with wide-field 55° SD-OCT.

Methods:

Thirty-three healthy individuals were scanned using 55° as well as 30° SD-OCT according to a standardized protocol. Automated retinal layer segmentation of standard and wide-field SD-OCTs was assessed using customized software.

Results:

Both lenses showed a high correlation when analyzing total retinal thickness within the central, the inner, and the outer retinal ring (r = > 0.9). Automated thickness measurements with the 55° system were marginally higher compared with the 30° lens. The thickness of each separate retinal layer using automated segmentation showed excellent correlations within the inner and outer rings (range: r = 0.6—r = 0.9 for the inner ring and range: r = 0.9—r = 1.0 for the outer ring).

Conclusion:

Fifty-five degree wide-field SD-OCT provides a good overview of the posterior pole and presents similar quantitative values as a standard 30° OCT lens. Therefore, thickness values are comparable when switching between these two lenses.

Atrophy of the central neuroretina in patients treated for diabetic macular edema

Purpose

To examine the prevalence of central retinal atrophy in patients treated for diabetic macular edema (DME) in a clinical setting.

Methods

Retrospective data analysis of patients with DME, focusing on those who developed central retinal thinning after DME treatment at the Department of Ophthalmology, Medical University Vienna. Patient characteristics and clinical data including best‐corrected visual acuity (BCVA), spectral domain optical coherence tomography and fluorescence angiography images were reviewed and DME treatment strategies analysed using descriptive statistics. The correlation between visual acuity and ocular, systemic or DME treatment factors was calculated using linear regression models and ancovas.

Results

A total of 6684 outpatient visits by 1437 patients with diabetes were analysed. Out of 149 patients, who had had a central subfield thickness (CST) below 200 μm, 32 (36 eyes) had previously been diagnosed with a centre involving DME with an average CST of 473 ± 103 μm and average visual acuity of 0.62 ± 0.44 logMAR at first presentation. At the time of central atrophy, 29 (81%) out of 36 eyes had a history of laser treatment, 11 (31%) a vitrectomy, 32 (88%) repeated intravitreal injections of anti‐vascular endothelial growth factor (VEGF; mean 5.3 ± 3.8) and 22 (61%) intravitreal corticosteroid injections (mean 2.5 ± 2.7). Visual function (0.67 ± 0.43 logMAR) at the time of atrophy was not significantly correlated to central retinal thickness (191 ± 7 μm) or any other ocular, systemic or treatment factors.

Conclusions

Only 4% of patients treated for DME developed central retinal thinning in our observation period. On average, our atrophy patients had higher CST and lower BCVA when they first presented with DME compared to the overall DME cohort, and they received a combination of intravitreal injections and laser for DME treatment. Central retinal atrophy might not be attributed to excessive use of intravitreally applied anti‐VEGF or any other DME therapy alone.

The impact of ganglion cell layer cysts in diabetic macular oedema treated with anti-vascular endothelial growth factor

PURPOSE

To investigate the prevalence and impact of ganglion cell layer cysts (GCLC) in patients with diabetic macular oedema (DME) under continuous anti-vascular endothelial growth factor (VEGF) therapy.

METHODS

The clinical findings and spectral domain optical coherence devices of baseline visits and follow-up after 12-24 and 36 months of DME patients under continuous anti-VEGF therapy were retrospectively collected and analysed for the impact of GCLC cysts. Previously established prognostic parameters were also assessed.

RESULTS

A total of 110 eyes of 110 DME patients (mean age 64 ± 10 years) were included. At baseline, 17% eyes had GCLC. With GCLC, the best-corrected visual acuity (BCVA) improvement was in mean 8.4 ± 2.4 Early-Treatment-Diabetic-Retinopathy-Study (ETDRS) letters less over the course of 36 months compared to the group lacking GCLC (p = 0.0009). Eyes with GCLC showed 68 ± 23.4 μm less central retinal thickness (CRT) decrease than eyes lacking GCLC (p < 0.0001). In the linear mixed effect models including external limiting membrane disruption, disintegration of inner retinal layer and epiretinal membrane, GCLC remained a statistical significant factor for the outcome parameter CRT, but missed statistical significance for BCVA.

CONCLUSION

Ganglion cell layer cysts (GCLC) seem to impact outcome in DME in patients receiving long-term treatment. This prognostic factor warrants further evaluation in the context of already well-established outcome parameters.

Spermine oxidase: A promising therapeutic target for neurodegeneration in diabetic retinopathy

Diabetic Retinopathy (DR), is a significant public health issue and the leading cause of blindness in working-aged adults worldwide. The vision loss associated with DR affects patients' quality of life and has negative social and psychological effects. In the past, diabetic retinopathy was considered as a vascular disease; however, it is now recognized to be a neuro-vascular disease of the retina. Current therapies for DR, such as laser photocoagulation and anti-VEGF therapy, treat advanced stages of the disease, particularly the vasculopathy and have adverse side effects. Unavailability of effective treatments to prevent the incidence or progression of DR is a major clinical problem. There is a great need for therapeutic interventions capable of preventing retinal damage in DR patients. A growing body of evidence shows that neurodegeneration is an early event in DR pathogenesis. Therefore, studies of the underlying mechanisms that lead to neurodegeneration are essential for identifying new therapeutic targets in the early stages of DR. Deregulation of the polyamine metabolism is implicated in various neurodegenerative diseases, cancer, renal failure, and diabetes. Spermine Oxidase (SMOX) is a highly inducible enzyme, and its dysregulation can alter polyamine homeostasis. The oxidative products of polyamine metabolism are capable of inducing cell damage and death. The current review provides insight into the SMOX-regulated molecular mechanisms of cellular damage and dysfunction, and its potential as a therapeutic target for diabetic retinopathy. Structural and functional changes in the diabetic retina and the mechanisms leading to neuronal damage (excitotoxicity, loss of neurotrophic factors, oxidative stress, mitochondrial dysfunction etc.) are also summarized in this review. Furthermore, existing therapies and new approaches to neuroprotection are discussed.

Longitudinal In Vivo Characterization of the Streptozotocin-Induced Diabetic Mouse Model: Focus on Early Inner Retinal Responses

Purpose

The goal of this study was to perform an extensive temporal characterization of the early pathologic processes in the streptozotocin (STZ)-induced diabetic retinopathy (DR) mouse model, beyond the vascular phenotype, and to investigate the potential of clinically relevant compounds in attenuating these processes.

Methods

Visual acuity and contrast sensitivity (CS) were studied in the mouse STZ model until 24 weeks postdiabetes onset. ERG, spectral domain optical coherence tomography (SD-OCT), leukostasis, and immunohistochemistry were applied to investigate neurodegeneration, inflammation, and gliosis during early-, mid- and late-phase diabetes. Aflibercept or triamcinolone acetonide (TAAC) was administered to investigate their efficacy on the aforementioned processes.

Results

Visual acuity and CS loss started at 4 and 18 weeks postdiabetes onset, respectively, and progressively declined over time. ERG amplitudes were diminished and OP latencies increased after 6 weeks, whereas SD-OCT revealed retinal thinning from 4 weeks postdiabetes. Immunohistochemical analyses linked these findings to retinal ganglion and cholinergic amacrine cell loss at 4 and 8 weeks postdiabetes onset, respectively, which was further decreased after aflibercept administration. The number of adherent leukocytes was augmented after 2 weeks, whereas increased micro- and macroglia reactivity was present from 4 weeks postdiabetes. Aflibercept or TAAC showed improved efficacy on inflammation and gliosis.

Conclusions

STZ-induced diabetic mice developed early pathologic DR hallmarks, from which inflammation seemed the initial trigger, leading to further development of functional and morphologic retinal changes. These findings indicate that the mouse STZ model is suitable to study novel integrative non-vascular therapies to treat early DR.

A Combination Therapy Targeting Endoglin and VEGF-A Prevents Subretinal Fibro-Neovascularization Caused by Induced Müller Cell Disruption

Purpose

Subretinal fibroneovascularization is one of the most common causes of vision loss in neovascular AMD (nAMD). Anti-VEGF therapy effectively inhibits vascular leak and neovascularization but has little effect on fibrosis. This study aimed to identify a combination therapy to concurrently inhibit subretinal neovascularization and prevent fibrosis.

Methods

We generated transgenic mice in which induced disruption of Müller cells leads to subretinal neovascularization, which is reliably accompanied by subretinal fibrosis. We conducted Western blots and immunohistochemistry to study changes in transforming growth factor-β (TGFβ) signaling including endoglin, a coreceptor essential for TGFβ signaling, and then tested the effects of monthly intravitreal injection of anti-VEGF-A and anti-endoglin, either alone or in combination, on the development of subretinal fibroneovascularization in our transgenic mice.

Results

Müller cell disruption increased expression of TGFβ1, TGFβ type 1 receptor, and phosphorylated-Smad3. Endoglin was strongly expressed in subretinal fibroneovascular tissue. Fluorescein angiography and measurements of retinal vascular permeability indicated that intravitreal anti-VEGF-A in combination with anti-endoglin treatment more efficiently inhibited vascular leak compared with either monotherapy. Immunostaining of retinal wholemounts with antibodies against glial fibrillary acidic protein and ionized calcium binding adaptor molecule 1 indicated that the combination therapy also effectively prevented subretinal fibrosis and inhibited microglial activation. Luminex cytokine assays indicated that intravitreal anti-VEGF-A and anti-endoglin treatment, either alone or in combination, reduced the production of IL33 and macrophage inflammatory protein-3α.

Conclusions

Our findings offer a potentially novel combination approach to concurrently managing subretinal neovascularization and fibrosis in nAMD.

Long-term effect of intravitreal ranibizumab therapy on retinal nerve fiber layer in eyes with exudative age-related macular degeneration

PURPOSE

To investigate long-term effect (96 months) of intravitreal ranibizumab administered for exudative age-related macular degeneration (AMD) on retinal nerve fiber layer (RNFL) thickness when used following a pro re nata regimen.

METHODS

In this prospective study, 20 eyes of 20 patients diagnosed with exudative AMD were included. Contralateral non-exudative AMD eyes of nine of these patients were included as controls. Data on intraocular pressure (IOP) and number of injections were recorded. Spectralis optic coherence tomography (OCT) of the circumpapillary RNFL was performed under dilation when diagnosis was made and before the three loading injections. "Follow-up" software was selected to accurately compare baseline with subsequent images through the 8 years of the study.

RESULTS

Baseline IOP was 14.1 mmHg both in study (standard deviation, SD: 0.8) and control eyes (SD: 0.9) and remained unchanged during the study. Mean number of injections was 21 (SD: 2.8) at the end of the study. Mean average thickness of RNFL in the study eye group at the end of the study was 96.5 μm (SD: 2.1). Mean loss for the study period was 5.3 μm (SD: 0.7; p < 0.0001). Corresponding RNFL values for controls were 92.9 (SD: 3.2) and 5.8 μm (SD: 1.2; p < 0.001). Superior temporal sector had the greatest loss in both groups, followed by inferior and nasal sectors. No statistically significant differences were found when comparing losses in injected eyes versus control eyes.

CONCLUSIONS

RNFL thickness decreased both equally in injected eyes and control eyes. Thus, no long-term effects of intravitreal ranibizumab were observed on the retinal nerve fiber layer thickness.

Anterior chamber paracentesis during intravitreal injections in observational trials: effectiveness and safety and effects

A paracentesis prior to an intravitreal injection is a very safe procedure and can prevent IOP-spikes after injections. As these spikes pose the risk of inducing glaucomatous changes particularly in patients with frequent injections and/or with a risk profile, a regular paracentesis prior to an injection may be considered and discussed with the patient.

Optic Nerve Head Perfusion Before and After Intravitreal Antivascular Growth Factor Injections Using Optical Coherence Tomography-based Microangiography

PURPOSE

To use optical coherence tomography angiography (OCTA) to evaluate the changes in optic nerve head perfusion following intravitreal antivascular endothelial growth factor injections.

METHODS

Preinjection and postinjection intraocular pressure (IOP) and OCTA images were taken of both the injected and uninjected fellow eyes.

RESULTS

Mean preinjection IOP was 16.6±4.7 mm Hg, which increased to a mean of 40.3±13.0 mm Hg (P<0.0001) during the first postinjection image and remained elevated at 36.1±11.5 mm Hg (P<0.0001) during the second postinjection image. Although no significant change was observed in flux, vessel area density, or normalized flux when comparing the OCTA preinjection and first postinjection images, a significant decrease at the second postinjection image was observed (P=0.03, 0.02, and 0.03, respectively). No significant change was observed in the uninjected fellow eye during the same time period (P=0.47, 0.37, and 0.38, respectively).

CONCLUSIONS

Following an antivascular endothelial growth factor injection, mean IOP increased significantly and OCTA imaging of the optic nerve demonstrated a mild but significant decrease in optic nerve head perfusion parameters. Clinicians performing these injections should be aware of these findings and monitor the status of the optic nerve in patients undergoing injections.

The role of placental growth factor (PlGF) and its receptor system in retinal vascular diseases

Placental growth factor (PlGF) is a member of the vascular endothelial growth factor (VEGF) family. Upon binding to VEGF- and neuropilin-receptor sub-types, PlGF modulates a range of neural, glial and vascular cell responses that are distinct from VEGF-A. As PlGF expression is selectively associated with pathological angiogenesis and inflammation, its blockade does not affect the healthy vasculature. PlGF actions have been extensively described in tumor biology but more recently there has been accumulating preclinical evidence that indicates that this growth factor could have an important role in retinal diseases. High levels of PlGF have been found in aqueous humor, vitreous and/or retina of patients exhibiting retinopathies, especially those with diabetic retinopathy (DR) and neovascular age-related macular degeneration (nvAMD). Expression of this growth factor seems to correlate closely with many of the key pathogenic features of early and late retinopathy in preclinical models. For example, studies using genetic modification and/or pharmacological treatment to block PlGF in the laser-induced choroidal neovascularization (CNV) model, oxygen-induced retinopathy model, as well as various murine diabetic models, have shown that PlGF deletion or inhibition can reduce neovascularization, retinal leakage, inflammation and gliosis, without affecting vascular development or inducing neuronal degeneration. Moreover, an inhibitory effect of PlGF blockade on retinal scarring in the mouse CNV model has also been recently demonstrated and was found to be unique for PlGF inhibition, as compared to various VEGF inhibition strategies. Together, these preclinical results suggest that anti-PlGF therapy might have advantages over anti-VEGF treatment, and that it may have clinical applications as a standalone treatment or in combination with anti-VEGF. Additional clinical studies are clearly needed to further elucidate the role of PlGF and its potential as a therapeutic target in ocular diseases.

Inner retinal thickening in newly diagnosed choroidal neovascularization

PURPOSE

Automated segmentation of retinal layers by spectral-domain optical coherence tomography (SD-OCT) is usually erroneous in the presence of retinal diseases. The purpose of this study is to report the changes in ganglion cell complex (GCC) comprising retina nerve fiber layer (RNFL), ganglion cell layer (GCL), and inner plexiform layer (IPL) in neovascular age-related macular degeneration (AMD) patients by manually correcting the automated segmentation errors.

METHODS

Thirty eyes of 30 patients with new-onset choroidal neovascularization secondary to neovascular AMD and 30 eyes of 30 healthy subjects were included. The inner retinal thicknesses were measured using early treatment diabetic retinopathy circle in the central 1 mm (fovea) and surrounding 3 mm diameter (parafovea) after checking the accuracy of automated segmentation lines. Manual segmentation was done to ensure the accurate segmentation, when needed.

RESULTS

Neovascular AMD patients had thicker mean RNFL, GCL, IPL, and GCC thicknesses within the fovea compared to healthy eyes (p = 0.04, p = 0.001, p = 0.032, and p = 0.005, respectively). In the parafoveal area, among the thickness-related measurements, the only significant difference was a thicker mean RNFL (p = 0.002).

CONCLUSION

Diffuse thickening of inner retinal layers in neovascular AMD may overestimate actual GCC thickness within fovea. This pseudo-increase in GCC thickness and inner retinal layers in general likely does not reflect more cells or tissue, but rather diffuse edema which leads to a falsely increased reading of layer thickness. Such false readings may also make the assessment of other conditions that lead to reduced inner retinal layer thickness such as glaucoma, optic nerve disease, or retinovascular occlusions more difficult.