Circadian Rhythms in Exudative Age-Related Macular Degeneration: The Key Role of the Canonical WNT/ß-Catenin Pathway.

Age-related macular degeneration (AMD) is considered as the main worldwide cause of blindness in elderly adults. Exudative AMD type represents 10 to 15% of macular degeneration cases, but is the main cause of vision loss and blindness. Circadian rhythm changes are associated with aging and could further accelerate it. However, the link between circadian rhythms and exudative AMD is not fully understood. Some evidence suggests that dysregulation of circadian functions could be manifestations of diseases or could be risk factors for the development of disease in elderly adults. Biological rhythms are complex systems interacting with the environment and control several physiological pathways. Recent findings have shown that the dysregulation of circadian rhythms is correlated with exudative AMD. One of the main pathways involved in exudative AMD is the canonical WNT/ß-catenin pathway. Circadian clocks have a main role in some tissues by driving the circadian expression of genes involved in physiological and metabolic functions. In exudative AMD, the increase of the canonical WNT/ß-catenin pathway is enhanced by the dysregulation of circadian rhythms. Exudative AMD progression is associated with major metabolic reprogramming, initiated by aberrant WNT/ß-catenin pathway, of aerobic glycolysis. This review focuses on the interest of circadian rhythm dysregulation in exudative AMD through the aberrant upregulation of the canonical WNT/ß-catenin pathway.

Incremental economic burden associated with exudative age-related macular degeneration: a population-based study.

BACKGROUND: The exudative age-related macular degeneration (AMD) causes considerable healthcare costs for patients and healthcare system, which are expected to grow as the population ages. The objective of this study was to assess the incremental economic burden of exudative AMD by comparing total healthcare costs between the exudative AMD group and non-AMD group to understand economic burden related to exudative AMD. METHODS: This retrospective cohort study used the National Health Insurance Service database including the entire Korean population. Exudative AMD group included individuals with at least one claim for ranibizumab and one claim using the registration code for exudative AMD (V201). Non-AMD group was defined as individuals without any claims regarding the diagnostic code of H35.3 or ranibizumab. The exudative AMD group and non-AMD group were matched using a propensity-score model. Incremental healthcare resource utilization and healthcare costs were measured during a one-year follow-up by employing econometric models: ordinary least squares (OLS) with log transformation and heteroscedastic retransformation; and generalized linear model (GLM) with a log link function and gamma distribution. RESULTS: A total of 7119 exudative AMD patients were matched to 7119 non-AMD patients. The number of outpatient visits was higher in the exudative AMD group (P-value < 0.0001), while the length of hospitalization was shorter in exudative AMD group (P-value < 0.0001). Exudative AMD patients had total costs 2.13 times (95%CI, 2.08-2.17) greater than non-AMD group using OLS, and total costs 4.06 times (95%CI, 3.82-4.31) greater than non-AMD group using GLM. Annual incremental total costs were estimated as $5519 (OLS) and $3699 (GLM). CONCLUSIONS: Exudative AMD was associated with significantly increased healthcare costs compared to the non-AMD group. Attention is needed to manage the socioeconomic burden of exudative AMD.

Therapeutic Approaches with Intravitreal Injections in Geographic Atrophy Secondary to Age-Related Macular Degeneration: Current Drugs and Potential Molecules.

The present review focuses on recent clinical trials that analyze the efficacy of intravitreal therapeutic agents for the treatment of dry age-related macular degeneration (AMD), such as neuroprotective drugs, and complement inhibitors, also called immunomodulatory or anti-inflammatory agents. A systematic literature search was performed to identify randomized controlled trials published prior to January 2019. Patients affected by dry AMD treated with intravitreal therapeutic agents were included. Changes in the correct visual acuity and reduction in geographic atrophy progression were evaluated. Several new drugs have shown promising results, including those targeting the complement cascade and neuroprotective agents. The potential action of the two groups of drugs is to block complement cascade upregulation of immunomodulating agents, and to prevent the degeneration and apoptosis of ganglion cells for the neuroprotectors, respectively. Our analysis indicates that finding treatments for dry AMD will require continued collaboration among researchers to identify additional molecular targets and to fully interrogate the utility of pluripotent stem cells for personalized therapy.

Sensitivity and specificity of optical coherence tomography angiography (OCT-A) for detection of choroidal neovascularization in real-life practice and varying retinal expertise level.

PURPOSE: To evaluate the diagnostic accuracy of OCT angiography (OCT-A) detecting or predicting choroidal neovascularization (CNV), by ophthalmologists of disparate degrees of skills in retinal diseases, using spectral domain optical coherence tomography (SD-OCT) and fluorescein angiography (FA) as a standard reference. METHODS: Retrospective observational case series. Patient presenting maculopathy and complete imaging were included. FA, SD-OCT, OCT-A and FA coupled to SD-OCT images were graded independently for presence or absence of CNV by ophthalmologists with varying expertise levels. RESULTS: Overall sensitivity of OCT-A was 85.62% (95% CI 79.04-90.76%) and specificity was 81.51% (95% CI 73.36-88.03). Sensitivity of FA was 74.51% (95% CI 66.84-81.20), and specificity was 82.35% (95% CI 74.30-88.73). Sensitivity of FA + SD-OCT was 92.72% (95% CI 87.34-96.30), and specificity was 90.91% (95% CI 84.31-95.37). CONCLUSION: OCT-A has good sensitivity and specificity for the detection of CNV in all expertise level groups. OCT-A may soon become a routine tool for CNV diagnosis and follow-up.

ARMS2 A69S polymorphism is associated with the number of ranibizumab injections needed for exudative age-related macular degeneration in a pro re nata regimen during 4 years of follow-up.

PURPOSE: To investigate whether single-nucleotide polymorphisms (SNPs) known to be strongly associated with the development of age-related macular degeneration (AMD) have an influence on recurrence rate of choroidal neovascularization (CNV) activity during 4-year ranibizumab treatment for exudative AMD. METHODS: This prospective study included 103 treatment-naïve patients (103 eyes) that received initially a loading dose of 3 monthly ranibizumab injections and thereafter, were treated according to an as-needed regimen for a 4-year follow-up period. Baseline values, visual outcome, and recurrence rate were examined. CFH Y402H and ARMS2 A69S polymorphisms were determined and their association with lesion recurrence and visual outcome was analyzed using a one-way analysis of variance (ANOVA) with post hoc comparison tested by Fisher's LSD method. Multivariate linear regression analysis was then used to identify factors associated with recurrence rate. RESULTS: The cumulative total mean number of ranibizumab injections at the end of each year of the follow-up was 5.3 ± 1.8, 9.2 ± 2.9, 12.6 ± 4.6, and 15.7 ± 6.1. There was great inter-patient variability. Nineteen eyes (18.5%) did not experience recurrence during the first year, and five (4.8%) still displayed inactive CNV after 4 years of follow-up. No significant association was found between the number of injections and mean best corrected visual acuity (BCVA) change or final BCVA at the end of the study period. Genotypes had no influence on baseline characteristics or visual outcome but a significant association was found between the A69S polymorphism and the number of injections needed by the patients. Homozygous for the T risk allele required more retreatments over the 48-month follow-up. CONCLUSIONS: The ARMS2 A69S polymorphism was associated with CNV recurrence rate in our patient cohort. Prediction of a greater risk of recurrence could help to design more appropriate follow-up treatment strategies for patients with neovascular AMD.

Evaluation of outer retinal tubulations in eyes switched from intravitreal ranibizumab to aflibercept for treatment of exudative age-related macular degeneration.

PURPOSE: To evaluate the changes of outer retinal tubulations (ORTs) as seen on spectral-domain optical coherence tomography (SD OCT) in eyes with neovascular age-related macular degeneration (AMD) where treatment was switched from intravitreal ranibizumab to intravitreal aflibercept. METHODS: This was a prospective study of eyes diagnosed with neovascular AMD and previously treated with >6 intravitreal ranibizumab injections and switched to aflibercept, conducted at a single centre (Department of Ophthalmology at Pitié Salpetriere Hospital, Paris VI University) from January to July 2015. Before and after treatment was switched from ranibizumab to aflibercept, SD-OCT was used to evaluate the presence of ORTs. Additional assessments in this patient group included best-corrected visual acuity (BCVA), fluorescein angiography (FA), indocyanine green angiography (ICGA). Changes in pigment epithelium detachments (PED), presence of intraretinal cysts, and presence of subretinal fluid (SRF) were also noted. RESULTS: Twenty-four eyes of 24 consecutive patients (15 female/nine male, mean age 70 years) diagnosed with neovascular AMD and previously treated with >6 intravitreal ranibizumab injections and switched to aflibercept were included in the analysis. After receiving aflibercept, patients were followed for a mean of 6.1 months. Prior to treatment switch, 97 % of eyes showed ORTs, while after treatment switch to aflibercept, at the end of the study period, 75 % had ORTs (p = 0.219). Changes in BCVA (LogMAR) were not statistically significant (1.16 ± 0.44 to 1.18 ± 1.06, p = 0.12), however, a significant reduction in central macular thickness (CMT) (from 406 µm ± 112 to 263 µm ± 68, p = 0.001), PED (from 70.8 % to 41.7 % , p = 0.016), presence of intraretinal cysts (from 83.3 % to 33.3 %, p = 0.002) and SRF (from 91.7 % to 25 %, p = 0.001 ) were noted. CONCLUSION: After switching from ranibizumab treatment to aflibercept, ORTs remained present in 75 % of eyes, and significant reductions in CMT, PED, and SRF, and presence of intraretinal cysts were observed.

Characteristics of type 1 and 2 CNV in exudative AMD in OCT-Angiography.

BACKGROUND: With FA and SD-OCT, different types of CNV in exudative AMD may be differentiated: type 1 CNV (within the sub-RPE space, typically corresponding to angiographically occult CNV), type 2 CNV (within the subretinal space, typically corresponding to angiographically classic CNV) and type 3 NV (intraretinal retinal angiomatous proliferation). OCT-angiography (OCT-A) is a new method to visualize vasculature based on flow characteristics. A correlation of type 1 and 2 CNV was performed. METHODS: Thirty-six eyes (17 type 1 CNV, 9 combined type 1 and 2 CNV, and 10 type 2 CNV) of 36 patients were examined by FA, SD-OCT and OCT-A. Standardized OCT-A segmentations were performed at the level of mid-choroid, choriocapillaris (CC), RPE and outer retina. On these images the size and demarcation of CNV lesions were classified: "not distinguishable", "minor" or "sharp" demarcation. Furthermore, the size of the different CNV subtypes was determined and compared. RESULTS: Both types of CNV were visible in OCT-A. They could be detected on the slabs "mid-choroid", "CC" and "RPE". While type 1 CNV showed most often a minor demarcation from the surrounding vasculature, type 2 CNV showed nearly always a sharp demarcation. In addition, type 2 CNV extended into the slab "outer retina" and were much smaller than type 1 CNV. CONCLUSIONS: Different types of CNV in exudative AMD can be visualized and differentiated with OCT-A. Type 1 CNV were larger with minor demarcation from the surrounding vasculature and were visible on the slab "mid-choroid", "CC" and "RPE". In contrast, type 2 CNV demonstrated a sharp demarcation from the surrounding vasculature reaching the slab "outer retina".

Association between polymorphism rs11200638 in the HTRA1 gene and the response to anti-VEGF treatment of exudative AMD: a meta-analysis.

BACKGROUND: Anti-angiogenesis treatments are the most commonly used treatments for the vision loss caused by exudative age-related macular degeneration (AMD), in which the anti-vascular endothelial growth factor (VEGF) drugs with ranibizumab and bevacizumab are current standard treatments. However, the outcome of anti-VEGF therapeutics is not uniform in all patients. METHODS: We performed a literature-based meta-analysis including, five published studies relevant to HTRA1 and response to anti-VEGF treatment (bevacizumab or ranibizumab). Summary odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using fixed- and random-effects models. Sensitivity analysis and meta-regression were also performed. Q-statistic test and Egger's test was used to evaluate heterogeneity and publication bias respectively. RESULTS: Overall, no association between the rs11200638 polymorphism in HTRA1 gene and the anti-VEGF treatment response was found in the genotype GG versus AA (OR = 1.06; 95% CI: 0.77 to 1.48; P = 0.98), genotype GA versus AA (OR = 1.11; 95% CI: 0.83 to 1.47; P = 0.93), genotype GG + GA versus AA (OR = 1.22; 95% CI: 0.94 to 1.57; P = 0.09), and allele G versus A (OR = 0.92; 95% CI: 0.78 to 1.08; P = 0.14). In the subgroup analysis by ethnicity Caucasian population, and a significant association was still not observed in all genetic models. Sensitivity analysis indicated the robustness of our findings, and no publication bias was observed in our meta-analysis. CONCLUSIONS: This study shows that there was no association between the polymorphism rs11200638 in HTRA1 gene and response to anti-VEGF treatment of exudative AMD. However, more studies are needed to further prove the conclusion of present study, especially well-designed and high quality randomised controlled trials or intervention studies.

Aflibercept administration in neovascular age-related macular degeneration refractory to previous anti-vascular endothelial growth factor drugs: a critical review and new possible approaches to move forward.

PURPOSE: The recent introduction of anti-VEGF drugs has widely changed the prognosis of exudative age-related macular degeneration (AMD), even if a variable percentage of patients showed an insufficient response. Aflibercept is a new anti-VEGF drug approved by FDA for the treatment of exudative AMD with a wider binding capacity than either bevacizumab or ranibizumab. Therefore, the purposes were as follows: (i) to report anatomical and functional outcomes of switching from bevacizumab/ranibizumab to aflibercept previously described in the scientific literature, (ii) to hypothesize the possible pathophysiological mechanisms of the resistance and tachyphylaxis to anti-VEGF drugs, and (iii) to suggest possible clinical actions to increase the chances of success for such difficult cases. METHODS: We reviewed the available scientific literature in Medline, Cochrane database, Current Contents, PubMed, and cross-referencing from identified articles, regarding the treatment of exudative AMD patients refractory to bevacizumab and/or ranibizumab and switched to aflibercept monotherapy. We included in this review all the cases in which the diagnosis of refractory or resistant exudative AMD was properly made, and the results of at least one aflibercept injection were described. FINDINGS: We reported the outcomes of 21 papers for a total of 1066 eyes affected by exudative AMD resistant to previous anti-VEGF drug injections and switched to aflibercept. Enrolled reports were divided into two groups: 5 prospective reports and 16 retrospective reports. All the reported papers conclude their analysis, stating that switching from bevacizumab/ranibizumab to aflibercept injections can improve outcomes successfully in refractory neovascular AMD patients. IMPLICATIONS: Analysis of the papers reported in this review demonstrates that switching from bevacizumab/ranibizumab to aflibercept injections can improve outcomes successfully in refractory neovascular AMD patients. The mechanism for these effects is not yet completely understood.

Thyroid dysfunction and exudative age-related macular degeneration - A longitudinal nationwide registry-based cohort study.

PURPOSE: The association between thyroid dysfunction and exudative age-related macular degeneration (AMD) is unknown. METHODS: In this Danish longitudinal nationwide registry-based cohort study we included all Danish residents aged 50-100 between 2008 and 2018. Using the Danish national registries, we studied the association between thyroid dysfunction and exudative AMD. Thyroid dysfunction was classified as two consecutive redeemed prescriptions of thyroid hormones (hypothyroidism) or anti-thyroid medication (hyperthyroidism). Exudative AMD was classified as an ICD diagnosis of AMD and a code for anti-VEGF treatment. All patients are treated for exudative AMD in a hospital in Denmark, and we therefore have complete registration of this patient group. RESULTS: We included 2 087 305 individuals, of which 1 072 567 (51.4%) were women; 59 318 (2.8%) had hypothyroidism, and 33 922 (1.6%) had hyperthyroidism. During a median follow-up of 11 years, 26 998 (1.3%) people developed exudative AMD. Hypothyroidism (adjusted hazard ratio [HR]: 1.17; 95% confidence interval [CI] 1.10-1.25; p < 0.001) and hyperthyroidism (HR: 1.23; 95% CI:1.13-1.34; p < 0.001) were both associated with the development of exudative AMD. The age-stratified analyses yielded similar results to the main analyses, except that the risks were exaggerated in the older part of the population. CONCLUSION: This is the first longitudinal nationwide study showing that both hypo- and hyperthyroidism are associated with an increased risk of exudative AMD. AMD is a quantitative problem in the population and our findings could have a public health impact. Further studies are needed to study the underlying mechanisms of the association.

Brolucizumab effectiveness in pigment epithelium detachment due to exudative AMD in naïve treatment or non-responder patients.

PURPOSE: To investigate outcomes after Brolucizumab injection in naïve treatment or non-responder patients with exudative age-related macular degeneration (AMD). METHODS: It is a retrospective, comparative, cohort study conducted at the tertiary referral center of the University Hospital Polyclinic of Bari, for 5 years, from November 2017 until May 2022. 41 eyes with wet-AMD (w-AMD) were included, undergoing anti-vascular endothelial growth factor (VEGF) intravitreal injections. The sample was divided into two groups, the Bro-Switch group, and the Bro-Naïve group. The Bro-Switch group previously received a slot of other anti-VEGF intravitreal drugs. The Bro-Naïve group received Brolucizumab (Bro) as the first treatment. The pigment epithelium detachment (PED) and the best-corrected visual acuity (BCVA) outcomes before and after Bro-injection were evaluated. RESULTS: A significant reduction in PED measurement was registered in all eyes treated with Bro-injection (p = 0.35). The Bro-Naïve group improved better in PED measurement (mean difference: 297.92 ± 72,32) as compared to the Bro-Switch group (mean difference: 185.06 ± 11.07). On the contrary, no significant reduction in BCVA in the two groups was recorded (p = 0.66). CONCLUSION: We suggest Bro-injection for w-AMD as effective anatomical outcomes in PED flattening, but not similar in visual results. Although this study evaluated short-term outcomes, the hopeful results can lead to interesting medium-long time effects.

Intraretinal, sub-retinal, and sub-retinal pigmented epithelium fluid in non-exudative age-related macular degeneration: follow-up with OCT imaging.

BACKGROUND/OBJECTIVES: To evaluate the presence and evolution of fluid in non-exudative age-related macular degeneration (AMD) through serial OCT. SUBJECTS/METHODS: A retrospective analysis of eyes with non-exudative AMD with a minimum of 4 year follow-up was done. Parameters including intraretinal fluid (IRF), subretinal fluid (SRF), and sub-retinal pigment epithelium (RPE) fluid (SRPEF); subfoveal choroidal thickness (SFCT) and type of drusen were evaluated using optical coherence tomography (OCT) scans at baseline and follow up visits. RESULTS: Seventy-two eyes (in 63 patients) were followed up for an average of 5.83 ± 2.17 years. A total of 26/72 (36%) and 29/65 (52%) of the non-exudative eyes had fluid during baseline and the last visit. Seven eyes (10%) out of 72 eyes converted into exudative AMD or neo-vascular AMD (nAMD) during the study period. SRPEF at baseline was most common fluid location for non-exudative eyes that eventually converted to nAMD. CONCLUSION: Non-exudative fluid including IRF, SRF, and SRPEF is seen in patients with non-exudative AMD with increasing incidence during long term follow-up.

OCT angiography analysis of choriocapillaris vascular density in different stages of age-related macular degeneration.

Objectives: To analyze the choriocapillaris vessel density (CVD) of eyes at different stages of Age-related Macular Degeneration (AMD) with Optical Coherence Tomography Angiography (OCTA). Methods: This is a prospective observational cross-sectional study on 21 age-matched healthy eyes and 84 eyes with AMD (i.e., early AMD, late AMD, Geographic Atrophy [GA], and disciform scar AMD). OCTA was used to automatically measure the CVD (%), on both the whole macula and the foveal area, in a layer going from 9 µm above to 30 µm below the Bruch's membrane. Furthermore, in the GA subgroup, the extension of the Ellipsoid Zone (EZ) interruption and the area of macular chorio-retinal atrophy was analyzed. Results: Macular CVD was significantly lower in the GA, late AMD and disciform scar AMD-subgroups compared to controls (respectively, p=0.0052; p<0.0001; p=0.0003), whereas it did not significantly vary in the early AMD group (p=0.86). A significant difference between the early AMD and both the late AMD and the disciform scar AMD subgroups was also found (p=0.0009 and 0.0095, respectively). When comparing the foveal CVD of healthy and AMD eyes, a significant difference was found with every AMD subgroup (early AMD, p=0.011; GA, p<0.0001; late AMD, p<0.0001; disciform scar AMD, p<0.0001). Furthermore, in the GA subgroup, the CVD had an inverse correlation with both the extension of the EZ-interruption (p=0.012) and with the calculated chorio-retinal atrophic area (p=0.009). Conclusions: OCTA could play a crucial role in the categorization of AMD, allowing for the evaluation of gradual flow impairment at different stages of the disease. Moreover, the detection of a decreased macular and foveal CVD may shed light on the pathogenesis of AMD.

Proteins Associated with Phagocytosis Alteration in Retinal Pigment Epithelial Cells Derived from Age-Related Macular Degeneration Patients.

Age-related macular degeneration (AMD) is partially characterized by retinal pigment epithelial (RPE) cell dysfunction. This study focused on phagocytosis activity and its involvement in AMD. Phagocytic activity was analyzed by flow cytometry using porcine photoreceptor outer segment (POS) and fluorescent beads in basal and under oxidative stress condition induced by Fe-NTA in fifteen hiPSC-RPE cell lines (six controls, six atrophic AMD and three exudative AMD). Oxidative stress exposure inhibited phagocytosis in the same manner for control, atrophic AMD (AMDa) and exudative AMD (AMDe) cell lines. However, altered phagocytosis in basal condition in hiPSC-RPE AMDa/e was observed compared to control cell lines. Gene expression after 3 or 24 h of POS incubation was analyzed by RNA-Seq based transcriptomic profiling. Differential gene expression was observed by RNA seq after 3 and 24 h POS exposure. We have focused on the genes involved in mTOR/PI3K-AKT/MEK-ERK pathway. We investigated differences in gene expression by analyzing the expression levels and activity of the corresponding proteins by Western blot. We showed the involvement of three proteins essential for phagocytosis activity: fak, tuberin and rictor. These findings demonstrate that hiPSC-RPE AMDa/e cells have a typical disease phenotype characterized by alteration of the main function of RPE cells, phagocytosis activity.

Longitudinal changes in the ganglion cell-inner plexiform layer thickness of age-related macular degeneration.

PURPOSE: To determine longitudinal changes of the ganglion cell-inner plexiform layer (GC-IPL) thickness in patients with non-exudative age-related macular degeneration (AMD) without other ophthalmic disease. METHODS: Thirty-three eyes of 33 patients with early and intermediate non-exudative AMD (non-exudative AMD group) and 33 normal control eyes were followed for 2 years, and GC-IPL thickness was measured by spectral domain optical coherence tomography at 1-year intervals. The mean rate of GC-IPL reduction was estimated using a linear mixed model and compared between two groups. RESULTS: The mean age of patients in the non-exudative AMD group and control groups were 68.82 ± 6.81 years and 67.73 ± 5.87 years, respectively (p = 0.488). The mean GC-IPL thickness at the first visit was 76.61 ± 16.33 µm in the non-exudative AMD and 81.76 ± 3.69 µm in control group (p = 0.387), and these values significantly decreased over time, with an average reduction rate of average GC-IPL -0.86 µm/year in the non-exudative AMD group and -0.32 µm/year in the control group. The difference between two groups was statistically significant (p < 0.001), and there was also a significant interaction between group and duration in linear mixed models in mean GC-IPL thickness (p = 0.001). CONCLUSIONS: The reduction rate of the GC-IPL thickness was greater in non-exudative AMD eyes, even at relatively early stages of the disease. Physicians should maintain awareness of the presence of non-exudative AMD in various cases of ophthalmic diseases where GC-IPL thickness evaluation is necessary.

Genetic Association between MMP9 and Choroidal Neovascularization in Age-Related Macular Degeneration.

Purpose: To evaluate the first association specific to exudative age-related macular degeneration (AMD) located near the matrix metalloproteinase 9 (MMP9) gene. Design: Genetic association study. Participants: One thousand seven hundred twelve patients with AMD (672 nonexudative, 1040 exudative) of predominantly northern European descent seeking treatment at the University of Iowa Hospitals and Clinics. Methods: We reanalyzed the International AMD Genetics Consortium (IAMDGC) data to validate the association of polymorphisms near MMP9 with exudative AMD and to identify additional associated single nucleotide polymorphisms (SNPs), especially MMP9 coding sequence SNPs. We genotyped a cohort of 1712 AMD patients from Iowa with 3 SNPs identified with our analysis of the IAMDGC cohort using commercially available real-time quantitative polymerase chain reaction (PCR) assays. Firth regression was used to measure the association between MMP9 SNP genotypes and exudative AMD in our cohort of patients from Iowa. In addition, we developed a PCR-based assay to genotype the Iowa cohort at a short tandem repeat polymorphism (STRP) at the MMP9 locus. Main Outcome Measures: Odds ratios and P values for exudative compared with nonexudative AMD patients in the Iowa cohort for MMP9 SNPs (rs4810482, rs17576, and rs17577) and STRP. Results: We identified 3 SNPs in the MMP9 locus (rs4810482, rs17576, and rs17577) that are highly associated with exudative AMD in patient cohorts of the IAMDGC. These MMP9 SNPs also are associated with exudative AMD in the cohort of 1712 AMD patients from Iowa (rs4810482: odds ratio [OR], 0.82; P = 0.010; rs17576: OR, 0.86; P = 0.046; and rs17577: OR, 0.80; P = 0.041). We also genotyped the cohort of AMD patients from Iowa at rs142450006, another MMP9 polymorphism that previously was associated with exudative AMD. We detected a 4bp STRP, (TTTC)n, at the rs142450006 locus that is highly polymorphic and associated significantly with exudative AMD (OR, 0.78; P = 0.016). Conclusions: This study independently confirms and expands an association between the MMP9 locus and exudative AMD, further implicating a role for extracellular matrix abnormalities in choroidal neovascularization.

Biomarkers in Early Response to Brolucizumab on Pigment Epithelium Detachment Associated with Exudative Age-Related Macular Degeneration.

BACKGROUND: The purpose of this study was to describe early changes in the morphology of pigment epithelium detachments (PED) after an intravitreal injection of Brolucizumab into eyes with macular neovascularization secondary to exudative age-related macular degeneration (e-AMD). METHOD: We included twelve eyes of 12 patients with PED secondary to e-AMD which were not responding to prior anti-VEGF treatments. An ophthalmic examination and an assessment of PED-horizontal maximal diameter (PED-HMD), PED-maximum high (PED-MH) and macular neovascularization (MNV) flow area (MNV-FA) by the means of structural optical coherence tomography (OCT) and OCT Angiography (OCT-A) were performed at baseline, as well as 1, 7, 14 and 30 days after the injection. RESULTS: The mean age of the population of study was 78.4 (SD ± 4.8). The mean number of previous Ranibizumab or Aflibercept injections was 13 (SD ± 8). At the last follow-up visit, the PED-HMD did not significantly change (p = 0.16; F(DF:1.94, 20,85) = 1.9), the PED-MH showed a significant reduction [p = 0.01; F(DF:1.31, 14.13) = 6.84.] and the MNV-FA did not significantly differ (p = 0.1; F(1.97, 21.67) = 2.54) from baseline. No signs of ocular inflammation were observed during follow-up. CONCLUSIONS: A single Brolucizumab injection was able to determine the short-term effects on PEDs' anatomical features of eyes with an unresponsive e-AMD.

A Review of Completed and Ongoing Complement Inhibitor Trials for Geographic Atrophy Secondary to Age-Related Macular Degeneration.

Age-related macular degeneration (AMD) is a leading cause of irreversible blindness among older adults in the Western world. While therapies exist for patients with exudative AMD, there are currently no approved therapies for non-exudative AMD and its advanced form of geographic atrophy (GA). The discovery of genetic variants in complement protein loci with increased susceptibility to AMD has led to the investigation of the role of complement inhibition in AMD with a focus on GA. Here, we review completed and ongoing clinical trials evaluating the safety and efficacy of these studies. Overall, complement inhibition in GA has yielded mixed results. The inhibition of complement factor D has failed pivotal phase 3 trials. Studies of C3 and C5 inhibition meeting their primary endpoint are limited by high rates of discontinuation and withdrawal in the treatment arm and higher risks of conversion to exudative AMD. Studies evaluating other complement members (CFB, CFH, CFI and inhibitors of membrane attack complex-CD59) are ongoing and could offer other viable strategies.

Choriocapillaris Vascular Density Changes: Healthy vs. Advanced Exudative Age-Related Macular Degeneration Previously Treated with Multiple Anti-VEGF Intravitreal Injections.

PURPOSE: To assess choriocapillaris vascular density (VD) in healthy and advanced exudative age-related macular degeneration (ae-AMD) patients by new full-range optical coherence tomography angiography (OCT-A). METHOD: In this observational, cross-sectional study, 21 healthy and 21 ae-AMD eyes, already treated with anti-VEGF, were enrolled. Angio-View retina patterns centered on fovea (6.4 × 6.4 mm) were acquired for all participants using Solix full-range OCT (Optovue Inc., Freemont, CA, USA). The main outcome was to compare choriocapillaris VD between healthy and ae-AMD eyes. Automated measurements of whole image choriocapillaris VD (%) and fovea grid-based (%) were collected for the analysis. Angio-View patterns were used to assess the flow area (mm2) of macular neovascularization (MNV) by contour flow measure algorithm. Best-corrected visual acuity (BCVA) of both groups was also used for the statistical analysis. RESULTS: The mean age was 60.9 (±8.3) in healthy and 73.33 (±15.05) in ae-AMD eyes. The mean BCVA (ETDRS letters) was 98.47 (±1.50) in healthy and 7.04 (±5.96) in ae-AMD eyes. The Mann-Whitney test comparing choriocapillaries VD for whole and fovea healthy and ae-AMD eyes showed statistical significance (p < 0.0001 (t = 4.91; df = 40) and p < 0.0001 (t = 6.84; df = 40), respectively). Regarding, the correlation between MNV and VD of choriocapillaries, neither whole nor fovea areas were statistically significant (F = 0.38 (R2 = 0.01) and 1.68 (R2 = 0.08), respectively). CONCLUSIONS: Choriocapillaris VD showed a statistically significant reduction in comparison to healthy eyes in ae-AMD eyes. Choriocapillaris impairment can be seen in the early phase of MNV pathogenesis.

Hypo-angiogenesis: a possible pathological factor in the development of dry age-related macular degeneration and a novel therapeutic target.

Background: Angiogenesis causes severe vision loss in patients with exudative or wet forms of age-related macular degeneration (AMD). The pathogenesis involves upregulation of several proangiogenic factors, particularly the vascular endothelial growth factor (VEGF). Contrary to the pathogenesis of exudative AMD, molecular events leading to the development of dry AMD remain unclear. Dry AMD is characterized by loss of the retinal pigment epithelium (RPE). The mechanism that triggers RPE cell loss remains unclear. Choriocapillaris development is absent in mice with RPE-specific deletion of VEGF. Moreover, in later life, background VEGF secretion promotes the survival of the RPE and maintains choriocapillaris integrity. Hypothesis: We hypothesized that reduced synthesis of VEGF (hypo-angiogenesis) or abnormalities in its receptors, VEGF receptor-1 (VEGFR1) and VEGFR2, may be involved in the pathogenesis of non-exudative AMD or dry AMD. If the concept of hypo-angiogenesis as a driver for dry AMD is proven, treatment with VEGF or induction of angiogenesis could be considered. Similar attempts at therapeutic angiogenesis have been actively investigated in cardiac and limb ischemia. Conclusions: The reasons for a patient developing exudative AMD or dry AMD remain poorly understood. Nevertheless, targeting increased VEGF production in patients with exudative AMD using anti-VEGF drugs is highly efficacious in preserving vision. Similarly, dry AMD may be a manifestation of reduced VEGF synthesis (hypo-angiogenesis) and subsequent decreased RPE cell survival. Experimental studies exploring the possibility of reduced VEGF secretion and/or increased receptor resistance/abnormality could pave the way for clinical trials of angiogenesis to treat dry AMD.