Genetic Association of Age-Related Macular Degeneration and Polypoidal Choroidal Vasculopathy

Genome-wide association study of subfoveal choroidal thickness in a longitudinal cohort of older adults

To identify genetic influences on subfoveal choroidal thickness of older adults using a genome-wide association study (GWAS). We recruited 300 participants from the population-based Korean Longitudinal Study on Health and Aging (KLoSHA) and Korean Longitudinal Study on Cognitive Aging and Dementia (KLOSCAD) cohort studies and 500 participants from the Bundang age-related macular degeneration (AMD) cohort study dataset. We conducted a GWAS on older adult populations in the KLoSHA and KLOSCAD cohorts. Single nucleotide polymorphisms (SNPs) associated with choroidal thickness were identified with P values < 1.0 × 10-4 in both the right and left eyes, followed by validation using the Bundang AMD cohort dataset. This association was further confirmed by a functional in vitro study using human umbilical vein endothelial cells (HUVECs). The ages of the cohort participants in the discovery and validation datasets were 73.5 ± 3.3 and 71.3 ± 7.9 years, respectively. In the discovery dataset, three SNPs (rs1916762, rs7587019, and rs13320098) were significantly associated with choroidal thickness in both eyes. This association was confirmed for rs1916762 (genotypes GG, GA, and AA) and rs7587019 (genotypes GG, GA, and AA), but not for rs13320098. The mean choroidal thickness decreased by 56.7 μm (AA, 73.8%) and 31.1 μm (GA, 85.6%) compared with that of the GG genotype of rs1916762, and by 55.4 μm (AA, 74.2%) and 28.2 μm (GA, 86.7%) compared with that of the GG genotype of rs7587019. The SNPs rs1916762 and rs7587019 were located close to the FAM124B gene near its cis-regulatory region. Moreover, FAM124B was highly expressed in vascular endothelial cells. In vitro HUVEC experiments showed that the inhibition of FAM124B was associated with decreased vascular endothelial proliferation, suggesting a potential mechanism of choroidal thinning. FAM124B was identified as a susceptibility gene affecting subfoveal choroidal thickness in older adults. This gene may be involved in mechanisms underlying retinal diseases associated with altered choroidal thickness, such as age-related macular degeneration.

Relationship between CCL2 gene 2518A/G (rs1024611) polymorphism and age-related macular degeneration susceptibility: meta-analysis and trial sequential analysis

PURPOSE

This study aimed to investigate the association between the CC-cytokine ligand-2 (CCL2) 2518A/G (rs1024611) single nucleotide polymorphism (SNP) and susceptibility to age-related macular degeneration (AMD).

METHODS

PubMed, Embase, Web of Science, and other databases were searched for articles published before August 24, 2023. After searching, data extraction, and quality assessment, meta-analysis and trial sequential analysis were conducted using RevMan 5.4, Stata 17.0, and TSA 0.9.5.10 Beta software. Combined OR, P values, and 95% confidence intervals (CIs) were calculated. Sensitivity analysis, subgroup analysis and publication bias assessment were also performed.

RESULTS

Six articles, comprising 1186 cases and 1124 controls, were included. No significant statistical difference was found in six main outcomes. However, due to observed heterogeneity and high sensitivity, subgroup analysis was performed, revealing statistically significant differences across different regions. No significant publication bias was observed. Trial sequential analysis suggested the need for additional follow-up case-control studies to further validate the findings.

CONCLUSION

The CCL2 gene 2518A/G (rs1024611) polymorphism is associated with AMD susceptibility. Among Caucasian populations in West Asia and Europe, the G allele is protective against AMD, whereas in East and South Asia, it poses a risk factor.

Genetic Insights into Age-Related Macular Degeneration

One of the major causes of vision impairment among elderly people in developed nations is age-related macular degeneration (AMD). The distinctive features of AMD are the accumulation of extracellular deposits called drusen and the gradual deterioration of photoreceptors and nearby tissues in the macula. AMD is a complex and multifaceted disease influenced by several factors such as aging, environmental risk factors, and a person's genetic susceptibility to the condition. The interaction among these factors leads to the initiation and advancement of AMD, where genetic predisposition plays a crucial role. With the advent of high-throughput genotyping technologies, many novel genetic loci associated with AMD have been identified, enhancing our knowledge of its genetic architecture. The common genetic variants linked to AMD are found on chromosome 1q32 (in the complement factor H gene) and 10q26 (age-related maculopathy susceptibility 2 and high-temperature requirement A serine peptidase 1 genes) loci, along with several other risk variants. This review summarizes the common genetic variants of complement pathways, lipid metabolism, and extracellular matrix proteins associated with AMD risk, highlighting the intricate pathways contributing to AMD pathogenesis. Knowledge of the genetic underpinnings of AMD will allow for the future development of personalized diagnostics and targeted therapeutic interventions, paving the way for more effective management of AMD and improved outcomes for affected individuals.

Genetic association of TIE2 with diabetic retinopathy and diabetic macular edema

PURPOSE

To evaluate the associations of the TIE2 gene with diabetic retinopathy (DR) and diabetic macular edema (DME).

METHODS

This study included a Chinese cohort of 285 non-proliferative DR patients and 433 healthy controls. The DR patients were classified further into those with or without DME. Thirty haplotype-tagging single-nucleotide polymorphisms (SNPs) in TIE2 were genotyped using TaqMan technology. Associations of DR and subtypes were analyzed by logistic regression adjusted for age and sex. Stratification association analysis by sex was performed.

RESULTS

TIE2 rs625767 showed a nominal but consistent association with DR [odds ratio (OR) = 0.71, P = 0.005] and subtypes (DR without DME: OR = 0.69, P = 0.016; DME: OR = 0.73, P = 0.045). SNP rs652010 was consistently associated with overall DR (OR = 0.74, P = 0.011) and DR without DME (OR = 0.70, P = 0.016), but not with DME. Moreover, SNPs rs669441, rs10967760, rs549099 and rs639225 showed associations with overall DR, whilst rs17761403, rs664461 and rs1413825 with DR without DME. In stratification analysis, three SNPs, rs625767 (OR = 0.62, P = 0.005), rs669441 (OR = 0.63, P = 0.006) and rs652010 (OR = 0.64, P = 0.007), were associated with DR in females, but not in males. Moreover, one haplotype T-T defined by rs625767 and rs669441 was significantly associated with DR in females only.

CONCLUSIONS

This study revealed TIE2 as a susceptibility gene for DR and DME in Chinese, with a sex-specific association in females. Further validation should be warranted.

Macular neovascularization and polypoidal choroidal vasculopathy: phenotypic variations, pathogenic mechanisms and implications in management

Advances in imaging have led to improved ability to characterize variations in clinical sub-phenotypes of macular neovascularization (MNV) in Age-related macular degeneration (AMD). Polypoidal choroidal vasculopathy (PCV) was initially described based on characteristic features observed in indocyanine green angiography (ICGA) and was thought to be a distinct entity from AMD. However, subsequent careful observations based on confocal scanning laser ophthalmoscopy-based ICGA, optical coherence tomography (OCT) and OCT angiography have led researchers to appreciate similarities between PCV lesion and type 1 MNV in typical neovascular AMD. Concurrently, clinical trials have shown that anti-VEGF monotherapy can achieve favourable visual outcome in the majority of eyes with PCV. These learnings have led to a shift in the way PCV is managed over the past decade. Recent studies have supported the use of non-ICGA based imaging modality to screen for PCV and the adoption of anti-VEGF monotherapy as initial therapy for PCV. A focus of recent research has been in the understanding of the role of choroidal alterations in the pathogenesis of PCV. The concept of pachychoroid in leading to outer retinal ischemia has garnered increasing support. Future research in this area should evaluate the potential of choroidal morphology in guiding personalized therapy in PCV.

Twenty-four-month real-life treatment outcomes of polypoidal choroidal vasculopathy versus type 1 macular neovascularization in Caucasians

BACKGROUND

To compare 24-month real-world outcomes of Vascular Endothelial Growth Factor (VEGF) inhibitors for Polypoidal Choroidal Vasculopathy (PCV) and type 1 Macular Neovascularization (MNV) in a Caucasian population.

METHODS

Retrospective analysis from a prospectively designed observational database. Data from Italian centres participating in the Fight Retinal Blindness! (FRB!) project were collected. Treatment-naïve PCV or type 1 MNV commencing treatment after January 2009 were included. The primary outcome was 24-month visual acuity (VA) change; other outcomes included baseline characteristics, number of anti-VEGF injections, time to lesion inactivation and proportion of active visits.

RESULTS

A total of 322 eyes (114 PCVs) from 291 patients were included. Median [Q1, Q3] VA at baseline was comparable (70 [55, 75.8] vs. 70 [58.8, 75] letters, p = 0.95). Adjusted VA change at 2 years was higher in PCV (mean [95% CI], +1.2 [-1.6, 4.1] vs. -3.6 [-6, -1.2] letters, p = 0.005). PCV received fewer anti-VEGF injections over the first 24 months of treatment than type 1 MNV (median [Q1, Q3], 8 [5, 10] vs. 9 [7, 12.2] injections, p = 0.001), inactivated earlier (median [Q1, Q3], 235 [184, 308] vs. 252 [169, 343] days, p = 0.04) and was less frequently graded 'active' (62% vs. 68% of visits, p = 0.001).

CONCLUSIONS

PCV had slightly better VA outcomes over 24 months of treatment than type 1 MNV after receiving less anti-VEGF injections. These results suggest a possible overlap of the two clinical entities with similar visual prognosis in Caucasians.

Vortex vein engorgement and different shapes of venous drainage systems in polypoid choroidal vasculopathy vs. age‑related macular degeneration on indocyanine green angiography

There are differences in vortex vein engorgement and appearance in polypoid choroidal vasculopathy (PCV), age-related macular degeneration (AMD), and healthy eyes. The present study aimed to use indocyanine green angiography (ICGA) to find a simple, clinically meaningful method for evaluating the filling degree of vortex veins in various eye diseases. Participant clinical characteristics were recorded. The number of vortex veins (NVV), central vortex vein diameter (CVVD), mean root area of the vortex vein (MRAVV), mean diameter of the thickest peripheral branch (MDPTB), subfoveal choroidal thickness and percentage of vortex vein anastomosis (PVVA) were obtained by marking the vortex veins on ICGA. The proportion of subretinal haemorrhage and the numbers and types of vortex veins in each quadrant were counted separately. The CVVD and MDPTB were significantly increased in the PCV compared with those in the AMD group (P<0.05). The CVVD, MRAV, and PVVA were significantly increased in the PCV compared with those in the healthy group (P<0.05). The type IV vortex vein (complete with ampulla) proportion was the lowest while the type I (vortex vein absent) proportion was the highest in the PCV group (P<0.001). NVV in the inferior-temporal region was increased in the PCV compared with that in the AMD group (P=0.034). Subretinal haemorrhage occurred in the inferior temporal choroid in 47.62% of examined eyes in PCV group, and in the superior temporal choroid in 23.81% of the PCV group, with significant differences between the quadrants (P<0.001). Vortex vein engorgement and shape differed significantly between PCV, AMD and healthy eyes. The vortex vein branches in PCV eyes were significantly dilated in the posterior pole; moreover, the peripheral choroid and the lower proportion of type IV vortex veins may be pathognomonic for PCV.

Subfoveal choroidal thickness as a potential predictor of treatment response after intravitreal ranibizumab injections for polypoidal choroidal vasculopathy

OBJECTIVE

To evaluate the impact of subfoveal choroidal thickness (SFCT) and other clinical biomarkers in intravitreal anti-vascular endothelial growth factor response in treatment-naive Caucasian patients diagnosed with polypoidal choroidal vasculopathy (PCV/AT1).

DESIGN

Cross-sectional study.

PARTICIPANTS

Treatment-naive patients diagnosed with PCV/AT1 recruited in a single centre from January 2013 to December 2020.

METHODS

Eligibility was determined in treatment-naive PCV patients who received a loading dose of 3 injections of 0.5 mg ranibizumab. A diagnosis of PCV/AT1 was made based on the diagnostic criteria in the efficacy and safety of verteporfin photodynamic therapy in combination with ranibizumab or alone versus ranibizumab monotherapy in patients with sumptomatic macular polypoidal choroidal vasculopathy study. Choroidal thickness was manually measured by enhanced depth imaging technology in Spectralis spectral domain optical coherence tomography.

RESULTS

Eighty-three eyes of 83 patients were included in this study, 47 patients diagnosed with PCV/AT1 with a good response to 3 intravitreal injections of ranibizumab and 36 with a poor response. The receiver operating characteristic curve of treatment effect against the SFCT revealed that the area under the curve was 0.85 (range, 0.74-0.96). Based on the Youden index, the optimal SFCT cut-off point for predicting a poor response to anti-vascular endothelial growth factor is 257 µm. In the multivariate analysis, the SFCT remained statistically significant (odds ratio 1.02 [range, 1.01-1.04]; P = 0.008). The combined effect of treatment effect against clinical biomarkers produced an area under the curve of 0.90 (range, 0.82-0.98).

CONCLUSION

SFCT is a risk factor for a poor response to the 3 loading injections of ranibizumab in treatment-naive PCV/AT1 Caucasian patients. A cut-off point of 257 µm could be a valuable parameter for defining the population at risk for an inadequate response to ranibizumab.

Association between glycemic status and age-related macular degeneration: A nationwide population-based cohort study

AIM

The risk of dry and wet age-related macular degeneration (AMD) based on fasting glucose levels and disease duration of type 2 diabetes was investigated.

METHODS

Using a health insurance claims database and the results of health examinations in South Korea, we conducted a retrospective, population-based cohort study of 2,103,604 adults ≥ 45 years of age who were AMD-free based on health checkups in 2009 and observed from January 1, 2011, to December 31, 2018. Glycemic status was classified into five groups: normal, impaired fasting glucose, new-onset diabetes (fasting glucose level ≥ 126 mg/dl but no diabetes diagnosis or diabetes medication), diabetes diagnosis < 5 years, and diabetes ≥ 5 years. According to the presence and absence of choroidal neovascularization, AMD was classified as wet AMD and dry AMD, respectively. Adjusted hazard ratios (HRs) of AMD occurrence were estimated in each category.

RESULTS

For dry AMD (n = 36,271, 1.72%), the HR was 1.192 (1.141-1.245) among subjects with diabetes < 5 years and 1.294 (1.242-1.349) among subjects with diabetes ≥ 5 years compared with subjects with normal glycemic status after adjusting for age, sex, body mass index, lifestyle, and medical history. For wet AMD (n = 12,912, 0.61%), the HR was 1.103 (1.011-1.203) among subjects with new-onset diabetes, 1.252 (1.167-1.344) among subjects with diabetes < 5 years, and 1.506 (1.413-1.605) among subjects with diabetes ≥ 5 years. The HR of AMD was significantly increased among participants ≤ 65 years old and those who did not have hypertension.

CONCLUSIONS

The incidence of dry and wet AMD increased among diabetes patients compared to the normal glycemic status group. These risks increased when the duration of diabetes was 5 years or more. The risk of wet AMD was increased among new-onset diabetes patients. These results suggest that high blood glucose levels without treatment might induce the vision-threatening condition of wet AMD, emphasizing the importance of early blood glucose management.

Polypoidal Choroidal Vasculopathy: Updates on Risk Factors, Diagnosis, and Treatments

There have been recent advances in basic research and clinical studies in polypoidal choroidal vasculopathy (PCV). A recent, large-scale, population-based study found systemic factors, such as male gender and smoking, were associated with PCV, and a recent systematic review reported plasma C-reactive protein, a systemic biomarker, was associated with PCV. Growing evidence points to an association between pachydrusen, recently proposed extracellular deposits associated with the thick choroid, and the risk of development of PCV. Many recent studies on diagnosis of PCV have focused on applying criteria from noninvasive multimodal retinal imaging without requirement of indocyanine green angiography. There have been attempts to develop deep learning models, a recent subset of artificial intelligence, for detecting PCV from different types of retinal imaging modality. Some of these deep learning models were found to have high performance when they were trained and tested on color retinal images with corresponding images from optical coherence tomography. The treatment of PCV is either a combination therapy using verteporfin photodynamic therapy and anti-vascular endothelial growth factor (VEGF), or anti-VEGF monotherapy, often used with a treat-and-extend regimen. New anti-VEGF agents may provide more durable treatment with similar efficacy, compared with existing anti-VEGF agents. It is not known if they can induce greater closure of polypoidal lesions, in which case, combination therapy may still be a mainstay. Recent evidence supports long-term follow-up of patients with PCV after treatment for early detection of recurrence, particularly in patients with incomplete closure of polypoidal lesions.

Aqueous microRNA profiling in age-related macular degeneration and polypoidal choroidal vasculopathy by next-generation sequencing

Although many studies demonstrated the differences of clinical features, natural course, and response to treatment between typical age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV), differential microRNAs (miRNAs) expression in the aqueous humor (AH) between them has not been reported yet. We investigated the roles of miRNAs in the AH of patients with typical AMD and PCV using next-generation sequencing (NGS) and quantitative PCR (qPCR). Target genes and predicted pathways of miRNAs were investigated via pathway enrichment analysis using the Kyoto Encyclopedia of Genes and Genomes database. A total of 161 miRNAs from eyes with typical AMD and 185 miRNAs from eyes with PCV were differentially expressed. 33 miRNAs were commonly upregulated, and 77 miRNAs were commonly downregulated in both typical AMD and PCV groups. Among them, hsa-miR-140-5p, hsa-miR-374c-3p, and hsa-miR-200a-5p were differentially expressed and were predicted to regulate proteoglycans in cancer, p53 signaling pathway, Hippo signaling pathway, and adherens junction. The differential expression profiles and target gene regulation networks of AH miRNAs may contribute to the development of different pathological phenotypes in typical AMD and PCV. The results of this study provide novel insights into the pathogenesis, associated prognostic biomarkers, and therapeutic targets in AMD and PCV.

Current Trends in Clinical Characteristics, Diagnosis, and Treatment of Polypoidal Choroidal Vasculopathy: A Perspective from Vietnam

Polypoidal choroidal vasculopathy (PCV) is a common choroidal disease in the Asian population including Vietnam and is characterized by subretinal red-orange nodules, pigmented epithelium detachment, and massive subretinal hemorrhage. The recent focus on PCV in Vietnam can be attributed to advancements in PCV diagnosis and treatment. However, there is a scarcity of published literature and clinical data on PCV in the Vietnamese population, highlighting a key knowledge gap in this region. In order to address this gap, we gathered the opinions of experienced clinicians and retinal experts in Vietnam and reviewed available medical literature with the aim of: (i) providing an overview of PCV in the Vietnamese population—in terms of epidemiology, clinical characteristics, and management; (ii) tailoring international/national guidelines for the diagnosis and management of PCV, in line with available resources and medical equipment in Vietnam; and (iii) identifying gaps in clinical data in order to guide future PCV research in Vietnam and other countries with similar clinical conditions. The present review will enable healthcare providers and researchers to gain insight into current clinical practices and the limitations of PCV management in Vietnam and provide optimal and effective solutions.

Extensive macular atrophy with pseudodrusen-like: Case series and review

PURPOSE

To describe the clinical characteristics of two patients affected by extensive macular atrophy with pseudodrusen-like (EMAP).

METHODS

Two patients affected by EMAP underwent multimodal imaging, including fundus autofluorescence and optical coherence tomography.

RESULTS

The patients showed the typical clinical appearance with macular atrophy with larger vertical axis surrounded by pseudodrusen-like deposits involving the midperiphery, associated with paving stone lesions in the retinal periphery.

CONCLUSION

EMAP is a complex condition sharing clinical characteristics of age-related macular degeneration. Further studies are warranted to identify the early biomarker of the disease.

Etiopathogenesis of non-exudative age-related macular degeneration (literature review)

The article presents an overview of modern publications on epidemiology, risk factors, and the main links of the etiology and pathogenesis of age-related macular degeneration (AMD). The nonexudative or “dry” form of age-related macular degeneration is a multifactorial progressive pathological process caused by hereditary predisposition, general and local disorders of lipid metabolism, negative changes in  the blood supply to the eye, age-related destruction of the Bruch’s membrane and retinal pigment epithelium, the appearance of signs of local and systemic inflammation, the development of oxidative stress with the impact of toxic lipoperoxidation products on the structures of the posterior segment of the eye. Recent studies have discovered new ways of retinal pigment epithelial cell death in response to oxidative stress in AMD, in particular necroptosis, which, in addition to classical apoptosis, is considered the main mechanism of this process. It is noted that the development of AMD may be associated with an age-related decrease in the level of estrogen in women. The analysis of the data on the etiopathogenesis of age-related macular degeneration presented in the modern literature indicates the need for further research and generalization of local and general pathological processes developing in the dynamics of retinal visual function disorders by specialists of various scientific disciplines. 

Multimodal Imaging Comparison of Polypoidal Choroidal Vasculopathy Between Asian and Caucasian Populations

PURPOSE

Differences in multimodal imaging features between Asian and Caucasian eyes may contribute to our understanding of the etiology of the polypoidal choroidal vasculopathy (PCV). The purpose of this study was to compare the multimodal imaging features of Asian and Caucasian eyes with PCV.

DESIGN

Cross-sectional, retrospective, multicenter, observational case series.

METHODS

Consecutive treatment-naïve patients diagnosed with PCV based on indocyanine green angiography in accordance with published guidelines. Demographic and multimodal imaging findings based on color fundus photography, spectral domain optical coherence tomography, fluorescein angiography, and indocyanine green angiography were graded.

RESULTS

A total of 250 participants with PCV (128 Asian vs 122 Caucasian participants) were included. Asian participants presented with lower best-corrected visual acuity (mean ± SD: 0.7 ± 0.6 logMAR vs 0.4 ± 0.3 logMAR; P < .001) compared with Caucasian participants. More Asian eyes had subretinal hemorrhage (mean ± SD: 53.9% vs 24.6%; P < .001) and larger areas of hemorrhage (mean ± SD: 7.5 ± 15.2 mm² vs 1.3 ± 3.3 mm²; P < .001). More Asian eyes had pachyvessels (84.4% vs 28.7%; P < .001), choroidal vascular hyperpermeability (70.3% vs 17.2%; P < .001), and widespread polypoidal lesions (19.5% vs 8.2%; P = .005), and Caucasian eyes had more drusen (79.5% vs 49.2%; P = .02).

CONCLUSIONS

Multimodal imaging analysis revealed ethnic differences in disease characteristics of PCV, suggesting pathophysiologic mechanism of the disease vary based on ethnicity.

Treat-and-Extend Regimens for the Management of Neovascular Age-related Macular Degeneration and Polypoidal Choroidal Vasculopathy: Consensus and Recommendations From the Asia-Pacific Vitreo-retina Society

PURPOSE

Review and provide consensus recommendations on use of treat-and-extend (T&E) regimens for neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy (PCV) management with relevance for clinicians in the Asia-Pacific region.

METHODS

A systematic search of MEDLINE, EMBASE, and Cochrane databases, and abstract databases of the Asia-Pacific Vitreo-retina Society, European Society of Retina Specialists, American Academy of Ophthalmology, and Controversies in Ophthalmology: Asia-Australia congresses, was conducted to assess evidence for T&E regimens in nAMD. Only studies with ≥100 study eyes were included. An expert panel reviewed the results and key factors potentially influencing the use of T&E regimens in nAMD and PCV, and subsequently formed consensus recommendations for their application in the Asia-Pacific region.

RESULTS

Twenty-seven studies were included. Studies demonstrated that T&E regimens with aflibercept, ranibizumab, or bevacizumab in nAMD, and with aflibercept in PCV, were efficacious and safe. The recommendation for T&E is, after ≥3 consecutive monthly loading doses, treatment intervals can be extended by 2 to 4 weeks up to 12 to 16 weeks. When disease activity recurs, the recommendation is to reinject and shorten intervals by 2 to 4 weeks until fluid resolution, after which treatment intervals can again be extended. Intraretinal fluid should be treated until resolved; however, persistent minimal subretinal fluid after consecutive treatments may be tolerated with treatment intervals maintained or extended if the clinical condition is stable.

CONCLUSIONS

T&E regimens are efficacious and safe for nAMD and PCV, can reduce the number of visits, and minimize the overall burden for clinicians and patients.

Binding of Gtf2i-β/δ transcription factors to the ARMS2 gene leads to increased circulating HTRA1 in AMD patients and in vitro

The disease-initiating molecular events for age-related macular degeneration (AMD), a multifactorial retinal disease affecting many millions of elderly individuals worldwide, are still unknown. Of the over 30 risk and protective loci so far associated with AMD through whole genome-wide association studies (GWAS), the Age-Related Maculopathy Susceptibility 2 (ARMS2) gene locus represents one of the most highly associated risk regions for AMD. A unique insertion/deletion (in/del) sequence located immediately upstream of the High Temperature Requirement A1 (HTRA1) gene in this region confers high risk for AMD. Using electrophoretic mobility shift assay (EMSA), we identified that two Gtf2i-β/δ transcription factor isoforms bind to the cis-element 5'- ATTAATAACC-3' contained in this in/del sequence. The binding of these transcription factors leads to enhanced upregulation of transcription of the secretory serine protease HTRA1 in transfected cells and AMD patient-derived induced pluripotent stem cells (iPSCs). Overexpression of Htra1 in mice using a CAG-promoter demonstrated increased blood concentration of Htra1 protein, caused upregulation of vascular endothelial growth factor (VEGF), and produced a choroidal neovascularization (CNV)-like phenotype. Finally, a comparison of 478 AMD patients to 481 healthy, age-matched controls from Japan, India, Australia, and the USA showed a statistically increased level of secreted HTRA1 blood concentration in AMD patients compared with age-matched controls. Taken together, these results suggest a common mechanism across ethnicities whereby increased systemic blood circulation of secreted serine protease HTRA1 leads to subsequent degradation of Bruch's membrane and eventual CNV in AMD.