Jennyfer Zerbib

Rare variants in CFI, C3 and C9 are associated with high risk of advanced age-related macular degeneration.

To define the role of rare variants in advanced age-related macular degeneration (AMD) risk, we sequenced the exons of 681 genes within all reported AMD loci and related pathways in 2,493 cases and controls. We first tested each gene for increased or decreased burden of rare variants in cases compared to controls. We found that 7.8% of AMD cases compared to 2.3% of controls are carriers of rare missense CFI variants (odds ratio (OR) = 3.6; P = 2 × 10−8). There was a predominance of dysfunctional variants in cases compared to controls. We then tested individual variants for association with disease. We observed significant association with rare missense alleles in genes other than CFI. Genotyping in 5,115 independent samples confirmed associations with AMD of an allele in C3 encoding p.Lys155Gln (replication P = 3.5 × 10−5, OR = 2.8; joint P = 5.2 × 10−9, OR = 3.8) and an allele in C9 encoding p.Pro167Ser (replication P = 2.4 × 10−5, OR = 2.2; joint P = 6.5 × 10−7, OR = 2.2). Finally, we show that the allele of C3 encoding Gln155 results in resistance to proteolytic inactivation by CFH and CFI. These results implicate loss of C3 protein regulation and excessive alternative complement activation in AMD pathogenesis, thus informing both the direction of effect and mechanistic underpinnings of this disorder.

rs5888 variant of SCARB1 gene is a possible susceptibility factor for age-related macular degeneration.

Major genetic factors for age-related macular degeneration (AMD) have recently been identified as susceptibility risk factors, including variants in the CFH gene and the ARMS2 LOC387715/HTRA1locus. Our purpose was to perform a case-control study in two populations among individuals who did not carry risk variants for CFHY402H and LOC387715 A69S (ARMS2), called “study” individuals, in order to identify new genetic risk factors. Based on a candidate gene approach, we analyzed SNP rs5888 of the SCARB1 gene, coding for SRBI, which is involved in the lipid and lutein pathways. This study was conducted in a French series of 1241 AMD patients and 297 controls, and in a North American series of 1257 patients with advanced AMD and 1732 controls. Among these individuals, we identified 61 French patients, 77 French controls, 85 North American patients and 338 North American controls who did not carry the CFH nor ARMS2 polymorphisms. An association between AMD and the SCARB1 gene was seen among the study subjects. The genotypic distribution of the rs5888 polymorphism was significantly different between cases and controls in the French population (p<0.006). Heterozygosity at the rs5888 SNP increased risk of AMD compared to the CC genotypes in the French study population (odds ratio (OR) = 3.5, CI95%: 1.4–8.9, p<0.01) and after pooling the 2 populations (OR = 2.9, 95% CI: 1.6–5.3, p<0.002). Subgroup analysis in exudative forms of AMD revealed a pooled OR of 3.6 for individuals heterozygous for rs5888 (95% CI: 1.7–7.6, p<0.0015). These results suggest the possible contribution of SCARB1, a new genetic factor in AMD, and implicate a role for cholesterol and antioxidant micronutrient (lutein and vitamin E) metabolism in AMD.

Genotype-phenotype correlations for exudative age-related macular degeneration associated with homozygous HTRA1 and CFH genotypes.

PURPOSE Major genetic factors for age-related macular degeneration (AMD) have recently been identified as susceptibility risk factors, including polymorphisms of HTRA1 and CFH genes. The purpose was to analyze the angiographic features of patients harboring homozygous genotypes for HTRA1 and CFH genes in a French exudative AMD population. METHODS Two hundred patients affected with exudative AMD were genotyped for the polymorphisms rs11200638 of the HTRA1 gene and rs10611710 of the CFH gene. Four homozygous groups were extracted from the entire cohort: double homozygous for wild-type alleles of both genes (group 1), homozygous for the polymorphism of the HTRA1 gene only (group 2), homozygous for the polymorphism of the CFH gene only (group 3), and double homozygous carriers for both polymorphisms (group 4). Choroidal neovascularization (CNV) was graded as classic and predominantly classic (PC), occult, minimally classic (MC), or retinal angiomatosis proliferation (RAP). RESULTS Group 1 (n = 9) presented 44.4% classic and PC, 33.3% occult, 11.1% MC, and 11.1% RAP. Group 2 (n = 12) presented 50.0% classic and PC, 33.3% occult, no MC CNV and 16.7% RAP. Group 3 (n = 28) presented 10.7% classic and PC, 67.9% occult, 14.3% MC, and 7.1% RAP. Group 4 (n = 17) presented 29.4% classic and PC, 52.9% occult, 11.8% MC, and 5.9% RAP. Occult CNV or MC CNV was more frequently observed in group 3 than in group 2 (82.1% vs 33.3%; P < 0.02). Classic and PC CNV were more frequently observed in group 2 than in group 3 (50% vs. 10.7%; P < 0.03). CONCLUSIONS This attempt at a genotypic-angiographic correlation in an exudative AMD sample suggests an association between occult or MC CNV and the CFH polymorphism and between classic and PC CNV and the HTRA1 polymorphism.

Genotypic Influences on Severity of Exudative Age-Related Macular Degeneration

PURPOSE Major genetic risk factors have recently been identified for age-related macular degeneration (AMD), including the ARMS2/LOC387715 and CFH at-risk polymorphisms. The study was conducted to establish correlations between the AMD genotype and both the phenotype and severity of AMD. METHODS In a prospective cohort of 1216 AMD patients, four genotypic homozygous groups were identified (n = 264): double homozygous for wild-type alleles (group 1, n = 49), homozygous for the at-risk allele of ARMS2/LOC387715 only (group 2, n = 57), homozygous for the at-risk allele of CFH only (group 3, n = 106), and double homozygous for both at-risk alleles (group 4, n = 52). The phenotypic classification of exudative AMD was based on fluorescein angiography. RESULTS Mean age at presentation was significantly lower in group 4 than in group 1 (P < 0.014). Patients in group 4 presented more often with bilateral CNV and fibrovascular scars than did patients in group 1 (P < 0.001 and < 0.0031 respectively) and with significantly lower visual acuity (VA) in the first affected eye than did patients in group 1 (P < 0.02). Patients in group 2 presented with worse VA than did patients in group 3 (P < 0.003). Classic CNV was more commonly associated with the at-risk allele of the ARMS2/LOC387715 locus than with the at-risk allele of the CFH gene (P < 0.026). CONCLUSIONS This study demonstrates an association between the at-risk allele of the ARMS2/LOC387715 locus and classic CNV, fibrovascular lesions, and poor VA. Individuals double homozygous for both at-risk alleles had a higher risk of being affected with a severe form of AMD at an earlier age.

Genetic factors associated with age-related macular degeneration.

Age-related macular degeneration (AMD) is a complex, multifactorial disease associated with environmental and genetic factors. This review emphasizes the clinical impact of the major genetic factors mainly located in the complement factor H gene and on the 10q26 locus, and their current and future implications for the management of AMD.

Genetic and environmental factors associated with reticular pseudodrusen in age-related macular degeneration.

Purpose: To analyze the genetic and environmental factors associated with reticular pseudodrusen (RPD) in age-related macular degeneration (AMD). Methods: In a large population, AMD patients (n = 519) with and without RPD were assessed with a standardized examination including infrared images and spectral domain optical coherence tomography scans. Three groups were defined: Group 1: AMD patients with RPD (n = 105); Group 2: AMD patients without RPD (n = 414); and Group 3: controls with no AMD and no RPD (n = 430). Four genes associated with AMD (CFH, ARMS2/HTRA1, C3, apolipoprotein E) and environmental factors were assessed between the 3 groups. Results: None of the environmental factors studied were more significantly associated to either Group 1 or Group 2. The odds ratios and 95% confidence intervals for individuals homozygous for the CFH risk allele were 4.0 (2.1–7.7) ([95% confidence interval: 2.1–7.7]; P < 0.0004) in Group 1 and 4.3 ([2.6–7.1]; P < 0.0004) in Group 2, compared with Group 3. The odds ratios for individuals homozygous for the ARMS2 risk allele for Groups 1 and 2 compared with Group 3 were 16.3 ([7.6–35.4]; P < 0.0004) and 11.9 ([6.3–22.3]; P < 0.0004), respectively. None of the genotypes studied were more significantly associated to Group 1 than Group 2. Conclusion: Genotypes known to be associated with AMD were similarly observed in patients with and without RPD.

The Spectrum of Subclinical Best Vitelliform Macular Dystrophy in Subjects with Mutations in BEST1 Gene

PURPOSE To describe the morphologic and functional characteristics of subclinical Best vitelliform macular dystrophy (VMD) in subjects with mutation in the BEST1 gene. METHODS Best-corrected visual acuity (BCVA), funduscopic appearance, fundus autofluorescence (FAF), spectral-domain optical coherence tomography (SD-OCT), and electro-oculography (EOG) were assessed in 23 consecutive subjects from nine unrelated families with known mutations in the BEST1 gene (eight distinct BEST1 mutations). RESULTS Six subjects were identified with BEST1 mutations (three male, three female; aged 8 to 30 years) without clinically detectable (subclinical) Best VMD (absence of both symptoms and funduscopic lesions). All six subjects showed 20/20 BCVA and normal FAF findings. In these 6 of 26 subjects from five different families, we found five distinct mutations in the BEST1 gene. In three (six eyes) out of these six subjects with BEST1 gene mutations (two families: p.G15D; p.A243V), SD-OCT showed overall normal findings. In the other three subjects (six eyes) with BEST1 gene mutations (three families: p.V9A; p.R92C; p.I230T), we found, on SD-OCT, a thicker and more reflective appearance of the layer between the retinal pigment epithelium and the interface of inner segments and outer segments of the photoreceptor (the Verhoeffs membrane). EOG showed a reduced light-peak:dark-trough ratio in 5 of 12 eyes. Changes on SD-OCT were present in the absence of EOG abnormalities (two of six eyes), and vice versa (one of six eyes). CONCLUSIONS Subclinical Best VMD (absence of both symptoms and funduscopic lesions) in subjects with BEST1 mutation may vary from the absence of any morphologic and functional abnormalities to the presence of specific SD-OCT and EOG changes.

Hyperreflective Pyramidal Structures On Optical Coherence Tomography In Geographic Atrophy Areas

Purpose: We observed hyperreflective dome-shaped or pyramidal structures (HPS) on spectral domain optical coherence tomography (SD-OCT) in patients affected with geographic atrophy (GA). Our purpose was to describe the multimodal imaging features of HPS identified in areas of GA in patients with age-related macular degeneration. Methods: This is a retrospective case series of patients with GA harboring HPS in atrophic areas. Multimodal imaging examination including infrared reflectance, fundus autofluorescence, and SD-OCT, was performed for each patient. Infrared and fundus autofluorescence appearance and mean SD-OCT height of HPS in GA were analyzed. Results: A total of 36 eyes of 25 patients (20 women; mean age, 82.3 ± 5.9 years, range, 73–92 years) with GA were included. A total of 96 HPS in GA were analyzed by SD-OCT. In all HPS (96/96, 100%), the peripheral part was hyperreflective. In 66 of 96 HPS (69%), the center was heterogeneously hyperreflective, whereas in 30 of 96 HPS (31%), the center was hyporeflective. On infrared reflectance images, HPS in GA appeared as hyporeflective lesions surrounded by hyperreflective halos, within an area of background hyperreflectivity because of GA in all eyes. On fundus autofluorescence, 39 of 96 HPS (41%) were heterogeneously hyperautofluorescent, whereas 57 of 96 HPS (59%) were hypoautofluorescent. Mean height of HPS was 91 ± 50.9 &mgr;m in the foveal scan (range, 42–291 &mgr;m). Conclusion: We describe a multimodal imaging of distinctive lesions that presented as hyperreflective pyramidal structures on SD-OCT. We suggest the name “ghost drusen” because these HPS appear in GA areas, and because of their pyramidal or dome-shaped aspect on SD-OCT.

En face enhanced depth imaging optical coherence tomography features in adult onset foveomacular vitelliform dystrophy

BackgroundOur purpose was to describe the different morphological features in adult onset foveomacular vitelliform dystrophy (AOFVD), using en face enhanced depth imaging (EDI) spectral-domain optical coherence tomography (SD-OCT).MethodsThirty eyes of 22 consecutive patients presenting with diagnosis of AOFVD were enrolled. Diagnosis of AOFVD was concluded based on fundus examination, autofluorescence imaging, fluorescein angiography and SD-OCT. En face OCT imaging was obtained with the Spectralis EDI SD-OCT; 97 inverted sections (nine averaged B-scans per image) were acquired.ResultsOn en face OCT, vitelliform lesions appeared as regular concentric rings of different reflectivity. From the periphery to center of the ring, we observed: (1) the hypereflective ring representing the inner segment/ outer segment (IS/OS) junction, which was continuous in 23 out of 30 eyes, and (2) a well-detectable hyporeflective ring between the IS/OS junction and vitelliform material in 20 out of 30 eyes; the innermost composant of the lesion was hypereflective, and it corresponded to vitelliform material. In eight out of 30 eyes, a hyporeflective “croissant”-shaped lesion with inferior concavity in the upper part of the hyperreflective material was present. Hypereflective retinal pigment epithelium (RPE) elevations or bumps were detected in 25 out of 30 eyes. These areas of focal RPE thickening or bumps appeared to be intensely hypereflective on infrared reflectance imaging.ConclusionEn face imaging of the retina helps visualizing the distribution of vitelliform material in AOFVD. The sedimentation of vitelliform lesions is characterized by a upper “croissant”-shaped hypoflectivity. The bumps/thickening of RPE appeared as hypereflective lesions on IR imaging.

Épidémiologie de la dégénérescence maculaire liée à l’âge

Age-related macular degeneration (ARMD) is a multifactorial and polygenic disease and is the main cause of vision loss in developed countries. The environmental factors of ARMD can modify prevalence and incidence of this disease. This article is a review of the main environmental factors currently recognized as at risk or protective factor for ARMD. Modification of these factors is of crucial importance because it could delay the onset of exudative or atrophic forms of the disease.