Disruption of the retinitis pigmentosa 28 gene Fam161a in mice affects photoreceptor ciliary structure and leads to progressive retinal degeneration.

Mutations in the FAM161A gene were previously identified as the cause for autosomal-recessive retinitis pigmentosa 28. To study the effects of Fam161a dysfunction in vivo, we generated gene-trapped Fam161a(GT/GT) mice with a disruption of its C-terminal domain essential for protein-protein interactions. We confirmed the absence of the full-length Fam161a protein in the retina of Fam161a(GT/GT) mice using western blots and showed weak expression of a truncated Fam161a protein by immunohistochemistry. Histological analyses demonstrated that photoreceptor segments were disorganized in young Fam161a(GT/GT) mice and that the outer retina was completely lost at 6 months of age. Reactive microglia appeared in the outer retina and electroretinography showed an early loss of photoreceptor function in 4-month-old Fam161a(GT/GT) animals. Light and electron microscopy revealed a remarkable phenotype of a significantly shortened connecting cilium, spread ciliary microtubule doublets and disturbed disk organization in Fam161a(GT/GT) photoreceptor cells. Co-immunolabeling experiments demonstrated reduced expression and mislocalization of centrin 3 and disturbed targeting of the Fam161a interactors lebercilin and Cep290, which were restricted to the basal body and proximal connecting cilium in Fam161a(GT/GT) retinas. Moreover, we identified misrouting of the outer segment cargo proteins opsin and rds/peripherin 2 in Fam161a(GT/GT) mice. In conclusion, our results suggest a critical role for the C-terminal domain of Fam161a for molecular interactions and integrity of the connecting cilium. Fam161a is required for the molecular delivery into the outer segment cilium, a function which is essential for outer segment disk formation and ultimately visual function.

Acid sphingomyelinase (aSMase) deficiency leads to abnormal microglia behavior and disturbed retinal function.

Mutations in the acid sphingomyelinase (aSMase) coding gene sphingomyelin phosphodiesterase 1 (SMPD1) cause Niemann-Pick disease (NPD) type A and B. Sphingomyelin storage in cells of the mononuclear phagocyte system cause hepatosplenomegaly and severe neurodegeneration in the brain of NPD patients. However, the effects of aSMase deficiency on retinal structure and microglial behavior have not been addressed in detail yet. Here, we demonstrate that retinas of aSMase(-/-) mice did not display overt neuronal degeneration but showed significantly reduced scotopic and photopic responses in electroretinography. In vivo fundus imaging of aSMase(-/-) mice showed many hyperreflective spots and staining for the retinal microglia marker Iba1 revealed massive proliferation of retinal microglia that had significantly enlarged somata. Nile red staining detected prominent phospholipid inclusions in microglia and lipid analysis showed significantly increased sphingomyelin levels in retinas of aSMase(-/-) mice. In conclusion, the aSMase-deficient mouse is the first example in which microglial lipid inclusions are directly related to a loss of retinal function.

Minocycline counter-regulates pro-inflammatory microglia responses in the retina and protects from degeneration.

BACKGROUND: Microglia reactivity is a hallmark of retinal degenerations and overwhelming microglial responses contribute to photoreceptor death. Minocycline, a semi-synthetic tetracycline analog, has potent anti-inflammatory and neuroprotective effects. Here, we investigated how minocycline affects microglia in vitro and studied its immuno-modulatory properties in a mouse model of acute retinal degeneration using bright white light exposure. METHODS: LPS-treated BV-2 microglia were stimulated with 50 µg/ml minocycline for 6 or 24 h, respectively. Pro-inflammatory gene transcription was determined by real-time RT-PCR and nitric oxide (NO) secretion was assessed using the Griess reagent. Caspase 3/7 levels were determined in 661W photoreceptors cultured with microglia-conditioned medium in the absence or presence of minocycline supplementation. BALB/cJ mice received daily intraperitoneal injections of 45 mg/kg minocycline, starting 1 day before exposure to 15.000 lux white light for 1 hour. The effect of minocycline treatment on microglial reactivity was analyzed by immunohistochemical stainings of retinal sections and flat-mounts, and messenger RNA (mRNA) expression of microglia markers was determined using real-time RT-PCR and RNA-sequencing. Optical coherence tomography (OCT) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) stainings were used to measure the extent of retinal degeneration and photoreceptor apoptosis. RESULTS: Stimulation of LPS-activated BV-2 microglia with minocycline significantly diminished the transcription of the pro-inflammatory markers CCL2, IL6, and inducible nitric oxide synthase (iNOS). Minocycline also reduced the production of NO and dampened microglial neurotoxicity on 661W photoreceptors. Furthermore, minocycline had direct protective effects on 661W photoreceptors by decreasing caspase 3/7 activity. In mice challenged with white light, injections of minocycline strongly decreased the number of amoeboid alerted microglia in the outer retina and down-regulated the expression of the microglial activation marker translocator protein (18 kDa) (TSPO), CD68, and activated microglia/macrophage whey acidic protein (AMWAP) already 1 day after light exposure. Furthermore, RNA-seq analyses revealed the potential of minocycline to globally counter-regulate pro-inflammatory gene transcription in the light-damaged retina. The severe thinning of the outer retina and the strong induction of photoreceptor apoptosis induced by light challenge were nearly completely prevented by minocycline treatment as indicated by a preserved retinal structure and a low number of apoptotic cells. CONCLUSIONS: Minocycline potently counter-regulates microgliosis and light-induced retinal damage, indicating a promising concept for the treatment of retinal pathologies.

Targeting translocator protein (18 kDa) (TSPO) dampens pro-inflammatory microglia reactivity in the retina and protects from degeneration.

BACKGROUND: Reactive microglia are commonly seen in retinal degenerative diseases, and neurotoxic microglia responses can contribute to photoreceptor cell death. We and others have previously shown that translocator protein (18 kDa) (TSPO) is highly induced in retinal degenerations and that the selective TSPO ligand XBD173 (AC-5216, emapunil) exerts strong anti-inflammatory effects on microglia in vitro and ex vivo. Here, we investigated whether targeting TSPO with XBD173 has immuno-modulatory and neuroprotective functions in two mouse models of acute retinal degeneration using bright white light exposure. METHODS: BALB/cJ and Cx3cr1(GFP/+) mice received intraperitoneal injections of 10 mg/kg XBD173 or vehicle for five consecutive days, starting 1 day prior to exposure to either 15,000 lux white light for 1 h or 50,000 lux focal light for 10 min, respectively. The effects of XBD173 treatment on microglia and Müller cell reactivity were analyzed by immuno-stainings of retinal sections and flat mounts, fluorescence-activated cell sorting (FACS) analysis, and mRNA expression of microglia markers using quantitative real-time PCR (qRT-PCR). Optical coherence tomography (OCT), terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) stainings, and morphometric analyses were used to quantify the extent of retinal degeneration and photoreceptor apoptosis. RESULTS: Four days after the mice were challenged with bright white light, a large number of amoeboid-shaped alerted microglia appeared in the degenerating outer retina, which was nearly completely prevented by treatment with XBD173. This treatment also down-regulated the expression of TSPO protein in microglia but did not change the TSPO levels in the retinal pigment epithelium (RPE). RT-PCR analysis showed that the microglia/macrophage markers Cd68 and activated microglia/macrophage whey acidic protein (Amwap) as well as the pro-inflammatory genes Ccl2 and Il6 were reduced after XBD173 treatment. Light-induced degeneration of the outer retina was nearly fully blocked by XBD173 treatment. We further confirmed these findings in an independent mouse model of focal light damage. Retinas of animals receiving XBD173 therapy displayed significantly more ramified non-reactive microglia and more viable arrestin-positive cone photoreceptors than vehicle controls. CONCLUSIONS: Targeting TSPO with XBD173 effectively counter-regulates microgliosis and ameliorates light-induced retinal damage, highlighting a new pharmacological concept for the treatment of retinal degenerations.

Patient preference of ranibizumab treatment regimen for neovascular age-related macular degeneration - monthly injections versus pro re nata.

PURPOSE: To identify preference of treatment regimen in patients with anti-VEGF therapy for neovascular age-related macular degeneration (AMD) in real life. METHODS: A cross-sectional study was conducted in 200 patients receiving ranibizumab therapy on a pro re nata regimen with monthly controls. One hundred and twenty-four patients were recruited in a tertiary health care clinic, and 76 patients were recruited in a private practice. Patients were asked to respond to a 14-item questionnaire covering items such as treatment burden and preference for treatment: either monthly injections or pro re nata. RESULTS: Mean time under anti-VEGF treatment was 33.7 months, and the mean number of intravitreal injections was 17.7. Despite a high treatment burden in 60.3 % of patients, there was an acceptance rate for monthly examinations or injections of 93 %. The proportion of patients who favoured a PRN regimen was 53.0 %, whereas 37.9 % of patients favoured continuous injections. Major concern was recurrent disease activity in 54.5 %. CONCLUSION: We identified two groups of patients of considerable size who would prefer either monthly injections or as-required. Overall, there was a high acceptance rate despite a high treatment burden. Nevertheless, efforts should be undertaken to improve examination and injection procedures and to consider the patient's preference for a treatment regimen.

Adherence to ranibizumab treatment for neovascular age-related macular degeneration in real life.

BACKGROUND: To identify factors and problems influencing treatment adherence in patients undergoing anti-VEGF therapy for neovascular age-related macular degeneration (AMD) under real-life conditions. METHODS: Cross-sectional study was conducted of 95 patients receiving ranibizumab therapy on a pro re nata (PRN) regimen with monthly controls in a tertiary health care clinic. Monthly controls included best corrected visual acuity, slit-lamp examination and spectral-domain optical coherence tomography. Adherence was measured using Kaplan-Meier time-to-discontinuation analysis. Patients were asked to respond to a 16-item questionnaire covering items such as anxiety, subjective benefit, and financial issues of therapy. RESULTS: Forty-two men and 53 women were included. After a mean follow-up time of 675 days (range 63-1008), adherence was 81.1% (77/95). The mean number of follow-up visits was 19 (3-30), the mean number of intravitreal injections was ten (3-23). Seven patients withdrew from treatment due to subjective dissatisfaction with benefit. Other reasons for loss to follow-up were death in one case, serious general disease in three patients, and treatment options closer to home in five cases. Two patients cancelled further follow-up after treatment cessation due to terminal fibrosis. 62.1% of patients were afraid of a negative examination result, whereas 19.0% were afraid of intravitreal injections. A major problem was travel to and from the hospital (46.3%), with 61.5% of patients requiring escort. CONCLUSION: Despite necessary monthly visits, patients showed a high adherence to therapy. The major problem was travel to and from the hospital. From the patients' point of view, anxiety of a negative examination result was more pronounced than fear of intraocular injections, which would be an argument for continuous injections rather than for a PRN regimen.

Analysis of aggregate impact factor inflation in ophthalmology.

PURPOSE: To analyze the aggregate impact factor (AIF) in ophthalmology, its inflation rate, and its relation to other subject fields. METHODS: A retrospective, database review of all subject fields in the Journal Citation Reports (JCR), Science edition. Citation data, AIF, number of journals and citations from the years 2003-2011 were analyzed. Data were retrieved from JCR. Future trends were calculated using a linear regression method. RESULTS: The AIF varies considerably between subjects. It shows also an inflation rate, which varies annually. The AIF inflation rate in ophthalmology was not as high as the background AIF inflation rate. CONCLUSIONS: The AIF inflation rate caused the AIF to increase annually. Not considering these variations in the AIF between years and between fields will make the AIF as a bibliometric tool inappropriate.

Anterior chamber aqueous flare is a strong predictor for proliferative vitreoretinopathy in patients with rhegmatogenous retinal detachment.

PURPOSE: To investigate preoperative aqueous flare as a predictive factor for proliferative vitreoretinopathy (PVR) redetachment in patients with rhegmatogenous retinal detachment. METHODS: Preoperatively, the aqueous flare of 116 consecutive patients with retinal detachment was measured quantitatively with a laser flare-cell meter (Kowa FM-500; Kowa Company, Ltd, Tokyo, Japan). Seventy-four healthy partner eyes and 41 eyes of healthy age-matched patients served as controls. At least 6 months after surgery, patients were reevaluated, whether surgery was performed again because of PVR redetachment. RESULTS: Eyes with retinal detachment that developed PVR redetachment later on (n = 12) had higher flare values than eyes with uncomplicated retinal detachment (n = 104) (median, 27.63 vs. 8.83 photon counts per millisecond; P < 0.0001). No eye with PVR redetachment had a flare value <10.8 photon counts per millisecond. In eyes with flare values exceeding 15 photon counts per millisecond, the odds of PVR redetachment development increases 16-fold. CONCLUSION: Our study shows that the breakdown of the blood-ocular barrier as determined by aqueous flare is a major risk factor for PVR redetachment. The laser flare-cell meter is a fast, noninvasive, and safe tool that allows predicting the PVR redetachment risk preoperatively. It provides the surgeon with an estimate to choose those patients who could benefit from intravitreal drugs to prevent PVR.

Variability of choroidal and retinal thicknesses in healthy eyes using swept-source optical coherence tomography - implications for designing clinical trials.

AIM: The aim was to study the variability of choroidal scleral interface (CSI) thickness in healthy subjects and its relevance for designing future studies. METHODS: A total of 123 volunteers were imaged using swept-source optical coherence tomography. Early treatment diabetic retinopathy grid was used. RESULTS: Mean central retinal thickness was 285.85±14.53 µm and 287.18±12.93 µm, and mean central CSI thickness was 273.94±77.77 µm and 271.19±78.85 µm for the right and left eyes, respectively. Mean retinal and CSI thicknesses correlated negatively with age (p=0.023, r=-0.208 and p<0.0001, r=-0.426, respectively) and axial length (p=0.016, r=-0.220 and p<0.0001, r=-0.504, respectively). To detect a CSI change of at least 112 µm, a sample size of 11 or 36 per group is needed for a single- or double-arm study, respectively (α=0.05, power =0.90, no loss to follow-up, assuming standard deviation in future studies as 100 µm). CONCLUSION: Future clinical studies using CSI as end point are possible with regard to sample size needed.

Analysis of the impact of allergy and atopy on new onset of uveitis.

PURPOSE: The inappropriate immune response to harmless foreign and self-antigens is a common feature of allergy, atopy and autoimmune disease. The influence of environmental factors in the initiation of autoimmunity is not well understood. It is conceivable that immune responses to allergens may also serve as a trigger of bystander immune reactions, including autoimmunity such as uveitis. Therefore, we wanted to investigate the prevalence of allergies and atopy in patients with different types of uveitis in comparison to a control cohort. METHODS: In total, 530 consecutive patients with new-onset anterior, intermediate, posterior and panuveitis were compared to a non-uveitis control cohort consisting of 1.060 consecutive new-referral patients who attended our specialized outpatient clinics for other reasons than uveitis. Allergy and atopy status as well as demographic data (age, gender and ethnicity) were obtained by standardized interviewer-assisted questionnaires. RESULTS: Uveitis case cohort and control cohort did not differ significantly in the allergy status (p = 0.910), such as the history of pollen allergy (p = 0.671), history of drug allergy (p = 0.920), history of food allergy (p = 0.941), history of house dust mite allergy (p = 0.197) or history of other allergens (p = 0.593), nor in the atopy status (p = 0.802), such as the history of atopic dermatitis (p = 0.365), history of asthma (p = 0.430) or history of allergic rhinitis (p = 0.115). CONCLUSIONS: Our results argue against a substantial influence of allergies and atopy on the onset of uveitis.

Alteration of retinal layers in healthy subjects over 60 years of age until nonagenarians.

PURPOSE: To assess alterations of retinal layers in healthy subjects over 60 years old. METHODS: Retinal layers of 160 healthy subjects (aged 60-100 years) without any retinal pathology were imaged using spectral domain optical coherence tomography. Mean thickness of retinal nerve fiber layer, ganglion cell/inner plexiform layer (GCLIPL), inner nuclear layer, outer plexiform layer/outer nuclear layer, photoreceptor complex (PR) and retinal thickness (RT) were measured in a 3.45 mm grid. Correlations between age and layers were estimated and linear regression equations were calculated. Different age-groups (60-69, 70-79, 80-89 years and nonagenarians, each group with 40 participants) were compared. RESULTS: Significant age-thickness correlations were observed for GCLIPL (P<0.001, r=-0.394), PR (P<0.001, r=-0.370) and RT (P<0.001, r=-0.290). A comparison between age groups 60-69 years and nonagenarians showed no significant thickness alteration of retinal nerve fiber layer (21.80±2.18 µm vs 22.82±2.97 µm, P=0.163), inner nuclear layer (37.23±3.02 µm vs 36.01±3.24 µm, P=0.07) and outer plexiform layer/outer nuclear layer (104.95±6.56 µm vs 104.23±7.59 µm, P=0.567), while GCLIPL (83.35±7.35 µm vs 74.38±9.09 µm), PR (83.03±3.31 µm vs 79.34±2.09 µm) and RT (330.64±12.63 µm vs 316.83±18.35 µm) showed a significant decrease (P<0.001 for all). CONCLUSION: Our study provides normative data of alterations of retinal layers for persons aged 60 years to nonagenarians and indicates a continuous decrease of RT, PR, and GCLIPL. This data may be useful for clinical trials investigating macular diseases in older patients.

Polysialic acid blocks mononuclear phagocyte reactivity, inhibits complement activation, and protects from vascular damage in the retina.

Age-related macular degeneration (AMD) is a major cause of blindness in the elderly population. Its pathophysiology is linked to reactive oxygen species (ROS) and activation of the complement system. Sialic acid polymers prevent ROS production of human mononuclear phagocytes via the inhibitory sialic acid-binding immunoglobulin-like lectin-11 (SIGLEC11) receptor. Here, we show that low-dose intravitreal injection of low molecular weight polysialic acid with average degree of polymerization 20 (polySia avDP20) in humanized transgenic mice expressing SIGLEC11 on mononuclear phagocytes reduced their reactivity and vascular leakage induced by laser coagulation. Furthermore, polySia avDP20 prevented deposition of the membrane attack complex in both SIGLEC11 transgenic and wild-type animals. In vitro, polySia avDP20 showed two independent, but synergistic effects on the innate immune system. First, polySia avDP20 prevented tumor necrosis factor-α, vascular endothelial growth factor A, and superoxide production by SIGLEC11-positive phagocytes. Second, polySia avDP20 directly interfered with complement activation. Our data provide evidence that polySia avDP20 ameliorates laser-induced damage in the retina and thus is a promising candidate to prevent AMD-related inflammation and angiogenesis.

Interferon-beta signaling in retinal mononuclear phagocytes attenuates pathological neovascularization.

Age-related macular degeneration (AMD) is a leading cause of vision loss among the elderly. AMD pathogenesis involves chronic activation of the innate immune system including complement factors and microglia/macrophage reactivity in the retina. Here, we show that lack of interferon-ß signaling in the retina accelerates mononuclear phagocyte reactivity and promotes choroidal neovascularization (CNV) in the laser model of neovascular AMD Complete deletion of interferon-α/ß receptor (Ifnar) using Ifnar1(-/-) mice significantly enhanced early microglia and macrophage activation in lesion areas. This triggered subsequent vascular leakage and CNV at later stages. Similar findings were obtained in laser-treated Cx3cr1(Cre) (ER):Ifnar1(fl/fl) animals that allowed the tamoxifen-induced conditional depletion of Ifnar in resident mononuclear phagocytes only. Conversely, systemic IFN-ß therapy of laser-treated wild-type animals effectively attenuated microgliosis and macrophage responses in the early stage of disease and significantly reduced CNV size in the late phase. Our results reveal a protective role of Ifnar signaling in retinal immune homeostasis and highlight a potential use for IFN-ß therapy in the eye to limit chronic inflammation and pathological angiogenesis in AMD.

Development of emulsification resistant heavier-than-water tamponades using high molecular weight silicone oil polymers.

PURPOSE: Developing new blends of heavier-than-water silicone oil tamponade agents containing high molecular weight polydimethylsiloxane polymer for use in vitreoretinal surgery. MATERIALS AND METHODS: The viscoelastic properties of heavier-than-water silicone oil blends (30.5% F6H8 + 69.5% polydimethylsiloxane) containing high molecular weight polymer additive at increasing concentrations were measured using a controlled-stress rheometer (TA Instruments Rheolyst AR 1000 N). Emulsification of the blends was induced using a sonication device and a pluronic surfactant as a strong emulsifier. The percentage emulsion area was photographed and measured using ImageJ software. In a second in vitro emulsification assessment, silicone oil blends were dispersed using a high shear homogenizer and the oil-in-water droplets were counted using a coulter counter particle analyser. RESULTS: The addition of the high molecular weight polymer increased shear viscosity and viscoelasticity of the oil blends, which were measureable and to some extent predictable. The in vitro emulsification models produced contradictory results. This demonstrates the difficulty of designing and using in vitro models to evaluate the emulsification tendency of tamponade agents in vivo. CONCLUSION: Addition of a high molecular weight polymer to heavy silicone oil can increase the viscoelasticity. These findings might contribute to the development of emulsification resistant heavy silicone oils.

Spectrum of Uveitis in A German Tertiary Center: Review of 474 Consecutive Patients.

PURPOSE: To analyze the spectrum of uveitis at a German tertiary center. PATIENTS AND METHODS: A total of 474 consecutive patients with uveitis were classified according to the primary anatomic site of inflammation, examined for laterality of disease, and screened for etiologies. RESULTS: Out of the total, 253 patients (53%) had anterior uveitis, 90 patients (19%) had intermediate uveitis, 100 patients (21%) had posterior uveitis, and 31 patients (7%) had panuveitis. Fifty-six percent of the patients had bilateral involvement, predominantly in intermediate uveitis (ratio 4:1) and panuveitis (ratio 3.4:1). Regarding the etiology of all uveitis cases we found 17% infectious, 23% specific clinical entities, 20% associated with systemic disease (most commonly sarcoidosis with 11%), and 41% idiopathic uveitis. CONCLUSIONS: Anterior uveitis was the most common anatomic site of intraocular inflammation. Using a tailored approach, screening for systemic etiologies is recommended, since 20% of all patients had associated systemic diseases.

Retinal layers measurements in healthy eyes and in eyes receiving silicone oil-based endotamponade.

PURPOSE: To characterize the concordance/symmetry of each retinal layers in individuals without macular pathology and to further characterize the localization of inner retinal thinning in eyes receiving silicone oil-based endotamponade. METHODS: Retinal layers of one hundred eyes of 50 individuals without macular pathology were imaged using spectral domain optical coherence tomography (SD-OCT) and manually segmented using ImageJ software (developed by Wayne Rasband, NIH, Bethesda, MD, USA). In the second part of the study, retrospective analysis of 3028 cases of pars plana vitrectomy in University Eye Hospital Cologne, Germany, was conducted, retrieving nine patients with silicone oil-based endotamponade with no macular condition interfering retinal layers measurements. These patients had retinal detachment not involving the macula due to various conditions. In these patients, retinal layer segmentation was performed and compared with the fellow eye. RESULTS: There is a moderate-to-high concordance for all retinal layers between the right and the left eye of the same individual. In eyes receiving silicone oil-based endotamponade, the inner retinal layers become subsequently thinner. Ganglion cell and inner plexiform layers contribute most to this thinning, that is, 0.537 ± 0.096 mm(3) compared with 0.742 ± 0.117 mm(3) ; p = 0.006. Outer retinal layers were not affected by silicone oil-based endotamponade (p = 0.439 for the differences of calculated outer retinal layers). CONCLUSION: Ganglion cell and inner retinal layers become subsequently thinner after the use of silicone oil-based endotamponade. This study advocates the use of spectral domain optical coherence tomography for patient management with silicone oil endotamponade to early detect subsequent retinal thinning.

Genetic and environmental risk factors for age-related macular degeneration in persons 90 years and older.

PURPOSE: We studied associations of genetic polymorphisms in age-related maculopathy susceptibility 2 (ARMS2) and complement factor H (CFH) in nonagenarians with age-related macular degeneration (AMD). METHODS: This case-control study comprised 2737 persons (1204 controls, 1433 AMD cases), including 166 nonagenarians (52 controls, 114 AMD cases). Single nucleotide polymorphisms (SNPs) in the genes ARMS2 and CFH were determined. Risk scores were computed by multiple logistic regression analysis, including genetic and environmental risk factors (smoking, hypertension, body mass index, diabetes) for different age groups (<70, 70-79, 80-89, ≥ 90 years [nonagenarians]). RESULTS: In nonagenarians, ARMS2 showed the weakest associations with AMD (odds ratio [OR] = 1.52, P = 0.127) compared to the other groups (OR, 70 years = 2.23, P = 1.03 × 10(-13); OR, 70-79 years = 2.70, P = 1.00 × 10(-13); OR, 80-89 years = 3.11, P = 6.56 × 10(-8)). For CFH, ORs for AMD increased with age (<70 years OR = 1.96, P = 1.80 × 10(-11); 70-79 years OR = 1.89, P = 4.48 × 10(-13); 80-89 years OR = 2.71, P = 1.28 × 10(-7)), but decreased again in the nonagenarians (OR = 2.21, P = 0.005). Compared to the group <70 years, reduced minor allele frequencies (MAFs) for AMD patients were observed in the nonagenarians (CFH 0.54 vs. 0.43, P = 0.009; ARMS2 0.44 vs. 0.29, P = 2.97 × 10(-5)), while the MAFs in controls were not significantly different. The genetic risk score revealed the lowest discriminative power in the nonagenarians with an area-under-curve (AUC) of 0.658 for receiver-operating characteristics (AUC 80-89 years = 0.768, 70-79 years = 0.704, <70 years = 0.682), while no significant difference was seen for the environmental risk score (AUC < 70 years = 0.579, 70-79 years = 0.567, 80-89 years = 0.600, >90 years = 0.608). CONCLUSIONS: Risk alleles in CFH and ARMS2 have a significantly smaller effect on AMD development in nonagenarians, while environmental factors retain a similar effect.

Environmental and genetic risk factors for retinal angiomatous proliferation.

PURPOSE: To identify genetic and environmental risk factors in patients with retinal angiomatous proliferation (RAP), a clinical subtype of age-related macular degeneration (AMD). METHODS: In this case-control study, 108 AMD cases with RAP, 258 AMD patients with choroidal neovascularization (CNV) without RAP and 443 healthy controls were evaluated. Single nucleotide polymorphisms in age-related maculopathy susceptibility 2 (ARMS2) and complement factor H (CFH) and various environmental risk factors were analysed. Statistical analysis was performed by univariate and multivariate regression analysis. RESULTS: High age, female sex and genetic variants in CFH and ARMS2 were identified as risk factors for developing any CNV. In RAP patients, arterial hypertension was also identified as a risk factor (OR 2.39; p = 0.0005). Compared with the 'non-RAP' CNV group, the association with high age (OR 1.05; p = 0.008) and arterial hypertension (OR 1.82; p = 0.02) was significantly higher in RAP patients, while the association with CFH risk alleles (homozygous OR 0.40; p = 0.003) was significantly lower, which was confirmed in a multivariate analysis (OR 0.41; p = 0.03 for the heterozygous risk allele and OR 0.38; p = 0.03 for the homozygous risk allele). CONCLUSION: The association with the CFH Y402 risk allele was less pronounced in RAP patients than in 'non-RAP' CNV patients, while the association with high age and arterial hypertension appeared to be stronger. These findings stress the importance of detailed phenotyping in AMD to identify homogeneous AMD subtypes and their different risk factors and disease mechanisms.