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to evaluate new onset uveitis or reactivated uveitis by biologic agents and characterize their features.This is a multicenter, retrospective case series. Patients under biologic therapy were included if they developed uveitis for the first time or experienced intraocular inflammation which was different in location or laterality to previous inflammation.Sixteen patients were identified. The underlying disorders included ankylosing spondylitis, juvenile idiopathic arthritis, rheumatoid arthritis, and Behçet's Disease. The biologic agents associated with a first episode of uveitis (n = 11) or with a new recurrence of uveitis (n = 5) were etanercept, adalimumab, abatacept, infliximab, and golimumab. Sarcoidosis based on bihilar lymphadenopathy, other computer tomography-findings, or biopsy was diagnosed in five patients under therapy with etanercep, adalimumab, and abatacept. Additionally, seven patients developed clinical changes in their uveitis pattern, suggesting sarcoid uveitis.Biologic treatment-induced uveitis often presents as granulomatous disease.

Purpose Alpha lipoic acid (ALA) is a nutraceutical and potent antioxidant that has shown efficacy in the retina light damage mouse model and in humans for multiple sclerosis. Our objective was to evaluate the efficacy and safety of oral ALA for the treatment of geographic atrophy (GA). Design Randomized, controlled, double-masked, multicenter phase 2 clinical trial of ALA versus placebo. Participants Participants with unilateral or bilateral GA from age-related macular degeneration. Methods Participants were randomized to 1200 mg daily of ALA or placebo. Fundus autofluorescence, fundus color photography, and spectral-domain OCT were conducted and best-corrected visual acuity (BCVA) was obtained at baseline and every 6 months through month 18. Main Outcome Measures Annual rate of change over 18 months in square root-transformed area of GA in study eyes as measured on fundus autofluorescence. Secondary outcomes included the number of adverse events (AEs), change in BCVA, and annual rate of change in area of GA measured on color photographs. Results Fifty-three participants (mean age, 80 years) were randomized (April 2016–August 2017). Twenty-seven participants (37 eyes) were in the placebo group, and 26 participants (36 eyes) were in the ALA group. Unadjusted mean (standard error) annual change in GA area was 0.28 (0.02) mm and 0.31 (0.02) mm for the placebo and ALA groups, respectively (difference, 0.04 mm; 95% confidence interval [CI], –0.03 to 0.11 mm; P = 0.30). Adjusting for baseline GA area, number of GA lesions, and presence of subfoveal GA, the mean annual change in GA area was 0.27 (0.04) mm and 0.32 (0.05) mm for the placebo and ALA groups, respectively (difference, 0.05 mm; 95% CI, –0.02 to 0.12 mm; P = 0.14). At 18 months, the percent of eyes losing 15 letters or more of BCVA was 22% (8 of 36) and 14% (5 of 36) in the placebo and ALA groups, respectively (P = 0.54). No difference was found in the percentage of participants with nonserious AEs (P = 0.96) or serious AEs (P = 0.28) between the placebo and ALA groups. Conclusions Results do not support ALA having beneficial effects on GA or BCVA. This trial design may be useful for other GA repurposing drug trials.

Purpose To characterize inheritance, penetrance, and trinucleotide repeat expansion stability in Fuchs endothelial corneal dystrophy (FECD). Methods One thousand unrelated and related subjects with and without FECD were prospectively recruited. CTG18.1 repeat length (CTG18.1L) was determined via short tandem repeat assay and Southern blotting of leukocyte DNA. Multivariable logistic regression and generalized estimating equation models were employed. Results There were 546 unrelated FECD cases (67.6% female; 70 ± 10 years) and 235 controls (63.8% female; 73 ± 8 years; all ≥ 50 years). CTG18.1 expansion (CTG18.1exp+) was observed in 424 (77.7%) cases and 18 (7.7%) controls (P = 2.48 × 10-44). CTG18.1 expansion was associated with FECD severity (P = 5.62 × 10-7). The family arm of the study included 331 members from 112 FECD-affected families; 87 families were CTG18.1exp+. Autosomal dominant inheritance with variable expression of FECD was observed, regardless of expansion status. FECD penetrance of CTG18.1 expansion increased with age, ranging from 44.4% in the youngest (19-46 years) to 86.2% in the oldest (64-91 years) age quartiles. Among 62 parent-offspring transmissions of CTG18.1exp+, 48 (77.4%) had a change in CTG18.1L ≤ 10 repeats, and eight (12.9%) were ≥50 repeats, including five large expansions (∼1000-2000 repeats) that contracted. Among 44 offspring who did not inherit the CTG18.1exp+ allele, eight (18.2%) exhibited FECD. Conclusions CTG18.1 expansion was highly associated with FECD but demonstrated incomplete penetrance. CTG18.1L instability occurred in a minority of parent-offspring transmissions, with large expansions exhibiting contraction. The observation of FECD without CTG18.1 expansion among family members in CTG18.1exp+ families highlights the complexity of the relationship between the FECD phenotype and CTG18.1 expansion.

Author(s): Sivakumaran, Theru A; Igo, Robert P; Kidd, Jeffrey M; Itsara, Andy; Kopplin, Laura J; Chen, Wei; Hagstrom, Stephanie A; Peachey, Neal S; Francis, Peter J; Klein, Michael L; Chew, Emily Y; Ramprasad, Vedam L; Tay, Wan-Ting; Mitchell, Paul; Seielstad, Mark; Stambolian, Dwight E; Edwards, Albert O; Lee, Kristine E; Leontiev, Dmitry V; Jun, Gyungah; Wang, Yang; Tian, Liping; Qiu, Feiyou; Henning, Alice K; LaFramboise, Thomas; Sen, Parveen; Aarthi, Manoharan; George, Ronnie; Raman, Rajiv; Das, Manmath Kumar; Vijaya, Lingam; Kumaramanickavel, Govindasamy; Wong, Tien Y; Swaroop, Anand; Abecasis, Goncalo R; Klein, Ronald; Klein, Barbara EK; Nickerson, Deborah A; Eichler, Evan E; Iyengar, Sudha K | Abstract: [This corrects the article DOI: 10.1371/journal.pone.0025598.].

Objective To determine whether genotypes at 2 major loci associated with late age-related macular degeneration (AMD), complement factor H ( CFH ) and age-related maculopathy susceptibility 2 ( ARMS2 ), influence the relative benefits of Age-Related Eye Disease Study (AREDS) supplements. Design Unplanned retrospective evaluation of a prospective, randomized, placebo-controlled clinical trial of vitamins and minerals for the treatment of AMD. Subjects AREDS participants (mean age, 69 years) who were at risk of developing late AMD and who were randomized to the 4 arms of AREDS supplement treatment. Methods Analyses were performed using the Cox proportional hazards model to predict progression to late AMD (neovascular or central geographic atrophy). Statistical models, adjusted for age, gender, smoking status, and baseline AMD severity, were used to examine the influence of genotypes on the response to therapy with 4 randomly assigned arms of AREDS supplement components: placebo, antioxidants (vitamin C, vitamin E, β-carotene), zinc, or a combination. Main Outcome Measures The influence of the genotype on the relative treatment response to the randomized components of the AREDS supplement, measured as progression to late AMD. Results Of the 1237 genotyped AREDS participants of white ethnicity, late AMD developed in 385 (31.1%) during the mean follow-up of 6.6 years. As previously demonstrated, CFH genotype ( P = 0.005), ARMS2 ( P CFH rs1061170 and rs1410996 combined with ARMS2 rs10490924 with the 4 randomly assigned arms of AREDS supplement and (2) analysis of the combination of CFH rs412852 and rs3766405 with ARMS2 c.372_815del443ins54 with the AREDS components resulted in no interaction ( P = 0.06 and P = 0.45, respectively, before multiplicity adjustment). Conclusions The AREDS supplements reduced the rate of AMD progression across all genotype groups. Furthermore, the genotypes at the CFH and ARMS2 loci did not statistically significantly alter the benefits of AREDS supplements. Genetic testing remains a valuable research tool, but these analyses suggest it provides no benefits in managing nutritional supplementation for patients at risk of late AMD.

Neurodegenerative diseases affecting the macula constitute a major cause of incurable vision loss and exhibit considerable clinical and genetic heterogeneity, from early-onset monogenic disease to multifactorial late-onset age-related macular degeneration (AMD). As part of our continued efforts to define genetic causes of macular degeneration, we performed whole exome sequencing in four individuals of a two-generation family with autosomal dominant maculopathy and identified a rare variant p.Glu1144Lys in Fibrillin 2 (FBN2), a glycoprotein of the elastin-rich extracellular matrix (ECM). Sanger sequencing validated the segregation of this variant in the complete pedigree, including two additional affected and one unaffected individual. Sequencing of 192 maculopathy patients revealed additional rare variants, predicted to disrupt FBN2 function. We then undertook additional studies to explore the relationship of FBN2 to macular disease. We show that FBN2 localizes to Bruch's membrane and its expression appears to be reduced in aging and AMD eyes, prompting us to examine its relationship with AMD. We detect suggestive association of a common FBN2 non-synonymous variant, rs154001 (p.Val965Ile) with AMD in 10 337 cases and 11 174 controls (OR = 1.10; P-value = 3.79 × 10(-5)). Thus, it appears that rare and common variants in a single gene--FBN2--can contribute to Mendelian and complex forms of macular degeneration. Our studies provide genetic evidence for a key role of elastin microfibers and Bruch's membrane in maintaining blood-retina homeostasis and establish the importance of studying orphan diseases for understanding more common clinical phenotypes.

Age-related macular degeneration (AMD) is a common cause of blindness in older individuals. To accelerate the understanding of AMD biology and help design new therapies, we executed a collaborative genome-wide association study, including >17,100 advanced AMD cases and >60,000 controls of European and Asian ancestry. We identified 19 loci associated at P

Purpose To assess anatomic and visual outcomes of ocriplasmin use for symptomatic vitreomacular adhesion (VMA). Design Retrospective chart review. Methods Macula Society members were surveyed online to collect data on ocriplasmin for symptomatic VMA. Clinical and optical coherence tomography data were collected using standardized data entry forms. Results There were 208 patients (208 eyes) with symptomatic VMA followed at least 3 weeks after receiving ocriplasmin. At baseline, VMA was focal (

The authors performed a systematic review of the association of complement component 2(C2)/complement factor B (CFB) gene polymorphisms with age-related macular degeneration (AMD). In total, data from 19 studies published between 2006 and 2011 were pooled for 4 polymorphisms: rs9332739 and rs547154 in the C2 gene and rs4151667 and rs641153 in the CFB gene. Data extraction and assessments for risk of bias were independently performed by 2 reviewers. Allele frequencies and allele and genotypic effects were pooled. Heterogeneity and publication bias were explored. Pooled minor allele frequencies for all 4 SNPs were between 4.7% and 9.6% for all polymorphisms, except for an Indian population in which the C allele at rs9332739 was the major allele. For the C2 polymorphisms, the minor C allele at rs9332739 and the minor T allele at rs547154 carried estimated relative risks (odds ratios) of 0.55 (95% confidence interval (CI): 0.46, 0.65) and 0.47 (95% CI: 0.39, 0.57), respectively. For the CFB polymorphisms, the minor A alleles at rs4151667 and rs614153 carried estimated risks of 0.54 (95% CI: 0.45, 0.64) and 0.41 (95% CI: 0.34, 0.51), respectively. These allele effects contributed to an absolute lowering of the risk of all AMD in Caucasian populations by 2.0%–6.0%. This meta-analysis provides a robust estimate of the protective association of C2/CFB with AMD.

To report patient acceptance and safety of repeated intravitreal injections of anti-VEGF agents for exudative AMD, by retina specialists, without an eye examination before every injection.Retrospective chart review. 115 eyes (110 patients) with exudative AMD underwent repeated intravitreal anti-VEGF injections with limited interval examination and diagnostic testing. Medication, laterality, number of injection cycles started and completed, number of injections per injection cycle, subjective visual changes, pre- and post-injection visual acuity (VA), pre- and post-injection intraocular pressure (IOP), nurse- and patient-initiated phone calls, emergency (non-scheduled) clinic visits, complications, new diagnoses, and patient complaints after each injection were recorded. The main outcome measures were complications and patient complaints.396 injections were administered in the injection clinic to 110 patients in 175 injection cycles (range: 0 to 5 injections per cycle). Of 175 injection cycles, there were 134 uninterrupted cycles and 41 interrupted cycles where an eye exam was performed. Fourteen new diagnoses were made: six during emergency visits, three at injection clinic appointments, and five at the next full examination after completion of a prescribed injection clinic cycle.Administration of anti-VEGF injections in a designated injection clinic, by retina specialists, according to a prescribed schedule, and with limited pre-injection testing, for patients with wet AMD, is well-tolerated.

Background Fuchs’s corneal dystrophy (FCD) is a leading cause of corneal transplantation and affects 5% of persons in the United States who are over the age of 40 years. Clinically visible deposits called guttae develop under the corneal endothelium in patients with FCD. A loss of endothelial cells and deposition of an abnormal extracellular matrix are observed microscopically. In advanced disease, the cornea swells and becomes cloudy because the remaining endothelial cells are not sufficient to keep the cornea dehydrated and clear. Although rare genetic variation that contributes to both early-onset and typical late-onset forms of FCD has been identified, to our knowledge, no common variants have been reported. Methods We performed a genomewide association study and replicated the most significant observations in a second, independent group of subjects. Results Alleles in the transcription factor 4 gene (TCF4), encoding a member of the E-protein family (E2-2), were associated with typical FCD (P = 2.3×10 −26 ). The association increased the odds of having FCD by a factor of 30 for persons with two copies of the disease variants (homozygotes) and discriminated between case subjects and control subjects with about 76% accuracy. At least two regions of the TCF4 locus were associated independently with FCD. Alleles in the gene encoding protein tyrosine phosphatase receptor type G (PTPRG) were associated with FCD (P = 4.0×10 −7 ), but the association did not reach genomewide significance. Conclusions Genetic variation in TCF4 contributes to the development of FCD. (Funded by the National Eye Institute and others.)

To evaluate the rate of infectious endophthalmitis associated with intravitreal injection of bevacizumab, ranibizumab, and pegaptanib sodium.A retrospective review of patients who received intravitreal injections of bevacizumab, ranibizumab, and pegaptanib sodium was undertaken. Cases of clinical diagnoses of endophthalmitis or suspected endophthalmitis resulting from intravitreal injection were identified and reviewed. From these data, the risk per injection was estimated.Three patients developed endophthalmitis after the intravitreal injection. The risk per injection was 0.00077 (0.077%). The rate of endophthalmitis was 1 per 1,291 injections.A similar risk of endophthalmitis per injection compared with some trials was obtained in this study. Although no definite risk factors could be identified, intravitreal injections performed by nonretina specialist physicians may be a risk factor for the development of endophthalmitis.

The inherited vitreoretinal degenerations or vitreoretinopathies are characterized by congenital and acquired disorders of the eye including early onset cataract, anomalies of the vitreous manifesting as optically empty vitreous, course fibrils, and membranes, and retinal detachment. These diseases include Stickler syndrome types I (STL1) and II (STL2), usually caused by mutations in COL2A1 and COL11A1 respectively. Wagner syndrome (WGN1) is associated with mutations in versican (CSPG2) and snowflake vitreoretinal degeneration (SVD) with a mutation in a potassium channel (KCNJ13). The cataract is often cortical and may be wedge-shaped, but does not distinguish between the different syndromes. The congenital vitreous defect is usually characterized as fibrillar degeneration (STL2, WGN1, and SVD) or as a vestigial membrane just behind the lens (STL1). Peripheral chorioretinal atrophy with nyctalopia is prominent in WGN1. Intraretinal crystals may be visible in the periphery using a contact lens in SVD and corneal guttae, a flat appearance to the optic nerve head and mild atrophy of the peripheral retinal pigment epithelium are also common features. Other vitreoretinal degenerations including a number of chondrodysplasias in addition to STL1 and STL2, enhanced S-cone syndrome caused by mutations in NR2E3, and autosomal dominant vitreoretinochoroidopathy caused by mutations in VMD2 are discussed. Patients with unexplained early onset cataract or retinal detachment should be carefully evaluated for vitreoretinal degeneration. Theses diseases share overlapping clinical features with common complex traits affecting the eye (myopia, corneal endothelial dystrophy, lattice degeneration), and may provide insight into the mechanisms of common eye diseases.

LOC387715 is a hypothetical gene located on human chromosome 10q26.13 that is associated with the development of age-related macular degeneration (AMD). The native open reading frame (ORF) of LOC387715 cDNA - LOC387715(ORF), contains a large number of Escherichia coli (E. coli) rare codons (RC) including 5.6% and 15.0% Group-I and IIa translational problem causative (TPC) RCs, respectively, which forms 3 and 4 simple E. coli rare codon clusters (RCC) where RCs are spaced by 1 and 2 respective non-TPC codons and one complex E. coli RCC where RCs and RCCs are spaced by

Objective Due to a lack of valid German instruments measuring shared decision-making (SDM), a theory-driven questionnaire (SDM-Q) to measure the process of SDM was developed and validated. Methods As a theoretical basis steps of the SDM process were defined in an expert panel. Item formulation was then conducted according to the Delphi method. For the first validation on a mixed sample Rasch analysis was used to eliminate items not fitting the construct thus receiving a unidimensional scale. Results After eliminating 4 items the remaining 11 form a unidimensional scale with an acceptable reliability for person measures (0.77) and very good reliability for item difficulties (0.95). Analysis of subgroups revealed a different use of items in different conditions. Furthermore the scale showed high ceiling effects. Conclusion A new theory-driven instrument to measure the process of SDM has been developed and validated by use of a rigorous method revealing first promising results. Yet the ceiling effects require the addition of more discriminating items, and the different use of items in different conditions demands an in depth analysis. Practice implications While the concept of SDM is constantly receiving more attention in medical practice, its valid and reliable measurement remains challenging.

Age-related macular degeneration (AMD) is a common, late-onset, and complex trait with multiple risk factors. Concentrating on a region harboring a locus for AMD on 1q25-31, the ARMD1 locus, we tested single-nucleotide polymorphisms for association with AMD in two independent case-control populations. Significant association ( P = 4.95 × 10 -10 ) was identified within the regulation of complement activation locus and was centered over a tyrosine-402 → histidine-402 protein polymorphism in the gene encoding complement factor H. Possession of at least one histidine at amino acid position 402 increased the risk of AMD 2.7-fold and may account for 50% of the attributable risk of AMD.

Purpose The ocular findings, systemic features, and genetic loci distinguishing known genetic causes of vitreoretinal degenerations were studied in the original Snowflake family. Design Prospective, comparative study and molecular genetic investigation. Participants Members of the original snowflake vitreoretinal degeneration family. Methods Clinical data were collected on 26 family members by history and examination. Thirteen of the 26 total family members underwent prospective examination. Linkage to known vitreoretinal degeneration loci ( COL2A1 , COL11A1 , and the Wagner disease locus) was evaluated with short tandem repeat markers. Main outcome measures Ocular and systemic features of known vitreoretinal degenerations. Results Six of the 13 prospectively examined subjects had snowflake vitreoretinal degeneration. Corneal guttae (4/5; 80%), early onset cataract (5/6; 83%), fibrillar vitreous degeneration (6/6; 100%), and peripheral retinal abnormalities (5/6; 83%), including minute crystallinelike deposits called snowflakes (4/6; 67%), were common. Retinal detachment was seen in 1 of 6 of these prospectively examined subjects (17%). A total of 14 affected subjects were identified within the family, and in 3 (21%), retinal detachment developed. Orofacial features, early-onset hearing loss, and arthritis typical of Stickler syndrome were absent. Linkage to known vitreoretinal degeneration loci was excluded. Conclusions The absence of vitreous gel in the retrolental space and presence of fibrillar vitreous degeneration were consistent with the vitreous structure reported for collagen 11A1 ( COL11A1 ) but not collagen 2A1 ( COL2A1 ) mutations. The absence of systemic features was characteristic of the vitreoretinopathies linked to chromosome 5q13 (Wagner disease and erosive vitreoretinopathy) and mutations in exon 2 of the COL2A1 gene. Snowflakes in the peripheral retina and the absence of nyctalopia, posterior chorioretinal atrophy, and tractional retinal detachment were inconsistent with the chromosome 5q13 vitreoretinopathies. The association of Fuchs' corneal endothelial dystrophy found in this family has not been reported previously in other vitreoretinal degenerations. These findings and the exclusion of known genetic loci suggest snowflake is a distinct vitreoretinal degeneration.

Stickler syndrome (progressive arthro-ophthalmopathy) is a genetically heterogeneous disorder resulting from mutations in at least three collagen genes. The most common disease-causing gene is COL2A1, a 54-exon–containing gene coding for type II collagen. At least 17 different mutations causing Stickler syndrome have been reported in this gene. Phenotypically, it is also a variably expressed disorder in which most patients present with a wide range of eye and extraocular manifestations including auditory, skeletal, and orofacial manifestations. Some patients, however, present without clinically apparent systemic findings. This observation has led to difficulty distinguishing this Stickler phenotype from other hereditary vitreoretinal degenerations, such as Wagner syndrome and Snowflake vitreoretinal degeneration. In this regard, review of the literature indicates type II collagen exists in two forms resulting from alternative splicing of exon 2 of the COL2A1 gene. One form, designated as type IIB (short form), is preferentially expressed in adult cartilage tissue. The other form, designated as type IIA (long form), is preferentially expressed in the vitreous body of the eye. Because of this selective tissue expression, mutations in exon 2 of the COL2A1 gene have been hypothesized to produce this Stickler syndrome phenotype with minimal or absent extraocular findings. We review the evidence for families with exon 2 mutations of the collagen COL2A1 gene presenting in a distinct manner from families with mutations in the remaining 53 exons, as well as other hereditary vitreoretinal degenerations without significant systemic manifestations.

Purpose To report posterior chorioretinal atrophy (PCRA) and correlate the vitreous phenotype with inheritance of the disease mutation in a family with vitreoretinal dystrophy. Design Prospective observational case series. Methods Twenty-four members of a family with 14 affected individuals were examined, and genetic linkage analysis was performed at the COL2A1, COL11A1, and Wagner disease loci. The vitreous phenotype was prospectively graded as optically empty with retrolenticular membrane, fibrillar, or normal. Ocular ultrasonography and optical coherence tomography (OCT) were performed on selected individuals to study the vitreous structure and vitreoretinal interface. Results The 6-year-old proband had PCRA and optically empty vitreous without systemic features, suggestive of Wagner disease. The family history was negative for systemic disease, except for one cousin with cleft palate. However, when examined, clinical features of the 14 affected subjects included 5 with small chin, 4 with at least submucosal cleft palate, and 9 with a myopic refractive error greater than 5 diopters. Lens opacity or previous cataract extraction was found in 13 family members. All affected individuals in whom the vitreous could be examined had an optically empty vitreous with retrolental membrane. Posterior chorioretinal atrophy was found in eight of the affected subjects. The finding was not limited to highly myopic subjects, nor did all the high myopes have PCRA. Ultrasonography and OCT revealed vitreous adherent to the retina, but without apparent retinal distortion or edema of the macula. Significant linkage was established to the COL2A1 locus; the other loci were excluded. A single nucleotide insertion mutation (c.2012^2013insC) was identified in exon 34, leading to a downstream premature stop codon in the COL2A1 gene. Conclusions Although posterior chorioretinal atrophy and vitreoretinal degeneration have been classically associated with Wagner disease, we demonstrate its presence in a family with typical Stickler syndrome. On the basis of clinical, ultrasonographic, and OCT studies, the etiology of PCRA in this family does not seem to be attributable to vitreomacular traction or myopia. The vitreous findings in this large family confirm reports that mutations in the COL2A1 gene lead to the optically empty vitreous with retrolenticular membrane phenotype.

Autosomal dominant Stargardt-like macular dystrophy is one of the early onset macular dystrophies. It is characterized clinically in its early stages by visual loss and by the presence of atrophic macular changes with or without the presence of yellowish flecks. It is an important retinal dystrophy to study, not only because it has implications in the care and treatment of patients with the condition, but because it also provides important information regarding retinal function. Review of the literature suggests that many of the reported families are linked to chromosome 6q. Genetic and genealogical evidence suggests that these families have descended from a common ancestor or founder. The recent identification of a disease-causing gene that is involved in fatty acid metabolism may have implications in the study of the more common age-related macular degeneration. We review the recent clinical, genetic, and genealogical aspects of autosomal dominant Stargardt-like macular dystrophy.

First syntheses of a deuterium-labeled very long C34-containing polyunsaturated fatty acid, C34:5n5.d(2), and three other unlabeled very long chain C30-32-containing polyunsaturated fatty acids are reported here. These syntheses were achieved by coupling chemically modified C22- and C20-containing polyunsaturated fatty acids with carbanions derived from arylalkyl sulfones, followed by sodium amalgam-mediated desulfonylation.

PURPOSE: To study the phenotypic variability in patients inheriting the disease gene for malattia leventinese (dominant macular drusen) and refine the localization of the gene. METHODS: A family with dominant radial drusen was ascertained and studied with clinical examination and DNA linkage analysis. Inheritance of the disease gene was determined by DNA analysis and used to document the variability in phenotypic expression. RESULTS: Fifty family members were studied with fundus photography and genotyping. Linkage analysis showed that the disease in this family was linked to chromosome 2p16-21 with a maximum lod score of 3.72 at D2S2153. An affected patient with obligate recombinations allowed refinement of the disease interval to a 6.2-cM region between D2S2227 and D2S378. The phenotype of older affected patients varied from severe geographic atrophy or subretinal fibrosis to a single druse adjacent to the optic disk. Small and medium-sized, nonradial, and soft macular drusen seen in four older individuals in the family were not specifically associated with the disease haplotype. CONCLUSIONS: Refinement of the localization of the gene for malattia leventinese will facilitate its positional cloning. Genotypic documentation of the variable expression of the disease shows that a single, large, subretinal druse adjacent to the optic disk is consistent with inheritance of the disease gene. Soft macular drusen in low abundance were not specifically associated with inheritance of the disease gene. These results will facilitate the genetic counseling of patients with malattia leventinese. It is unknown what proportion of age-related macular degeneration arises from mutations in disease genes for dominant drusen.

Snowflake Vitreoretinal Degeneration (SVD) is associated with the R162W mutation of the Kir7.1 inwardly-rectifying potassium channel. Kir7.1 is found at the apical membrane of Retinal Pigment Epithelial (RPE) cells, adjacent to the photoreceptor neurons. The SVD phenotype ranges from RPE degeneration to an abnormal b-wave to a liquid vitreous. We sought to determine how this mutation alters the structure and function of the human Kir7.1 channel. In this study, we expressed a Kir7.1 construct with the R162W mutation in CHO cells to evaluate function of the ion channel. Compared to the wild-type protein, the mutant protein exhibited a non-functional Kir channel that resulted in depolarization of the resting membrane potential. Upon co-expression with wild-type Kir7.1, R162W mutant showed a reduction of IKir7.1 and positive shift in '0' current potential. Homology modeling based on the structure of a bacterial Kir channel protein suggested that the effect of R162W mutation is a result of loss of hydrogen bonding by the regulatory lipid binding domain of the cytoplasmic structure.

KCNJ13 encodes Kir7.1, an inwardly rectifying K+channel that is expressed in multiple ion-transporting epithelia. A mutation in KCNJ13 resulting in an arginine-to-tryptophan change at residue 162 (R162W) of Kir7.1 was associated with snowflake vitreoretinal degeneration, an inherited autosomal-dominant disease characterized by vitreous degeneration and mild retinal degeneration. We used the Xenopus laevis oocyte expression system to assess the functional properties of the R162W (mutant) Kir7.1 channel and determine how wild-type (WT) Kir7.1 is affected by the presence of the mutant subunit. Recordings obtained via the two-electrode voltage-clamp technique revealed that injection of oocytes with mutant Kir7.1 cRNA resulted in currents and cation selectivity that were indistinguishable from those in water-injected oocytes, suggesting that the mutant protein does not form functional channels in the plasma membrane. Coinjection of oocytes with equal amounts of mutant and WT Kir7.1 cRNAs resulted in inward K+and Rb+currents with amplitudes that were ∼17% of those in oocytes injected with WT Kir7.1 cRNA alone, demonstrating a dominant-negative effect of the mutant subunit. Similar to oocytes injected with WT Kir7.1 cRNA alone, coinjected oocytes exhibited inwardly rectifying Rb+currents that were more than seven times larger than K+currents, indicating that mutant subunits did not alter Kir7.1 channel selectivity. Immunostaining of Xenopus oocytes or Madin-Darby canine kidney cells expressing mutant or WT Kir7.1 demonstrated distribution of both proteins primarily in the plasma membrane. Our data suggest that the R162W mutation suppresses Kir7.1 channel activity, possibly by negatively impacting gating by membrane phosphadidylinositol 4,5-bisphosphate.

Fuchs endothelial corneal dystrophy (FECD) is a common, familial disease of the corneal endothelium and is the leading indication for corneal transplantation. Variation in the transcription factor 4 (TCF4) gene has been identified as a major contributor to the disease. We tested for an association between an intronic TGC trinucleotide repeat in TCF4 and FECD by determining repeat length in 66 affected participants with severe FECD and 63 participants with normal corneas in a 3-stage discovery/replication/validation study. PCR primers flanking the TGC repeat were used to amplify leukocyte-derived genomic DNA. Repeat length was determined by direct sequencing, short tandem repeat (STR) assay and Southern blotting. Genomic Southern blots were used to evaluate samples for which only a single allele was identified by STR analysis. Compiling data for 3 arms of the study, a TGC repeat length >50 was present in 79% of FECD cases and in 3% of normal controls cases (p50 TGC repeats, 13 (20%) had 50 repeats, 60 (95%) had 50 TGC repeats identifying FECD in this patient cohort was 79% and 96%, respectively Expanded TGC repeat was more specific for FECD cases than the previously identified, highly associated, single nucleotide polymorphism, rs613872 (specificity = 79%). The TGC trinucleotide repeat expansion in TCF4 is strongly associated with FECD, and a repeat length >50 is highly specific for the disease This association suggests that trinucleotide expansion may play a pathogenic role in the majority of FECD cases and is a predictor of disease risk.

The major focus of our research is to understand how age-related macular degeneration (AMD) develops. It is known that genetic variation can explain much of the risk of developing AMD. However, we do not know what controls the transition between a normal fundus and the extensive accumulation of subretinal inflammatory material that we recognize as drusen in AMD. We do know that the accumulation of this inflammatory material that characterizes the maculopathy underlying AMD is by far the most important predictor of late AMD. Late or advanced forms of AMD include geographic atrophy in which there is patchy death of the retina and exudation in which abnormal neovascularization invades the subretinal or subretinal pigment epithelial space. Thus, preventing the accumulation of the inflammatory debris underneath the retina could be expected to alleviate much of the vision loss from this devastating disease.

Retinal pigment epithelium (RPE) is a polarized cell layer critical for photoreceptor function and survival. The unique physiology and relationship to the photoreceptors make the RPE a critical determinant of human vision. Therefore, we performed a global expression profiling of native and cultured human fetal and adult RPE and determined a set of highly expressed ‘signature’ genes by comparing the observed RPE gene profiles to the Novartis expression database (SymAtlas: http://wombat.gnf.org/index.html) of 78 tissues. Using stringent selection criteria of at least 10-fold higher expression in three distinct preparations, we identified 154 RPE signature genes, which were validated by qRT-PCR analysis in RPE and in an independent set of 11 tissues. Several of the highly expressed signature genes encode proteins involved in visual cycle, melanogenesis and cell adhesion and Gene ontology analysis enabled the assignment of RPE signature genes to epithelial channels and transporters (ClCN4, BEST1, SLCA20) or matrix remodeling (TIMP3, COL8A2). Fifteen RPE signature genes were associated with known ophthalmic diseases, and 25 others were mapped to regions of disease loci. An evaluation of the RPE signature genes in a recently completed AMD genomewide association (GWA) data set revealed that TIMP3, GRAMD3, PITPNA and CHRNA3 signature genes may have potential roles in AMD pathogenesis and deserve further examination. We propose that RPE signature genes are excellent candidates for retinal diseases and for physiological investigations (e.g. dopachrome tautomerase in melanogenesis). The RPE signature gene set should allow the validation of RPE-like cells derived from human embryonic or induced pluripotent stem cells for cell-based therapies of degenerative retinal diseases.

The major focus of our research is to understand how age-related macular degeneration (AMD) develops. It is known that genetic variation can explain much of the risk of developing AMD. However, we do not know what controls the transition between a normal fundus and the extensive accumulation of subretinal inflammatory material that we recognize as drusen in AMD. We do know that the accumulation of this inflammatory material that characterizes the maculopathy underlying AMD is by far the most important predictor of late AMD. Late or advanced forms of AMD include geographic atrophy in which there is patchy death of the retina and exudation in which abnormal neovascularization invades the subretinal or subretinal pigment epithelial space. Thus, preventing the accumulation of the inflammatory debris underneath the retina could be expected to alleviate much of the vision loss from this devastating disease.

Trimeric and tetrameric short tandem repeats (STRs) represent a rich source of highly polymorphic markers in the human genome that may be studied with the polymerase chain reaction (PCR). We report the analysis of a multilocus genotype survey of 97-380 chromosomes in U.S. Black, White, Mexican-American, and Asian populations at five STR loci located on chromosomes 1, 4, 11, and X. The heterozygote frequencies of the loci ranged from 0.36 to 0.91 and the number of alleles from 6 to 20 for the 20 population and locus combinations. Relative allele frequencies exhibited differences between populations and unimodal, bimodal, and complex distributions. Although deviations were noted at some locus-population test combinations, genotype data from the loci were consistent overall with Hardy-Weinberg equilibrium by three tests. Population subheterogeneity within each ethnic group was not detected by two additional tests. No mutations were detected in a total of 860 meioses for two loci studied in the CEPH kindreds and five loci studied in other families. An indirect estimate of the mutation rates gave values from 2.3 x 10(-5) to 15.9 x 10(-5) for the five loci. Higher mutation rates appear to be associated with greater numbers of tandem repeats in the core motif. The most frequent genotype for all five loci combined appears to have a frequency of 7.59 x 10(-4). Together, these results suggest that trimeric and tetrameric STR loci are useful markers for the study of new mutations and genetic linkage analysis and for application to personal identification in the medical and forensic sciences.

Activation of the alternative pathway of complement is implicated in common neurodegenerative diseases including age-related macular degeneration (AMD). We explored the impact of common variation in genes encoding proteins of the alternative pathway on complement activation in human blood and in AMD. Genetic variation across the genes encoding complement factor H (CFH), factor B (CFB) and component 3 (C3) was determined. The influence of common haplotypes defining transcriptional and translational units on complement activation in blood was determined in a quantitative genomic association study. Individual haplotypes in CFH and CFB were associated with distinct and novel effects on plasma levels of precursors, regulators and activation products of the alternative pathway of complement in human blood. Further, genetic variation in CFH thought to influence cell surface regulation of complement did not alter plasma complement levels in human blood. Plasma markers of chronic activation (split-products Ba and C3d) and an activating enzyme (factor D) were elevated in AMD subjects. Most of the elevation in AMD was accounted for by the genetic variation controlling complement activation in human blood. Activation of the alternative pathway of complement in blood is under genetic control and increases with age. The genetic variation associated with increased activation of complement in human blood also increased the risk of AMD. Our data are consistent with a disease model in which genetic variation in the complement system increases the risk of AMD by a combination of systemic complement activation and abnormal regulation of complement activation in local tissues.

PURPOSE. Nonsynonymous coding single nucleotide polymorphisms (nsSNPs) in complement component 3 (C3) alter the risk of age-related macular degeneration (AMD). This was a study of the effect of haplotypes across C3 on AMD risk. METHODS. Nine SNPs tagging haplotypes across C3 were genotyped on 738 subjects at the Mayo Clinic. Haplotype analyses were performed with and without conditioning on individual SNPs. Replication studies were performed using 1541 subjects from the age-related eye disease study (AREDS). RESULTS. Two nsSNPs located 5125 bp apart in the 5 end of C3 showed the highest association (rs1047286 or P314L, P 9.2E-05; rs2230199 or R102G, P 4.1E-05) with AMD. The minor alleles of both SNPs tagged a single risk haplotype. The effects of the two nsSNPs could not be distinguished due to high linkage disequilibrium. The risk SNPs preferentially promoted the development of advanced AMD relative to early AMD in both the Mayo and AREDS subjects. Haplotypes in the 3 end of the C3 locus were associated with AMD in both the Mayo and AREDS subjects. The effect persisted after conditioning on the nsSNPs only in the Mayo subjects. No interaction was found between rs2230199 and smoking or other AMD loci. CONCLUSIONS. nsSNPs in C3 increased the risk of developing AMD 1.8-fold for 1 risk allele or 2.4-fold for two risk alleles and were preferentially associated with advanced AMD. Further study is needed to determine whether haplotypes in the 3 end of C3 have an independent association with AMD. (Invest Ophthalmol Vis Sci. 2009;50:3386–3393) DOI:10.1167/iovs.083231

Purpose To report the outcomes and complications of bilateral simultaneous intravitreal injections performed in the office. Design Retrospective case series. Methods Records of 35 patients receiving simultaneous bilateral intravitreal injections between November 2007 and November 2008 were reviewed. Data collected included indication for injection, preinjection and postinjection intraocular pressure (IOP), preinjection and postinjection visual acuity (VA), and complications/complaints after each injection. Results A total of 208 injections were administered to 35 patients, with a mean of 5.9 injections per patient (range, 2 to 14; standard deviation [SD], 3.68). One hundred and thirty-three eyes received bevacizumab (Avastin; Genentech Inc, South San Francisco, California, USA) alone, 14 received bevacizumab plus preservative-free intravitreal triamcinolone or Triescence (Kenalog; Bristol-Myers Squibb Co, New York, New York, USA), 56 received ranibizumab (Lucentis; Genentech Inc), and 5 received bevacizumab plus dexamethasone (Decadron; Merck, Whitehouse Station, New Jersey, USA). Mean time of postinjection follow-up was 39 days. Postinjection VA follow-up measurements were available for 194 injections. The indication for initiating therapy was choroidal neovascularization from age-related macular degeneration (49 eyes), diabetic macular edema (ME) (13 eyes), proliferative diabetic retinopathy (4 eyes), ME attributable to retinal vein occlusion (2 eyes), and ME attributable to autoimmune retinopathy (2 eyes). The mean VA before each injection was 20/96 and at the next follow-up was 20/91 ( P = .40). One patient had a painless, culture-negative endophthalmitis in 1 eye 3 days after bilateral bevacizumab; at 1 year VA improved from 20/400 to 20/80. Conclusions Simultaneous bilateral intravitreal injections in the office are well tolerated. A separate povidone-iodine preparation, speculum, needle, and syringe were used for each eye. None of the patients requested alternating unilateral injections, after receiving bilateral injections. Patients should be counseled as to the risk of complications.

Determination of the complete nucleotide sequence of the human genome will require accurate, efficient, and automated DNA sequencing methods. The random DNA sequencing strategy is being utilized in large-scale sequencing projects at present and is being considered for incorporation into the methods that will be utilized in the sequencing of genomes. Herein we present some concepts relevant to random DNA sequencing and discuss the design and implementation of the method. Strategies for overlapping contigs and sequencing gaps are suggested and discussed in detail, as the closure phase appears to be the limiting step in efficient application of random DNA sequencing approaches. Performance of a modified random DNA sequencing strategy used to sequence 60 kb of the human HPRT locus is presented in the context of closure. It is suggested that the efficiency of random DNA sequencing may be improved by simple modifications facilitating closure.

Genome-wide association studies (GWASs) assess correlation between traits and DNA sequence variation using large numbers of genetic variants such as single nucleotide polymorphisms (SNPs) distributed across the genome. A GWAS produces many trait-SNP associations with low p-values, but few are replicated in subsequent studies. We sought to determine if characteristics of the genomic loci associated with a trait could be used to identify initial associations with a higher chance of replication in a second cohort. Data from the age-related eye disease study (AREDS) of 100,000 SNPs on 395 subjects with and 198 without age-related macular degeneration (AMD) were employed. Loci highly associated with AMD were characterized based on the distribution of genotypes, level of significance, and clustering of adjacent SNPs also associated with AMD suggesting linkage disequilibrium or multiple effects. Forty nine loci were highly associated with AMD, including 3 loci (CFH, C2/BF, LOC387715/HTRA1) already known to contain important genetic risks for AMD. One additional locus (C3) reported during the course of this study was identified and replicated in an additional study group. Tag-SNPs and haplotypes for each locus were evaluated for association with AMD in additional cohorts to account for population differences between discovery and replication subjects, but no additional clearly significant associations were identified. Relying on a significant genotype tests using a log-additive model would have excluded 57% of the non-replicated and none of the replicated loci, while use of other SNP features and clustering might have missed true associations.

Genetic association studies are identifying genetic risks for common complex ocular traits such as age-related macular degeneration (AMD). The subjects used for discovery of these loci have been largely from clinic-based, case-control studies. Typically, only the primary phenotype (e.g., AMD) being studied is systematically documented and other complex traits (e.g., affecting the eye) are largely ignored. The purpose of this study was to characterize these other or secondary complex ocular traits present in the cases and controls of clinic-based studies being used for genetic study of AMD. The records of 100 consecutive new patients (of any diagnosis) age 60 or older for which all traits affecting the eye had been recorded systematically were reviewed. The average patient had 3.5 distinct diagnoses. A subset of 10 complex traits was selected for further study because they were common and could be reliably diagnosed. The density of these 10 complex ocular traits increased by 0.017 log-traits/year (P = 0.03), ranging from a predicted 2.74 at age 60 to 4.45 at age 90. Trait-trait association was observed only between AMD and primary vitreomacular traction (P = 0.0009). Only 1% of subjects age 60 or older had no common complex traits affecting the eye. Extrapolations suggested that a study of 2000 similar subjects would have sufficient power to detect genetic association with an odds ratio of 2.0 or less for 4 of these 10 traits. In conclusion, the high prevalence of complex traits affecting the aging eye and the inherent biases in referral patterns leads to the potential for confounding by undocumented secondary traits within case-control studies. In addition to the primary trait, other common ocular phenotypes should be systematically documented in genetic association studies so that adjustments for potential trait-trait associations and other bias can be made and genetic risk variants identified in secondary analyses.

PURPOSE. Evidence from genetic-association studies in conjunction with the demonstration of complement deposition in the retina and choroid implicates noncellular pathways of innate immunity in the pathogenesis of age-related macular degeneration (AMD). The purpose of this study was to determine whether common variation in the 10 human toll-like receptors (TLRs) alters the risk of AMD. METHODS. Sixty-eight SNPs were iteratively genotyped across the TLR genes in a cohort of 577 subjects, with and without AMD. Two additional cohorts were used for replication studies. Standard genetic-association methods were used to analyze the results for association with disease and interaction with other loci. RESULTS. Coding SNPs in TLR3 (rs3775291) and TLR7 (rs179008) showed association with AMD in one group (P = 0.01 and P = 0.02, respectively) before correction for multiple testing. For both SNPs, the association with AMD arose due to an excess of heterozygotes compared with homozygotes for the major allele. The two coding SNPs were not associated with AMD in another case-control cohort or an extended-family cohort. Although an intronic SNP in TLR4 was associated marginally with AMD (P = 0.03), it was not possible to replicate a previous association with the rare coding SNP D299G in this gene (P = 0.6). CONCLUSIONS. Although borderline support for association between polymorphisms in TLR genes and AMD was reported for some cohorts, these initial observations of coding SNPs in TLR3, TLR4, and TLR7 were not replicated. TLR variants are unlikely to have a major impact on overall AMD risk, and the common variants studied were not associated with AMD.

To describe the occurrence of ocular hypertension in four patients following injection of ranibizumab intravitreally.Case series.Four patients had high intraocular pressure after intravitreal ranibizumab 0.5 mg. Ocular hypertension occurred 1 month after the second ranibizumab injection in patients 1 and 3, and 1 month after the first ranibizumab in patient 2. In patient 4, it occurred several hours after the first ranibizumab injection. In all patients, the IOP increase was sustained across several visits, requiring control with topical glaucoma therapy, and in two cases the addition of a systemic carbonic anhydrase inhibitor. None of the patients had a previous history of glaucoma, ocular hypertension or IOP asymmetry and the IOP was as high as 30, 34, 46, and 50 mmHg in the four patients.Severe and sustained ocular hypertension may occur after intravitreal ranibizumab. Although the mechanism of the pressure rise is unknown, all eyes in our series were controlled with medical therapy.

Snowflake vitreoretinal degeneration (SVD, MIM 193230) is a developmental and progressive hereditary eye disorder that affects multiple tissues within the eye. Diagnostic features of SVD include fibrillar degeneration of the vitreous humor, early-onset cataract, minute crystalline deposits in the neurosensory retina, and retinal detachment. A genome-wide scan previously localized the genetic locus for SVD to a 20 Mb region flanked by D2S2158 and D2S2202. This region contains 59 genes, of which 20 were sequenced, disclosing a heterozygous mutation (484C > T, R162W) in KCNJ13, member 13 of subfamily J of the potassium inwardly rectifying channel family in all affected individuals. The mutation in KCNJ13, the gene encoding Kir7.1, was not present in unaffected family members and 210 control individuals. Kir7.1 localized to human retina and retinal pigment epithelium and was especially prevalent in the internal limiting membrane adjacent to the vitreous body. Molecular modeling of this mutation predicted disruption of the structure of the potassium channel in the closed state located immediately adjacent to the cell-membrane inner boundary. Functionally, unlike wild-type Kir7.1 whose overexpression in CHO-K1 cells line produces highly selective potassium current, overexpression of R162W mutant Kir7.1 produces a nonselective cation current that depolarizes transfected cells and increases their fragility. These results indicate that the KCNJ13 R162W mutation can cause SVD and further show that vitreoretinal degeneration can arise through mutations in genes whose products are not structural components of the vitreous.

There have been major advances over the past two years in identifying genetic risks for age-related macular degeneration (AMD). The complexity of genetic association and genetic epidemiology studies and differences in the conclusions and data reported from various laboratories make it difficult for the general scientific reader to understand the significance and limitations of these advances. Thus, the scientific foundations and limitations of these genetic studies are not widely understood. The general scientific reader needs an approach to recognize spurious genetic association from those that are real and to understand what genetic association studies can teach us about AMD and where we need to be cautious. The purpose of this article is to provide an overview of the genetics of AMD and explain how to approach a genetic association study.

The Lesch-Nyhan (LN) syndrome is a genetically lethal human neurological disease that results from mutations that inactivate the hypoxanthine phosphoribosyltransferase (HPRT) gene. The elucidation of the complete DNA sequence of the human HPRT gene locus has enabled the construction of multiple oligonucleotide primer sets for the simultaneous in vitro amplification of all nine HPRT exons. The multiplex polymerase chain reaction provides a facile assay for the detection of HPRT exon deletions and the reaction products can be analyzed by direct automated fluorescent DNA sequencing to identify subtle alterations in the gene. Alterations have been identified in the HPRT genes from 15 independent LN cases, and 10 LN family studies were performed. The sequencing method uses solid supports and is sufficiently simple and sensitive to be a favored approach for LN diagnosis. LN heterozygotes can be diagnosed without reference to the affected male. In addition, these procedures will be useful for somatic mutagenesis studies.

Injection of drugs into the vitreous can lead to intraocular inflammation through infectious and non-infectious processes. Failure to recognize an eye with anterior chamber and vitreous cell as sterile inflammation can lead to unnecessary treatment for endophthalmitis.Four cases of uveitis following intravitreal bevacizumab (Avastin) for exudative age-related macular degeneration are described followed by review of the literature.Four patients presented with uveitis. Two patients presented with pain and red eye associated with iritis and two patients with vitritis, several days following intravitreal injection of bevacizumab. No paracentesis was performed and no corneal epithelial defect was created. Both patients with iritis were presumed to have sterile intraocular inflammation since the anterior chamber cell was much greater than the vitreous cell and resolved with cycloplegic and topical corticosteroid therapy. The third patient presented only with vitreous cell which resolved without therapy. The fourth patient had anterior chamber cell and vitreous cell with clumps, which resolved with topical prednisolone acetate. The inflammation resolved in all cases within 1 to 2 weeks.There are few published cases of uveitis following bevacizumab. With its rising use, it is important to be aware of its potential to be associated with intraocular inflammation.

Author(s): Thomas, George; Grassi, Michael A; Lee, John R; Edwards, Albert O; Gorin, Michael B; Klein, Ronald; Casavant, Thomas L; Scheetz, Todd E; Stone, Edwin M; Williams, Andrew B | Abstract: PurposeTo use the power of knowledge acquisition and machine learning in the development of a collaborative computer classification system based on the features of age-related macular degeneration (AMD).MethodsA vocabulary was acquired from four AMD experts who examined 100 ophthalmoscopic images. The vocabulary was analyzed, hierarchically structured, and incorporated into a collaborative computer classification system called IDOCS. Using this system, three of the experts examined images from a second set of digital images compiled from more than 1000 patients with AMD. Images were annotated, and features were identified and defined. Decision trees, a machine learning method, were trained on the data collected and used to extract patterns. Interrelationships between the data from the different clinicians were investigated.ResultsSix drusen classes in the structured vocabulary were largely sufficient to describe all the identified features. The decision trees classified the data with 76.86% to 88.5% accuracy and distilled patterns in the form of hierarchical trees composed of 5 to 15 nodes. Experts were largely consistent in their characterization of soft, and to a lesser extent, hard drusen, but diverge in definition of other drusen. Size and crystalline morphology were the main determinants of drusen type across all experts.ConclusionsMachine learning is a powerful tool for the characterization of disease phenotypes. The creation of a defined feature set for AMD will facilitate the development of an IDOCS-based classification system.

To become highly proficient at a given surgical procedure and to reduce risk to patients, physicians must gain experience through a number means. Some surgical procedures can be learned through practice on cadavers, animals, or physical models. Today computer models can provide the required realism to provide highly effective training. This paper presents a computer-based system that will be used for training ophthalmologists in the performance of two processes involving the application of laser to the retina: photodynamic therapy and panretinal photocaoagulation.