Retinocytoma Undergoing Retinoblastoma Transformation in an Adult Patient.

We report a 46-year-old male patient with retinocytoma who presented at the age of 31 asymptomatically. An intraocular retinal mass was incidentally found in his right eye, when he underwent ophthalmological assessment for refractive surgery. This tumor consisted of a calcified sessile basis partially covered by a pedunculated salmon-pink growth. Initially, the tumor was diagnosed as a retinocytoma with clinical suspicion of malignant transformation into retinoblastoma and treated by four sessions of laser photocoagulation. Six and a half years later, the tumor relapsed, and he was treated with a Ruthenium plaque. Following brachytherapy, he had two episodes of right-sided vitreous hemorrhage that spontaneously cleared up, and the remaining finding in the vitreous cavity was interpreted as asteroid hyalosis. He underwent vitrectomy about five years following brachytherapy. The analysis of the vitreous material revealed the presence of inactive vitreous seeds composed of small round blue cells, compatible with a type 2 regression.

Potential blindness in children of patients with hereditary bone disease.

Mono- and bi-allelic mutations in the low-density lipoprotein receptor related protein 5 (LRP5) may cause osteopetrosis, autosomal dominant and recessive exudative vitreoretinopathy, juvenile osteoporosis, or persistent hyperplastic primary vitreous (PHPV). We report on a child affected with PHPV and carrying compound mutations. The father carried the splice mutation and suffered from severe bone fragility since childhood. The mother carried the missense mutation without any clinical manifestations. The genetic diagnosis of their child allowed for appropriate treatment in the father and for the detection of osteopenia in the mother. Mono- and bi-allelic mutations in LRP5 may cause osteopetrosis, autosomal dominant and recessive exudative vitreoretinopathy, juvenile osteoporosis, or PHPV. PHPV is a component of persistent fetal vasculature of the eye, characterized by highly variable expressivity and resulting in a wide spectrum of anterior and/or posterior congenital developmental defects, which may lead to blindness. We evaluated a family diagnosed with PHPV in their only child. The child presented photophobia during the first 3 weeks of life, followed by leukocoria at 2 months of age. Molecular resequencing of NDP, FZD4, and LRP5 was performed in the child and segregation of the observed mutations in the parents. At presentation, fundus examination of the child showed a retrolental mass in the right eye. Ultrasonography revealed retinal detachment in both eyes. Thorough familial analysis revealed that the father suffered from many fractures since childhood without specific fragility bone diagnosis, treatment, or management. The mother was asymptomatic. Molecular analysis in the proband identified two mutations: a c.[2091+2T>C] splice mutation and c.[1682C>T] missense mutation. We report the case of a child affected with PHPV and carrying compound heterozygous LRP5 mutations. This genetic diagnosis allowed the clinical diagnosis of the bone problem to be made in the father, resulting in better management of the family. It also enabled preventive treatment to be prescribed for the mother and accurate genetic counseling to be provided.

Molecular Analysis of NOTCH2 in Patients with Primary Open-Angle Glaucoma.

BACKGROUND AND PURPOSE: Transgenic mice overexpressing Notch2 in the uvea exhibit a hyperplastic ciliary body leading to increased IOP and glaucoma. The aim of this study was to investigate the possible presence of NOTCH2 variants in patients with primary open-angle glaucoma (POAG). METHODS: We screened DNA samples from 130 patients with POAG for NOTCH2 variants by denaturing high-performance liquid chromatography after PCR amplification and validated our data by direct Sanger sequencing. RESULTS: No mutations were observed in the coding regions of NOTCH2 or in the splice sites. 19 known SNPs (single nucleotide polymorphisms) were detected. An SNP located in intron 24, c.[4005+45A>G], was seen in 28.5% of the patients (37/130 patients). As this SNP is reported to have a minor allele frequency of 7% in the 1000 genomes database, it could be associated with POAG. However, we evaluated its frequency in an ethnic-matched control group of 96 subjects unaffected by POAG and observed a frequency of 29%, indicating that it was not related to POAG. CONCLUSION: NOTCH2 seemed to be a good candidate for POAG as it is expressed in the anterior segment in the human eye. However, mutational analysis did not show any causative mutation. This study also shows that proper ethnic-matched control groups are essential in association studies and that values given in databases are sometimes misleading.

Cone-rod dystrophy caused by a novel homozygous RPE65 mutation in Leber congenital amaurosis.

BACKGROUND: The aim of this study was to describe an unexpected phenotype in a family with Leber congenital amaurosis (LCA) due to a retinal pigment epithelium-specific protein 65 kDa (RPE65) homozygous mutation. HISTORY AND SIGNS: We analyzed a family from Yemen in which 3 individuals were affected with LCA. Linkage analysis using markers flanking the known LCA genes was done, followed by direct sequencing of RPE65. THERAPY AND OUTCOME: Severe visual impairment and night blindness were observed during infancy. We observed photophobia only in the 8-year-old patient. The youngest affected had bilateral hyperopia of +3.50 and visual acuity of 1/60. The oldest two had visual acuity limited to hand movements in the right eye (OD) and counting fingers in the left eye (OS) for the oldest and of 5/60 OD, 6/60 OS for the other. They showed disc pallor, attenuated vessels, white flecks in the retina mid-periphery and bull's eye maculopathy. ERGs of the oldest child were completely unresponsive. Genomic sequencing identified a novel homozygous missense mutation, IVS2-3C>G, in the second RPE65 intron. CONCLUSIONS: We identified a novel LCA-related homozygous RPE65 mutation associated with a severe clinical presentation including an early and severe cone dysfunction. This is in contrast with the presentation associated with other RPE65 mutations predominantly causing rod-cone dystrophy with residual visual function.

Retinal dystrophy in the oculo-auricular syndrome due to HMX1 mutation.

PURPOSE: To report on the clinical and electrophysiological findings in a patient with oculo-auricular syndrome due to HMX1 mutation, with a follow-up of 12 years. BACKGROUND: Oculo-auricular syndrome (MIM: 612109) is a rare developmental recessive condition affecting the eye and external ear that results from a mutation in the HMX1 gene. Previously described ocular abnormalities include bilateral microcornea, posterior synechiae, cataract, chorioretinal colobomas and rod-cone dystrophy. METHODS: Retrospective chart review of an affected boy followed over a period of 12 years who had serial complete ophthalmologic examinations, fundus photographs, Goldmann perimetry and full-field electroretinograms (ERG). RESULTS: Initial ERG tracings revealed generalized rod more than cone dysfunction. Thereafter, a rapid deterioration in rod and cone function was detected on follow up ERGs. CONCLUSION: The retinal degeneration in the recessively inherited oculo-auricular syndrome is a progressive rod-cone dystrophy. Visual prognosis is guarded considering the progressive nature of the retinal dystrophy in early infancy.

[The IC3D classification of the corneal dystrophies]. / IC3D-Klassifikation von Hornhautdystrophien.

BACKGROUND: The recent availability of genetic analyses has demonstrated the shortcomings of the current phenotypic method of corneal dystrophy classification. Abnormalities in different genes can cause a single phenotype, whereas different defects in a single gene can cause different phenotypes. Some disorders termed corneal dystrophies do not appear to have a genetic basis. PURPOSE: The purpose of this study was to develop a new classification system for corneal dystrophies, integrating up-to-date information on phenotypic description, pathologic examination, and genetic analysis. METHODS: The International Committee for Classification of Corneal Dystrophies (IC3D) was created to devise a current and accurate nomenclature. RESULTS: This anatomic classification continues to organize dystrophies according to the level chiefly affected. Each dystrophy has a template summarizing genetic, clinical, and pathologic information. A category number from 1 through 4 is assigned, reflecting the level of evidence supporting the existence of a given dystrophy. The most defined dystrophies belong to category 1 (a well-defined corneal dystrophy in which a gene has been mapped and identified and specific mutations are known) and the least defined belong to category 4 (a suspected dystrophy where the clinical and genetic evidence is not yet convincing). The nomenclature may be updated over time as new information regarding the dystrophies becomes available. CONCLUSIONS: The IC3D Classification of Corneal Dystrophies is a new classification system that incorporates many aspects of the traditional definitions of corneal dystrophies with new genetic, clinical, and pathologic information. Standardized templates provide key information that includes a level of evidence for there being a corneal dystrophy. The system is user-friendly and upgradeable and can be retrieved on the website www.corneasociety.org/ic3d .

Genotype-phenotype correlation of age-related macular degeneration: influence of complement factor H polymorphism.

BACKGROUND/AIMS: Complement factor H (CFH) Y402H polymorphism shows a strong association with age-related macular degeneration (AMD). Although the phenotypic concordance of AMD has been shown in sibling/twin studies, little is known about the genotype-phenotype association. In this study, we investigated whether CFH Y402H is associated with early phenotypic features. METHODS: Statistical analysis was performed on 420 patients with AMD with complete clinical and genetic data (graded colour fundus photographs, according to the International Classification and Grading System for AMD and successful testing for CFH Y402H). RESULTS: In this Swiss population, an OR of 2.95 was confirmed for AMD in the presence of at least one risk C allele and OR of 9.05 for the CC homozygotes, corrected for age and sex. No difference was found between the AMD stages. Patients homozygous for the risk allele showed significant association with peripheral drusen (p = 0.028) and for central drusen location (p = 0.049). No trend was found for other drusen criteria (size, total surface, location nasal to disc) and for pigmentary changes. CONCLUSIONS: The CFH Y402H polymorphism showed a genotype-phenotype association for some drusen features. Additional genetic factors are likely to influence drusen phenotype.

Patient with Fanconi Syndrome (FS) and retinitis pigmentosa (RP) caused by a deletion and duplication of mitochondrial DNA (mtDNA).

BACKGROUND: We report a patient with a highly unusual presentation of a mitochondrial disorder. HISTORY AND SIGNS: An 8-year old girl presented with muscular cramps as well as height and weight deceleration. Investigations revealed lactic acidosis, electrolytic imbalance and urinary loss of glucose and electrolytes secondary to proximal renal tubulopathy consistent with Fanconi syndrome (FS). Ophthalmic examination revealed asymptomatic retinitis pigmentosa (RP) with no other ocular manifestations. A mitochondriopathy was suspected and genetic analysis performed. THERAPY AND OUTCOME: Southern blotting documented a heteroplasmic mutation of mtDNA with deletion/duplication. Three discrete mitochondrial genomes were detected: normal; deletion of 6.7 kb and a deletion/duplication consisting of 1 normal and 1 deleted genome. The relative proportions varied considerably between tissues. CONCLUSIONS: The association of FS and RP combines features of Kearns-Sayre syndrome and Pearson marrow-pancreas syndrome, without being typical of either. This highly unusual clinical presentation emphasises the need for systemic investigation of patients with FS and further underlines the importance of mtDNA analysis in patients with unexpected associations of affected tissues.

Keratoepithelin in secondary corneal amyloidosis.

BACKGROUND: Amyloid is found in several corneal dystrophies, including distinct lattice corneal dystrophies (LCD) and Avellino corneal dystrophy. Recently, point mutations in the transforming growth factor-beta-induced gene (TGFBI) encoding for keratoepithelin (KE) have been demonstrated in these corneal disease entities. We intended to investigate if KE was also a component of the rarely seen secondary corneal amyloid deposits. METHODS: Immunohistochemical staining with a polyclonal antibody against KE was performed on formalin-fixed paraffin-embedded tissue of five corneal buttons with secondary amyloid obtained after keratoplasty. Secondary amyloidosis was due to Fuchs endothelial dystrophy (FED) with bullous keratopathy and/or recurrent erosions in all cases. The diagnosis had been established by light microscopy using Congo red staining. Two cases of LCD type I served as positive controls and three corneas with FED and one with keratoconus without amyloid served as negative controls. RESULTS: All corneas with secondary amyloidosis as well as LCD type I revealed positive staining in the respective amyloid deposits. KE was localized in the subepithelial pannus and in the anterior stroma in the corneas with secondary amyloidosis. In the specimens with LCD type I it was distributed in the amyloid deposits located in the anterior and mid-stroma. Staining for KE showed a granular appearance in all cases. The intensity of staining was variable among the specimens. CONCLUSIONS: KE is found not only in primary amyloid deposits of hereditary corneal dystrophies, but also in secondary amyloidosis of the cornea of diverse ethiologies.

Lentiviral vector-mediated gene transfer in adult mouse photoreceptors is impaired by the presence of a physical barrier.

Gene transfer offers a substantial promise for the therapy of degenerative ocular diseases. Lentiviral vectors have the ability to efficiently transduce murine photoreceptors during the first days of life, but they are poorly effective on photoreceptors during adulthood. Here, we studied whether a physical barrier was responsible for this impairment. Previous studies have described the capacity of enzymes, such as chondroitinase ABC and neuraminidase X, to modify the structure of the interphotoreceptor matrix (IPM) when subretinally injected. Considering the IPM as a physical barrier that may decrease photoreceptor transduction, we injected different enzymes into the subretinal space of the adult mouse simultaneously with the lentiviral vector preparation, to increase viral transduction by fragilizing the IPM. Subretinal injection of neuraminidase X and chondroitinase ABC induces modifications in the IPM by, respectively, revealing or decreasing peanut agglutinin sites on photoreceptors. The simultaneous subretinal injection of neuraminidase X with a lentiviral vector driving the expression of a reporter gene in the photoreceptors increases the number of transduced cells significantly (around five-fold). After the enzyme treatment, the diffusion of the vector between the pigmented epithelium and the photoreceptors appears to facilitate the lentiviral vector transduction. Such approach targeting the IPM may help to design new strategies to improve gene delivery into the adult photoreceptors.

[Optical coherence tomography in Malattia Leventinese]. / Tomographie a coherence optique dans la Malattia leventinese.

BACKGROUND: Malattia Leventinese (ML) is a genetically homogeneous macular dystrophy with an autosomal dominant mode of inheritance. Ophthalmoscopically it is recognisable by a radial pattern of drusen-like deposits in the macula and by parapapillary deposits, named Forni's verrucosities. The aim of this study is to describe optical coherence tomographic (OCT) findings and to compare them with histological data. PATIENTS AND METHODS: Six patients underwent ophthalmological examination, angiography and OCT. Diagnosis was confirmed by genetic analysis of the R345W mutation. A histopathological study of an ML donor eye was performed. RESULTS: OCT revealed a diffuse RPE-choriocapillaris thickening with nodular features in the macular and parapapillary areas. The protrusions reached as far as the outer nuclear layer. CONCLUSIONS: OCT is a non-invasive technique that provides a cross-sectional picture of the retina comparable to a histological section. In ML, OCT revealed a diffuse alteration of the RPE-Bruch's membrane complex. The macular and parapapillary nodular lesions are the tomographic equivalents of drusen and Forni's verrucosities.

Idiopathic cyclitic retrolental membrane in children.

BACKGROUND: Cyclitic retrolental membranes (CRM) in children are usually associated with chronic uveitis or genetic syndromes. We report two rare cases of idiopathic CRM. PATIENTS AND METHODS: Two girls aged 9 and 13 years with visual acuities (VA) of 0.05 underwent lensectomy and anterior vitrectomy with dissection of the central part of the retrolental membrane and intraocular lens (IOL) implantation. RESULTS: The clinical evolution was excellent for the 9 year old girl who recovered 1.0 VA after 2 months. Histological examination revealed a fibroelastic tissue of unknown origin without inflammatory components. The 13 year old girl showed VA of 0.6 within 1 month. However, a recurrent CRM developed with retinal detachment and proliferative vitreoretinopathy (PVR). Vitrectomy, complete excision of the CRM and 360 degrees retinotomy with silicon oil tamponade attached the retina with limited visual recovery. Histology showed fibrovascular tissue with inflammatory components infiltrating the CRM. CONCLUSIONS: Idiopathic CRM in children are rare and can be composed of different histological tissues with very different clinical outcomes.

Clinical and immunopathological corneal phenotype in homozygotes for the BIGH3 R124H mutation.

A family was previously reported as suffering from severe granular dystrophy. The phenotypic picture suggested a mix of homozygous and heterozygous family members. Genetic analysis confirms the homozygousity in the patients most severely affected, but shows the disease state to be one of Avellino corneal dystrophy. The previous case reports are extended immunohistological staining using polyclonal antibodies raised against keratofepithelin. This genotype/phenotype correlation study is consistent with incomplete dominance.

A molecular perspective on corneal dystrophies.

Corneal dystrophies refer to a group of corneal diseases and that are genetically determined. These have been traditionally classified with respect to the layer of cornea involved. We now know that this does not reflect the underlying pathobiology. Most of the corneal dystrophies are of Mendelian inheritance with some phenotype diversity and a variable degree of penetrance. The dystrophies involving enzymatic processes tend to be of autosomal recessive inheritance. In some cases, such as keratoconus, the inheritance pattern is not always clear and is considered complex. The age of onset of the disease, as in most inherited eye disorders, is variable and does not reflect the underlying pathogenic defect. Few cases are congenital. Our understanding of corneal dystrophies is undergoing somewhat of a revolution as over 12 chromosomes have been associated with corneal dystrophies with mutations identified in at least 14 genes if one includes anterior segment dysgenesis in this group of conditions. Several dystrophies remain without a gene or a genetic location (locus) and more familial studies are required. The new molecular information is challenging the traditional thinking about these conditions that was usually guided by the histopathological findings. As this new knowledge becomes more refined, the classification of this group of disorders will eventually be revisited to have a molecular basis. The elucidation of the underlying biochemical pathways may allow us to envisage the possibility of modulating these phenotypes in the future.