Butterfly-shaped pigment dystrophy of the fovea

Using Multimodal Imaging to Refine the Phenotype of PRPH2-associated Retinal Degeneration

OBJECTIVE

To refine retinal peripherin-2 (PRPH2)-associated retinal degeneration (PARD) phenotypes using multimodal imaging.

DESIGN

Retrospective review of clinical records and multimodal imaging.

SUBJECTS

Patients who visited the inherited retinal degeneration (IRD) clinic at 2 tertiary referral eye centers with molecularly confirmed IRD due to PRPH2 variants.

METHODS

Retinal imaging was reviewed using ultrawidefield (UWF) pseudocolor, UWF fundus autofluorescence, and spectral-domain OCT. Phenotypes were identified in the macular or peripheral region. A combined phenotype was considered if any phenotypes were present in both macular and peripheral regions. Mixed phenotypes in the macula or peripheral retina were considered if there were 2 distinct phenotypes identified in the same eye. The presence or absence of atrophy in the macular or peripheral area was also noted.

MAIN OUTCOME MEASURE

Grading of multimodal imaging by phenotype and atrophy.

RESULTS

A total of 144 eyes of 72 patients were included in this study. The majority of the eyes had combined macular and peripheral phenotypes (89/144, 61.8%), whereas 44 (30.6%) eyes had isolated macular findings, and 11 (7.6%) had isolated peripheral findings. Twenty-five eyes were classified with mixed macular phenotypes, whereas fundus flavimaculatus dystrophy type was the most common combined macular and peripheral phenotype (54/144, 37.5%): n = 10 with macular dystrophy and macular flavimaculatus dystrophy (MFD), and n = 15 with butterfly pattern dystrophy and MFD. Nearly half of the eyes (71/144, 49.3%) were identified to have concomitant outer retinal atrophy. Fundus flavimaculatus type dystrophy was also associated with the highest proportion of concomitant atrophy (57/71, 80.3%).

CONCLUSIONS

Peripherin-2-associated retinal degeneration demonstrates a wide array of phenotypes using multimodal imaging. We report that combinations of classically described phenotypes were often seen. Additionally, macular and peripheral atrophy were often associated with PARD phenotypes. Refinement of PARD phenotypes using newer multimodal imaging techniques will likely assist diagnosis and future clinical trials.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Comparative study of PRPH2 D2 loop mutants reveals divergent disease mechanism in rods and cones

Mutations in the photoreceptor-specific tetraspanin gene peripherin-2 (PRPH2) lead to widely varying forms of retinal degeneration ranging from retinitis pigmentosa to macular dystrophy. Both inter- and intra-familial phenotypic heterogeneity has led to much interest in uncovering the complex pathogenic mechanisms of PRPH2-associated disease. Majority of disease-causing mutations in PRPH2 reside in the second intradiscal loop, wherein seven cysteines control protein folding and oligomerization. Here, we utilize knockin models to evaluate the role of three D2 loop cysteine mutants (Y141C, C213Y and C150S), alone or in combination. We elucidated how these mutations affect PRPH2 properties, including oligomerization and subcellular localization, and contribute to disease processes. Results from our structural, functional and molecular studies revealed that, in contrast to our understanding from prior investigations, rods are highly affected by PRPH2 mutations interfering with oligomerization and not merely by the haploinsufficiency associated with these mutations. On the other hand, cones are less affected by the toxicity of the mutant protein and significantly reduced protein levels, suggesting that knockdown therapeutic strategies may sustain cone functionality for a longer period. This observation provides useful data to guide and simplify the current development of effective therapeutic approaches for PRPH2-associated diseases that combine knockdown with high levels of gene supplementation needed to generate prolonged rod improvement.

Electrophysiological Evaluation of Macular Dystrophies

Macular dystrophies are a heterogeneous group of genetic disorders that often severely threatens the bilateral central vision of the affected patient. While advances in molecular genetics have been instrumental in the understanding and diagnosis of these disorders, there remains significant phenotypical variation among patients within any particular subset of macular dystrophies. Electrophysiological testing remains a vital tool not only to characterize vision loss for differential diagnosis but also to understand the pathophysiology of these disorders and to monitor the treatment effect, potentially leading to therapeutic advances. This review summarizes the application of electrophysiological testing in macular dystrophies, including Stargardt disease, bestrophinopathies, X-linked retinoschisis, Sorsby fundus dystrophy, Doyne honeycomb retina dystrophy, autosomal dominant drusen, occult macular dystrophy, North Carolina macular dystrophy, pattern dystrophy, and central areolar choroidal dystrophy.

Observations for Sjögren's Pigment Epithelial Reticular Dystrophy in a 16-Year-Old Boy-An Extremely Rare Retinal Case Report

The purpose of this publication is to present an extremely rare case of Sjögren's pigment epithelial reticular dystrophy. So far, 10 such publications have been found in world literature. A 16-year-old boy was diagnosed due to a slight loss of visual acuity, confirmed in static perimetry/24-2/. Abnormal dense clusters of retinal pigment epithelium (RPE) cells forming a reticular network pattern (resembling a fishing net) with marked knots were detected by fundoscopy in the macular area and the mid-periphery of the retina. No abnormalities were found in the anterior segment, intraocular pressure, kinetic perimetry, Ishihara or Farnsworth D-15 tests or OCT. Fluorescein angiography confirmed blocked fluorescence from the choroidal vessels caused by the pigment in RPE. An autofluorescence test showed hypofluorescent foci corresponding to symmetrical and bilateral retinal hyperpigmentation with an RPE reticular pattern. Multifocal ERG (mfERG) revealed slight cone photoreceptor and bipolar bioelectrical dysfunction. Electrooculography (EOG) showed significant asymmetry (Arden Ratio 1.8), suggesting bioelectrical dysfunction of RPE/photoreceptors. Flash ERG (ERG) revealed only slight increase in implicit time of the a and b waves of the rod and cone responses and exclude cone-rod dystrophies. This article highlights the importance of the results of ophthalmoscopy, fluorescein angiography, autofluorescence, mfERG, fERG, EOG and genetic tests for Sjögren's reticular dystrophy with a pathogenic variant in the region of the C2 gene-c.841_849+19del (dbSNP rs9332736).

Investigating the role of BEST1 and PRPH2 variants in the molecular aetiology of adult-onset vitelliform macular dystrophies

Objective: To determine the clinical relevance and frequency of BEST1 and PRPH2 mutations in a clinically diagnosed adult-onset vitelliform macular dystrophy (AVMD) group with Caucasian ethnicity. Methods: The study comprised 24 patients who had been diagnosed with AVMD via indirect fundus ophthalmoscopy and presented with a dome-shaped appearance between the retinal pigment epithelium and photoreceptors on their spectral-domain optical coherence tomography. They had lesion hyper- autofluorescence on their fundus autofluorescence images and were also investigated for BEST1 and PRPH2 mutations for a probable molecular aetiology. Results: No pathogenic or likely pathogenic mutation was detected in the BEST1 and PRPH2 genes of any of the clinically diagnosed AVDM patients. A heterozygous NM_000322.5:c.938C>T (p.Pro313Leu) variant of the PRPH2 gene was detected in 2 non-consanguineous patients. According to current guidelines, this variant was classified as a 'variant of uncertain significance'. Conclusion: In conclusion, AVMD is a genotypic and phenotypic heterogeneous disease. The genetic aetiology could not be explained by sequencing BEST1 and PRPH2 genes in the AVMD patients; however, the variant of PRPH2 could be a cause of predisposition relevant to the phenotype.

Age-Dependent Phenotypic Expression of a Pattern Dystrophy of the Retina

We studied a family with pattern dystrophy of the retina (PDR) in order to elucidate the clinical course of the disorder, relations between the different forms, and the mode of inheritance. Thirty-nine family members, representing three generations, underwent a thorough ophthalmological examination, with fluorescein angiography whenever a macular abnormality was suspected. Of family members over the age of 32 years, 46.7% showed signs of PDR. We classified the clinical forms of PDR in this family into four types: minimal lesion, pseudovitelliform type, butterfly-spider type, and late-stage lesion. These forms were predominant in the order cited in age groups 31-40 years, 41-50, 51-60, and > 60 years. Significant visual loss occurred only after the age of 50 years, when 8 of 14 eyes had visual acuity of less than 20/25. Inheritance was autosomal dominant. PDR presented different clinical forms in members of this family, and in successive age classes patterns of increasing severity prevailed. Thus, the different phenotypic forms apparently represent transient stages related to the age of the patient.

Multimodal imaging in a case of butterfly pattern dystrophy of retinal pigment epithelium

AIMS

To report multi-modal imaging findings in a case of butterfly pattern dystrophy of retinal pigment epithelium.

METHODS

A middle-aged female with butterfly pattern dystrophy, who presented with progressive loss of vision, was examined using coloured fundus photographs, short wave autofluorescence, swept source optical coherence tomography (SS-OCT), fundus fluorescein angiography and enface optical coherence tomography.

RESULTS

Multi-modal imaging was useful in the characterization of the various disease features. Autofluorescence pattern was opposite to that of fluorescein angiogram and SS-OCT showed disruption in the outer retinal layers. Enface OCT images depicted the pigment deposition prominently.

CONCLUSION

The features of butterfly pattern dystrophy on these modalities correlated well with the histopathological findings described in the literature. Enface imaging highlights the deposition of pigment/lipofuscin and has never been described in BPD.

Autosomal Dominant Retinal Dystrophies Caused by a Founder Splice Site Mutation, c.828+3A>T, in PRPH2 and Protein Haplotypes in trans as Modifiers

Purpose

We determined the phenotypic variation, disease progression, and potential modifiers of autosomal dominant retinal dystrophies caused by a splice site founder mutation, c.828+3A>T, in the PRPH2 gene.

Methods

A total of 62 individuals (19 families) harboring the PRPH2 c.828+3A>T mutation, had phenotype analysis by fundus appearance, electrophysiology, and visual fields. The PRPH2 haplotypes in trans were sequenced for potential modifying variants and generalized estimating equations (GEE) used for statistical analysis.

Results

Several distinct phenotypes caused by the PRPH2 c.828+3A>T mutation were observed and fell into two clinical categories: Group I (N = 44) with mild pattern dystrophies (PD) and Group II (N = 18) with more severe cone-rod dystrophy (CRD), retinitis pigmentosa (RP), and central areolar chorioretinal dystrophy (CACD). The PRPH2 Gln304-Lys310-Asp338 protein haplotype in trans was found in Group I only (29.6% vs. 0%), whereas the Glu304-Lys310-Gly338 haplotype was predominant in Group II (94.4% vs. 70.4%). Generalized estimating equations analysis for PD versus the CRD/CACD/RP phenotypes in individuals over 43 years alone with the PRPH2 haplotypes in trans and age as predictors, adjusted for correlation within families, confirmed a significant effect of haplotype on severity (P = 0.03) with an estimated odds ratio of 7.16 (95% confidence interval [CI] = [2.8, 18.4]).

Conclusions

The PRPH2 c.828+3A>T mutation results in multiple distinct phenotypes likely modified by protein haplotypes in trans; the odds of having the CACD/RP-like phenotype (versus the PD phenotype) are 7.16 times greater with a Glu304-Lys310-Gly338 haplotype in trans. Further functional studies of the modifying haplotypes in trans and PRPH2 splice variants may offer therapeutic targets.

Mutations in CTNNA1 cause butterfly-shaped pigment dystrophy and perturbed retinal pigment epithelium integrity

Butterfly-shaped pigment dystrophy is an eye disease characterized by lesions in the macula that can resemble the wings of a butterfly. Here, we report the identification of heterozygous missense mutations in the α-catenin 1 (CTNNA1) gene in three families with butterfly-shaped pigment dystrophy. In addition, we identified a Ctnna1 missense mutation in a chemically induced mouse mutant, tvrm5. Parallel clinical phenotypes were observed in the retinal pigment epithelium (RPE) of individuals with butterfly-shaped pigment dystrophy and in tvrm5 mice, including pigmentary abnormalities, focal thickening and elevated lesions, and decreased light-activated responses. Morphological studies in tvrm5 mice revealed increased cell shedding and large multinucleated RPE cells, suggesting defects in intercellular adhesion and cytokinesis. This study identifies CTNNA1 gene variants as a cause of macular dystrophy, suggests that CTNNA1 is involved in maintaining RPE integrity, and suggests that other components that participate in intercellular adhesion may be implicated in macular disease.

OTX2 mutations cause autosomal dominant pattern dystrophy of the retinal pigment epithelium

PURPOSE

To identify the genetic cause of autosomal-dominant pattern dystrophy (PD) of the retinal pigment epithelium (RPE) in two families.

METHODS AND RESULTS

Two families with autosomal-dominant PD were identified. Eight members of family 1 (five affected) were subjected to whole-genome SNP genotyping; multipoint genome-wide linkage analysis identified 7 regions of potential linkage, and genotyping four additional individuals from family 1 resulted in a maximum logarithm of odds score of 2.09 observed across four chromosomal regions. Exome sequencing of two affected family 1 members identified 15 shared non-synonymous rare coding sequence variants within the linked regions; candidate genes were prioritised and further analysed. Sanger sequencing confirmed a novel heterozygous missense variant (E79K) in orthodenticle homeobox 2 (OTX2) that segregated with the disease phenotype. Family 2 with PD (two affected) harboured the same missense variant in OTX2. A shared haplotype of 19.68 cM encompassing OTX2 was identified between affected individuals in the two families. Within the two families, all except one affected demonstrated distinct 'patterns' at the macula. In vivo structural retinal imaging showed discrete areas of RPE-photoreceptor separation at the macula in all cases. Electroretinogram testing showed generalised photoreceptor degeneration in three cases. Mild developmental anomalies were observed, including optic nerve head dysplasia (four cases), microcornea (one case) and Rathke's cleft cyst (one case); pituitary hormone levels were normal.

CONCLUSIONS

This is the first report implicating OTX2 to underlie PD. The retinal disease resembles conditional mice models that show slow photoreceptor degeneration secondary to loss of Otx2 function in the adult RPE.

PRPH2 (Peripherin/RDS) mutations associated with different macular dystrophies in a Spanish population: a new mutation

PURPOSE

To assess the occurrence of PRPH2 mutations in patients presenting macular dystrophies and to describe their phenotype-genotype correlation.

METHODS

A total of 32 sporadic cases and 13 individuals from 5 families were studied. The patients presented early onset drusen, suspected pattern dystrophy (including adult-onset foveomacular vitelliform dystrophy [AOFVD]), or any presumed macular dystrophy producing neovascularization or atrophic changes documented before patients reached 50 years of age. In case of atrophy, this could be confined to the macula, which was considered to be central areolar choroidal dystrophy (CACD), or extend to the midperiphery of the retina, which we called diffuse macular dystrophy (DMD). Clinical workup and analysis of PRPH2, EFEMP1, and TIMP3 genes were done.

RESULTS

Four mutations of the PRPH2 gene were found in 3 sporadic cases and 3 families (n = 11). A p.R46X mutation, previously described in CACD, was found in 3 members of a family with AOFVD and in a sporadic case with DMD. A p.L45F mutation, described before in retinitis pigmentosa, was found in a sporadic case of AOFVD. A p.R195L mutation previously described in CACD was found in 2 members of a family with CACD. The latter was found in a family and a sporadic case (from the same village as the family) and all of them presented DMD. A new p.V2091 mutation was found in a patient with AOFVD.

CONCLUSIONS

New phenotypes were found for known mutations. No phenotype variation was observed in the members of the 3 families. A new mutation in PRPH2 gene was found.

Mimickers of age-related macular degeneration

In the Western World, the leading cause of irreversible blindness is Age- Related Macular Degeneration (ARMD). It can have significant visual impairment, and it is important that the practicing ophthalmologist is knowledgeable in the diagnosis and treatment of ARMD. Equally important is knowledge in the diagnosis of other disease entities that may mimic ARMD, as this may change the prognosis, treatment and visual outcome of patients. This article discusses those diseases that mimic ARMD and their distinguishing features.

Fundus autofluorescence imaging of retinal dystrophies

Fundus autofluorescence (FAF) is a non-invasive imaging technique that enables the visualization of lipofuscin changes in the retinal pigment epithelium. This study aims to illustrate the spectrum of FAF changes in a variety of retinal dystrophies. For this purpose, we examined patients with retinal dystrophies such as Stargardt disease, Best vitelliform macular dystrophy, and retinal dystrophies associated with mutations in the peripherin/RDS gene. All retinal dystrophies were confirmed by molecular genetic analysis. A broad range of characteristic FAF patterns was observed. Our results indicate that FAF imaging constitutes a useful additive tool in the diagnosis and follow-up of various retinal dystrophies.

The spectrum of retinal dystrophies caused by mutations in the peripherin/RDS gene

Peripherin/rds is an integral membrane glycoprotein, mainly located in the rod and cone outer segments. The relevance of this protein to photoreceptor outer segment morphology was first demonstrated in retinal degeneration slow (rds) mice. Thus far, over 90 human peripherin/RDS gene mutations have been identified. These mutations have been associated with a variety of retinal dystrophies, in which there is a remarkable inter- and intrafamilial variation of the retinal phenotype. In this paper, we discuss the characteristics of the peripherin/RDS gene and its protein product. An overview is presented of the broad spectrum of clinical phenotypes caused by human peripherin/RDS gene mutations, ranging from various macular dystrophies to widespread forms of retinal dystrophy such as retinitis pigmentosa. Finally, we review the proposed genotype-phenotype correlation and the pathophysiologic mechanisms underlying this group of retinal dystrophies.

Intrafamilial clinical heterogeneity associated with a novel mutation of the retinal degeneration slow/peripherin gene

AIMS

To identify the phenotypic variations in 6 related individuals affected by a novel mutation in the retinal degeneration slow/peripherin gene.

METHODS

Ten family members underwent ophthalmologic assessment with slit-lamp biomicroscopy, dilated fundus examination, fundus photography, autofluorescence imaging and electrophysiological tests. Genomic DNA was extracted from blood samples of all family members (n = 15) using the standard salting-out procedure.

RESULTS

The novel C165R mutation was identified in 8 individuals. Of these 8 patients, only 6 gave consent to the clinical study. They had a retinal disease characterized by an adulthood onset of symptoms, and their best corrected visual acuity was between 20/50 and 20/20. Fundus examination showed that 3 patients had typical fundus flavimaculatus: 1 had butterfly-shaped pattern dystrophy and 2 had incipient retinal changes.

CONCLUSION

We identified a novel mutation of the retinal degeneration slow/peripherin gene in a family affected by different patterns of retinal dystrophy. This is the first report of an association of fundus flavimaculatus with butterfly-shaped pattern dystrophy.

A NOVEL COMPLEX MUTATION EVENT IN THE PERIPHERIN/RDS GENE IN A FAMILY WITH RETINAL PATTERN DYSTROPHY

PURPOSE

To report a complex mutation in the peripherin/RDS gene found in a family in whom retinal pattern dystrophy is segregating as an autosomal dominant trait.

METHODS

Clinical data were collected from family members of a large Swiss family affected by autosomal dominant retinal pattern dystrophy. Single strand conformation polymorphism (SSCP) analysis of the candidate gene peripherin/RDS and subsequent sequencing of the first exon were performed.

RESULTS

Pattern dystrophy of the retina was suspected in 18 family members aged 30 years or older. Assuming a homogeneous phenotype, the candidate locus peripherin/RDS was investigated. SSCP analysis of the first exon of the peripherin/RDS gene showed an aberrant pattern in 18 affected individuals. Direct sequencing of polymerase chain reaction products detected a complex mutation, del265-268GCCA ins AGGGCC, leading to a stop codon at amino acid position 99.

CONCLUSION

To our knowledge, we report the first complex mutation in the peripherin/RDS gene as the cause of a mild macular phenotype, supporting the importance of molecular diagnosis in genetic counseling.

Autosomal dominant pattern dystrophy: identification of a novel splice site mutation in the peripherin/RDS gene

PURPOSE

To describe the clinical features of and identify the mutation responsible for an autosomal dominant pattern dystrophy occurring in a three-generation family.

METHODS

Five affected family members underwent clinical examination and additional testing including intravenous fluorescein angiography where indicated. Mutation screening of the peripherin/RDS gene was performed.

RESULTS

Visual acuity ranged from 20/20 to counting fingers. All patients who reported vision loss noted the onset after the age of 40 years. Predominantly perifoveal, discrete, retinal pigment epithelial changes were present in all patients. Two patients had extensive peripheral yellowish flecks, and one had an atrophic macular scar. Mutation screening of the complete peripherin/RDS coding sequence and exon/intron boundaries revealed a novel splice site mutation.

CONCLUSION

A three-generation family with an autosomal dominant pattern dystrophy arising from a previously unreported splice site mutation in the RDS gene is described.

A novel mutation in the RDS/Peripherin gene causes adult-onset foveomacular dystrophy

PURPOSE

To describe a novel mutation in the RDS/Peripherin gene that results in a moderately severe form of adult-onset foveomacular dystrophy.

DESIGN

Observational case series.

METHODS

Selected members of a family with adult-onset foveomacular dystrophy underwent complete ophthalmic evaluation, including fundus photography and fluorescein angiography, in a tertiary care referral center. The study population consisted of 12 members of a Caucasian kindred. After providing informed consent, patients donated blood for genomic DNA extraction and mutational screening using standard techniques. The main outcome measure were the presence of a RDS/Peripherin gene mutation in a patient with the disease and its absence in unaffected family members and controls.

RESULTS

Eight affected family members and no unaffected family members demonstrated a single guanine base deletion at nucleotide 112 that led to premature termination at amino acid 38 of RDS/Peripherin polypeptide. This frameshift mutation results in truncation of nearly 90% of the gene product, thus probably representing a null allele. That results in a relatively severe phenotype, with choroidal neovascularization developing in two patients and geographic atrophy involving the macula in three patients.

CONCLUSIONS

We describe a frameshift null mutation in the RDS/Peripherin gene associated with a relatively severe manifestation of adult-onset foveomacular dystrophy in affected family members.

Atypical presentation of pattern dystrophy in two families with peripherin/RDS mutations

PURPOSE

To describe the atypical clinical presentations of pattern dystrophy (PD) in two unrelated families with novel peripherin/RDS mutations.

DESIGN

Observational case reports and family genetic study with review of peripherin/RDS mutations.

PARTICIPANTS

Affected and unaffected members of two families with PD.

METHODS

The probands of two families, as well as other family members, underwent an ophthalmologic assessment including slit-lamp biomicroscopy, applanation tonometry, and a dilated fundus examination. Goldmann visual fields and fluorescein angiography were performed, wherever appropriate. Blood samples were obtained from affected and selected unaffected members of the families for DNA analysis.

RESULTS

The proband of family 1 had an acute onset of decreased vision and a yellowish lesion in both maculae that appeared inflammatory. However, resolution of the acute lesion ultimately resulted in fundus changes more typical for PD. Moreover, the proband's sister showed more classic-appearing PD lesions. Screening of the peripherin/RDS gene for sequence variations showed a 2-bp deletion, resulting in a translational frameshift at codon 290 in affected members of the family. The proband's father, who showed this sequence variation, did not have a macular lesion. The proband of family 2 was asymptomatic and showed a fundus phenotype similar to fundus flavimaculatus. The patient had normal visual acuity and did not demonstrate a "dark choroid" on fluorescein angiography. Molecular screening showed a Gln331stop variation in the peripherin/RDS gene.

CONCLUSIONS

We describe two novel mutations in the peripherin/RDS gene in two unrelated families with PD. Clinicians should recognize the atypical features that may occur in patients with PD. A suspected diagnosis of PD may be confirmed by the identification of a mutation in the peripherin/RDS gene. In isolated family members with PD, a mutation in this gene may occur even in the absence of a clinically discernible macular lesion.

Visual outcome following subretinal hemorrhage in Best disease

PURPOSE

To review cases of Best disease associated with subretinal hemorrhage to better understand their long-term visual prognosis.

SUBJECT AND METHODS

Patients were identified through the photographic file database at the University of Iowa. Seventy-eight files of patients with clinical evidence of Best disease were reviewed and 12 patients (14 eyes) were identified with subretinal hemorrhage. The visual acuity and clinical course were reviewed in all of these patients when possible. Three patients demonstrated subretinal hemorrhage on their last follow-up visit. Nine patients (11 eyes) were followed through to resolution of subretinal hemorrhage. Eight patients were screened on the VMD2 gene and all were found to have disease-causing sequence variations.

RESULTS

All patients noted visual loss at presentation with subretinal hemorrhage (median 20/100; range 20/30-20/400). The median final visual acuity in the 11 eyes with follow-up was 20/50 (20/16-20/400 range). Ten of 11 eyes demonstrated improvement of vision with 9/11 having a final visual acuity of 20/50 or better.

CONCLUSION

The natural history of patients with Best disease with subretinal hemorrhage and moderate visual loss is relatively good. The presence of subretinal hemorrhage in Best disease may be related to mild, incidental trauma.

Splice site mutation in the peripherin/RDS gene associated with pattern dystrophy of the retina

PURPOSE

To report the phenotype and genotype of a splice site mutation at intron 2 of the peripherin/RDS gene in four half-siblings with pattern dystrophy of the retina.

DESIGN

Experimental study.

METHODS

In four siblings with a common mother and three separate fathers, complete ophthalmic examination, pedigree, electrophysiologic testing, and fluorescein angiography studies were obtained. Genomic DNA from serum lymphocytes was isolated and used as a template for primers specific for the cone homeobox gene (CRX), rhodopsin (RHO), and peripherin/RDS genes to conduct single stranded conformational analysis and cycle sequencing.

RESULTS

The pedigree of four affected siblings suggested probable autosomal dominance transmission of pattern dystrophy. In the four siblings, best corrected visual acuity ranged from 20/20 to 20/80 by Snellen chart. Clinical findings included discrete, localized degenerative changes of the macular retinal pigment epithelium in all patients, with subclassification foveal. One patient exhibited pigment clumping within the atrophic areas. Another patient exhibited yellow flecks diffusely in the macula. Fluorescein angiographic findings included central hypofluorescence with a surrounding rim of hyperfluorescence that corresponded to the observed fundus lesions and window defects. There was a range of electroretinography (ERG) and electrooculography (EOG) findings. One patient demonstrated both cone and rod dysfunction on ERG testing and another demonstrated decreased rod function. EOG testing was normal in two patients and mildly diminished in one patient. DNA sequencing identified a point mutation in intron 2 of the peripherin/RDS gene, consisting of an A to T change at 1068+3, present in all four affected patients.

CONCLUSIONS

Four siblings with pattern dystrophy of the retina presented a splice site mutation in the peripherin/RDS gene.

Presumed sertraline maculopathy

PURPOSE

To report a unique case of a woman who developed simultaneous bilateral maculopathy presumed to result from intake of sertraline hydrochloride, a serotonin reuptake inhibitor.

METHODS

Full clinical ocular examination, color vision testing, automated static perimetry, electroretinography, electrooculography and fundus fluorescein angiography were performed. Living members of her family were also examined.

RESULTS

The patient had normal electroretinography and electrooculography results. Automated static perimetry showed generalized reduction of sensitivity and central scotomas. Macular lesions resolved 6 months after discontinuation of sertraline, however, during twenty months of follow-up her visual acuity and abnormalities in other psychophysical tests did not improve.

CONCLUSION

Patients started on sertraline should be informed of the potential risk of developing maculopathy, and they should be examined regularly to detect possible early alterations.

Butterfly-shaped pigment dystrophy of the fovea associated with subretinal neovascularization

BACKGROUND

The association of butterfly-shaped pigment dystrophy of the fovea, an uncommon inherited macular disease, with subretinal neovascularization has rarely been reported in the literature.

CASE REPORT

We describe the clinical history of a patient affected with butterfly-shaped pigment dystrophy of the fovea, myopia, and optic nerve head dysplasia. She was followed up for 23 years. During the course of the disease, bilateral subretinal neovascularization in the macular area occurred. Fluorescein angiography confirmed the diagnosis. Recently, indocyanine green (CG) videoangiography was also performed. Because of the bilateral subfoveal localization no laser treatment was advised.

DISCUSSION

Usually, good visual acuity is maintained in this uncommon inherited macular disease. However, acute visual loss can be caused by the ingrowth of subretinal new vessels. Therefore, if visual acuity decreases or metamorphopsia develops in these patients, careful biomicroscopic examination and fluorescein/ICG angiography is advisable.

Pattern dystrophies of the retinal pigment epithelium

Pattern dystrophies of the retinal pigment epithelium are infrequent fundus abnormalities arranged in various patterns of dots, lines and branches. The basic lesion appears to be yellow deposits of abnormal lipofuscin accumulated within degenerated retinal pigment epithelium cells. Examinations were carried out on two families who had developed different patterned alterations in the retinal pigment epithelium. The proband of family 1 had diffuse changes associated with equatorial folds. One sister had a macular alteration. A daughter was normal; a son had bilateral atrophy of the temporal retinal pigment epithelium. The proband of family 2 had bilateral, symmetrical retinal pigment epithelium lesions that simulated fundus flavimaculatus. His first daughter had a central lesion in her right eye. The second daughter, a peripapillary crescent of hyperpigmentation in her right eye, and circumpapillary chorioretinal atrophy associated with foveolar abnormalities in the left. This report provides further evidence that variable types of pattern dystrophy can occur within a single family pedigree and support the current opinion that all forms of pattern dystrophies are variants of a single pathogenic mechanism.

Genetic and molecular studies of macular dystrophies: recent developments

Macular degeneration is a heterogeneous group of disorders characterized by progressive central visual loss and degeneration of the macula and underlying retinal pigment epithelium (RPE) of the eye. Age-related macular degeneration (ARMD), the most common form of the disease, is the leading cause of legal blindness in the elderly population in the United States and in the many developed countries throughout the world. Despite its prevalence, its etiology and pathogenesis are poorly understood, and effective treatment options are limited for most patients. Inherited macular dystrophies share many important features with ARMD but are more readily studied by molecular genetic approaches. Over the past few years, significant progress has been made in the molecular genetics of inherited macular dystrophies. Genes responsible for dominant and recessive Stargardt's macular dystrophy as well as Best's disease have been localized to specific chromosomal regions. The peripherin/RDS gene when defective is associated with butterfly-shaped pattern dystrophy. Molecular studies of genes involved in macular dystrophies may yield insights into the mechanisms of pathogenesis of macular degeneration and provide new rationale for the management and treatment of patients with these diseases.

Unusual association of juvenile macular dystrophy with congenital hypotrichosis: occurrence in two siblings suggesting autosomal recessive inheritance

A familial association between juvenile macular dystrophy and congenital hypotrichosis is described in two siblings aged 25 and 23 years. We put forward arguments for locating the retinal alteration at the level of the retinal pigment epithelium and suggest that the hair disorder could be a Marie-Unna type hypotrichosis. This association is transmitted as an autosomal recessive condition.

Extensive intrafamilial and interfamilial phenotypic variation among patients with autosomal dominant retinal dystrophy and mutations in the human RDS/peripherin gene

Clinical phenotypes of patients with mutations in the human RDS/peripherin gene are described. A 67-year-old woman, who carried a 1 base pair deletion in codon 307, presented with typical late onset autosomal dominant retinitis pigmentosa (RP). In another autosomal dominant pedigree, a nonsense mutation at codon 46 caused 'inverse' retinitis pigmentosa-like fundus changes associated with progressive cone-rod degeneration in a 58-year-old man, whereas his 40-year-old son presented with yellow deposits in the retinal pigment epithelial layer resembling a pattern dystrophy, and with moderately reduced rod and cone function, as determined by two colour dark adapted threshold perimetry and electroretinography. It is suggested that both clinical pictures within this latter family may represent manifestations of fundus flavimaculatus. The clinical data of the three patients provide further evidence for the remarkable variety of disease expression within and between families with mutations in the RDS/peripherin gene. Currently, the most comprehensive statement could be that RDS/peripherin mutations are associated either with typical RP or with various forms of flecked retinal disease.

The importance of fluorescein angiography in diagnosing pattern dystrophies of the retinal pigment epithelium

We describe three different types of pattern dystrophies in the retinal pigment epithelium: annular dystrophy, butterfly-shaped dystrophy with features of cone dystrophy, and butterfly dystrophy. In all the cases, fluorescein angiography was a good method to evaluate the morphology and range of macular changes. The butterfly-shaped lesions were not always easily visible with the ophthalmoscope, therefore, the fluorescein angiography was diagnostic. We also examined 17 relatives of these patients to discover the mode of inheritance in these diseases. The annular dystrophy seemed to be recessively inherited or a possible sporadic case, as was the unusual pattern dystrophy with features of cone dystrophy. The dominant heredity was found in the typical cases of butterfly-pattern dystrophy.

Butterfly-shaped macular dystrophy. Longitudinal case study of two siblings

Two brothers with butterfly-shaped macular dystrophy (BSMD) are reported. The anatomical and functional data were analyzed in 11 family members. Progressive photoreceptor dysfunction, supported by ERG abnormalities, was documented in both patients. The progression of the disease was observed over a period of seven years. The present observations emphasize that BSMD, at least in some cases, can be a chronic progressive disorder with secondary involvement of the photoreceptors.

A variant of central areolar choroidal dystrophy

This article describes the variable ophthalmoscopic features of a macular disorder in five generations of one family. This disease shares similarities with central areolar choroidal dystrophy and other progressive dominant macular dystrophies but demonstrates significant differences that required further consideration. The milder affected individuals had confluent hyperfluorescence around the macular area while the more severe lesions consisted of marked chorioretinal atrophy of the macula. The visual fields revealed a central scotoma. The disorder was transmitted as an autosomal dominant trait.

Butterfly-shaped pigment dystrophy of the fovea caused by a point mutation in codon 167 of the RDS gene

Butterfly-shaped pigment dystrophy of the fovea is an autosomal dominant eye disease characterized by a bilateral accumulation of yellowish or pigmented material at the level of the retinal pigment epithelium. It shares some clinical and histopathologic features with age related macular degeneration which is the most common cause of legal blindness in older patients. We screened affected patients from a three generation family with butterfly dystrophy for mutations in candidate genes. A base substitution was identified in the peripherin (RDS) gene and DNA sequencing revealed a G to A transition in codon 167 that substitutes aspartic acid for a highly conserved glycine. The mutation segregates with the disease phenotype (Zmax = 4, theta = 0) strongly suggesting that it causes the macular disease in this family.

Phenotypic similarities between Stargardt's flavimaculatus and pattern dystrophies

Some heredomacular diseases share ophthalmoscopic and morphologic similarities despite being nosologically distinct. In part, this may arise from pathologic reaction patterns such as lipopigment accumulation and drusen deposition which are common to a variety of disorders of the photoreceptor--retinal pigment epithelium--Bruch's membrane complex. Two of these disorders, Stargardt's flavimaculatus and the pattern dystrophies of the retinal pigment epithelium may be especially difficult to differentiate clinically since they are characterised by both a similar ophthalmoscopic appearance and considerable inter and intrafamilial variation in their expression. Stargardt's flavimaculatus may, however, be distinguished from the retinal pigment epithelial pattern dystrophies by certain clinical and morphological features that are outlined below.

Genetic linkage of vitelliform macular degeneration (Best's disease) to chromosome 11q13

Macular degeneration is the most common cause of legal blindness in older patients in developed countries. Best's vitelliform dystrophy is an early-onset, autosomal dominant form of macular degeneration characterized by an egg-yolk-like collection of lipofuscin beneath the pigment epithelium of the retinal macula. Fifty-seven members of a five-generation family affected with this disease were studied. A combination of ophthalmoscopy and electro-oculography was used for diagnosis; 29 patients were found to be affected and 16 unaffected. Linkage analysis mapped the disease-causing gene to chromosome 11q13. Three markers in this region were found to be significantly linked (Zmax > 3.0) to the disease. Multipoint analysis yielded a maximum Lod score of 9.3 in the interval between markers INT2 and D11S871.

Pattern dystrophies of the retinal pigment epithelium. The study of three generations in a family

Three members of a family in one generation were affected by a pattern dystrophy of the retinal pigment epithelium. The patients present typical hyperpigmented macular RPE lesions in a butterfly-shaped to (macro-)reticular pattern, and were all asymptomatic. Examination of 26 family members in 3 generations suggests autosomal recessive inheritance. The family showed some cases of congenital deutanomaly, and a female subject presented both disorders.

Patterns of rod and cone dysfunction in Bardet-Biedl syndrome

We studied visual function in 16 patients with the Bardet-Biedl syndrome. Visual acuity, kinetic perimetry, and electroretinography results indicated a severe loss of central and peripheral vision and rod and cone function by the second or third decade of life. Light- and dark-adapted static perimetry in patients 10 to 15 years of age with early involvement showed a parallel and marked loss of rod and cone sensitivity across the visual field. Patients with more advanced disease and no measurable peripheral visual field showed different patterns of central visual dysfunction: an island of only cone function centered in a bull's-eye lesion; patches of rod function surrounding geographic atrophy; or a central island of excellent rod sensitivity but severely impaired cones. In the two least-affected patients, a 13-year-old boy and the asymptomatic 45-year-old sibling of a patient, there were more rod than cone abnormalities as determined by electroretinography and static perimetry.

Patterned dystrophies of the retinal pigment epithelium. A review

Pigmentations and depigmentations, accompanied or not by yellow subretinal lipofuscin accumulations, are the ophthalmologically visible manifestations of dystrophies of the retinal pigment epithelium. The pigmentations may or may not become confluent and form concentric, butterfly-shaped or reticular configurations. Different patterns of pigment migration may occur in a family and even in one individual. Hence these dystrophies are called pattern(ed) dystrophies of the retinal pigment epithelium. The visual functions are relatively well-preserved, although severe visual impairment is not excluded. The pattern(ed) dystrophies are inherited as an autosomal dominant, an autosomal recessive or an X-linked recessive trait. The author suggests that some cases diagnosed as atypical pigmentary dystrophies with near-normal visual functions probably are dystrophies of the retinal pigment epithelium.

Reticular-like pigmentary patterns in pseudoxanthoma elasticum

Of 14 consecutive patients with pseudoxanthoma elasticum (PXE), 9 (64%) had a spectrum of peculiar, sometimes reticular, pigmentary changes in the retina. Ten of 18 (56%) eyes had a random scattering of small, round pigment dots throughout the macula and around the optic nerve, sometimes extending to the equator. In four of 18 (22%) eyes, the pigment clumps appeared in lines, resembling a string of pearls. These strings occasionally radiated from the macula in a spoke-like fashion. In 4 of the 18 (22%) eyes, the pigment clumping occurred in a fishnet, or truly reticular, pattern. Of the 18 eyes in these 9 patients, 12 (67%) had subretinal neovascularization. Of the ten eyes in the five patients who did not show this pigmentary change, two (20%) had subretinal neovascularization.

Pattern dystrophy of the retinal pigment epithelium

We describe six related patients presenting with an autosomal dominantly inherited pattern dystrophy of the retinal pigment epithelium, significantly abnormal electro-oculogram and minor colour vision abnormalities. There is a continuum of variable phenotypic expression within the pattern dystrophies of the retinal pigment epithelium.

Macular disease resembling adult foveomacular vitelliform dystrophy in older adults

Fifty-three eyes of 31 patients over age 50 with macular disease were reviewed. Clinical appearance of the macula was of two types: a yellow slightly elevated lesion (29 eyes) and a pigmented flat lesion with surrounding atrophy (24 eyes). Drusen were found in 60% of affected eyes. No familial tendencies were documented. A reduced electro-oculogram (EOG) was present in approximately 50% of all eyes tested. Fluorescein angiographic findings and differential diagnosis are described. Visual prognosis was markedly different for the two groups: 69% of eyes with yellow elevated lesions lost two or more lines of visual acuity and 48% went on to visual acuity equal to or less than 20/200, whereas 33% of eyes with pigmented flat lesions lost two or more lines of visual acuity and 8% went on to visual acuity equal to or less than 20/200.