Occult Macular Dystrophy Research Articles

Inherited Macular Dystrophies in a Tertiary Care Centre.

Inherited macular dystrophies constitute a group of diseases characterized by bilateral central visual loss with symmetrical macular abnormalities usually presenting in the first two decades of life. The aim of this study were to find out the demographic characteristics and disease pattern of inherited retinal dystrophies in subjects attending retina outpatient department in a tertiary care center. An observational study among twenty-six participants diagnosed as macular dystrophy visiting a tertiary care centre in Nepal, during January 2018 to June 2018 were included in the study. Detailed history, slit lamp examination, dilated fundus examination, coloured fundus photography, full field electroretinogram, multifocal electroretinogram, automated visual field and colour vision were done. A total of 52 eyes of 26 subjects were diagnosed with macular dystrophy. The male to female ratio was 1:1. The mean age of presentation was 28.38 years. Most common symptom was blurring of vision seen in 96.15%.The mean visual acuity was 0.67 log mar units in right eye and 0.71 log mar units in the left eye. The most common macular dystrophy was cone dystrophy followed by adult vitelliform macular dystrophy and Stargardts dystrophy. Cone dystrophy is the most common followed by Stargardt's disease and adult vitelliform macular dystrophy. Most presented in the first two decades of life and the most common presenting symptom was blurring of vision.

Clinical and Genetic Characteristics of Chinese Patients with Occult Macular Dystrophy.

PurposeTo investigate the clinical and genetic characteristics of occult macular dystrophy (OMD) based on a Chinese patient cohort.MethodsFifteen Chinese OMD patients from nine unrelated families underwent genetic testing, and all of them harbored a pathogenic RP1L1 variant. Comprehensive ophthalmic examinations were performed in nine probands, including spectral-domain optical coherence tomography (SD-OCT), near-infrared reflectance (NIR), fundus autofluorescence (AF), and multifocal electroretinography.ResultsThe RP1L1 variants p.R45W and p.S1199C were identified in 13 patients and two patients, respectively, and one was a de novo mutation. Among the nine probands, the median ages at onset and examination were 25.0 years (range, 6–51 years) and 27.0 years (range, 14–55 years), respectively. The median decimal visual acuity was 0.20 (range, 0.04–0.5). Foveal photoreceptor thickness and visual acuity showed a significant correlation (r = 0.591; P = 0.01). All eyes presented with an absent interdigitation zone and blurred ellipsoid zone of photoreceptors when examined by SD-OCT. In addition, central round lesions with low NIR reflectance were observed in 66.7% (12/18) of eyes by NIR reflectance imaging, corresponding to the regions with abnormal photoreceptor microstructures observed by SD-OCT. Of the 18 eyes, only four eyes showed ring-like faint hyperfluorescence around the macula by AF.ConclusionsTo the best of our knowledge, this is the largest study in a cohort of Chinese OMD patients with RP1L1 mutations. Our findings revealed that the two recurrent RP1L1 variants are related to OMD in the Chinese population. Furthermore, multimodal imaging combined with genetic testing is valuable for diagnosing and monitoring OMD progression.

Role of multifocal electroretinogram in the prediction of visual prognosis in patients with occult macular dystrophy

Background Occult macular dystrophy (OMD) is a rare hereditary macular dystrophy characterized by severe bilateral progressive loss of central vision with normal fundus appearance and normal fundus fluorescein angiography.Aim The aim of this study was to assess the correlation between multifocal electroretinogram (mf-ERG) parameters and best-corrected visual acuity (BCVA) in patients with OMD.Patients and methods In all, 20 eyes of 10 patients with OMD and 20 eyes of 10 age-matched and sex-matched normal individuals were included in this study. Full ophthalmic examination, fundus fluorescein angiography, optical coherence tomography, full-field ERG and mf-ERG were performed for all participants. The average amplitude density of P1 wave, amplitude, and implicit time of P1 and N1 waves were recorded in the five concentric hexagonal rings. Correlation between these mf-ERG parameters and BCVA (LogMAR) was analyzed.Results There were no statistically significant differences in age, sex, and refraction between the studied groups (P=0.54, 1.0, and 0.82, respectively). Mf-ERG parameters in OMD patients showed significant central depression with less affection of peripheral rings. The average amplitude density of P1 wave and the amplitude of P1 and N1 waves were significantly reduced in the central rings (rings 1, 2, and 3), with less impairment in paracentral areas (rings 4 and 5). The implicit time of P1 and N1 waves were significantly delayed across the central rings in OMD patients. The BCVA (LogMAR) was significantly negatively correlated with the amplitude of P1 and N1 waves (P≤0.001). The BCVA (LogMAR) was significantly positively correlated with the implicit time of P1 and N1 waves (P≤0.001). Multiple regression analysis demonstrated that the amplitude and latency of P1 and N1 waves in the central rings (1 and 2) were the most important determinants for BCVA.Conclusion Mf-ERG has a key role in the detection of OMD and can be considered as a valuable objective test for the detection of central/macular dysfunction. The amplitude and latency of P1 and N1 waves in rings 1 and 2 may be used as biomarkers for the prediction of visual prognosis in these patients.

Clinical Stages of Occult Macular Dystrophy Based on Optical Coherence Tomographic Findings.

To determine the course of occult macular dystrophy (OMD, Miyake's disease) and to propose stages of OMD based on the optical coherence tomographic (OCT) findings. Sixty-one patients from 33 families with OMD who carried one of the proven variants of the RP1L1 gene were studied at seven centers in Japan. Ophthalmological examinations including the best-corrected visual acuity (BVCA) and OCT were performed. The median age at the last visit was 50 years with a range of 10 to 88 years, and the median age at the symptom onset was 30 years with a range of 3 to 60 years. There were significant negative correlations between the duration of OMD and BCVA, the central retinal thickness (CRT) and the thickness between external limiting membrane and retinal pigment epithelium (ERT). The BCVA gradually decreased for 10 years after symptom onset and was stable thereafter. Kaplan-Meier survival curves of the BCVA and retinal thickness showed that all of the patients had retained a vision of 1.0 logMAR, and over 80% of the patients had retained 50% thickness of the normal CRT and ERT for at least 60 years after symptom onset. The stages of OMD based on the visual symptoms and OCT findings are proposed. The photoreceptors do not become completely atrophic even at the late stage, which may account for the good retinal pigment epithelium (RPE) structure and normal-appearing fundus. The proposed stages facilitate the investigation of the pathogenicity of OMD and provide information to determine the effectiveness of therapeutic procedures.

Clinical and Genetic Characteristics of East Asian Patients with Occult Macular Dystrophy (Miyake Disease): East Asia Occult Macular Dystrophy Studies Report Number 1

To describe the clinical and genetic characteristics of the cohort enrolled in the East Asian studies of occult macular dystrophy (OMD). International, multicenter, retrospective cohort studies. A total of 36 participants from 21 families with a clinical diagnosis of OMD and harboring pathogenic RP1L1 variants (i.e., Miyake disease) were enrolled from 3 centers in Japan, China, and South Korea. A detailed history was obtained, and comprehensive ophthalmological examinations including spectral-domain OCT were performed. All detected sequence variants in the RP1L1 gene were reviewed, and in silico analysis was performed, including allele frequency analyses and pathogenicity predictions. Onset of disease, visual acuity (VA) converted to the logarithm of the minimum angle of resolution (logMAR), OCT findings, and effect of detected variants. Eleven families from Japan, 6 from South Korea, and 4 from China were recruited. There were 12 female and 24 male participants. The median age of onset was 25.5 years (range, 2-73), and the median age at the latest examination was 46.0 years (range, 11-86). The median VA (logMAR) was 0.65 (range, -0.08-1.22) in the right eye and 0.65 (-0.08-1.10) in the left eye. A significant correlation between onset of disease and VA was revealed. The Classical morphologic phenotype showing both blurred ellipsoid zone and absence of interdigitation zone of the photoreceptors was demonstrated in 30 patients (83.3%), and subtle photoreceptor architectural changes were demonstrated in 6 patients (16.6%). Eight pathogenic RP1L1 variants were identified, including 6 reported variants and 1 novel variant: p.R45W, p.T1194M/p.T1196I (complex), p.S1199C, p.G1200A, p.G1200D, p.V1201G, and p.S1198F, respectively. Two variants were recurrent: p.R45W (11 families, 52.4%) and p.S1199C (5 families, 23.8%). The pathogenic missense variants in 10 families (47.6%) were located within the previously reported unique motif, including 6 amino acids (1196-1201). There is a large spectrum of clinical findings in Miyake disease, including various onset of disease and VA, whereas the characteristic photoreceptor microstructures were shared in most cases. Two hot spots including amino acid numbers 45 and 1196-1201 in the RP1L1 gene were confirmed in the East Asian population.

Phenotype Variations Caused by Mutations in the RP1L1 Gene in a Large Mainly German Cohort.

Mutations in the retinitis pigmentosa-1-like-1 (RP1L1) gene are the major cause of autosomal dominant occult macular dystrophy (OCMD), while recessive mutations have been linked to autosomal recessive retinitis pigmentosa (arRP). We present the clinical phenotype of a large German OCMD cohort, as well as four RP patients. A total of 42 OCMD patients (27 families) and 4 arRP patients (3 families) with genetically confirmed mutations in RP1L1 were included. Genomic DNA was analyzed by targeted analysis of the c.133C>T;p.R45W mutation for all RP or macular dystrophy-related genes. All patients underwent ophthalmologic examination including psychophysical tests, electrophysiology, fundus autofluorescence (FAF), and spectral domain optical coherence tomography (SD-OCT). Follow-up time was up to 12 years. In 25 OCMD index patients genomic testing revealed the heterozygous mutation c.133C>T;p.R45W in RP1L1; one patient was homozygous for the mutation. Two OCMD patients displayed the variants c.3599G>A;p.G1200D and c.2849G>A;p.R950H, respectively, in a heterozygous state. All OCMD patients showed characteristic clinical findings and typical microstructural photoreceptor changes. Two arRP patients displayed the novel homozygous mutations c.3022C>T;p.Q1008* and c.1107G>A;p.W369*, respectively, while two RP-siblings carried the two heterozygous mutations c.455G>A;p.R152Q and c.5959C>T;p.Q1987*, the first also being novel. All arRP cases were mild with disease onset ≈30 years and preserved ERG-responses. OCMD phenotype showed consistent clinical findings including classical microstructural changes on SD-OCT. An important hallmark of RP1L1-related OCMD is the dominant family history with reduced penetrance. Furthermore, novel mutations in association with arRP were identified, outlining the complexity of the protein.

Occult Macular Dystrophy.

Patients with occult macular dystrophy (OMD) are usually middle-aged and have progressive loss of central vision or notice central scotoma, but no significant abnormality is seen in the fundus or fluorescein angiography. Optical coherence tomography (OCT) shows loss of the ellipsoid band in the central area (Fig. 19.1). Full-field electroretinography (ERG) is normal or may show diminished cone response; multifocal ERG reveals diminished amplitude in the central retina.

Parafoveal Photoreceptor Abnormalities in Asymptomatic Patients With RP1L1 Mutations in Families With Occult Macular Dystrophy.

To report the clinical characteristics of asymptomatic cases with RP1L1 gene mutations in four families with occult macular dystrophy (OMD). Four asymptomatic cases from four families were selected from a cohort of 40 subjects (16 families) with RP1L1 pathogenic variants. Clinical data of the four asymptomatic cases and three symptomatic patients in the same families were reviewed. The three asymptomatic cases did not have any visual symptoms in either eye, and one was unilaterally affected. Ophthalmologic examinations, including spectral-domain optical coherence tomography (OCT) were performed, and the morphologic characteristics of the photoreceptor layer of the asymptomatic cases were compared to those of the symptomatic patients within the same family. The OCT images demonstrated photoreceptor abnormalities in the parafoveal regions in all of the four asymptomatic cases (i.e., absence of the interdigitation zone and blurring of the ellipsoid zone). However, these microstructures were preserved at the foveal center. The longitudinal reflectivity profiles clearly identified this distinct pattern in the asymptomatic cases. In contrast, no distinct abnormalities were detected by other examinations including perimetry, fundus autofluorescence images, and multifocal electroretinograms (ERGs). The sparing of the central foveal photoreceptor layer accounts for the well-preserved visual acuity in the asymptomatic patients. The sparing may represent either the initial phase of typical OMD or a subtype of macular lesion associated with OMD. It is necessary to examine asymptomatic subjects in families with OMD because some of them may progress to the typical phenotype of OMD.

Next-Generation Sequencing-Aided Rapid Molecular Diagnosis of Occult Macular Dystrophy in a Chinese Family.

Purpose: To show early, rapid and accurate molecular diagnosis of occult macular dystrophy (OMD) in a four-generation Chinese family with inherited macular dystrophy.Methods: In the current study, we comprehensively screened 130 genes involved in common inherited non-syndromic eye diseases with next-generation sequencing-based target capture sequencing of the proband of a four-generation Chinese family that has suffered from maculopathy without a definitive diagnosis for over 10 years. Variants were filtered and analyzed to identify possible disease-causing variants before validation by Sanger sequencing.Results: Two heterozygous mutations—RP1L1 c.133 C > T (p.Arg45Trp), which is a hot spot for OMD, and ABCA4 c.6119 G > A (p.Arg2040Gln), which was identified in Stargardt’s disease were found in three patients, but neither of the mutations was found in the unaffected individuals in the same family, who are phenotypically normal or in the normal control volunteers.Conclusion: These results cannot only confirm the diagnosis of OMD in the proband, but also provide presymptomatic diagnosis of the proband’s children before the onset of visual acuity impairment and guidance regarding the prognosis and management of these patients. Heterozygous mutations of RP1L1 c.133 C > T (p.Arg45Trp) and ABCA4 c.6119 G > A (p.Arg2040Gln) are likely responsible for OMD. Our results further extend our current understanding of the genetic basis of OMD, and emphasize the importance of molecular diagnosis and genetic counseling for OMD.

ERG and OCT findings of a patient with a clinical diagnosis of occult macular dystrophy in a patient of Ashkenazi Jewish descent associated with a novel mutation in the gene encoding RP1L1

A 57-year-old man with a past medical history of diabetes presented for consultation with a several year history of slowly progressive vision loss in both eyes, which continued to deteriorate...

Novel RP1L1 Variants and Genotype-Photoreceptor Microstructural Phenotype Associations in Cohort of Japanese Patients With Occult Macular Dystrophy.

To determine the clinical and genetic characteristics of Japanese patients with occult macular dystrophy (OMD) in a nationwide multicenter study. Twenty-three patients from 21 families with clinically diagnosed OMD were studied at 10 institutions throughout Japan. Ophthalmologic examinations including spectral-domain optic coherence tomography were performed. Patients were classified into two phenotype groups: a classical group having both blurred ellipsoid zone and absence of interdigitation zone of the photoreceptors, and a nonclassical group lacking at least one of these two features. Whole-exome sequencing, direct sequencing, and in silico molecular analysis were performed to detect the pathogenic RP1L1 variants. Statistical associations between the phenotype and genotypes based on the presence of pathogenic RP1L1 variants were investigated. There were 12 families with the classical findings and 9 families with the nonclassical findings. Nine pathogenic RP1L1 missense variants were identified in 12 families (57%) including three reported variants, namely, p.R45W, p.S1199C, and p.G1200A, and six novel variants, p.G221R, p.T1194M, p.T1196I, p.G1200D, p.G1200V, and p.V1201G. The pathogenic missense variants in seven families (33%) were located between amino acid numbers 1196 and 1201. A significant association was found between the photoreceptor microstructural phenotypes and molecular genotypes. The spectrum of the morphologic phenotypes and pathogenic RP1L1 variants was documented in a well-characterized Japanese cohort with OMD. A unique motif including six amino acids (1196-1201) downstream of the doublecortin domain could be a hot spot for RP1L1 pathogenic variants. The significant association of the morphologic phenotypes and genotypes indicates that there are two types of pathophysiology underlying the occult macular dysfunction syndrome: a hereditary OMD with the classical phenotype (Miyake's disease), and a nonhereditary OMD-like syndrome with progressive occult maculopathy.

Occult Macular Dystrophy.

Occult macular dystrophy is an inherited macular dystrophy characterized by a progressive decline of bilateral visual acuity with normal fundus appearance, fluorescein angiogram and full-field electroretinogram. This case report presents a 20-year-old female patient with bilateral progressive decline of visual acuity for six years. Her visual acuity was 3-4/10 in both eyes. Anterior segment and fundus examination, fluorescein angiogram and full-field electroretinogram were normal. She could read all Ishihara pseudoisochromatic plates. Fundus autofluorescence imaging was normal. There was a mild central hyporeflectance on fundus infrared reflectance imaging in both eyes. Reduced foveal thickness and alterations of the photoreceptor inner and outer segment junction were observed by optical coherence tomography in both eyes. Central scotoma was also found by microperimetry and reduced central response was revealed by multifocal electroretinogram in both eyes. These findings are consistent with the clinical characteristics of occult macular dystrophy.

Occult macular dystrophy in an Italian family carrying a mutation in the RP1L1 gene

Occult macular dystrophy (OMD) is an inherited macular disease characterized by progressive visual decline with the absence of visible retinal abnormalities. Typical alterations of the retinal structure are detectable by spectral domain optical coherence tomography (SD‑OCT). Mutations in the RP1L1 gene have been identified to be responsible for the disease in Asian subjects. The present study assessed the role of mutations in the RP1L1 gene in an Italian family with OMD. One patient with OMD and five related subjects (two male offspring affected by progressive visual decline and three asymptomatic siblings of the patient) were subjected to complete ophthalmological examination. SD‑OCT was also performed. All subjects were screened for OMD‑associated genetic mutations in the RP1L1 gene. The OMD patient and the two symptomatic offspring presented with a reduced best‑corrected visual acuity. Although no fundus abnormalities were observed, SD‑OCT examination showed that the external limiting membrane and the inner segment/outer segment band were not clearly identifiable and a focal disruption of the photoreceptor layer was present. The degree of photoreceptor alterations was correlated with the severity of visual impairment. Clinical and tomographic results in the three asymptomatic relatives were normal. A p.Arg45Trp mutation in the RP1L1 gene was identified in the OMD patient, in the two symptomatic offspring and also in two of the asymptomatic siblings of the patient. The identification of RP1L1 mutations in subjects with OMD may improve the accuracy of diagnosis of this rare condition and may aid in enhancing the efficacy of genetic counseling.

High resolution adaptive optics imaging complements standard spectral domain optical coherent tomography in retinal diseases with micro-structural details: a case series

Purpose: To evaluate if high resolution adaptive optics confocal scanning laser ophthalmoscopy (AO-SLO) can be used as an adjunct complementary diagnostic tool to spectral domain optical coherent tomography ( SD-OCT) in characterizing three macular diseases: rod-cone dystrophy, acute retinal pigment epitheliitis (Krill’s disease), and occult macular dystrophy. Methods: As part of a complete clinical examination, each patient was subjected to color fundus pictures, multimodal imaging scans with Heidelberg Spectralis TM and high resolution retinal images with a custom built adaptive optics scanning laser ophthalmolscope (AO-SLO). The registered AO-SLO images were averaged to improve the signal to noise ratio and used to generate larger photoreceptor mosaics. Results: AO-SLO mosaics for all three conditions showed distinct, characteristic disruptions of the photoreceptors in areas that corresponded to the abnormalities observed on fundus photography and SD-OCT scans. Conclusions: AO-SLO defined fine structural changes associated with retinal pathology at the photoreceptor level that could not be achieved using standard diagnostic methods. A combination of adaptive optics scanning laser ophthalmoscopy (AO-SLO) and SD-OCT provided views of the retina with enhanced lateral and axial resolution. High-resolution, ultra-structural details of the retina may provide additional insights into the disease etiology, progression and management of patients with vision threatening macular diseases.

Pathologic Changes of Cone Photoreceptors in Eyes With Occult Macular Dystrophy.

Occult macular dystrophy (OMD) is an inherited retinal disease characterized by a progressive decrease of vision and appearance of normal fundus. To determine the pathologic features of OMD, we investigated the alternation of the photoreceptors using quantitative image analysis. We studied 22 eyes of 11 OMD patients. Three of them had a mutation (R45W) in RP1L1. The relative intensities of the ellipsoid zone in the spectral-domain optical coherence tomography (SD-OCT) images and the density of the cone photoreceptors in the adaptive optics (AO) fundus images of the OMD patients were compared to those of normal controls. The relative intensities of the ellipsoid zone in the SD-OCT images of patients with OMD were significantly lower (P < 0.001) by an average of 16% compared to that of the normal controls. Normal cone mosaics were not observed in the AO images of the macula in the eyes with OMD. The mean ± SD of cone density of the 9 OMD patients was 1970 ± 884 cells/mm2 at 2°, 1124 ± 483 cells/mm2 at 3°, and 1288 ± 715 cells/mm2 at 4° nasal to the fovea. The cone densities at 2°, 3°, and 4° nasal to the fovea of OMD were significantly lower than those of the normal controls (P < 0.001). A sparse array of cone photoreceptors with significantly reduced density of the macula is one of the morphologic features of OMD.

Multimodal Approach to Monitoring and Investigating Cone Structure and Function in an Inherited Macular Dystrophy

To examine a female subject, her father, and a brother harboring a missense mutation of the retinitis pigmentosa 1-like 1 (RP1L1) gene, over 2 years of follow-up. Observational case series. setting: Fondazione G.B. Bietti IRCCS, Rome, Italy. RP1L1 family members and controls. Images of the cone mosaic acquired with an adaptive optics retinal camera, spectral-domain optical coherence tomography (SD OCT), and full-field and multifocal electroretinography (mfERG). In the proband, best-corrected visual acuity (≤0.7 logMAR) was stable in both eyes during follow-up, though analysis of adaptive optics images showed decreased cone density in the central 9 degrees from the fovea with respect to controls (P < .05) and cone density loss in the parafoveal area (2 degrees; <12%-16%) during follow-up. Texture analysis of SD OCT images identified abnormalities of the ellipsoid zone in the central 7 degrees, while mfERG response amplitudes were reduced only in the central 5 degrees relative to controls. In the proband's father, who had 0.0 logMAR visual acuity, significant cone loss was found in the central 7 degrees from the fovea (P < .05); abnormal SD OCT and mfERG values with respect to controls were found in corresponding retinal areas. No defects in the cone structure and function were found in the proband's brother, who had 0.0 logMAR visual acuity. Occult macular dystrophy was diagnosed based on genetic and multimodal ophthalmic findings. The quantitative assessment of photoreceptor survival or loss, based on analysis of adaptive optics retinal images, was valuable to monitor disease progression at a cellular level.

Occult macular dystrophy.

Occult macular dystrophy (OMD) was first reported in 1989 as a hereditary macular disease without visible fundus abnormalities. Patients with OMD are characterized by a progressive decrease of visual acuity but have normal fundus and fluorescein angiograms with both the rod and cone components of the full-field electroretinograms (ERGs) essentially normal. However, the focal macular ERGs and multifocal ERGs are severely attenuated. These findings indicate that the retinal dysfunction is confined to the macula. Optical coherence tomography (OCT) has shown structural changes in the outer nuclear and/or photoreceptor layers. Genetic analyses of OMD pedigrees have identified dominant mutations in the RP1L1 gene. However, the same mutations were not detected in sporadic cases, suggesting that several independent mutations can lead to the OMD phenotype. The purpose of this paper is to review the history of OMD, the visual functions determined psychophysically, ERG findings, OCT characteristics and genetic findings in patients with OMD.

Multimodal imaging and multifocal electroretinography demonstrate autosomal recessive Stargardt disease may present like occult macular dystrophy.

To describe multimodal imaging and electrophysiologic characteristics of an unusual subset of patients with genetically confirmed autosomal recessive Stargardt disease (STGD1) who exhibited a central form of cone dysfunction resembling occult macular dystrophy that preceded the development of lipofuscin flecks, atrophy of retinal pigment epithelium (RPE), or full-field electroretinography abnormalities. Retrospective, observational descriptive case series. Five patients with compound heterozygous ABCA4 mutations presented with bilateral visual acuity reduction, normal-appearing fundi, and blocked choroidal fluorescence on fluorescein angiography. One sibling each of two probands with identical genotypes was also included for analysis. Full-field electroretinography testing was normal in all patients, but multifocal electroretinography demonstrated centripetally depressed amplitudes exceeding areas of fundus autofluorescence, infrared imaging, and spectral domain optical coherence tomography abnormalities. Spectral domain optical coherence tomography initially revealed disruption of the inner segment ellipsoid band accompanying an ovoid hypofluorescent foveolar lesion. Progression to later stages was accompanied by the loss of the foveal photoreceptor outer segments, creating foveal cavitation with preservation of the RPE. Fundus autofluorescence and infrared imaging demonstrated corresponding bull's eye lesions. Over time, the foveal potential space on spectral domain optical coherence tomography collapsed, and three patients developed RPE atrophy and visible lipofuscin flecks. The flecks were detectable by fundus autofluorescence and infrared imaging earlier than by biomicroscopy. From these findings, a staging system for this subset of Stargardt disease presenting with central cone dysfunction was developed and presented herein. Autosomal recessive Stargardt disease may present as a central cone dysfunction syndrome before the development of lipofuscin flecks, atrophy of RPE, or full-field electroretinography abnormalities. If emerging therapies for Stargardt disease succeed, early recognition and treatment of patients with preserved foveal photoreceptor and RPE cell bodies may yield a more favorable visual prognosis.

Clinical features of retinal diseases masquerading as retrobulbar optic neuritis

Background Managements of optic neuritis (ON) included high-dose corticosteroids or combined with systemic immunomodulatory agents. It was important to make a correct diagnosis of ON before initiation of treatment. The purpose of the study was to report and analyze the clinical features of retinal diseases in patients who were misdiagnosed as having retrobulbar ON. Methods Retrospective review of 26 patients (38 eyes) initially diagnosed with retrobulbar ON but were ultimately diagnosed with retinal or macular diseases. Data obtained from fundus examination, fluorescence fundus angiography (FFA), automated static perimetry, full-field electroretinogram (ffERG), multifocal electroretinogram (mfERG), and optical coherence tomography (OCT) were evaluated. Results Thirty-eight eyes of 26 patients were found to have misdiagnosis of retrobulbar ON, based on normal or slight abnormal fundus findings and abnormal visual evoked potentials (VEP). The mean age of the patients was 34 years and the correct diagnosis of the patients included acute zonal occult outer retinopathy (AZOOR, 15 eyes, 14 patients), occult macular dystrophy (OMD, 8 eyes, 4 patients), cone or cone-rod dystrophy (10 eyes, 5 patients), acute macular neuroretinopathy (AMNR, 3 eyes, 2 patients), and cancer-associated retinopathy (CAR, 2 eyes, 1 patient). Conclusion When attempting to diagnose retrobulbar ON in clinical practice, it is crucial to carry out necessary examinations of the retinal function and morphology to decrease misdiagnosis.

Clinical and Genetic Characteristics of Korean Occult Macular Dystrophy Patients

We investigated the genetic characteristics of retinitis pigmentosa 1-like 1 (RP1L1) gene in patients with occult macular dystrophy (OMD) and identified genotype-phenotype correlations. We sequenced the entire exons and flanking regions of the RP1L1 gene in 19 Korean OMD patients. Detailed retinal morphologic abnormalities were evaluated using spectral domain optical coherence tomography and infrared reflectance imaging. Clinical features, retinal morphologic abnormalities, and disease progression were compared among the subtypes separated on the basis of genotypes. Ten of 19 (52.6%) patients had RP1L1 mutations: 7 (36.8%) had the previously reported mutation, p.Arg45Trp, and the other 3 (15.8%) had novel variants (p.Gln2311Pro, p.Ser676Cys, and p.Asp1425His). p.Gln2311Pro, p.Asp1425His, and p.Ser676Cys were predicted as pathogenic in 3, 2, and none of 5 computational assessment tools, respectively. Photoreceptor disruption across the fovea was symmetric in all eyes with RP1L1 mutations, but asymmetric in 3 eyes without the mutations. Symmetric round hyporeflectance centered on the fovea in infrared reflectance images was seen in all patients with the p.Arg45Trp mutation, but in only 2 of 12 patients without the mutation. The patients with p.Arg45Trp showed greater extent of photoreceptor disruption than those without the mutation. Progression of photoreceptor disruption was remarkable in patients with RP1L1 mutations, but insignificant in those without. OMD is clinically and genetically heterogeneous, with different morphologic features and progression in outer retinal pathology according to RP1L1 gene mutations, indicating the genotype-phenotype correlation in patients with OMD.