Novel biallelic loss-of-function KCNV2 variants in cone dystrophy with supernormal rod responses.

PURPOSE: To report clinical and genetic features including long-term full-field electroretinography (FF-ERG) findings of a patient with cone dystrophy with supernormal rod responses (CDSRR). METHODS: Ophthalmological medical records including FF-ERG were retrospectively reviewed. Genetic analysis using whole-exome sequencing (WES) was performed. Identified KCNV2 variants were confirmed by Sanger sequencing. RESULTS: A 30-year-old female patient was referred to our hospital for assessment of decreased vision from childhood. Funduscopy showed macular atrophy in both eyes. FF-ERG showed decreased amplitudes and delayed peak time of b-waves for dark-adapted (DA) 0.01 ERG, increased b/a-wave ratio with a slightly diminished a-wave for DA 3.0 and DA 25.7 ERG, residual a-waves and almost extinguished b-waves for light-adapted (LA) 3.0 ERG, and extremely diminished amplitudes in LA 30-Hz flicker responses. At 45 years of age, funduscopy showed progressive macular atrophy, whereas the responses for her FF-ERG remained unchanged compared to those observed at 30 years of age. WES identified the compound heterozygous KCNV2 variants (p.W67X and p.D174GfsX198) in the patient. These variants have previously been unreported as pathogenic variants. Each parent had one of the variants. Subsequently, the patient was finally diagnosed with CDSRR with the novel compound heterozygous KCNV2 variants. CONCLUSIONS: Biallelic loss-of-function KCNV2 variants (p.W67X and p.D174GfsX198) were identified as the cause of CDSRR. Long-term FF-ERG findings demonstrated there were no ERG changes during 15 years of observation, indicating that there was no evidence of progressive peripheral retinal dysfunction, in spite of worsening macular atrophy.

Early postoperative evaluation of retinal function by electroretinography after vitreous surgery for idiopathic epimacular membrane.

PURPOSE: In this study, we used the PuREC to carry out electroretinography (ERG) measurements using skin electrodes to assess changes before and after microincision vitreous surgery (MIVS) for epiretinal membrane (ERM) and evaluate the stress on retinal function soon after MIVS. METHODS: The study subjects were 18 eyes of 18 patients who underwent MIVS for ERM simultaneously with cataract surgery. ERG measurements were performed using a skin electrode on the day before vitreous surgery, on the day after surgery, and 1 week later. The amplitude and implicit time of each waveform were measured, and the changes between preoperative results and those 1 day and 1 week postoperatively were investigated. RESULTS: Preoperatively, the dark-adapted (DA) 0.01 ERG, the DA 3.0 ERG a-wave amplitude, and the light-adapted (LA) 3.0 ERG b-wave amplitude were significantly smaller in affected eyes compared with their fellow eyes (P < 0.05, Wilcoxon's signed-rank test). The day after surgery, all-wave amplitude showed no significant difference compared to preoperatively (repeated-measures analysis of variance (ANOVA) post hoc test). One week after surgery, the LA 3.0 ERG for b-waves and flicker ERG amplitude had improved from the value on the day after surgery (P < 0.05, ANOVA post hoc test). CONCLUSIONS: Cone ERG components have improved within 1 week after surgery by MIVS for ERM.

Somatic instability of expanded CAG repeats of ATXN7 in Japanese patients with spinocerebellar ataxia type 7.

PURPOSE: Spinocerebellar ataxia type 7 (SCA7) is a disease characterized by progressive ataxia syndrome and retinal degeneration. SCA7 is caused by expansion of CAG repeats in the ataxin 7 gene. The purpose of this study was to describe the clinical and genetic features in a two-generation Japanese family with SCA7. METHODS: The female proband underwent systemic examinations that included neurological and ophthalmic examinations and magnetic resonance imaging (MRI) scans. We interviewed her affected mother about the clinical history at the bedside. Genomic DNA was purified from peripheral blood lymphocytes. The number of CAG repeats in the proband, and her affected mother was determined by a polymerase chain reaction-based assay that used the GeneScan analysis software. RESULTS: Neurological examinations showed limb ataxia, truncal ataxia, explosive speech, and hyperactive deep tendon reflexes. The MRI scans showed atrophy of the cerebellum and fundus of pons and tegmentum. Ophthalmologically, loss of visual acuity, macular degenerations, and central scotomas were observed in both eyes. Full-field electroretinography revealed reduced cone responses with preserved rod responses. The mother had hand-motion vision. Genetic analysis revealed that various expanded CAG repeat lengths (43-57) and the peak number of repeats (47 and 48) were the same in both patients. CONCLUSIONS: The proband exhibited a typical phenotype of SCA7, which includes cone dystrophy and spinocerebellar ataxia. Genetic analysis demonstrated somatic instability of the CAG repeats in the blood lymphocytes and suggested that there was no genetic anticipation through the maternal transmission.

Multimodal imaging of a case of peripheral cone dystrophy.

PURPOSE: To characterize the peripheral cones in the images obtained by spectral-domain optical coherence tomography (OCT), swept source OCT, and adaptive optics fundus camera in a patient with peripheral cone dystrophy. METHODS: A 28-year-old Japanese man underwent detailed ophthalmic evaluations including high-resolution imaging of the fundus of both eyes. RESULTS: The decimal best-corrected visual acuity was 1.2 in both eyes. The results of slit-lamp biomicroscopy and ophthalmoscopy were essentially normal. Fluorescein and indocyanine green angiographies did not show any hyper- or hypofluorescent areas of the retina. Goldmann perimetry showed full peripheral visual fields but relative central scotomas within the central 20°. The results of the Humphrey Visual Field Analyzer showed a limited preservation of the central sensitivity. Color vision tests showed no errors in both eyes. Spectral-domain OCT showed attenuation of both the ellipsoid and interdigitation zones throughout the macular region except the center of the fovea. The scotopic full-field ERGs were normal, but the photopic ERGs were markedly reduced. Regular cone mosaics were not observed especially more than 450 µm radius from the fovea in the adaptive optics retinal images. The parafoveal cone densities were severely decreased in both eyes. CONCLUSIONS: Our findings indicate that the peripheral cone dystrophy diagnosed by full-field ERGs and perimetry is due to a reduction in the density of parafoveal and peripheral cones.

Improved Photoreceptor Function in Male Acute Zonal Occult Outer Retinopathy.

PURPOSE: To describe male acute zonal occult outer retinopathy (AZOOR) patients with improvement of photoreceptor structure and visual function. CASE SERIES: Medical records for eight eyes in seven patients (mean age, 36.9 years; range, 22 to 57 years) with AZOOR were reviewed retrospectively. Of the seven patients, four were treated with high-dose methylprednisolone therapy and three were not treated. All patients presented with photopsias and severe vision loss in the affected eyes. Visual acuity ranged from 0.2 to 1.5 on a Snellen decimal scale and Humphrey visual field testing showed blind spot enlargement or ring scotomas. Fundus and angiographic examinations found no specific abnormalities, leading to a diagnosis of AZOOR. Spectral domain optical coherence tomography showed attenuation of the photoreceptor inner segment ellipsoid zone. Multifocal electroretinography demonstrated that there were decreased responses at the site of the spectral domain optical coherence tomography abnormalities and corresponding visual field loss. Three patients had a spontaneous resolution with restoration of photoreceptor structure and visual function, and four patients had a visual improvement with restoration of photoreceptor structure and visual function after steroid pulse therapy. CONCLUSIONS: These results suggest that male AZOOR patients may have a tendency of visual improvement both with and without treatment.

Autosomal recessive cone-rod dystrophy associated with compound heterozygous mutations in the EYS gene.

BACKGROUND: EYS mutations have been identified only in patients with autosomal recessive retinitis pigmentosa (arRP). This study was conducted to describe clinical and genetic features of a Japanese patient with autosomal recessive cone-rod dystrophy (arCRD) and EYS mutations. METHODS: We performed complete ophthalmic examinations including full-field electroretinography (ERG). Genetic analysis using whole-exome sequencing and Sanger sequencing was performed to identify the disease-causing mutation in a 31-year-old male patient. RESULTS: At the initial visit, the patient's decimal best-corrected visual acuity (BCVA) was 0.9 and 0.6 in his right and left eyes, respectively. Funduscopy indicated retinal degenerations were predominantly affected within the vascular arcades and preserved retinal vessels in the mid-periphery in both eyes. Visual field testing showed there were relative central scotomas and preserved peripheral visual fields in both eyes. ERG indicated there was a decreased pattern for both the rod and cone responses. At the age of 36 years, his BCVA decreased to 0.2 in both eyes. Optical coherence tomography showed marked retinal thinning of the macular regions in both eyes. Genetic analysis identified compound heterozygous truncating mutations (p.Y2935X and p.S1653KfsX2) in the EYS gene. His unaffected parents were heterozygous for each mutation. CONCLUSIONS: Our results demonstrated that EYS mutations can be the cause of not only arRP but also arCRD. Our findings extend the phenotypic spectrum of patients with EYS mutations.

OAT mutations and clinical features in two Japanese brothers with gyrate atrophy of the choroid and retina.

BACKGROUND: Gyrate atrophy (GA) of the choroid and retina is an extremely rare inherited chorioretinal dystrophy. Ornithine aminotransferase (OAT) gene mutations are identified in patients with GA. The purpose of this study was to report a novel deletion mutation of the OAT gene and describe clinical features of two brothers with GA in a Japanese family. METHODS: We performed ophthalmic examinations, including best-corrected visual acuity, slit-lamp biomicroscopy, dilated funduscopy, fundus autofluorescence imaging, optical coherence tomography, visual field testing, and full-field electroretinography (ERG). Serum ornithine concentrations and OAT activities were analyzed. Mutation screening of the OAT gene was performed using Sanger sequencing. RESULTS: Both brothers had compound heterozygous mutations (p.K169DfsX10 and p.R426X), one of which was novel. Their unaffected parents carried one of the mutations heterozygously. An arginine-restricted diet was started in the younger brother at the age of 2 years, while the diet was not initiated in the older brother until the age of 6 years. After more than 15 years of follow-up, the dietary treatment seemed to slow the progression of the chorioretinal lesions in the younger brother. However, when compared at the same age, the younger brother had more reduced ERG amplitudes and constricted visual fields than his older brother. CONCLUSIONS: We identified a novel frameshift mutation (p.K169DfsX10) in the OAT gene. While an early arginine-restricted dietary treatment suppressed the fundus changes of GA to some degree in the younger brother, the efficacy of suppressing the progression of visual function loss could not be clearly determined.

Multifocal electroretinographic evaluation of macular function in acute posterior multifocal placoid pigment epitheliopathy.

BACKGROUND: In acute posterior multifocal placoid pigment epitheliopathy (APMPPE), little is known about the long-term outcome of electroretinographic macular function. The purpose of this study was to report 2-year follow-up results of multifocal electroretinography (mfERG) in a 26-year-old Japanese woman diagnosed with APMPPE. METHODS: Clinical and electrophysiological investigations of a single patient. RESULTS: Best-corrected visual acuity at initial examination was 1.5 and 0.5 in her right and left eyes, respectively. In addition to characteristic fundus lesions bilaterally, fluorescein angiography demonstrated diagnostic early blockage and late staining of the lesions. Optical coherence tomography revealed a hyperreflective spot (corresponding to the lesion) in the outer retinal layer in the right eye and intraretinal fluid in the left eye. On mfERG, the amplitudes were generally preserved, but markedly reduced amplitudes were detected in the central region of the left eye and in the paracentral region of the right eye. Five days later, visual acuity improved to 1.0, and the intraretinal fluid spontaneously disappeared without medication in the left eye. Light-to-dark ratios on electrooculography were 2.68 and 2.23 in the right and left eyes, respectively, both within the normal range. Two years later, visual acuity was 2.0 in both eyes, and ophthalmoscopically, there were neither retinal nor retinal pigment epithelial (RPE) abnormalities. mfERG revealed that the amplitudes were considerably improved (nearly normal level) in both eyes. CONCLUSIONS: The outcome suggests that longitudinal macular function in both visual acuity and mfERG may be favorable, unless areas of retinal or RPE alteration remain.

Improvement of central visual function following steroid pulse therapy in acute zonal occult outer retinopathy.

The purpose of this study was to report a patient with acute zonal occult outer retinopathy (AZOOR) unilaterally, who received steroid pulse therapy. A 42-year-old woman presented with photopsias and severe vision loss in her left eye. Visual acuity was 0.04, and Humphrey visual field testing showed overall depression with a mean deviation (MD) value of -25.78 dB in the left eye. Fundus and angiographic examinations found no specific abnormal findings, leading to a diagnosis of AZOOR. Optical coherence tomography showed attenuation of the photoreceptor inner segment/outer segment junction (IS/OS) line. Focal macular electroretinography (fmERG) demonstrated that there were non-detectable responses at 5°, 10° and 15° (in diameter). Following steroid pulse therapy, her visual acuity was 1.0, her MD value improved to -16.08 dB, and there were both partial recovery of the IS/OS line and apparent improvements of fmERG responses (at 10° and 15°). The present findings suggest that steroid pulse therapy might potentially be an effective treatment in some AZOOR patients.

Autosomal dominant occult macular dystrophy with an RP1L1 mutation (R45W).

PURPOSE: To characterize clinical features in occult macular dystrophy (OMD) patients with the RP1L1 gene mutation (p.R45W), one of two previously described mutations in Japanese OMD patients. METHODS: Mutational screening of the RP1L1 gene was performed via polymerase chain reaction and direct sequencing for seven unrelated probands (one autosomal dominant and six sporadic probands) with OMD. A comprehensive ophthalmic examination was performed, including Cirrus optical coherence tomography. Full-field electroretinography (ERG), multifocal ERG, and focal macular ERG were performed. RESULTS: The heterozygous mutation (p.R45W) was found in only one female proband with autosomal dominant OMD, whose mother was also diagnosed with OMD and carried the mutation. Ophthalmoscopy showed bilateral normal fundi in the proband but subtle retinal pigment epithelium mottling in the mother. Both the proband and her mother had typical OMD findings: decreased visual acuity and markedly reduced central responses in the multifocal ERG and focal macular ERG. Although full-field ERG revealed normal rod and standard combined responses, photopic and 30-Hz flicker responses were slightly reduced in both the proband and her mother. Optical coherence tomography revealed that the external limiting membrane and inner segment-outer segment boundary were disorganized despite normal macular thickness in the proband, whereas the mother exhibited macular thinning with discontinuous reflectivity of the external limiting membrane and inner segment-outer segment boundary. CONCLUSIONS: The clinical phenotypes differed between the proband and her mother and were indistinguishable from other sporadic or RP1L1-unassociated OMD patients, suggesting that mutation-dependent clinical features may not be present.

RDH5-Related Fundus Albipunctatus in a Large Japanese Cohort.

Purpose: To investigate clinical characteristics of RDH5-related fundus albipunctatus (FAP) in a Japanese cohort. Methods: Twenty-five patients from 22 pedigrees with RDH5-related FAP were studied. Ophthalmic medical records were reviewed. For genetic analysis, either Sanger sequencing of the RDH5 gene or whole-exome sequencing was performed. Results: Genetic analysis identified eight different RDH5 variants, including seven known RDH5 variants (p.G35S, p.G107R, p.R167H, p.A240GfsX19, p.R278X, p.R280H, and p.L310delinsEV) and a novel variant: c.259C>T (p.Q87X). The most frequently observed variant was p.L310delinsEV (65.2%, 30/46 alleles). Of 50 eyes examined, 44 eyes (88.0%) showed logMAR best-corrected visual acuity (BCVA) of 0.10 or better. In optical coherence tomography, macular involvement was observed in 12 patients (24 eyes). Ten patients (83.3%) who had good BCVA (0.10 or better) exhibited diffuse disruption of the outer retina with foveal sparing, and two patients (16.7%) exhibited diffuse disruption throughout the macula and decreased BCVA. Among the 24 eyes, ring-or crescent-shaped hyperautofluorescence or irregular autofluorescence around the fovea was observed in 15 eyes (83.3%) of 18 eyes examined by fundus autofluorescence imaging. Full-field electroretinography showed extinguished or severely decreased rod responses in all 23 examined patients, whereas decreased cone responses were seen in 17 patients (73.9%). Conclusions: Multimodal imaging and electroretinography of RDH5-related FAP revealed high frequencies of macular involvement in older patients and decreased cone responses. Our findings suggest that progressive macular/cone dysfunction, as well as delayed rod function, may be key phenotypic features of RDH5-related FAP.

Analysis of Changes in Corneal Topography after 27-Gauge Transconjunctival Microincision Vitrectomy Combined with Cataract Surgery.

PURPOSE: To investigate changes in the corneal shape before and after vitrectomy, over a period of time, using a 27-gauge system. METHODS: Forty-five eyes underwent a combination of cataract surgery and vitrectomy. The surgeries were performed using a 27-gauge transconjunctival vitrectomy system, in which the corneal topography could be performed up to three months after the surgery. The surgeries were performed for an epiretinal membrane in 11 eyes, a macular hole in 14 eyes, and rhegmatogenous retinal detachment in 20 eyes. All of the surgeries were performed by the same surgeon, and in all cases, a 4-port 27-gauge vitrectomy device was used. Cataract surgery in all patients was performed with a 2.4 mm corneoscleral incision at 11 o'clock. The surgeries were performed without suturing the operative wound in all cases. Corneal topography was performed using a TMS-4 topographer (Tomey Corporation, Tokyo, Japan). The examinations were performed the day before and 1 day, 1 week, 1 month, and 3 months after the surgery. The results of corneal topography for the spherical, regular astigmatic, asymmetric, and high-order irregular astigmatic components were compared before and after surgery. RESULTS: No significant differences were seen in any of the components in the epiretinal membrane group, but significant differences were seen in the asymmetric components and the high-order irregular astigmatic components between the macular hole and rhegmatogenous retinal detachment groups (p < 0.05). There were no significant changes in intraocular pressure on any measurement time in the postoperative period compared to preoperative intraocular pressure. CONCLUSION: Irregular astigmatism was seen after surgery when 27-gauge vitrectomy with a 4-port system was performed together with cataract surgery with a 2.4 mm incision.

Long-Term Course Following Vitreous Surgery for Epiretinal Membrane.

BACKGROUND AND OBJECTIVE: To follow the long-term course of visual acuity (VA) and central retinal thickness (CRT) over at least a 3-year follow-up after vitreous surgery in patients with epiretinal membrane (ERM). PATIENTS AND METHODS: This study examined 43 eyes of patients who underwent 23- or 25-gauge vitreous surgery for ERM. RESULTS: There was significant improvement of the VA at 3 months after surgery compared with baseline, with the improvements maintained for 5 years (analysis of variance [ANOVA]; P < .05). There was a significant decrease in the mean CRT from 1 month up to 5 years (ANOVA; P < .05). There was also a significantly worse mean VA found for cases exhibiting an outer retinal layer disorder before surgery. CONCLUSION: Disorders of the outer layer of the retina before surgery have an influence on the VA outcome, with changes sometimes occurring even after the long-term postoperative follow-ups. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:e105-e111.].

A novel homozygous GRK1 mutation (P391H) in 2 siblings with Oguchi disease with markedly reduced cone responses.

PURPOSE: The only mutations reported to date in Japanese patients with Oguchi disease, a rare form of stationary night blindness with autosomal recessive transmission, have been in the SAG (arrestin) gene. The objective of this study was to describe the ophthalmic features and a novel mutation in the GRK1 (rhodopsin kinase) gene in 2 Japanese patients with Oguchi disease. DESIGN: Molecular genetic and observational case study. PARTICIPANTS: A consanguineous family including 2 siblings with Oguchi disease (a 35-year-old man and a 31-year-old woman). METHODS: Best-corrected visual acuity (BCVA), fundus examinations, Goldmann perimetry, color vision tests, and full-field electroretinograms (ERGs) were evaluated. Mutation screening of the SAG and GRK1 genes was performed with polymerase chain reaction amplification and direct sequencing. MAIN OUTCOME MEASURES: Mutations in the GRK1 gene, BCVA, color vision, fundus photographs, visual fields, and ERG findings. RESULTS: Molecular analysis revealed a novel homozygous missense mutation (p.P391H) in the GRK1 gene in both patients. Proline 391 is not only within the functionally important catalytic domain, but is also a phylogenetically conserved amino acid residue among GRK1 orthologs and homologs. No mutation was found in the SAG gene. The unaffected parents were heterozygous carriers of the mutation. Both patients had night blindness, 1.5 BCVA for each eye, normal color vision, and typical fundus appearance with golden-yellow discoloration. The visual fields were normal in the male sibling. The ERGs showed no rod B waves, reduced standard combined responses, and markedly reduced single-flash cone and 30-Hz flicker responses in both patients. CONCLUSIONS: A novel homozygous GRK1 mutation (p.P391H) was found in 2 Japanese siblings with Oguchi disease. Visual function in the 2 patients has not deteriorated with age, indicating that the disease is stationary. This is the first report of any patient with GRK1-associated Oguchi disease with markedly reduced cone responses.

A case of traction retinal detachment in a patient with Gaucher disease.

BACKGROUND: This is the first report of vitreous surgery for traction retinal detachment in a patient with type III Gaucher disease with multiple vitreous opacities. MATERIALS AND METHODS: A 16-year-old boy who was diagnosed with Gaucher disease at age two and was undergoing enzyme replacement therapy presented with numerous white opacities of varying sizes in the vitreous bodies of both eyes. Visual acuity was 20/40 in the right eye and 20/2000 in the left eye. The retina of the left eye was completely detached, and vitreous surgery was performed. RESULTS: Liquefaction of the vitreous body was advanced, and the central part of the vitreous cavity contained almost no vitreous humor. The macular region was successfully aspirated with a vitreous cutter to form a posterior vitreous detachment. From the optic disk to the nasal side, however, posterior vitreous detachment formation was prevented by strong adhesions between the retina and the vitreous body. The traction retinal detachment of the posterior fundus improved after vitreous body resection alone. CONCLUSIONS: Traction retinal detachment may occur as a result of severe vitreous liquefaction in cases of Gaucher disease with numerous vitreous opacities.

Spontaneous Resolution of Large Macular Retinoschisis in Enhanced S-Cone Syndrome.

The authors previously reported details on enhanced S-cone syndrome (ESCS) in a 23-year-old male patient with a homozygous NR2E3 mutation (p.Q350X) who developed large bilateral macular retinoschisis. Subsequent optical coherence tomography follow-up showed that although the large bilateral macular retinoschisis remained at the age of 28, there was dramatic improvement in the retinoschisis by the age 32, with bilateral resolution of the macular retinoschisis without any treatment by the age of 34. Although there is no established treatment for macular retinoschisis complicated by ESCS, this case demonstrated that intervention may not be required in some patients with ESCS.

Efficacy of Intravitreal Triamcinolone Acetonide for Diabetic Macular Edema After Vitrectomy.

PURPOSE: To compare the efficacy of intravitreal injection of triamcinolone acetonide (IVTA) for diabetic macular edema (DME) in vitrectomized eyes with DME without vitrectomy eyes. METHODS: This retrospective comparative study evaluated the efficacy of IVTA treatment of DME in 26 consecutive eyes (23 patients). Changes in mean best-corrected visual acuity (VA) and mean central retinal thickness (CRT) were retrospectively evaluated before IVTA and during the 6-month period after IVTA. RESULTS: Subjects were divided into 2 groups: 13 consecutive eyes (11 patients) with proliferative diabetic retinopathy or DME that underwent vitrectomy (vitrectomized group), and 13 consecutive eyes (12 patients) with DME who received IVTA, but did not undergo vitrectomy (nonvitrectomized group). In the vitrectomized group, there was a significantly decreased CRT for up to 4 months as compared to the thicknesses before IVTA. In the nonvitrectomized group, there was a significantly decreased CRT for up to 5 months after IVTA. In both groups, there was significant improvement in the VA for up to 4 months after IVTA. CONCLUSION: IVTA may represent a valid treatment option for DME, even in vitrectomized eyes.

Treatment of Dropped Nucleus with a 27-Gauge Twin Duty Cycle Vitreous Cutter.

We report herein a method for the treatment of dropped nucleus during cataract surgery with a 27-gauge twin duty cycle (TDC) vitreous cutter. When a TDC vitreous cutter is used, suction flow volume is maintained even when the cutter is driven at a high speed. This enables an Emery-Little grade 3 nucleus that had been difficult to treat with a conventional 27-gauge cutter to be successfully excised using only a vitreous cutter, with no intra- or postoperative complications. A dropped lens during cataract surgery of up to moderate hardness can be removed using a TDC cutter alone with a 27-gauge cutter system.

Novel C8orf37 Mutations in Patients with Early-onset Retinal Dystrophy, Macular Atrophy, Cataracts, and High Myopia.

PURPOSE: More than 50 genes are reported as causative genes of autosomal recessive (ar) retinitis pigmentosa (RP) and cone-rod dystrophy (CRD). It is challenging to identify causative mutations for arRP and arCRD. The purpose of the present study was to investigate clinical and genetic features of two siblings with early-onset retinal dystrophy. METHODS: Whole-exome sequencing was conducted for the two affected siblings and their unaffected brother and mother from a Japanese family. We performed complete ophthalmic examinations, including visual acuity, funduscopy, visual-field testing, electroretinography and optical coherence tomography. RESULTS: Whole-exome sequencing analysis identified novel compound heterozygous mutations, a splice site mutation (c.374 + 2T > C in intron 4) and a deletion mutation (c.575delC [p.T192MfsX28] in exon 6) of chromosome 8 open reading frame 37 (C8orf37) gene, which encodes a ciliary protein, in both patients. The mother carried the truncating mutation, and the brother carried neither mutation. Ophthalmic examinations revealed diffuse retinal degeneration, macular atrophy, non-recordable electroretinography responses, cataracts, and high myopia in both patients, who could not be diagnosed with either RP or CRD because of the severe retinal degeneration and early onset disease. Longitudinal follow-up of the patients revealed highly progressive retinal degeneration, macular atrophy, and visual field loss. CONCLUSIONS: Recessive C8orf37 mutations have been identified in early to adolescent-onset arRP and arCRD with macular involvement. Our study identified two novel truncating mutations of the C8orf37 gene in siblings with early-onset retinal dystrophy, macular atrophy, cataracts, and high myopia.

High-Resolution Adaptive Optics Retinal Image Analysis at Early Stage Central Areolar Choroidal Dystrophy With PRPH2 Mutation.

BACKGROUND AND OBJECTIVE: To report the clinical features of Japanese patients at Stage 1 and 2 of central areolar choroidal dystrophy (CACD). PATIENTS AND METHODS: Five family members had comprehensive ophthalmic examinations including adaptive optics (AO) retinal imaging. Mutation analysis of the PRPH2 gene was performed by Sanger sequencing. The protocol conformed to the tenets of the Declaration of Helsinki and was approved by the institutional review board of The Jikei University School of Medicine. RESULTS: Four family members had a heterozygous PRPH2 mutation, p.R172Q; however, one member with a mutation did not show any ophthalmological abnormalities. Two patients had mild parafoveal retinal dystrophy and a reduction of cone density determined by AO analysis. CONCLUSION: The results indicate that the parafoveal cone photoreceptors can be affected even at the early stage of CACD. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:1115-1126.].