Identification of novel variants in retinitis pigmentosa genes by whole-exome sequencing

SUMMARY OBJECTIVE: Retinitis pigmentosa is an inherited degenerative disorder causing severe retinal dystrophy and visual impairment, mainly with onset in the first or second decades. The next-generation sequencing has become an efficient tool to identify disease-causing mutations in retinitis pigmentosa. The aim of this retrospective study was to investigate novel gene variants and evaluate the utility of whole-exome sequencing in patients with retinitis pigmentosa. METHODS: The medical records of 20 patients with retinitis pigmentosa at Eskişehir City Hospital between September 2019 and February 2022 were analyzed retrospectively. Peripheral venous blood was obtained, followed by the extraction of genomic DNAs. The medical and ophthalmic histories were collected, and ophthalmological examinations were performed. Whole-exome sequencing was performed to determine the genetic etiology of the patients. RESULTS: The proportion of genetically solved cases was 75% (15/20) in the patients with retinitis pigmentosa. Molecular genetic testing identified 13 biallelic and 4 monoallelic mutations in known retinitis pigmentosa genes, including 11 novel variants. According to in silico prediction tools, nine variants were predicted as pathogenic or possibly pathogenic. We identified six previously reported mutations to be associated with retinitis pigmentosa. The age of onset of the patients ranged from 3 to 19, with a mean age of onset of 11.6. All patients had a loss of central vision. CONCLUSION: As the first study of the application of whole-exome sequencing among patients with retinitis pigmentosa in a Turkish cohort, our results may contribute to the characterization of the spectrum of variants related to retinitis pigmentosa in the Turkish population. Future population-based studies will enable us to reveal the detailed genetic epidemiology of retinitis pigmentosa.

Genetic analysis of the CACNA1F gene in a family affected with incomplete form Schubert-Bornschein type congenital stationary night blindness / 中华眼底病杂志

Objective:To determine the pathogenic gene mutation in a family with incomplete congenital quiescent night blindness (CSNB) of Schubert-Bornschein type.Methods:A retrospective clinical study. In February 2021, one patient and his parents and elder brother from a Han Chinese incomplete CSNB of Schubert-Bornschein type family diagnosed by clinical and genetic examination at Henan Provincial People's Hospital were included in the study. The patient’s medical history, family history were inquired; best corrected visual acuity (BCVA), color vision, fundus color photography, full-field electroretinogram (ERG), and frequency domain optical coherence tomography (OCT) were examined in detail. Five ml of the subject’s peripheral venous blood was collected and the whole genome DNA was extracted. The genomic DNA of the subject was library constructed, and all-exon probes were polymerized for capture. The suspected pathogenic mutation site was verified by Sanger, and the pathogenicity of the gene mutation site was determined by parallel bioinformatics analysis.Results:The BCVA of both eyes of the proband (Ⅱ2) was 0.4; the color vision test could not recognize the red color. Fundus examination showed no obvious abnormalities. The retina thickness in the macular area of both eyes was slightly thinned. ERG examination of the whole field showed that the amplitude of ERG b wave was significantly reduced under the stimulation of binocular dark adaptation 3.0 and showed a negative waveform. The mother of the proband (Ⅰ2) had normal BCVA, color vision, fundus color photography, and frequency domain OCT examination. The full-field ERG examination showed that the amplitude of each eye reaction was slightly reduced, and the amplitude of the dark adaptation shock potential was significantly reduced. Genetic testing showed that the proband (Ⅱ2) had a c.1761dupC hemizygous mutation in exon 14 of the voltage-dependent calcium channel α1F subunit gene ( CACNA1F gene). The results of protein sequence homology analysis showed that the site was highly conserved in multiple species; the results of bioinformatics analysis showed that the CACNA1F gene c.1761dupC (pY588fs) subsequently had a frameshift mutation and became a stop at position 10. Codons appear translational termination in the conserved regions of the protein. According to the standards and guidelines of the American College of Medical Genetics and Genomics, the mutation was judged to be a possible pathogenic variant. The mother of the proband (Ⅰ2) was a carrier of this site mutation. The clinical and genetic test results of the father and elder brother of the proband were not abnormal. Conclusion:CACNA1F gene c.1761dupC is the pathogenic mutation site of the Schubert-Bornschein type incomplete CSNB family.

Pseudoretinitis pigmentosa due to syphilis: a case report and literature review / Pseudorretinose pigmentária por sífilis: relato de caso e revisão de literatura

ABSTRACT Syphilis is a sexually transmitted infection caused by the spirochete Treponema pallidum. Ocular involvement can occur at any time, and it may affect 10% of patients in the secondary stage, and from 2% to 5% in the tertiary stage. Uveitis is the most common presentation of ocular syphilis, affecting 0.4% to 8% of patients with systemic disease. Chorioretinitis is the most common posterior alteration. We present the case of a 53-year-old male patient, presenting with bilateral low visual acuity and nyctalopia for 3 years. His physical examination revealed decreased pupillary reflex, anterior vitreous cells, physiologic papillae, arteriolar attenuation, reduced foveal reflex, diffuse retinal pigment epithelium atrophy, peripapillary and perivascular punctate pigment accumulation and peripheral chorioretinitis. Full-field electroretinogram was extinct in both eyes. Treponemal syphilis test was positive. Previously diagnosed as retinitis pigmentosa, evolved to blindness, despite proper treatment. Our case shows syphilis as a significant cause of blindness. Atypical presentations of retinitis pigmentosa must warn ophthalmologists to etiologies of pseudoretinitis pigmentosa, such as syphilis.

RESUMO A sífilis é uma infecção sexualmente transmissível causada pela espiroqueta Treponema pallidum. A sífilis ocular pode ocorrer em qualquer estágio da doença, chegando a 10% na forma secundária e a 2% a 5% em sua forma terciária. A uveíte é a manifestação ocular mais comum, ocorrendo em 0,4% a 8% dos pacientes com a doença sistêmica. A coriorretinite é a manifestação mais comum do segmento posterior. Apresentamos o caso de um paciente do sexo masculino, 53 anos, com queixa de baixa acuidade visual e nictalopia há ٣ anos. Seu exame físico revelou lentificação dos reflexos pupilares, celularidade no vítreo anterior, papilas fisiológicas, atenuação arteriolar, redução do reflexo foveal, atrofia difusa do epitélio pigmentar da retina, acúmulo punctato de pigmento em regiões peripapilar e perivascular e coriorretinite periférica. Eletrorretinograma de campo total extinto em ambos os olhos. O teste treponêmico foi positivo. Foi previamente diagnosticado como portador de retinose pigmentar, evoluindo com cegueira, a despeito do tratamento correto instituído. Esse caso mostra a sífilis como importante causadora de cegueira. Casos atípicos de retinose pigmentar devem alertar o oftalmologista para causas de pseudorretinose pigmentar, como a sífilis.

Comparative study on composition regularities of traditional Chinese medicine formulas for five kinds of ophthalmic diseases using association rules / 中草药

Objective: To analyze the composition regularities of the traditional Chinese medicine formulas (TCMFs) for treating five kinds of ophthalmic diseases, including swelling and pain of eyes, night blindness, pterygium, blepharitis marginalis and nebula based on the data mining methodology. Methods: A total of 1999 TCMFs for ophthalmic diseases were collected from the Dictionary of Chinese Medicine Prescriptions. Then frequency analyses and association rules analyses were conducted with the three indicators of support, confidence and lift based on the Apriori algorithm. Results: The diaphoretic drugs and heat-clearing drugs were the commonly used types of the traditional Chinese medicines (TCMs) for swelling and pain of eyes, pterygium and blepharitis marginalis. The heat-clearing drugs and tonifying drugs were the commonly used types of TCMs for night blindness and nebula. Coptidis Rhizoma was frequently used for swelling and pain of eyes, Schizonepetae Herba was for blepharitis marginalis, and Chuanxiong Rhizoma was for nebula. The latent association rules with significant lift included Margarita→Calamina for swelling and pain of eyes, Myrrha→Olibanum for pterygium, Notopterygii Rhizoma et Radix→Saposhnikoviae Radix for blepharitis marginalis, and Lithargite→Sal Ammoniac for nebula. Conclusion: Using association rules, the comparative study on the five kinds of ophthalmic diseases can reveal the similarities and differences of treatments for these ophthalmic diseases and explore the composition regularities of TCMs, which helps to explore the hidden value of TCMFs.

An assessment of Xeropthalmia problem among school going children in Urban Slums of Raipur

Introduction:Present study was carried out in school children (6-15 years age) from slum areas of Raipur city near its Urban Health Centre to see the Magnitude of Xerophthalmia. Very few studies have been done to clinically assess the extent of Ocular manifestations of Vitamin A deciency in primary school children Method:Study was designed as a cross sectional study conducted in primary schools of urban slums of Raipur city near its Urban Health Centre . 1000 children were randomly selected from 10 schools and examined . From each school 100 children were randomly selected from standard I-VII. Xerophthalmia was diagnosed if there was a history of night blindness, or on examination, there were signs of conjunctival xerosis, Bitot's spots, corneal xerosis or keratomalacia. Information was analysed by using the Microsoft Excel and SPSS . Chi square test was used for analysis.Results:0.5%casesofnightblindness,1.4%casesofconjunctivalxerosisand2.1%casesofBitot'sspotwerefound.Typesoffamily,lowersocialclass(classIV&V)andpoorintakesofgreenvegetablesweresignicantlyassociatedwiththevitaminAdeciency.Conclusion:Study showed that this preventable cause of ocular morbidity is still prevalent in fair magnitude. Studies are needed on this issue to highlight the importance.

Enhanced S-cone syndrome: Clinical spectrum in Indian population

Purpose: Enhanced S-cone syndrome (ESCS), a rare disorder, is often misdiagnosed as other forms of retinal degenerations, which have a poorer prognosis than ESCS. The aim of this study is to report the varied clinical features of ESCS and distinguish it from other similar disorders. Methods: We retrospectively scrutinized the records of patients with confirmed diagnosis of ESCS and analyzed the findings. Results: We included 14 patients (age range 4–39 years) who were confirmed to have ESCS according to pathognomonic electroretinography (ERG) showing reduced photopic, combined responses, and 30 Hz flicker with reduced L, M cone responses and supernormal S cone responses. The disease presented in the 1st decade with night blindness and was almost stationary or minimally progressive. Mid-peripheral fundus changes in form of nummular pigmentary alterations, yellow punctate lesions, and macular schisis were noted. The vision ranged from 6/6 to 6/36 with follow-up ranging from 1month to 22 years. Conclusion: ESCS shows varied clinical features ranging from unremarkable fundus to pigment clumping and atrophic lesions. It has good prognosis with patients mostly maintaining their vision. ERG is diagnostic. More awareness and knowledge about this entity can help to differentiate it from other forms of night blindness.

Serum levels of vitamin A, visual function and ocular surface after bariatric surgery / Níveis séricos de vitamina A, função visual e superfície ocular após cirurgia bariátrica

ABSTRACT BACKGROUND Bariatric surgery is the most effective treatment for severe obesity, but the surgery increases the risk of developing nutritional deficiencies, such as vitamin A deficiency. In human metabolism, vitamin A plays a role in vision. OBJECTIVE To evaluate serum vitamin A, visual function and ocular surface of patients undergoing bariatric surgery. METHODS A cross-sectional and analytical study was conduced with 28 patients undergoing bariatric surgery for at least 6 months. Ophthalmologic evaluation was done through color vision test, contrast sensitivity test, ocular surface tests and confocal microscopy, as well as vitamin A serum measurement. RESULTS Vertical sleeve gastrectomy was performed in seven (25.0%) patients and Roux -en-Y gastric by-pass in 21 (75.0%). Mean serum vitamin A level was 1.7±0.5 µmoL/L. Most patients (60.7%) had symptoms of dry eye. Five (17.9%) patients had contrast sensitivity impairment and 18 (64.3%) color vision changes. In the group of patients undergoing Roux -en-Y gastric by-pass , mean vitamin A levels were 1.8±0.6 µmoL/L, whereas they were 1.7±0.5 µmoL/L in patients submitted to the restrictive technique vertical sleeve gastrectomy . The analysis of the influence of serum levels of vitamin A in the visual function and ocular surface was performed by Pearson correlation test and there was no significant correlation between any of the variables and vitamin A. CONCLUSION There was no influence of the bariatric surgery technique used on serum vitamin A levels, on the visual function or on the ocular surface. Moreover, there was no correlation between serum levels of vitamin A and the visual function or the ocular surface changes.

RESUMO CONTEXTO A cirurgia bariátrica é o tratamento mais efetivo para obesidade grave, entretanto aumenta o risco de desenvolvimento de deficiência de nutrientes, como vitamina A. No metabolismo humano, a vitamina A exerce função importante na visão. OBJETIVO Avaliar níveis séricos de vitamina A, função visual e superfície ocular de pacientes submetidos à cirurgia bariátrica. MÉTODOS Estudo transversal e analítico. População de 28 pacientes submetidos à cirurgia bariátrica há pelo menos 6 meses. Foi feita avaliação oftalmológica por meio de teste de visão de cores, teste de sensibilidade ao contraste, acuidade visual com correção, testes de superfície ocular e microscopia confocal, além da dosagem de vitamina A sérica. RESULTADOS Sete (25,0%) pacientes foram submetidos à gastrectomia vertical e 21 (75,0%), à derivação gástrica em Y de Roux. A média do valor sérico de vitamina A foi de 1,7±0,5 µmoL/L. A maioria dos pacientes (60,7%) apresentavam sintomas de olho seco. Cinco (17,9%) pacientes apresentaram alteração da sensibilidade ao contraste e 18 (64,3%) alteração da visão de cores. Quando considerados apenas os pacientes submetidos à derivação gástrica em Y de Roux, a média de vitamina A foi de 1,8±0,6 µmoL/L, enquanto os submetidos à técnica gastrectomia vertical tiveram média de 1,7±0,5 µmoL/L. A análise da influência dos níveis séricos de vitamina A na função visual e na superfície ocular foi realizada pelo teste de correlação de Pearson e não houve correlação significativa. CONCLUSÃO Não houve influência do tipo de técnica de cirurgia bariátrica utilizada nos níveis séricos de vitamina A, na função visual, nem na superfície ocular. Da mesma forma, não houve correlação dos níveis séricos de vitamina A com a função visual nem com as alterações de superfície ocular.

Phenotype of Dent Disease in a Cohort of Indian Children.

Objective: To describe the clinical and genotypic features of Dent disease in children diagnosed at our center over a period of 10 years. Design: Case series. Setting: Pediatric Nephrology Clinic at a referral center in Northern India. Methods: The medical records of patients with Dent disease diagnosed and followed up at this hospital from June 2005 to April 2015 were reviewed. The diagnosis of Dent disease was based on presence of all three of the following: (i) low molecular weight proteinuria, (ii) hypercalciuria and (iii) one of the following: nephrolithiasis, hematuria, hypophosphatemia or renal insufficiency, with or without mutation in CLCN5 or OCRL1 genes. Results: The phenotype in 18 patients diagnosed with Dent disease during this period was characterized by early age at onset (median 1.8 y), and polyuria, polydipsia, salt craving, hypophosphatemic rickets and night blindness. Rickets was associated with severe deformities, fractures or loss of ambulation in six patients. Nephrocalcinosis was present in three patients, while none had nephrolithiasis. Generalized aminoaciduria was seen in 13 patients, two had glucosuria alone, and one had features of Fanconi syndrome. Over a median follow up of 2.7 years, one patient developed renal failure. Genetic testing (n=15) revealed 5 missense mutations and 3 nonsense mutations in CLCN5 in 13 patients. Five of these variations (p.Met504Lys, p.Trp58Cys, p.Leu729X, p.Glu527Gln and p.Gly57Arg) have not been reported outside the Indian subcontinent. Conclusion: Our findings suggest a severe phenotype in a cohort of Indian patients with Dent disease.

Concurrent retinitis pigmentosa and pigmented paravenous retinochoroidal atrophy phenotypes in the same patient.

We report a unique case of a patient with retinitis pigmentosa (RP) phenotype in one eye and pigmented paravenous retinochoroidal atrophy (PPRCA) phenotype in the other eye. We describe in detail the symptoms, clinical findings, and investigations done for a 32‑year‑old Indian woman. This patient had phenotypical picture resembling typical RP in the right eye, with characteristic symptoms of night blindness and constricted field of vision and a nonrecordable electroretinogram (ERG). The left eye of the same patient revealed typical PPRCA phenotype, with no night blindness, normal field, and normal ERG. RP and PPRCA phenotypes are part of the same spectrum of genetic disorder. However, it is rare to see them coexist in the same patient.

Caracterización clínico-epidemiológica y genética de una familia con retinosis pigmentaria recesiva ligada al cromosoma X / Clinical-Epidemiological Characterization and Genetics of a Family with Chromosome X-linked Recessive Retinitis Pigmentosa

Introducción: la retinosis pigmentaria es una enfermedad hereditaria, que afecta a fotorreceptores y el epitelio pigmentario y provoca una atrofia retiniana. La forma recesiva ligada al cromosoma X es la más severa en su evolución clínica. Esta enfermedad constituye un problema de salud en la provincia de Holguín. Objetivo: caracterizar clínica epidemiológica y genéticamente a esta familia con retinosis pigmentaria recesiva ligada al cromosoma X. Métodos: se realizó un estudio descriptivo, retrospectivo, que incluye a un total de 15 individuos, de ellos, siete enfermos, seis portadoras y dos posibles afectados, pertenecientes a una familia afectada con retinosis pigmentaria recesiva ligada al cromosoma X del municipio de Urbano Noris de la provincia Holguín. Con su consentimiento informado se le realizó examen oftalmológico detallado (campo visual, función retinal) y estudio genético que incluyó confección de árbol genealógico hasta la cuarta generación y extracción de sangre periférica, para análisis de ADN por técnica de reacción en cadena de la polimerasa, en el exón 15, del gen RPGR, que busca la mutación más frecuente. Resultados: predominó el grupo de las edades comprendidas entre 10-19 y 20-29 años, con el 28,57 % en ambos casos. La edad de comienzo fue precoz en la totalidad de los enfermos, las alteraciones vítreas predominaron en el 71,43 %. El 42,85 % de los enfermos estaba en el estadio final de la enfermedad y presentaron electrorretinograma no registrable el 71,43 %. El 60 % de las portadoras presentaron en el fondo de ojo lesiones pre-pigmento, reflejo tapetal, coincidiendo algunas con electrorretinogramas subnormales. Conclusiones: el debut de la enfermedad se presentó de forma precoz. Entre las características clínicas prevalecieron las alteraciones vítreas y electrorretinograma no registrable. La mayoría de los pacientes se encontraban en el estadio IV de la enfermedad. Las lesiones en el fondo de ojo y del electrorretinograma, se presentaron en un alto por ciento de las portadoras afectadas. Las alteraciones oftalmológicas, perimétricas y electrorretinográficas de estos enfermos muestran las características propias de este tipo de herencia. En el estudio genético molecular del exón 15 no se encontró la mutación buscada.

Introduction: retinitis pigmentosa is an inherited disease that affects photoreceptors and pigment epithelium, causing retinal atrophy. Recessive X -linked form is the most severe in the clinical course. This disease is a health problem in our province. Objective: to characterize epidemiological and clinical genetically a family with chromosome X-linked recessive retinitis pigmentosa. Methods: a descriptive, retrospective study in 15 individuals, including seven patients and six carriers and two possibly affected, belonging to a family affected with recessive chromosome X-linked retinitis pigmentosa of Urbano Noris municipality, Holguín province was carried out. To participate in the study the patients gave their informed consent for detailed ophthalmological examination, which included visual field, retinal function and genetic study involving making tree to the fourth generation and extraction peripheral blood for DNA analysis by PCR-SSCP ORP-in exon 15 of the RPGR gene, looking for the most frequent mutation. Results the age group between 10-19 and 20-29 years predominated with 28.57 % in both cases. The age at onset was early in all patients; vitreous abnormalities predominated in 71.43 %. 42.85 % of the patients was in the final stage of the disease and had no registrable electroretinogram (71.43 %). 60 % of the carriers presented pigment pre-injury in the fundus, tapetal reflection, coinciding with subnormal electroretinograms. Conclusions: the disease onset was presented early. Vitreous features and no registrable electroretinogram alterations were the most prevailing clinical features. Most patients were in stage IV of the disease. Lesions in the fundus and electroretinograms were present in a high percentage of the affected carriers. Ophthalmic perimeter and electroretinographic alterations of these patients show the characteristics of this type of heritage features. In the molecular genetic study of exon ORP-15 the necessary mutation was not found.

Night Blindness Induced by Long-term External Bile Drainage / 이화의대지

Vitamin A deficiency can occur as a result of malnutrition, malabsorption, or poor vitamin metabolism due to liver disease and night blindness might develop as the first symptom. Although there have been foreign reports about night blindness due to vitamin A deficiency which was derived from liver cirrhosis, primary biliary cirrhosis, intestinal bypass surgery or bariatric operation, it is hard to find reports about night blindness after percutaneous transhepatic biliary drainage for external bile drainage. We report a case of night blindness derived from fat-soluble vitamin A deficiency developed after long-term (18 months) external bile drainage for benign biliary stricture occurred after left hepatic lobectomy and hepaticojejunostomy due to the Klatskin tumor (IIIb). Her night blindness and low serum retinol level (0.02 mg/L) was dramatically improved after vitamin A supplementation. We recommend lipid-soluble vitamin supplementation on the case of long-term external bile drainage.

Retinosis pigmentaria y embarazo / Retinitis pigmentosa and pregnancy

Introducción: la retinosis pigmentaria comprende un grupo de enfermedades degenerativas de origen genético y hereditario que causan importante invalidez visual.Objetivo: evaluar cambios oftalmológicos de la agudeza y campo visual en mujeres con retinosis pigmentaria durante y después del embarazo.Métodos: estudio descriptivo, prospectivo, longitudinal realizado en el Centro de Referencia Nacional de Retinosis Pigmentaria de La Habana (1999-2011). Agudeza y campo visuales fueron evaluados en seis etapas por 21 meses desde la captación. Se tomaron los valores cuantitativos de estos parámetros utilizando estándares visuales de la Asociación Médica Americana. Se realizó análisis estadístico con SPSS versión 11.5, con un nivel de significación de 0,01 e intervalo de confianza de 95 porciento para la consideración de media, desviación estándar y frecuencia como medida de resumen.Resultados: se estudiaron 59 mujeres con edad media de 27,11 años (DS 6,7), diferentes tipos de herencia de la retinosis pigmentaria y número variable de gestaciones. Presentaban 24 embarazadas (40,7 porciento), herencia autosómica-recesiva y 18 (30,5 porciento) sin herencia definida. Durante el embarazo 36 (61,0 porciento) empeoraron la agudeza visual y 47 (79,7 porciento) disminuyeron el campo visual lo que fue más notable a partir del 3er. trimestre. Al final del estudio 50 gestantes (84,7 porciento) deterioraron su función visual, sobre todo en aquellas con herencia autosómica recesiva y multigrávidas.Conclusiones: existieron cambios irreversibles en la agudeza y campo visual durante y aún después de la gestación en las mujeres con retinosis pigmentaria. El embarazo ha afectado negativamente de forma moderada la función visual y la evolución de la retinosis pigmentaria

Introduction: retinitis pigmentosa is a group of degenerative diseases of genetic origin and hereditary cause which results in important visual disability.Objective: to assess eye acuity and visual field changes in retinitis pigmentosa women during and after pregnancy.Methods: a descriptive, prospective, longitudinal study was conducted at the National Reference Center of Retinitis Pigmentosa in Havana (1999-2011). Acuity and visual field were evaluated in six stages for 21 months since recruitment. The quantitative values of these parameters were taken using visual standards of the American Medical Association. Statistical analysis was performed with SPSS version 11.5, with a significance level of 0.01 and confidence interval of 95 per cent for the consideration of mean, standard deviation and frequency as a measure of summary.Results: 59 women were studied with a mean age of 27.11 years (SD 6.7), different types of inheritance of retinitis pigmentosa and variable number of pregnancies. 24 were pregnant (40.7 per cent) had autosomal-recessive and 18 (30.5 per cent) no definite inheritance. During pregnancy, 36 (61.0 per cent) worsened visual acuity and 47 (79.7 per cent) decreased the visual field that was most remarkable from the 3rd. quarter. At the end of the study, 50 pregnant women (84.7 per cent) deteriorated visual function, especially those with autosomal recessive inheritance and multigravidae.Conclusions: there were irreversible changes in visual acuity and field during and even after pregnancy in women with retinitis pigmentosa. Pregnancy has negatively affected moderately visual function and evolution of retinitis pigmentosa

Alterações eletrofisiológicas na doença de Oguchi / Electrophysiological findings in Oguchi disease

Descrever as alterações eletrofuncionais em um caso raríssimo da Doença de Oguchi. Paciente do sexo feminino, italiana de 17 anos de idade se queixava de cegueira noturna. A resposta escotópica de bastonetes, do ERG era não registrável. A resposta escotópica ao estímulo branco forte demonstrava uma diminuição de amplitude da onda B. As respostas ao flicker de 30Hz e ao EOG eram dentro dos limites da normalidade. Era presente o fenômeno de Mizuo-Nakamura. Os exames eletrofuncionais são muito importantes no diagnóstico de certeza da doença de Oguchi. É nítida, no presente caso, a discordância entre EOG e ERG. Considerando a função dos bastonetes, as respostas normais do EOG contrastam com a ausência de respostas dos bastonetes em condições escotópicas no ERG. Mais estudos são necessários para entender o complexo mecanismo eletrofuncional dessa doença e melhor definir a origem dos componentes sensíveis à luz do EOG...

To describe the electrophysiological alterations in a very rare case of Oguchi's disease. A 17-year-old italian girl complaining of night blindness underwent complete ophthalmological exams, including electrophysiological tests. Rod responses were nondetectable in full-field electroretinogram (ERG). The photopic ERG funtions, including the 30 Hz flicker ERG response was normal, while the scotopic b-wave was diminished in amplitude. The electrooculography (EOG) ratios within the normal range were 208% in the right eye and 222% in the left eye. The Mizuo-Nakamura phenomenon was present. The electrophysiological tests are important tools in Oguchi's disease diagnosis. In the present case, it's clear the non correspondance between EOG and ERG. Considering the rod function, the normal EOG ratio contrast with non-detectable rod ERG responses. More studies are necessary to understand the compless electrofuntional mecanism of the disease helping to understand the origin of the light-sensitive component of the EOG...

Separation of rod- and cone-driven oscillatory potential from retinal cone degeneration rat and congenital stationary night blindness rat / 中华实验眼科杂志

BackgroundOscillatory potentials (OPs) has been used extensively in experimental research and clinical diagnosis,but it is well known that OPs are the summating potentials originated from retinal rod and cone.To separate the rod and cone OPs is helpful for us to diagnose some retinal diseases.ObjectiveThis study was to analyze the characteristics of cone-and rod-driven OPs. Methods The retinal cone degeneration ( RCD ) and congenital stationary night blindness(CSNB) rats were used in this study and SD rats served as control,and 6 rats for each kinds of animals.Scotopic and photopic OPs were recorded in each rat under the dark adaptation for 12 hours and light adaptation for 10 minutes at the stimulate light intensities of -35,-25,-15,-5,0,5 db respectively with RETIscan Visual Electrophysical System.The scotopic and photopic OPs were extracted from flash electroretinogram (FERG) with Maflab7.0 Butterworth filtering waves,and the frequency spectrum of the OPs was analyzed by fast Fourier transform.The characteristics of OPs from RCD rats and CSNB rats were assessed and compared.Results The a wave and b wave of ERG were showed under the dark adaptation condition in both SD and RCD rats,but the b wave was absent in CSNB rat.Under the light adaptation condition,b wave was seen in both SD and CSNB rats,but a wave and b wave of RCD rat were absent.Two peaks were exhibited in both SD and RCD rats under the darkadaptation condition and high intensity of stimulate light at the lower frequency( domain frequency) of 75-110 Hz,90-120 Hz and high frequency ( minor frequency) 90- 120 Hz,110- 135 Hz respectively.In various intensities of stimulate light,CSNB rats appeared a peak at 70-100 Hz.But in light-adaptation and various intensities of stimulate light,the frequency peaks were seen at 75-95 Hz and 70-85 Hz from both SD and CSNB rats respectively.However,under the light adaptation condition,only one peak was seen in SD and CSNB rats at the 75-95 Hz and 70-85 Hz respectively.Compared with SD rats,the mean implied time of b wave was delayed and the amplitude was lowed under the light adaptation (P＜0.05 ),however,no significant differences were found in the implied time and amplitude of b wave of scotopic ERG between SD rats and RCD rats( P＞0.05 ).The scotopic OPs showed the prolong implied time and depressed amplitudes in RCD rats and CSNB rats compared with SD rats( P＜0.05 ),and the photopic OPs presented the prolong implied time and lowed amplitude in CSNB rat in comparison with SD rats (P ＜ O.05 ).ConclusionsCone- and rod-driven OPs appear very different characteristics.The results of this study imply that rod pathway gives more contribution to OPs than cone pathway.Analysis of these results will be helpful for the exploration of the origin of OPs and the diagnosis of the related disease.

Associação entre deficiência de vitamina A e variáveis socioeconômicas, nutricionais e obstétricas de gestantes / Association between Vitamin A deficiency and socioeconomic, nutritional and obstetric variables

Este estudo investigou a prevalência de cegueira noturna e sua associação com as variáveis socioeconômicas, nutricionais e obstétricas de 92 gestantes atendidas em um posto municipal de saúde da cidade de Diamantina, Alto Vale do Jequitinhonha (MG). Para a coleta de dados, utilizou-se a entrevista preconizada pela OMS (1996) para o diagnóstico da cegueira noturna. Na análise estatística, utilizou-se o teste exato de Fisher e o de teste de Wilcoxon. Os resultados demonstraram uma prevalência maior de cegueira noturna nos distritos de Diamantina (15,38 por cento) e cidades vizinhas (13,04 por cento). Não foi encontrada associação significativa entre cegueira noturna e as variáveis socioeconômicas e obstétricas (p>0,05). No entanto, observou-se um menor consumo de vitamina A pelas gestantes com cegueira noturna (4,4 por cento). Tais achados apontam a necessidade de realizar novas investigações acerca da deficiência de vitamina A, a fim de subsidiar ações de prevenção e combate a esse agravo neste grupo em particular.

This study verified the night blindness prevalence, the first manifestation of this deficiency, and its association with socioeconomic, nutritionals and obstetric variables of 92 pregnant who were assisted on a health municipal center in Diamantina, Vale do Jequitinhonha. Data was collected through a model interview recommended by WHO (1996) to diagnose night blindness. The statistic analysis used Fisher exact test and Wilcoxon test. The results showed a higher prevalence of night blindness at Diamantina districts and neighbor cities (13.04 percent). No significant association was found between night blindness and socioeconomic and obstetric variables (p>0.05). It was observed a low vitamin A levels by pregnant with night blindness (4.4). This found shows the necessity of more investigations on vitamin A deficiency in order to help prevent, diagnose and combat this issue.

Congenital Stationary Night Blindness with Myopia

PURPOSE: To report a case of Congenital stationary night blindness associated with myopia. METHODS: A 19-year-old male with night blindness was referred to our hospital. We studied patient's family history, refraction, color vision test, fundus examination, electroretinogram and visual field. RESULTS: Both fundi showed temporal conus and myopic change. Both visual field revealed generalized depression. The light- and dark-adapted electroretinogram showed a normal a wave with extremely reduced b wave, resulting in a typical "negative" wave form.

Acquired Unilateral Night Blindness

Night blindness is not an uncommon symptom and may occur in a wide variety of disease.However, the occurrence of acquired unilateral night blindness that has no specific clinical symptoms and signs including retinal pigment degeneration is very rare. We studied patient's family history, ocular examinations, perimetry, fluorescein angiography, electroretinogram, visual evoked potential and electrooculogram. No ocular abnormality could be found on clinical examination including fundus examnination in both eyes.Two patients had hyperfluo-rescence of optic disc in late phase of fluorescein angiography, and signifi-cantly reduced b wave and intact a wave were registered in the scotopic electroretinogram. We report 2 cases of acquired unilateral night blindness that have similar clinical findings with congenital stationary night blindness[CSNB]and melanoma-associated retinopathy[MAR].

A Case of Unilateral Retinitis Pigmentosa

Retinitis pigmentosa has been recognized as a symmetrical, bilateral, hereditary, tapetoretinal degeneration with night blindness, visual field loss, and abnormal ERG. Unilateral retinitis pigmentosa is a rather rare disease. Pedraglia described first reported a case of suspected unilateral retinitis pigmentosa in 1865. Francois and Verriest proposed the following four criteria of the unilateral retinitis pigmentosa: the presence of functional changes ophthalmoscopically typical primary pigmentary degeneration in the affected eye, the absence of a tapetoretinal dystrophy in the fellow eye with normal ERG over five years and exclusion of the inflammatory cause in the affected eye. We report a case of unilateral retinitis pigmentosa in 29 year-old female who has been followed for over five years.

A Case of Oguchi's Disease

Oguchi's disease is an unusual form of congenital stationary night blindness that is characterized by a peculiar grey-white discoloration of the retina that gives a metallic sheen. After prolonged dark adaptation, the unusual fundus discoloration disappeared and the retina slowly reverted to its original metallic color after exposure to the light. A 20-year-old man was referred for study because of a complaint of night blindness since childhood. As results of diagnostic work up, especially based on typical ocular fundus finding, dark adaptometry and electrophysiologic studies of the retina the authors have diagnosed as a Oguchi's disease. We report this case with the review of the literature.