Clinical characteristics of gyrate atrophy compared with a gyrate atrophy-like retinal phenotype.

INTRODUCTION: Gyrate atrophy (GA) is a rare retinal dystrophy due to biallelic pathogenic variants in the ornithine aminotransferase (OAT) gene, causing a 10-fold increase in plasma ornithine levels. It is characterized by circular patches of chorioretinal atrophy. However, a GA-like retinal phenotype (GALRP) without elevated ornithine levels has also been reported. The aim of this study is to compare the clinical characteristics of GA and GALRP and to identify possible discriminators. METHODS: A multicenter, retrospective chart review was performed at three German referral centres on patient records between 01/01/2009 and 31/12/2021. Records were screened for patients affected by GA or GALRP. Only patients with examination results for plasma ornithine levels and / or genetic testing of the OAT gene were included. Further clinical data was gathered where available. RESULTS: Ten patients (5 female) were included in the analysis. Three suffered from GA, while seven had a GALRP. Mean age (± SD) at onset of symptoms was 12.3 (± 3.5) years for GA compared with 46.7 (± 14.0) years for GALRP patients (p = 0.002). Mean degree of myopia was higher in GA (-8.0 dpt. ± 3.6) compared to GALRP patients (-3.8 dpt. ± 4.8, p = 0.04). Interestingly, all GA patients showed macular oedema, while only one GALRP patient did. Only one patient with GALRP had a positive family history, while two were immunosuppressed. DISCUSSION: Age of onset, refraction and presence of macular cystoid cavities appear to be discriminators between GA and GALRP. GALRP may encompass both genetic and non-genetic subtypes.

Foveoschisis associated with gyrate atrophy in ornithine aminotransferase deficiency: A case report.

Ornithine aminotransferase (OAT) deficiency is an autosomal recessive disease characterized by elevated serum ornithine levels caused by mutations in genes encoding for ornithine aminotransferase, a vitamin B6-dependent mitochondrial matrix enzyme. Gyrate atrophy (GA) is characteristic findings in OAT that characterized by sharply demarcated circular, pigmentary, brain-like areas of chorioretinal atrophy in the peripheral retina. This case report presents rare assosiation between OAT and GA and describes the characteristic imaging findings of this unique, not fully understood clinical entity. The coexistence of GA and foveoschisis is extremely rare in OAT deficiency. We report a case of foveoschisis in a patient with OAT, and we will discuss the possible mechanisms that lead to it. A 24-year-old male patient presented with complaints of decreased vision and nictalopia for 1 year. The patient, who was diagnosed with oat 6 years ago, had typical gyrate atrophy in his Fundus floresein angiography and foveoschisis in his Optical coherence tomography. He was diagnosed with gyrate atrophy and foveoschisis. GA caused by OAT deficiency may present with macular involvement in the form of foveoschisis causing central visual impairment. Ophthalmologists should not ignore detailed fundus examination in children and young patients with visual impairment and should be aware of possible systemic diseases.

Regression of treatment-resistant gyrate atrophy-associated intraretinal cystic spaces using long-term diet restriction: A case report.

PURPOSE: Gyrate atrophy of the choroid and retina (GA) is a rare genetic ophthalmologic condition which primarily manifests in childhood. It is characterized by hyperornithinemia and progressive chorioretinal atrophy. Patients may develop macular intraretinal cystic spaces (ICS) for which various treatment modalities have been reported. We report a patient who failed to demonstrate visual or anatomic improvement following multiple treatments for GA-associated ICS but showed improvement following prolonged dietary modification and vitamin supplementation. CASE DESCRIPTION: A 6-year-old male patient presented with previously undiagnosed GA associated with ICS. He received 6 consecutive monthly intravitreal bevacizumab injections as well as topical nepafenac and dorzolamide for treatment of ICS without significant change detected by optical coherence tomography (OCT) following treatment. He was also maintained on an arginine restricted diet with vitamin B6 supplementation. Over the course of the ensuing year, the patient was lost to follow-up due to the coronavirus disease 2019 pandemic. When he returned, his vision was stable, and OCT showed regression of the ICS. His mother reported that he had continued only on dietary restriction and vitamin B6 supplementation with no other medications or interventions. Plasma ornithine level measurement confirmed dietary compliance. Further follow-up showed continued stabilization of the condition. CONCLUSION: In addition to retarding progressive chorioretinal atrophy, prolonged dietary modifications may result in improvement of treatment-resistant GA-associated ICS. Parents' education on the value of dietary modifications for patients with GA is highly recommended.

Gyrate Atrophy of the Choroid and Retina: A Review.

Gyrate atrophy (GA) of the choroid and retina is a rare autosomal recessive genetic condition characterized by elevation of the plasma level of the amino acid ornithine due to deficiency of the enzyme ornithine ketoacid aminotransferase. Accumulation of ornithine occurs in various body tissues but leads primarily to characteristic ophthalmic manifestations including myopia, cataract, progressive chorioretinal atrophy, and macular changes. Patients usually present with night blindness that starts in the first decade of life followed by visual field constriction and eventually diminution of the central visual acuity and blindness. The condition has been reported worldwide and its differential diagnosis is broad and includes choroideremia and retinitis pigmentosa. Treatment currently depends on life-long dietary modifications including restriction of the amino acid arginine in diet. This article describes in detail the pathogenesis, clinical features, multimodal imaging findings, and treatment options for GA of the choroid and retina and its complications.

A Case of Foveoschisis Associated with Ornithine Aminotransferase Deficiency and Gyrate Atrophy.

Gyrate atrophy is a metabolic disorder characterised by typical progressive circular chorioretinal atrophy, myopia and early developmental cataract. The disease is caused by deficiency of ornithine aminotransferase (OAT) enzyme. Although OAT is expressed in most tissues of the body, but the main target of the disease appears to be the retina. A case is presented here of a 21-year woman, who came to our clinic with the complaint of decline in central vision for eight months. She had progressive poor night vision and was diagnosed with OAT deficiency five years ago. Her systemic history was unremarkable, except for femoral deep vein thrombosis (DVT) which occurred two years ago. Laboratory tests performed at that time had revealed elevated serum ornithine and low serum lysin levels. Optic coherence tomography (OCT) scans showed foveoschisis bilaterally. In summary, gyrate atrophy may present as macular involvement in the form of foveoschisis and may lead to impaired central vision. Key Words: Foveoschisis, Gyrate atrophy, Ornithine aminotransferase.

Variable phenotypes of gyrate atrophy in siblings with a nonsense mutation in OAT gene.

Background: Gyrate Atrophy (GA) is a rare autosomal recessive disorder characterized by progressive chorioretinal degeneration. It is caused due to mutations in OAT gene that encodes a defective ornithine-δ-aminotransferase enzyme. We aim to identify the molecular cause of the disease and correlate it with the phenotype.Materials and Methods: Clinical, biochemical and genetic analyses were performed in siblings with GA.Case Description: A 10-year-old girl presented with impaired vision was clinically diagnosed to have peripheral chorioretinal degeneration in both eyes due to GA with vitreous hemorrhage in the right eye. Similar chorioretinal degeneration was observed in the patient's sibling, while parents were normal. Biochemical analysis of plasma by LC-MS/MS showed an elevated ornithine level of 892.8 µmol/L in the patient and 572.3 µmol/L in the sibling. Familial genetic screening by Sanger sequencing revealed a nonsense mutation in exon 11 of the OAT gene (c.1192C>T; p.Arg398Ter) in all the family members with a homozygous mutation in the patient and sibling, and heterozygous mutation in the parents. The patient was under follow-up with an arginine-restricted diet. At the last follow-up, the vitreous hemorrhage of right eye had resolved with an improvement in visual acuity and left eye remained stable with 6/12.Conclusion: Our patient is a rare case of gyrate atrophy presented with vitreous hemorrhage and nonsense OAT gene mutation, inherited in the autosomal recessive pattern. This report highlights the phenotypic variability among the siblings with the same mutation in OAT gene for the first time.

First report of c.425-1G>A mutation in ornithine aminotransferase gene causing gyrate atrophy of the choroid and retina with hyperornithinemia.

BACKGROUND: Gyrate atrophy is a rare autosomal recessive inherited genetic disease. Progressive deterioration of peripheral night vision and blindness are the foremost clinical manifestations of the disease caused by mutations of ornithine aminotransferase gene. CASE: The presented case was an 18-year-old male referred for a progressive reduction of visual acuity, which started when the subject was 7 years old, blurred vision, and hypotonic muscles. OBSERVATIONS: The findings by liquid chromatography with tandem mass spectrometry and high-performance liquid chromatography methods exhibited a high level of ornithine: 248 µmol/L (reference range: 44-206 µmol/L) and 818 µmol/L (reference: 25-123 µmol/L), respectively. After genetic counseling and conducting further investigation, a novel mutation (c.425-1G>A) in ornithine aminotransferase gene was recognized through whole exome sequencing and the mutation was verified using Sanger sequencing method, which is associated with gyrate atrophy phenotype. CONCLUSION: The exact mechanism of chorioretinal atrophy in hyperornithinemia is not known but the increased ornithine level is the clinical manifestation of gyrate atrophy of choroid and retina, muscle weakness, moderate mental retardation, and low cerebral creatine. Pathogenic variant in the ornithine aminotransferase gene associated with gyrate atrophy, may be beneficial as a biomarker to initial diagnosis and treatment of gyrate atrophy disease.

Treatment of Intraretinal Cystic Spaces Associated With Gyrate Atrophy of the Choroid and Retina With Intravitreal Bevacizumab.

PURPOSE: To evaluate the use of intravitreal bevacizumab injections for the treatment of intraretinal cystic spaces associated with gyrate atrophy of the choroid and retina. METHODS: Retrospective chart review of 5 eyes of 3 patients with intraretinal cystic spaces associated with gyrate atrophy and treated with intravitreal bevacizumab injections was performed. Information obtained included history, examination findings, optical coherence tomography (OCT), OCT angiography, fluorescein angiography, and microperimetric findings before and after the injections. RESULTS: The mean age of patients was 11 ± 4.6 years. All patients received three monthly bevacizumab injections. The mean corrected distance visual acuity was 0.27 ± 0.10 at baseline and improved to 0.36 ± 0.12 after the injections (P = .015). The mean central macular thickness was 569 ± 127 µm at baseline and improved to 422 ± 123 µm after the injections (P = .067). Microperimetry and OCT angiography performed in 1 patient before and after the three injections showed improved macular sensitivity and vascular density measurements following the injections. CONCLUSIONS: Intravitreal bevacizumab is safe and effective in the treatment of intraretinal cystic spaces associated with gyrate atrophy. [J Pediatr Ophthalmol Strabismus. 2020;57(6):400-406.].

Diagnostic value of a combination of next-generation sequencing, chorioretinal imaging and metabolic analysis: lessons from a consanguineous Chinese family with gyrate atrophy of the choroid and retina stemming from a novel OAT variant.

BACKGROUND/AIM: Gyrate atrophy of the choroid and retina (GACR) is an extremely rare autosomal recessive inherited disorder characterised by progressive vision loss. To identify the disease-causing gene in a consanguineous Chinese pedigree with GACR, we aimed to accurately diagnose patients with GACR through a combination of next-generation sequencing (NGS) genetic diagnosis, clinical imaging and amino acid metabolic analysis. METHODS: A consanguineous Chinese pedigree with GACR, including two patients, was recruited and a comprehensive ophthalmological evaluation was performed. DNA was extracted from a proband and her family members, and the sample from the proband was analysed using targeted NGS. Variants detected by NGS were confirmed by Sanger sequencing and subjected to segregation analysis. Tandem mass spectrometry (MS/MS) was subsequently performed for metabolic assessment. RESULTS: We identified a novel, deleterious, homologous ornithine aminotransferase (OAT) variant, c.G248A: p.S83N, which contributes to the progression of GACR in patients. Our results showed that the p.S83N autosomal recessive variant of OAT is most likely pathogenic, with changes in protein stability drastically decreasing functionality. MS/MS verified that ornithine levels in patients were significantly elevated. CONCLUSIONS: Recruitment of a third-degree first cousin consanguineous marriage family with GACR allowed us to identify a novel pathogenic OAT variant in the Chinese population, broadening the mutation spectrum. Our findings reported the diagnostic value of a combination of NGS, retinal imaging and metabolic analysis of consanguineous marriage pedigrees in low-income/middle-income and low-incidence countries, including China, and may help to guide accurate diagnosis and treatment of this disease.

Bevacizumab for the treatment of intraretinal cystic spaces in a patient with gyrate atrophy of the choroid and retina.

BACKGROUND: Gyrate atrophy of the choroid and retina is a rare autosomal recessive condition characterized by chorioretinal atrophy due to deficiency of the enzyme ornithine aminotransferase that can be complicated by intraretinal cystic spaces. CASE REPORT: A 15-year-old female complaining of gradually progressive diminution of vision in both eyes preceded by night blindness was found to have gyrate atrophy of the choroid and retina with intraretinal cystic spaces that was evaluated using multimodal imaging including fluorescein angiography, optical coherence tomography, and optical coherence tomography angiography. Functional and anatomical improvement of the intraretinal cystic spaces was achieved with monthly intravitreal bevacizumab injections. CONCLUSION: Repeated intravitreal bevacizumab injections can result in anatomical and functional improvement of intraretinal cystic spaces in patients with gyrate atrophy of the choroid and retina.

Multimodal characterization of a novel mutation causing vitamin B6-responsive gyrate atrophy.

PURPOSE: Gyrate atrophy (GA) is a rare chorioretinal degeneration that results in the deterioration of night and peripheral vision, eventually leading to blindness. The disorder is caused by mutations in the gene encoding ornithine aminotransferase (OAT), causing increased levels of plasma ornithine. Treatment revolves around lowering plasma ornithine levels, with vitamin B6 supplementation being the preferred treatment. Nevertheless, most patients do not respond to this therapy. Here, we report a rare case of vitamin B6-responsive GA caused by a novel mutation in OAT and characterize the presentation with multimodal imaging. METHODS: This is a single-patient case report with a clinical diagnosis based on history, multimodal retinal imaging, laboratory findings, and DNA sequencing analysis. We include a 3D structure prediction of the novel mutant protein. RESULTS: DNA sequencing analysis demonstrated that there is a homozygous, novel variant c.473A>C: p.Y158S in OAT. Upon undergoing two weeks of vitamin B6 supplementation, the patient exhibited a 28.5% reduction in plasma ornithine levels. In a follow-up visit two years later, plasma ornithine levels were reduced by 24.1% from the levels at initial presentation and disease progression was retarded based on clinical findings. CONCLUSION: One novel homozygous missense mutation in OAT was identified and considered to be pathogenic in a patient with GA. The response for the vitamin B6 supplementation was positive, which is rare in all the GA cases reported in the literature. Our data suggests that further studies regarding the relationship between genotype and responsiveness to vitamin B6 should be conducted.

Bilateral choroidal neovascularization associated with gyrate atrophy managed with intravitreal bevacizumab.

PURPOSE: To report a case with gyrate atrophy (GA) complicated by bilateral choroidal neovascularization (CNV) treated with intravitreal bevacizumab. CASE PRESENTATION: A 20-year-old man presented with a complaint of sudden visual decrease in his both eyes. Best-corrected visual acuity (BCVA) was 20/400 and 20/500, with a spherical refractive error of -2.00 and -1.75 D, in the right and left eyes, respectively. Dilated fundus examination revealed multiple bilateral, sharply defined chorioretinal atrophy areas in the midperipheral and peripheral zone with the suspicion of CNV in both eyes. Spectral-domain optical coherence tomography revealed bilateral cystoid macular edema consistent with CNV development which was confirmed by fundus fluorescein angiography. Single dose of intravitreal bevacizumab injections were performed to both eyes of the patient. At the first month after the injection, the BCVA improved and OCT revealed scar formation without any intraretinal/subretinal fluid in both eyes. At the first-year follow-up, the maculas remained dry on the OCT and the BCVA was preserved. No additional injections were needed. CONCLUSION: Intravitreal bevacizumab might be a treatment alternative, which provides satisfactory anatomical and functional results and leads to a better central vision in cases with GA complicated by CNV.

Hiperornitinemia con atrofia gyrata de coroides y retina / Hyperornithinemia with gyrate atrophy of the choroid and retina

La atrofia gyrata de coroides y retina fue descrita por vez primera por Fuchs en el año 1896 como una entidad clínicamente definida. La deficiencia de la enzima ornitina delta aminotransferasa se hereda de forma autosómica recesiva; resulta en incremento plasmático de las concentraciones de ornitina y se asocia con atrofia gyrata de coroides y retina. Se presenta una paciente de 6 años de edad que es llevada a consulta, ya que en la escuela la maestra notaba mala visión de lejos. En un examen inicial del fondo de ojo el oftalmólogo observó cambios sugestivos de distrofia retiniana. En la oftalmoscopia binocular indirecta se encontraron extensas zonas confluentes de atrofia coroidea por fuera de las arcadas vasculares que respetaban el polo posterior; la mácula impresionaba normal. Se realizó un estudio de tomografía de coherencia óptica en dominio espectral en tomógrafo Spectralis que demostró la presencia de edema macular cistoide en ambos ojos. La determinación de niveles de ornitina en sangre arrojaron niveles muy elevados de este aminoácido (975 µmol/mL). Con todos estos hallazgos se llegó al diagnóstico de hiperornitinemia y atrofia gyrata de coroides y retina. Se indicó tratamiento dietético y vitamina B6 oral a pesar de que no se ha obtenido hasta el momento reducción significativa de los niveles de ornitina en plasma(AU)

Gyrate atrophy of the choroid and the retina was first described by Fuchs as a clinically defined condition in 1896. Human hereditary deficiency of ornithine aminotransferase activity is transmitted as an autosomal recessive trait and results in increased level of plasma ornithine and is associated with gyrate atrophy of the choroid and the retina. A 6-year-old girl was taken to the ophthalmologist's because of her far poor vision detected by her teacher at the school. In the initial eye fundus examination the ophthalmologist observed some changes indicating retinal dystrophy. The indirect binocular funduscopy revealed extensive areas of choroidal atrophy outside the vascular archades respected the posterior pole whereas the macula impressed as normal. Cystoid macular edema was evident in both eyes according to the results of the optic coherence tomography performed with Spectralis tomograph. The aminoacid analysis revealed high serum ornithine level (975 µmol/mL). The clinical diagnosis of the patient was consistent with hyper-ornithinemia and gyrate atrophy of the choroid and the retina. She was treated with vitamin B6 and dietary supplementation but no significant reduction on her serum ornithine level was observed(AU)

Hiperornitinemia con atrofia gyrata de coroides y retina / Hyperornithinemia with gyrate atrophy of the choroid and retina

La atrofia gyrata de coroides y retina fue descrita por vez primera por Fuchs en el año 1896 como una entidad clínicamente definida. La deficiencia de la enzima ornitina delta aminotransferasa se hereda de forma autosómica recesiva; resulta en incremento plasmático de las concentraciones de ornitina y se asocia con atrofia gyrata de coroides y retina. Se presenta una paciente de 6 años de edad que es llevada a consulta, ya que en la escuela la maestra notaba mala visión de lejos. En un examen inicial del fondo de ojo el oftalmólogo observó cambios sugestivos de distrofia retiniana. En la oftalmoscopia binocular indirecta se encontraron extensas zonas confluentes de atrofia coroidea por fuera de las arcadas vasculares que respetaban el polo posterior; la mácula impresionaba normal. Se realizó un estudio de tomografía de coherencia óptica en dominio espectral en tomógrafo Spectralis que demostró la presencia de edema macular cistoide en ambos ojos. La determinación de niveles de ornitina en sangre arrojaron niveles muy elevados de este aminoácido (975 µmol/mL). Con todos estos hallazgos se llegó al diagnóstico de hiperornitinemia y atrofia gyrata de coroides y retina. Se indicó tratamiento dietético y vitamina B6 oral a pesar de que no se ha obtenido hasta el momento reducción significativa de los niveles de ornitina en plasma(AU)

Gyrate atrophy of the choroid and the retina was first described by Fuchs as a clinically defined condition in 1896. Human hereditary deficiency of ornithine aminotransferase activity is transmitted as an autosomal recessive trait and results in increased level of plasma ornithine and is associated with gyrate atrophy of the choroid and the retina. A 6-year-old girl was taken to the ophthalmologist’s because of her far poor vision detected by her teacher at the school. In the initial eye fundus examination the ophthalmologist observed some changes indicating retinal dystrophy. The indirect binocular funduscopy revealed extensive areas of choroidal atrophy outside the vascular archades respected the posterior pole whereas the macula impressed as normal. Cystoid macular edema was evident in both eyes according to the results of the optic coherence tomography performed with Spectralis tomograph. The aminoacid analysis revealed high serum ornithine level (975 µmol/mL). The clinical diagnosis of the patient was consistent with hyper-ornithinemia and gyrate atrophy of the choroid and the retina. She was treated with vitamin B6 and dietary supplementation but no significant reduction on her serum ornithine level was observed(AU)

Carbonic Anhydrase Inhibitor with Topical NSAID Therapy to Manage Cystoid Macular Edema in a Case of Gyrate Atrophy.

PURPOSE: Gyrate atrophy of the choroid and retina (GACR) is a rare chorioretinal dystrophy characterized by a deficiency of the enzyme ornithine aminotransferase, inherited in an autosomal recessive pattern. CASE REPORT: We report a case of a 17-year-old girl with GACR, for whom the level of serum ornithine had been reduced by an arginine-restricted diet. The patient was responsive to an association of topical nonsteroidal anti-inflammatory drugs (NSAIDs) and a carbonic anhydrase inhibitor (CAI) to reduce cystoid macular edema (CME). CONCLUSIONS: The efficacy of topical NSAIDs and systemic CAI association indicates that the imbalance in the distribution of retinal pigment epithelium membrane-bound carbonic anhydrase could play a major role in CME pathogenesis in GACR. To our knowledge, this is the first case of therapy with CAI treatment for GACR-related CME.

Gyrate Atrophy-Like Phenotype: Normal Plasma Ornithine and Retinal Crystals.

PURPOSE: To report an unusual case of a gyrate atrophy-like presentation with retinal crystal deposition in a patient with normal plasma ornithine levels. CASE REPORT: A 50-year-old Hispanic female patient presented with complaints of blurred vision and nyctalopia. Examination revealed bilateral multiple round islands of peripheral chorioretinal degeneration in addition to small crystal-like deposits in the posterior pole. Spectral domain optical coherence tomography confirmed the crystalline deposits to be above the retinal pigment epithelium. Electrophysiology revealed reduced photopic responses with no recordable scotopic response. Testing for elevated plasma ornithine, which is typical in gyrate atrophy patients, was performed; however, the patient's levels were normal. CONCLUSIONS: Diagnosis of conditions that cause nyctalopia can be challenging because they are rare and often similar in appearance and presenting symptoms. Retinal crystal deposition and normal plasma ornithine illustrate the phenotypical variation that can be seen in a gyrate atrophy-like phenotype.