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Aland island eye disease (AIED), an incomplete form of X-linked congenital stationary night blindness (CSNB2A), and X-linked cone-rod dystrophy type 3 (CORDX3) display many overlapping clinical findings. They result from mutations in the CACNA1F gene encoding the α1F subunit of the Cav1.4 channel, which plays a key role in neurotransmission from rod and cone photoreceptors to bipolar cells. Case report: A 57-year-old Caucasian man who had suffered since his early childhood from nystagmus, nyctalopia, low visual acuity and high myopia in both eyes (OU) presented to expand the diagnostic process, because similar symptoms had occurred in his 2-month-old grandson. Additionally, the patient was diagnosed with protanomalous color vision deficiency, diffuse thinning, and moderate hypopigmentation of the retina. Optical coherence tomography of the macula revealed retinoschisis in the right eye and foveal hypoplasia in the left eye. Dark-adapted (DA) 3.0 flash full-field electroretinography (ffERG) amplitudes of a-waves were attenuated, and the amplitudes of b-waves were abolished, which resulted in a negative pattern of the ERG. Moreover, the light-adapted 3.0 and 3.0 flicker ffERG as well as the DA 0.01 ffERG were consistent with severely reduced responses OU. Genetic testing revealed a hemizygous form of a stop-gained mutation (c.4051C>T) in exon 35 of the CACNA1F gene. This pathogenic variant has so far been described in combination with a phenotype corresponding to CSNB2A and CORDX3. This report contributes to expanding the knowledge of the clinical spectrum of CACNA1F-related disease. Wide variability and the overlapping clinical manifestations observed within AIED and its allelic disorders may not be explained solely by the consequences of different mutations on proteins. The lack of distinct genotype-phenotype correlations indicates the presence of additional, not yet identified, disease-modifying factors.

Vitamin A is a micronutrient critical for retinal function. Patients with a deficiency may notice a progressive decline in night vision as rod photoreceptors become unable to regenerate rhodopsin. Although uncommon in developed nations, vitamin A deficiency should be considered in symptomatic patients with chronic, severe liver disease.
This report presents a rare case of night blindness secondary to poor vitamin A metabolism due to severe liver cirrhosis.
A 62-year-old White woman presented with progressively worsening vision in dim lighting over the past 6 to 8 months. She was asymptomatic in daylight but \"blind in the dark\" to the extent that she was afraid to go outside at night. She had no personal or family history of night blindness or retinal disorders. Ocular health was unremarkable with dilation. Given her medical history of severe nonalcoholic liver cirrhosis, malabsorption of vitamin A was suspected and subsequently confirmed by the very low vitamin A level in her serum analysis. The patient was sent to endocrinology for evaluation, and appropriate repletion therapy was implemented. Subjective improvement in symptoms, along with better performance on visual field testing, was noted after initiating oral vitamin A supplementation for 5 months.
Although vitamin A deficiency is a relatively rare disorder in the United States, it should be suspected in patients with severe liver disease or other conditions causing malabsorption who experience a loss of night vision.

Vitamin A deficiency (VAD) is common in developing countries but rare in resource-rich countries. In developed countries, malabsorption and behavioral issues are more common reasons for VAD. The current case is an example of a healthy child who developed ocular symptoms due to vitamin A deficiency in the setting of cultural influences and emotional stressors.

OBJECTIVE: Bardet-Biedl Syndrome (BBS) is an autosomal recessive systemic disorder characterized by retinitis pigmentosa, polydactyly, obesity, intellectual disability, renal impairments, and hypogonadism. The purpose of this study was to determine the ocular characteristics of a boy with BBS caused by a novel homozygous variant in the ARL6 (alternative named BBS3) gene who had been originally diagnosed with retinitis punctata albescens.
METHODS: This was an observational case study. The patient underwent ophthalmological examinations, electroretinography, and genetic analyses using whole-exome sequencing.
RESULTS: A 7-year-old boy was examined in our hospital with complaints of a progressive reduction of his visual acuity and night blindness in both eyes. There was no family history of eye diseases and no consanguineous marriage. Fundus examinations showed numerous white spots in the deep retina and retinal pigment epithelium. Fundus autofluorescence showed hypofluorescence consistent with these spots. Both the scotopic and photopic components of the full-field electroretinographies were non-detectable. Based on these clinical findings, this boy was suspected to have retinitis punctata albescens. Subsequent genetic testing using whole-exome sequencing revealed a novel homozygous variants in the ARL6/BBS3 gene (NM_001278293.3:c.528G>A, (p.Trp176Ter)). A systemic examination by the pediatric department revealed that this boy had a history of a surgical excision of polydactyly on his left foot when he was born, and that he was mildly obese. There were no prominent intellectual or gonadal dysfunctions, no craniofacial or dental abnormalities, no congenital heart disease, and no hearing impairment. He was then clinically and genetically diagnosed with BBS.
CONCLUSIONS: In children with night blindness and progressive visual dysfunction, it is important for ophthalmologists to consult clinical geneticists and pediatricians to rule out the possibility of systemic diseases such as BBS.

Congenital Stationary Night Blindness (CSNB) constitutes a group of non-progressive retinal disorders characterized by disturbances in scotopic vision and/or by a delay in adaptation to darkness, as well as by low visual acuity, myopia, nystagmus, and strabismus. Color vision and fundus appearance tend to be normal. To date, several CACNA1F gene variants have been linked to a CSNB phenotype but only few reports have focused on the optic nerve in this disease.
Twelve patients underwent standard ophthalmological and genetic evaluation including spectral domain optical coherence tomography (SD-OCT), full-field electroretinography (ffERG), kinetic perimetry, fundus photography, magnetic resonance imaging (MRI), and next-generation sequencing (NGS). Bilateral thinning of the peripapillary nerve fiber layer (pRNFL) and the ganglion cell complex (GCC) supported involvement of the optic nerves. MRI, when available, was assessed for gross intracranial optic pathway abnormalities.
All patients were shown to carry pathogenic variants in the CACNA1F gene, and all showed signs of optic nerve involvement. All patients showed a certain degree of myopic refractive error. Low average pRNFL thickness was evident in all patients. In three of them, pRNFL thickness was evaluated longitudinally and was proven to be stable over time. MRI imaging was unremarkable in all cases.
Our data support the hypothesis that CACNA1F could be related to early-onset or congenital optic nerve involvement without any signs of a progressive optic neuropathy. Even though additional data from larger cohorts and longer follow-up periods are needed to further support and confirm our findings, there is a clear significance to our findings in the preparation for future CACNA1F gene therapy trials.

The purpose of this paper is to present a case study illustrating the importance of electrophysiological investigation in the diagnosis and serial monitoring of isolated congenital nystagmus.
Serial electophysiological monitoring was undertaken in the male proband over a 9-year period commencing with initial assessment at 12 weeks of age: Skin electroretinograms (sERGs) were initially absent but subsequently revealed low-amplitude responses, electronegative morphologies and notched flicker responses suggestive of incomplete congenital stationary night blindness (CSNB2), but with an absent dark-adapted rod-specific response, while flash visual evoked potentials (fVEPs) demonstrated persistent crossed asymmetry, typical of albinoid misrouting of the optic nerves. Molecular investigation confirmed a novel hemizygous frame shift mutation in the CACNA1F gene, considered to be pathogenic and causative of X-linked CSNB2; additionally, a novel heterozygous missense variation in one copy of the RIMS1 gene was identified, pathogenic mutations of which underpin late-onset autosomal dominant cone-rod dystrophy (type 7). Segregation studies confirmed maternal inheritance of both mutations in the clinically asymptomatic mother in whom depressed rod-specific responses were confirmed on sERG. The child\'s visual acuity has remained stable as have the sERGs which have been verified by recordings using scleral electrodes.
The importance of recording ERGs as part of evaluating infants who present with nystagmus, even with a normal fundus appearance, is supported. Further, sERGs were able to distinguish an apparent variant of CSNB2 and could give consistent results over many years. FVEP results add to the evidence that albinoid misrouting of the optic nerves may occur in cases of CSNB2. ERGs and fVEPs can provide valuable information in discriminating the relative diagnostic importance of multiple genetic abnormalities.

It is of utmost importance to define the molecular diagnosis of patients with retinitis pigmentosa (RP) due to existing targeted therapeutic option: voretigene neparvovec.We provide clinical evidence for pathogenicity reclassification of variants of uncertain significance (VUSs) RPE65 c.1580A>G (p.His527Arg).
A case report of a 10-year-old boy with progressive vision loss. The patient manifested disease highly suggestive of RPE65 retinal dystrophy: nyctalopia, fairly good central vision, severely depressed full-field electroretinography responses and complete loss of peripheral fundus aut ofluorescence.
Invitae Inherited Retinal Disorders Panel identified likely pathogenic mutation RPE65 c.499G>T (p.Asp167Tyr) and RPE65 c.1580A>G (p.His527Arg), variant of uncertain significance. Segregation analysis confirmed that these variants are in trans.
We conclude that the variant RPE65 c.1580A>G (p.His527Arg) has contributed to the pathologic phenotype, demonstrating its significance clearly in the case presented, and should be reclassified according to the criteria of evidence as pathogenic. Therefore, patients with this specific variant in homozygous or compound heterozygous form would likely benefit from genetic treatment based on recombinant adeno-associated virus vector, providing a working RPE65 gene to act in place of a mutated RPE65 gene.

An eight-year-old boy with autism developed gradual onset of vision loss and nyctalopia. Dietary history revealed a diet of only French fries and potato chips for the past four years. As a result, serum vitamin A was severely below the normal level. Ophthalmologic examination revealed a normal anterior segment with bilateral optic atrophy. Vitamin A supplementation was given to restore to normal level; however, the visual impairment was irreversible. Vitamin A deficiency is common in developing countries; however, to the best of our knowledge, there are no other reported cases of permanent visual loss secondary to vitamin A deficiency in Malaysia.

BACKGROUND: Oguchi disease is a rare autosomal recessive form of congenital quiescent night blindness. Oguchi disease has been found to be associated with gene mutations in SAG and GRK1, which are vital factors in the recovery phase of phototransduction after light stimuli. We report a case of Oguchi disease with novel heterozygous mutations in SAG.
METHODS: A 7-year-old girl with a history of night blindness since childhood, was referred to our hospital. Ophthalmologic examinations included visual acuity, fundus examinations, fundus photography, spectral-domain optical coherence tomography, electroretinographic (ERG). Mutation screening of the SAG and GRK1 genes was performed. This patient exhibited typical clinical characteristics of Oguchi disease, including night blindness, golden fundus with the Mizuo-Nakamura phenomenon, packed structure of the parafovea in optical coherence tomography and reduced a-waves and b-waves in scotopic 3.0 ERG. Genetic testing revealed a heterozygous change in nucleotide c.72_75+15delATCGGTGAGTGGTGCACAA in exon 2 of the SAG gene in this patient, her unaffected mother and younger brother. A splicing alteration of nucleotide c.376-2A>C was identified in exon 6 of the SAG gene with heterozygous status in this patient and her unaffected father.
CONCLUSIONS: Compound heterozygosity of a nonsense p.S25X mutation in exon 2 and a splicing alteration in exon 6 of the SAG gene is the cause of this patient with Oguchi type 1 disease in China.