Visual signs and symptoms in patients with the visual variant of Alzheimer disease.

BACKGROUND: Prominent visual symptoms can present in the visual variant of Alzheimer's disease (VVAD). Ophthalmologists have a significant role to play in the early diagnosis of VVAD. METHODS: We retrospectively reviewed the files of ten consecutive patients diagnosed with VVAD. All patients had a full neuro-ophthalmologic examination, a formal neurological and neuro-psychological testing, and cerebral MRI to confirm diagnosis. In addition, functional neuroimaging was obtained in seven patients. RESULTS: The common primary symptom at presentation with all patients was difficulty with near vision (reading difficulty n = 8, "visual blur" in near vision n = 2), and difficulty writing (n = 3). Following assessment, impaired reading and writing skills were evident in 9/10 and 8/10 patients respectively. Median distance visual acuity was 20/25 and at near the median visual acuity was J6. Partial homonymous visual field defect was detected in 80 % (8/10) of the patients. Color vision was impaired in all patients when tested with Ishihara pseudoisochromatic plates, but simple color naming was normal in 8/9 tested patients. Simultanagnosia was present in 8/10 patients. Vision dysfunction corresponded with cerebral MRI findings where parieto-occipital cortical atrophy was observed in all patients. PET scan (5 patients) or SPECT (2 patients) revealed parieto-occipital dysfunction (hypometabolism or hypoperfusion) in all 7 tested patients CONCLUSIONS: Visual difficulties are prominent in VVAD. Dyslexia, incomplete homonymous hemianopia, preserved color identification with abnormal color vision on Ishihara, and simultanagnosia were all symptoms observed frequently in this patient series. Ophthalmologists should be aware of the possibility of neurodegenerative disorders such as VVAD in patients with unexplained visual complaints, in particular reading difficulties

Macular dystrophy associated with the mitochondrial DNA A3243G mutation: pericentral pigment deposits or atrophy? Report of two cases and review of the literature.

BACKGROUND: The A3243G point mutation in mitochondrial DNA (mtDNA) is associated with MELAS (mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes) and MIDD syndromes (maternally inherited diabetes and deafness). Both MELAS and MIDD patients can present with visual symptoms due to a retinopathy, sometimes before the genetic diagnosis is made. CASE PRESENTATION: Patient 1: 46 year-old woman with diabetes mellitus and hearing loss was referred for an unspecified maculopathy detected during screening evaluation for diabetic retinopathy. Visual acuity was 20/20 in both eyes. Fundus examination showed bilateral macular and peripapillary hyperpigmented/depigmented areas.Patient 2: 45 year-old woman was referred for recent vision loss in her left eye. History was remarkable for chronic fatigue, migraine and diffuse muscular pain. Visual acuity was 20/20 in her right eye and 20/30 in her left eye. Fundus exhibited several nummular perifoveal islands of retinal pigment epithelium atrophy and adjacent pale deposits in both eyes.Retinal anatomy was investigated with autofluorescence, retinal angiography and optical coherence tomography. Retinal function was assessed with automated static perimetry, full-field and multifocal electroretinography and electro-oculography. Genetic testing of mtDNA identified a point mutation at the locus 3243. CONCLUSION: Observation of RPE abnormalities in the context of suggestive systemic findings should prompt mtDNA testing

Cross-sectional study assessing the addition of contrast sensitivity to visual acuity when testing for fitness to drive.

The aim of this study is to quantify the importance of loss of contrast sensitivity (CS) and its relationship to loss of visual acuity (VA), driving restrictions and daytime, on-road driving evaluations in drivers aged 70+. A predictive cross-sectional study. Volunteer participants to a drivers' refresher course for adults aged 70+ delivered by the Swiss Automobile Club in western Switzerland from 2011 to 2013. 162 drivers, male and female, aged 70 years or older. We used a vision screener to estimate VA and the The Mars Letter Contrast Sensitivity Test to test CS. We asked drivers to report whether they found five driving restrictions useful for their condition; restrict driving to known roads, avoid driving on highways, avoid driving in the dark, avoid driving in dense traffic and avoid driving in fog. All participants also underwent a standardised on-road evaluation carried out by a driving instructor. Moderate to severe loss of CS for at least one eye was frequent (21.0% (95% CI 15.0% to 28.1%)) and often isolated from a loss of VA (11/162 cases had a VA ≥0.8 decimal and a CS of ≤1.5 log(CS); 6.8% (95% CI 3.4% to 11.8%)). Drivers were more likely (R <sup>2</sup> =0.116, P=0.004) to report a belief that self-imposed driving restrictions would be useful if they had reduced CS in at least one eye. Daytime evaluation of driving performance seems limited in its ability to correctly identify difficulties related to CS loss (VA: R <sup>2</sup> =0.004, P=0.454; CS: R <sup>2</sup> =0.006, P=0.332). CS loss is common for older drivers. Screening CS and referring for cataract surgery even in the absence of VA loss could help maintain mobility. Reduced CS and moderate reduction of VA were both poor predictors of daytime on-road driving performances in this research study

Inner Retinal Dysfunction in the Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay.

The autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is associated with structural retinal abnormalities either directly visible on funduscopy or revealed by optical coherence tomography (OCT). Most patients with ARSACS have a whitish peripapillary appearance corresponding to a thickening of the peripapillary retinal nerve fiber layer. OCT has also shown an absence of the physiological foveal depression. Abnormal electroretinography (ERG) has previously been reported in only two cases, without further details. This report describes a patient with ARSACS in whom careful full-field ERG revealed dysfunction of the retinal On- bipolar cells with sparing of photoreceptor function. This is the first report of inner retinal dysfunction in ARSACS

Paraneoplastic Vitelliform Retinopathy Secondary to Metastatic Melanoma.

Paraneoplastic vitelliform retinopathy secondary to metastatic melanom

Phenotype of three consanguineous Tunisian families with early-onset retinal degeneration caused by an R91W homozygous mutation in the RPE65 gene.

PURPOSE: To identify the genetic defect, and to phenotype, three consanguineous Tunisian families presenting with early-onset retinal degeneration (EORD). METHODS: All accessible family members were included. They underwent blood sampling and ophthalmological examination including, when possible, full-field ERG and pupillometry. A genome-wide linkage analysis was initiated. Mutation analysis of the RPE65 gene within the linked interval was performed by bi-directional sequencing. RESULTS: Eleven out of 53 examined members were clinically affected with an EORD. Linkage analysis revealed a maximal lod score of 4.02 (theta=0.1) for the marker D1S207 on 1p31. Mutational screening of the RPE65 gene identified a homozygous R91W mutation co-segregating with the disease in all affected individuals. Eleven homozygotes had nystagmus and acuities ranging from CF to NLP. Two retinal patterns were identified: pattern 1 presented mid-peripheral deep white dot deposits and virtually no clumped pigmentation, whereas pattern 2 showed mid-peripheral pigmented clumps without any white deposits. Homozygotes had no detectable full-field ERG and an abnormal pupillary light reflex. Eleven heterozygotes had normal visual function. CONCLUSION: We identified and characterised an endemic form of early onset rod-cone dystrophy in a consanguineous population from northeastern Tunisia, due to the prevalence of a single RPE65 mutation. Two funduscopic patterns were identified: white dot deposits in earlier stages and clumped pigment in later stages

Photopsies: symptome souvent méconnu et apport de l'électrorétinographie [Photopsia: an often unrecognized symptom and sensitivity of electroretinography]

BACKGROUND: Photopsias are unformed luminous spontaneous visual hallucinations, often described as flickering or wiggling lights, sometimes like a glare. Phosphenes are more intense and of shorter duration whereas migraine fortifications have a specific time course and succession of events. Recognition of this symptom is often poor, hence patients are wrongly investigated. PURPOSE: To describe the clinical presentation and electroretinographic characteristics of patients with photopsias. METHODS: 4 patients were worked-up with clinical, psychophysical, angiographic and electroretinographic examinations. RESULTS: Despite normal fundus and angiographic examinations, full-field electroretinogram was diagnostic in all cases. Retinal dysfunction involved either inner or outer retina. Paraneoplastic, and probable autoimmune/inflammatory retinopathies were found in our cases. CONCLUSION: Photopsias are often secondary to sick retinal cells. In the presence of photopsias, investigations should be directed towards the retina and electroretinography is the gold standard. Recognition of the symptom should prevent useless and potentially harmful investigations for the patient