Neuronal ceroid lipofuscinosis. Ocular histopathologic and electron microscopic studies in the late infantile, juvenile, and adult forms

An ERG and OCT study of neuronal ceroid lipofuscinosis CLN2 Battens retinopathy

BACKGROUND

Late infantile neuronal ceroid lipofuscinosis (CLN2 Batten disease) is a rare, progressive neurodegenerative disease of childhood. The natural history of motor and language regression is used to monitor the efficacy of CNS treatments. Less is known about CLN2 retinopathy. Our aim is to elaborate the nature, age of onset, and symmetry of CLN2 retinopathy using visual electrophysiology and ophthalmic imaging.

SUBJECTS AND METHODS

We reviewed 22 patients with genetically confirmed CLN2 disease; seventeen showing classical and five atypical disease. Flash electroretinograms (ERGs), flash and pattern reversal visual evoked potentials (VEPs), recorded from awake children were collated. Available fundus images were graded, optical coherence tomography (OCT) central subfoveal thickness (CST) measured, and genotype, age, clinical vision assessment and motor language grades assembled.

RESULTS

ERGs show cone/rod system dysfunction preceded by localised macular ellipsoid zone disruption on OCT from 4.8 years. Electroencephalogram (EEG) time-locked spikes confounded both pattern 6/17 (35%) and flash VEPs 12/16 (75%). Paired right eye (RE) and left eye (LE) ERG amplitudes did not differ significantly for each flash stimulus at the p 0.001 level, Wilcoxon ranked signed test. Cone ERGs show a functional deficit before CST thinning in classical disease. Optomap hyper fundus autofluorescence (FAF) at the fovea was noted in three patients with normal ERGs. The oldest patient showed an ovoid aggregate above the external limiting membrane at the fovea, which did not affect the PERG.

CONCLUSION

ERG findings in CLN2 retinopathy show symmetrical cone-rod dysfunction, from 4y10m in this series, but a broad range of ages when ERG function is preserved.

Juvenile Batten Disease (CLN3): Detailed Ocular Phenotype, Novel Observations, Delayed Diagnosis, Masquerades, and Prospects for Therapy

Purpose

To characterize the retinal phenotype of juvenile neuronal ceroid lipofuscinosis (JNCL), highlight delayed and mistaken diagnosis, and propose an algorithm for early identification.

Design

Retrospective case series.

Participants

Eight children (5 female) with JNCL.

Methods

Review of clinical notes, retinal imaging including fundus autofluorescence and OCT, electroretinography (ERG), and both microscopy and molecular genetic testing.

Main Outcome Measurements

Demographic data, signs and symptoms, visual acuity (VA), fundus autofluorescence and OCT findings, ERG phenotype, and microscopy/molecular genetics.

Results

Participants presented with rapid bilateral vision loss over 1 to 18 months, with mean VA deteriorating from 0.44 logarithm of the minimum angle of resolution (logMAR) (range, 0.20–1.78 logMAR) at baseline to 1.34 logMAR (0.30 logMAR - light perception) at last follow-up. Age of onset ranged from 3 to 7 years (mean, 5.3 years). The age at diagnosis of JNCL ranged from 7 to 10 years (mean, 8.3 years). Six children displayed eccentric fixation, and 6 children had cognitive or neurologic signs at the time of diagnosis (75%). Seven patients had bilateral bull’s-eye maculopathy at presentation. Coats-like exudative vasculopathy, not previously reported in JNCL, was observed in 1 patient. OCT imaging revealed near complete loss of outer retinal layers and marked atrophy of the nerve fiber and ganglion cell layers at the central macula. An electronegative ERG was present in 4 patients (50%), but with additional a-wave reduction, there was an undetectable ERG in the remaining 4 patients. Blood film microscopy revealed vacuolated lymphocytes, and electron microscopy showed lysosomal (fingerprint) inclusions in all 8 patients.

Conclusions

In a young child with bilateral rapidly progressive vision loss and macular disturbance, blood film microscopy to detect vacuolated lymphocytes is a rapid, readily accessible, and sensitive screening test for JNCL. Early suspicion of JNCL can be aided by detailed directed history and high-resolution retinal imaging, with subsequent targeted microscopy/genetic testing. Early diagnosis is critical to ensure appropriate management, counseling, support, and social care for children and their families. Furthermore, although potential therapies for this group of disorders are in early-phase clinical trial, realistic expectations are that successful intervention will be most effective when initiated at the earliest stage of disease.

OPTICAL COHERENCE TOMOGRAPHY IN JUVENILE NEURONAL CEROID LIPOFUSCINOSIS

Optical coherence tomography in two 7-year-old girls with juvenile neuronal ceroid lipofuscinosis showed the same degenerative retinal changes, despite different mutations in the CLN3 gene.

Purpose:

To report optical coherence tomography findings obtained in two patients with juvenile neuronal ceroid lipofuscinosis.

Methods:

Two case reports.

Results:

Two 7-year-old girls presented with decreased visual acuity, clumsiness, night blindness, and behavioral problems. Optical coherence tomography showed an overall reduction in thickness of the central retina, as well as the outer and the inner retinal layers. The degenerative retinal changes were the same, despite different mutations in the CLN3 gene.

Conclusion:

In these rare cases of juvenile neuronal ceroid lipofuscinosis, optical coherence tomography enabled unambiguous detection of prominent morphologic abnormalities of the retina at the patient's first presentation. The advanced stage of photoreceptor degeneration seen in our patients shows that a diagnosis can potentially be made much earlier.

Novel morphological macular findings in juvenile CLN3 disease

AIMS

Juvenile CLN3 disease, one of the most common forms of a group of lysosomal storage diseases called neuronal ceroid lipofuscinoses (NCLs), is a progressive neurodegenerative disorder with initial visual deterioration. The objective of this study was to analyse the retinal phenotype of patients with CLN3 disease with the help of recent ophthalmic imaging modalities to distinguish CLN3 disease from other inherited retinal dystrophies.

METHODS

Patients underwent ophthalmic evaluations, including anterior and posterior segment examinations, optical coherence tomography, fundus autofluorescence, near infrared imaging and fundus photography. Patients were also assessed according to the Hamburg juvenile NCL (JNCL) score. Each ophthalmic finding was assessed by three independent examiners and assigned to a clinical severity score.

RESULTS

22 eyes of 11 patients were included. The mean age at examination was 14.4 years (range 11.8-26.4 years), with an average age at initial diagnosis of 8 years (range 4.5-11 years). The mean Hamburg JNCL score was 7.3 (range 0-13). All patients showed a specific macular striation pattern on optical coherence tomography that was independent of age and progression of the disease. Other previously described retinal features of CLN3 disease were classified into four severity grades.

CONCLUSIONS

This study represents the first prospective observational case series documenting retinal abnormalities in CLN3 disease with the aid of the spectral domain optical coherence tomography. The major finding was a characteristic, striated macular pattern in all patients studied. Particularly in early disease cases, macular striae can potentially help to discriminate CLN3 disease from other inherited forms of retinitis pigmentosa.

Cataract and glaucoma development in juvenile neuronal ceroid lipofuscinosis (batten disease)

BACKGROUND

Ophthalmologic studies of Juvenile Neuronal Ceroid Lipofuscinosis (JNCL) have focused mainly on retinal involvement, and so far no anterior segment abnormalities have been described. In the present study, we report the findings of pre-senile cataract in five patients with JNCL.

MATERIAL AND METHODS

Our sample consisted of 35 patients (19 males, 16 females) with JNCL associated to the Centre for Rare Disease, Aarhus University Hospital. They represent all patients with JNCL born in Denmark in the period 1971-2003. At the half-yearly routine outpatient visits, the anterior section was examined by ordinary penlight without instillation of a mydriatic, and if abnormalities such as cataracts were detected or suspected, the patients were referred for an ophthalmologic examination including slit lamp examination. Follow up was obtained on all patients referred for ophthalmologic examination.

RESULTS

During the study period (1996-2012), five patients were identified with cataract. The patients' average age at detection of cataract was 20.1 + 1.6 years (mean + 2SD). Two of the five patients developed acute glaucoma, and in one case prophylactic cataract surgery was performed.

CONCLUSIONS

Cataract formation and a secondary acute glaucoma are complications in JNCL which do occur. We recommend that a complete ophthalmological examination of the anterior segment should be performed routinely in patients with JNCL beyond the age of 16 years of age in order to prevent a painful and harmful acute glaucoma which may occur due to mature cataract formation.

Spectrum of ocular manifestations in CLN2-associated batten (Jansky-Bielschowsky) disease correlate with advancing age and deteriorating neurological function

Background

Late infantile neuronal ceroid lipofuscinosis (LINCL), one form of Batten’s disease is a progressive neurodegenerative disorder resulting from a CLN2 gene mutation. The spectrum of ophthalmic manifestations of LINCL and the relationship with neurological function has not been previously described.

Methods

Patients underwent ophthalmic evaluations, including anterior segment and dilated exams, optical coherence tomography, fluorescein and indocyanine green angiography. Patients were also assessed with the LINCL Neurological Severity Scale. Ophthalmic findings were categorized into one of five severity scores, and the association of the extent of ocular disease with neurological function was assessed.

Results

Fifty eyes of 25 patients were included. The mean age at the time of exam was 4.9 years (range 2.5 to 8.1). The mean ophthalmic severity score was 2.6 (range 1 to 5). The mean neurological severity score was 6.1 (range 2 to 11). Significantly more severe ophthalmic manifestations were observed among older patients (p<0.005) and patients with more severe neurological findings (p<0.03). A direct correlation was found between the Ophthalmic Severity Scale and the Weill Cornell Neurological Scale (p<0.002). A direct association was also found between age and the ophthalmic manifestations (p<0.0002), with older children having more severe ophthalmic manifestations.

Conclusions

Ophthalmic manifestations of LINCL correlate closely with the degree of neurological function and the age of the patient. The newly established LINCL Ophthalmic Scale may serve as an objective marker of LINCL severity and disease progression, and may be valuable in the evaluation of novel therapeutic strategies for LINCL, including gene therapy.

Juvenile neuronal ceroid lipofuscinosis (JNCL) and the eye

Juvenile neuronal ceroid lipofuscinoses, or Batten disease, is the most common type of NCL in the United States and Europe. This devastating disorder presents with vision failure and progresses to include seizures, motor dysfunction, and dementia. Death usually occurs in the third decade, but some patients die before age twenty. Though the mechanism of visual failure remains poorly understood, recent advances in molecular genetics have improved diagnostic testing and suggested possible therapeutic strategies. The ophthalmologist plays a crucial role in both early diagnosis and documentation of progression of juvenile neuronal ceroid lipofuscinoses. We update Batten disease research, particularly as it relates to the eye, and present various theories on the pathophysiology of retinal degeneration.

The negative ERG: clinical phenotypes and disease mechanisms of inner retinal dysfunction

Inner retinal dysfunction is encountered in a number of retinal disorders, either inherited or acquired, as a primary or predominant defect. Fundus examination is rarely diagnostic in these disorders, although some show characteristic features, and careful electrophysiological assessment of retinal function is needed for accurate diagnosis. The ERG in inner retinal dysfunction typically shows a negative waveform with a preserved a-wave and a selectively reduced b-wave. Advances in retinal physiology and molecular genetics have led to a greater understanding of the pathogenesis of these disorders. This review summarizes current knowledge on normal retinal physiology, the investigative techniques used and the range of clinical disorders in which there is predominantly inner retinal dysfunction.

Phenotypic characterization of a mouse model of juvenile neuronal ceroid lipofuscinosis

Juvenile neuronal ceroid lipofuscinosis (JNCL) is an autosomal recessively inherited neurodegenerative disorder that results from mutations in the CLN3 gene. JNCL is characterized by accumulation of autofluorescent lysosomal storage bodies, vision loss, seizures, progressive cognitive and motor decline, and premature death. Studies were undertaken to characterize the neuronal ceroid lipofuscinosis phenotype in a Cln3 knockout mouse model. Progressive accumulation of autofluorescent storage material was observed in brain and retina of affected mice. The Cln3(-/-) mice exhibited progressively impaired inner retinal function, altered pupillary light reflexes, losses of inner retinal neurons, and reduced brain mass. Behavioral changes included reduced spontaneous activity levels and impaired learning and memory. In addition, Cln3(-/-) mice had significantly shortened life spans. These phenotypic features indicate that the mouse model will be useful for investigating the mechanisms underlying the disease pathology in JNCL and provide quantitative markers of disease pathology that can be used for evaluating the efficacies of therapeutic interventions.

Retinitis pigmentosa, pigmentary retinopathies, and neurologic diseases

Retinitis pigmentosa (RP) refers to a group of inherited retinal diseases with phenotypic and genetic heterogeneity. The pathophysiologic basis of the progressive visual loss in patients with RP is not completely understood but is felt to be due to a primary retinal photoreceptor cell degenerative process mainly affecting the rods of the peripheral retina. In most cases RP is seen in isolation (nonsyndromic), but in some other cases it may be a part of a genetic, metabolic, or neurologic syndrome or disorder. Nyctalopia, or night blindness, is the most common symptom of RP. The classic fundus appearance of RP includes retinal pigment epithelial cell changes resulting in retinal hypo- or hyperpigmentation ("salt-and-pepper"), retinal granularity, and bone spicule formation. The retinal vessels are often narrowed or attenuated and there is a waxy pallor appearance of the optic nerve head. Electroretinography will demonstrate rod and cone photoreceptor cell dysfunction and is a helpful test in the diagnosis and monitoring of patients with RP. A detailed history with pedigree analysis, a complete ocular examination, and the appropriate paraclinical testing should be performed in patients complaining of visual difficulties at night or in dim light. This review discusses the clinical manifestations of RP as well as describing the various systemic diseases, with a special emphasis on neurologic diseases, associated with a pigmentary retinopathy.

Involvement of two different cell death pathways in retinal atrophy of cathepsin D-deficient mice

To understand the mechanisms of retinal atrophy in cathepsin D-deficient mice, the postnatal development of their retinae was analyzed. TUNEL-positive cells appeared abundantly in the outer nuclear layer (ONL) and slightly in the inner nuclear layer (INL). Nitric oxide synthase (NOS) was induced in microglial cells which invaded retinal layers and phagocytosed dead cell debris, while NOS inhibitors prevented cell death in the INL but not in the ONL. Caspases 9 and 3 were activated only in the ONL after P15. Moreover, no atrophic change was detected in the retina of mice deficient in cathepsin B or L. These results suggest that cathepsin D is essential for the metabolic maintenance of retinal photoreceptor cells and that its deficiency induces apoptosis of the cells, while the loss of INL neurons is mediated by NO from microglial cells.

Neuronal ceroid lipofuscinosis in the Polish Owczarek Nizinny (PON) dog. A retinal study

Visual dysfunction and neurological symptoms were found in Polish Owczarek Nizinny (PON) dogs. Two dogs were examined, one at 2 years of age and the other one at 4 years. The oldest dog was totally blind. The 2-year-old dog developed mental disturbances and the 4-year-old dog became severely ataxic. Ophthalmoscopical findings were retinal hyper-reflectivity, attenuation of the retinal vessels and the presence of greyish to brown spots in the fundus. Electrophysiological and ultrastructural studies were performed in the 2-year-old dog. Scotopic ERG responses were absent, whereas 30 Hz cone flicker responses were recordable, although with an amplitude reduced to about 30% of the normal level. A slow negative potential replaced the c-wave, indicating a dysfunction of the RPE. Intracellular inclusions with a granular appearance or containing membranous fingerprint-like or curvilinear profiles, resembling ceroid, were found in different retinal cells. The RPE cells in the central areas were charged with autofluorescent material having similar structure, Photoreceptor degeneration was most severe in the central areas, corresponding to the RPE changes. It appears than the PON dog may provide a new animal model for neuronal ceroid lipofuscinosis.

Olivopontocerebellar atrophy with retinal degeneration. Fundus characteristics and diagnostic MRI findings

Olivopontocerebellar atrophy with retinal degeneration (OPCA type III) and autosomal dominant cerebellar atrophy of late onset (type II) appear to represent the same disease which is characterized by dominantly inherited cerebellar ataxia and pigmentary retinal degeneration. In June, 1988, a 15-year-old girl presented with objective visual acuity loss but no other findings. When seen again in January, 1991, macular changes were noted. At this time, her mother, diagnosed with multiple sclerosis, was examined and found to have atrophic macular lesions and poor vision. A brain MRI was performed which showed findings diagnostic of OPCA type III, including cerebellar and pontine atrophy and specific loss of the inferior olives. Fundus features, electroretinographic results and other clinical findings in OPCA type III are discussed and diagnostic MRI lesions are demonstrated.

The peroxisome and the eye

Several childhood multisystem disorders with prominent ophthalmological manifestations have been ascribed to the malfunction of the peroxisome, a subcellular organelle. The peroxisomal disorders have been divided into three groups: 1) those that result from defective biogenesis of the peroxisome (Zellweger syndrome, neonatal adrenoleukodystrophy, and infantile Refsum's disease); 2) those that result from multiple enzyme deficiencies (rhizomelic chondrodysplasia punctata); and 3) those that result from a single enzyme deficiency (X-linked adrenoleukodystrophy, primary hyperoxaluria type 1). Zellweger syndrome, the most lethal of the three peroxisomal biogenesis disorders, causes infantile hypotonia, seizures, and death within the first year. Ophthalmic manifestations include corneal opacification, cataract, glaucoma, pigmentary retinopathy and optic atrophy. Neonatal adrenoleukodystrophy and infantile Refsum's disease appear to be genetically distinct, but clinically, biochemically, and pathologically similar to Zellweger syndrome, although milder. Rhizomelic chondrodysplasia punctata, a peroxisomal disorder which results from at least two peroxisomal enzyme deficiencies, presents at birth with skeletal abnormalities and patients rarely survive past one year of age. The most prominent ocular manifestation consists of bilateral cataracts. X-linked (childhood) adrenoleukodystrophy, results from a deficiency of a single peroxisomal enzyme, presents in the latter part of the first decade with behavioral, cognitive and visual deterioration. The vision loss results from demyelination of the entire visual pathway, but the outer retina is spared. Primary hyperoxaluria type 1 manifests parafoveal subretinal pigment proliferation. Classical Refsum's disease may also be a peroxisomal disorder, but definitive evidence is lacking. Early identification of these disorders, which may depend on recognizing the ophthalmological findings, is critical for prenatal diagnosis, treatment, and genetic counselling.

Autosomal-dominant fundus flavimaculatus. Clinicopathologic correlation

The authors report the first clinicopathologic study of autosomal-dominant fundus flavimaculatus with late-onset atrophic macular degeneration in a 62-year-old man. Results of histopathologic examination disclosed the retinal pigment epithelium (RPE) to be distended by a periodic acid-Schiff (PAS)-positive, acid mucopolysaccharide-negative material. Transmission electron microscopy showed marked accumulation of lipofuscin and melanolipofuscin granules within the RPE. The different modes of genetic transmission and ultrastructural heterogeneity suggest that fundus flavimaculatus is a clinical syndrome representing several genetically and mechanistically distinct disorders whose common end-stage is a topographically similar accumulation of lipofuscin.