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

Intravitreal Enzyme Replacement Therapy Slows Retinopathy in Late Infantile Ceroid Lipofuscinosis Type 2

Ceroid lipofuscinosis type 2 (CLN2) is caused by biallelic pathogenic variants in the TPP1 gene, encoding lysosomal tripeptidyl peptidase 1 (TPP1). The classical late-infantile phenotype has an age of onset between 2 and 4 years and is characterized by psychomotor regression, myoclonus, ataxia, blindness, and shortened life expectancy. Vision loss occurs due to retinal degeneration, usually when severe neurological symptoms are already evident.Intracerebroventricular enzyme replacement therapy (ICV-ERT) using recombinant human TPP1 (rhTPP-1) was shown to slow the neurological decline; however, it does not prevent loss of vision. Intravitreal rhTPP-1 (IVT-ERT) was described to halt retinal degeneration in a canine CLN2 model and a compassionate-use study in humans.We report on the clinical and ophthalmological outcome in an early-treated patient homozygous for a pathogenic variant in TPP1 known to be associated with severe CLN2 retinopathy.He was started on ICV-ERT at the age of 40 months and 4 weekly IVT-ERT in one eye at the age of 60 months. The other eye served as untreated control.Baseline best corrected visual acuity (BCVA) was 0.5 with mild bull's eye maculopathy evident in both eyes. After 24 months of IVT-ERT, BCVA in the treated eye was 0.2 with bull's eye maculopathy sparing outer retinal layers, whereas the untreated eye had progressed to endstage retinopathy and BCVA <0.02. No intraocular side effects occurred.Our results provide further evidence that IVT-ERT appears to be safe and markedly delays retinal degeneration preserving visual function and increasing the patient's quality of life, especially if started early.

A Rare Case Report of Neurodegenerative Disease With Oro-Dental Trauma

Batten disease, also known as Spielmeyer-Vogt-Sjögren-Batten disease, is a rare and deadly autosomal recessive neurodegenerative disease. It is the most prevalent type among a group of diseases known as neuronal ceroid lipofuscinoses (NCLs).  The patient, a 31-year-old woman, presented to the Oral Medicine and Radiology Department with the primary complaint of knocking out her upper front teeth after she had suffered a seizure and fell out of bed onto the floor. She has Batten disease, according to her medical history (NCL2). The diagnosis and treatment of an oro-dental issue are presented in this instance. As an oral physician, understanding Batten disease is crucial because it requires a multidisciplinary approach to manage the oral health issues associated with it. Early intervention and continuous support are essential to maintaining the well-being of affected individuals.

Enzyme Replacement Therapy in CLN2-Associated Retinopathy

Neuronal ceroid lipofuscinoses, also known as Batten disease, are comprised of a group of genetically heterogenous neurodegenerative conditions, characterized by dementia, epilepsy, motor deterioration, and blindness. The underlying pathology is a dysregulation of lysosomal catabolic protein metabolism, resulting in an accumulation of lipofuscein-like material within the lysosomes in neuronal tissue, which ultimately leads to atrophy in the central nervous system and in the retina. Ceroid lipofuscinosis type 2 (CLN2) is caused by biallelic pathogenic variants in the TPP1 gene, encoding lysosomal tripeptidyl peptidase 1 (TPP-1). The classic late-infantile phenotype of CLN2 disease has an age of onset between 2 and 4 years and manifests with seizures and speech delay, followed by progressive cognitive and motor decline, vision loss, and early death. Vision loss occurs secondary to retinal degeneration and begins in the perifoveal ellipsoid zone, leading to bull's eye maculopathy, followed by generalized retinal thinning. In 2017, an intracerebroventricular enzyme replacement therapy (ERT) using recombinant human TPP1 (rhTPP1), cerliponase alfa, was approved as a disease-modifying treatment for CLN2 disease. The therapy slows psychomotor decline but fails to prevent loss of vision. In a canine model of CLN2 disease, intravitreal rhTPP1 was shown to halt retinal degeneration. A prospective, interventional, controlled, open-label compassionate-use study evidenced safety of 0.2 mg intravitreal rhTPP1 every 8 weeks in humans and its efficacy in reducing the rate of macular volume loss in patients who were still in the degenerative phase. One ongoing clinical phase I/II study is investigating the safety and efficacy of intravitreal rhTPP1 at 4 weekly intervals over 24 months (NCT05152914); another clinical phase II dose escalation trial is planned. In this review, we summarize the current knowledge on ERT for CLN2 retinopathy, complemented with our own experience from an individual treatment. The treatment now appears to be safe and markedly delays retinal degeneration, thereby preserving visual function and increasing the quality of life of the patient. This could be particularly relevant for those patients who were started on intracerebroventricular ERT early and still have good motor and language function. For this patient population, intravitreal ERT could be a valuable bridging therapy until other therapies such as gene therapy become available.

The use of nanocarriers in treating Batten disease: A systematic review

The neuronal ceroid lipofuscinoses, commonly known as Batten disease, are a group of lysosomal storage disorders affecting children. There is extensive central nervous system and retinal degeneration, resulting in seizures, vision loss and a progressive cognitive and motor decline. Enzyme replacement and gene therapies are being developed, and mRNA and oligonucleotide therapies are more recently being considered. Overcoming the challenges of the blood-brain barrier and blood-ocular barrier is crucial for effectively targeting the brain and eye, whatever the therapeutic approach. Nanoparticles and extracellular vesicles are small carriers that can encapsulate a cargo and pass through these cell barriers. They have been investigated as drug carriers for other pathologies and could be a promising treatment strategy for Batten disease. Their use in gene, enzyme, or mRNA replacement therapy of all lysosomal storage disorders, including Mucopolysaccharidoses, Niemann-Pick diseases, and Fabry disease, is investigated in this systematic review. Different nanocarriers can efficiently target the lysosome and cross the barriers into the brain and eyes. This supports continued exploration of nanocarriers as potential future treatment options for Batten disease.

Syndromic Retinitis Pigmentosa: A Narrative Review

Retinitis pigmentosa (RP) encompasses inherited retinal dystrophies, appearing either as an isolated eye condition or as part of a broader systemic syndrome, known as syndromic RP. In these cases, RP includes systemic symptoms impacting other organs, complicating diagnosis and management. This review highlights key systemic syndromes linked with RP, such as Usher, Bardet-Biedl, and Alström syndromes, focusing on genetic mutations, inheritance, and clinical symptoms. These insights support clinicians in recognizing syndromic RP early. Ocular signs like nystagmus and congenital cataracts may indicate systemic disease, prompting genetic testing. Conversely, systemic symptoms may necessitate eye exams, even if vision symptoms are absent. Understanding the systemic aspects of these syndromes emphasizes the need for multidisciplinary collaboration among ophthalmologists, pediatricians, and other specialists to optimize patient care. The review also addresses emerging genetic therapies aimed at both visual and systemic symptoms, though more extensive studies are required to confirm their effectiveness. Overall, by detailing the genetic and clinical profiles of syndromic RP, this review seeks to aid healthcare professionals in diagnosing and managing these complex conditions more effectively, enhancing patient outcomes through timely, specialized intervention.

Peripapillary Retinal Nerve Fiber Layer (pRNFL) Thickness - A Novel Biomarker of Neurodegeneration in Late-Infantile CLN2 Disease

Purpose

To investigate the presence of peripapillary retinal nerve fiber layer (pRNFL) degeneration in patients with late-infantile neuronal ceroid lipofuscinosis type 2 (CLN2) disease and to evaluate the role of optical coherence tomography (OCT) assessed pRNFL thickness as a biomarker for CLN2 disease progression.

Patients and Methods

Forty eyes of 20 patients with genetically and enzymatically confirmed diagnosis of late-infantile CLN2 disease were included in this retrospective cohort study. All patients received 300 mg of intracerebroventricular enzyme replacement treatment (cerliponase alfa) once every two weeks. OCT imaging was performed under general anesthesia using spectral domain OCT (Heidelberg Engineering, Heidelberg, Germany). PRNFL thickness and central retinal thickness (CRT) values were manually confirmed with the Heidelberg Eye Explorer software. Corresponding pediatric data were extracted from the DEM-CHILD database. Spearman correlation coefficient values (rs) were calculated between pRNFL and CRT values, age at examination, the Weill Cornell Late Infantile Neuronal Ceroid Lipofuscinosis (Weill Cornell LINCL) Scale and the Hamburg Motor and Language (HML) Scale.

Results

Fourteen of 20 patients underwent serial examinations resulting in a total of 84 OCT Scans and 42 Weill Cornell LINCL and HML Scale scores. Mean age was 6.90 years and mean follow-up time was 1.38 years. Mean global pRNFL (G-pRNFL) thickness was 77.02 μm presenting a significant decrease compared to normative values from healthy children (106.45 μm; p < 0.0001). G-pRNFL displayed significant correlations towards age at examination (rs = - 0.557, p < 0.01), the Weill Cornell LINCL Scale (rs = 0.849, p < 0.01), and the HML Scale (rs = 0.833, p < 0.01). Repeated measurements indicated decreases in pRNFL thickness over time in most patients.

Conclusion

Patients with late-infantile CLN2 disease exhibit early onset progressive pRNFL loss regardless of outer retinal degeneration, highlighting the potential of pRNFL as an independent ocular biomarker for retinal pathology in late-infantile CLN2 disease.

OCT Biomarkers in Ocular CLN2 Disease in Patients Treated With Intraventricular Enzyme Replacement Therapy

Purpose

Bilateral progressive, symmetrical loss of central retinal thickness (CRT) has been described in neuronal ceroid lipofuscinosis type 2 (CLN2) disease. This study details the pattern of morphological changes underlying CRT loss and disease progression in patients receiving intracerebroventricular (ICV) enzyme replacement therapy (ERT) with cerliponase alfa.

Methods

Spectral-domain optical coherence tomography macular cube scans were collected from 16 patients with classic CLN2 disease receiving ICV ERT. Detailed retinal structure analyses were performed on manually segmented horizontal B-scans through the fovea to determine the thickness of six retinal parameters and the extent of ellipsoid zone (EZ) loss.

Results

Anatomical changes primarily occurred in photoreceptor (PR)-related retinal parameters and correlated with ocular disease severity. Retinal degeneration began with initial focal parafoveal EZ discontinuities signaling the onset of rapid PR degeneration in a predictable pattern: parafoveal PR involvement with foveal sparing followed by profound parafoveal and foveal PR loss with additional thinning beyond the central retina. PR degeneration began with outer segment loss and progressed to outer nuclear layer (ONL) involvement. Longitudinal analyses confirmed these observations. The rate of PR loss was fastest at the fovea at ∼58 mm per year and became slower at locations farther away from the fovea.

Conclusions

Retinal degeneration in CLN2 disease is primarily associated with PR loss in a predictable pattern, with EZ disruption signaling early PR stress. CRT, ONL thickness, and PR layer thickness are useful anatomical biomarkers for understanding disease progression and treatment efficacy in CLN2. Studies using en face images will further clarify CLN2-related retinal degeneration.

Intravitreal enzyme replacement for inherited retinal diseases

PURPOSE OF REVIEW

This paper provides an update on intravitreal (IVT) enzyme replacement therapy (ERT) in metabolic retinal diseases; particularly neuronal ceroid lipofuscinosis type 2 (CLN2) also known as Batten disease.

RECENT FINDINGS

ERT is being explored in CLN2 related Batten disease, a fatal neurodegenerative condition associated with retinopathy and blindness that is caused by the deficiency of lysosomal enzyme TPP1. Cerliponase alfa, a recombinant human tripeptidyl-peptidase1 (rhTPP1) administered by intraventricular infusions has been demonstrated to slow the rate of neurodegenerative decline but not retinopathy. A preclinical study of IVT rhTPP1 in a CLN2 canine model demonstrated efficacy in preserving retinal function and retinal morphology shown on histology. More recently, intravitreal (IVT) administration of rhTPP1 was reported in a first-in-human compassionate use study. Patients received 12-18 months of 8-weekly IVT ERT (0.2 mg rhTPP-1 in 0.05 ml) in one eye. No significant ocular adverse reactions were reported. Treatment decreased the rate of retinal thinning but modestly.

SUMMARY

The evidence suggests that IVT ERT with rhTPP1 may be a safe and effective treatment for CLN2 retinopathy. However, the optimal dosage and frequency to achieve the best possible outcomes requires further investigation as does patient selection.

Peripheral retinal finding on fluorescein angiography in neuronal ceroid lipofuscinosis type 2 (CLN2)

Classically, peripheral vascular changes in the retina in patients with neuronal ceroid lipofuscinosis type 2 (CLN2) are described as vascular attenuation seen in the late stages of disease on the Weill Connell Ophthalmic Severity Score (WCOSS) staging system. We describe isolated, mild, peripheral vasculitis with peripheral arteriolar dropout identified by fluorescein angiography in patients with a WCOSS grade of stage 2. We believe this vasculitis represents an early vasodegenerative phase of disease that leads to the vascular attenuation seen in later stages of the disease.

Optical coherence tomography in children with inherited retinal disease

Recent advances have led to therapeutic options becoming available for people with inherited retinal disease. In particular, gene therapy has been shown to hold great promise for slowing vision loss from inherited retinal disease. Recent studies suggest that gene therapy is likely to be most effective when implemented early in the disease process, making consideration of paediatric populations important. It is therefore necessary to have a comprehensive understanding of retinal imaging in children with inherited retinal diseases, in order to monitor disease progression and to determine which early retinal biomarkers may be used as outcome measures in future clinical trials. In addition, as many optometrists will review children with an inherited retinal disease, an understanding of the expected imaging outcomes can improve clinical care. This review focuses on the most common imaging modality used in research assessment of paediatric inherited retinal diseases: optical coherence tomography. Optical coherence tomography findings can be used in both the clinical and research setting. In particular, the review discusses current knowledge of optical coherence tomography findings in eight paediatric inherited retinal diseases - Stargardt disease, Bests disease, Leber's congenital amaurosis, choroideremia, RPGR related retinitis pigmentosa, Usher syndrome, X-linked retinoschisis and, Batten disease.

First in man study of intravitreal tripeptidyl peptidase 1 for CLN2 retinopathy

BACKGROUND/OBJECTIVES

CLN2 Batten Disease is a fatal neurodegenerative condition of childhood associated with retinal dystrophy and blindness. Intracerebroventricular infusion of rhTPP1 greatly slows the rate of neurodegenerative decline but not retinopathy. Intravitreal rhTPP1 is known to slow retinal degeneration in a canine model of CLN2. We report a first-in-man controlled clinical trial of intravitreal rhTPP1 for CLN2 associated retinal dystrophy.

SUBJECTS/METHODS

8 children aged 5-9 with CLN2 Batten Disease were prospectively enroled. Severely affected patients were preferentially selected, provided that vision was better than no perception of light. Children underwent 8 weekly intravitreal injections of rhTPP1 (0.2 mg in 0.05 ml) into the right eye for 12-18 months. The left eye was untreated and acts as a paired control. The primary outcome was safety based on the clinical detection of complications. A secondary outcome was paracentral macular volume (PMV) measured by spectral domain OCT. Linear regression/paired t tests were used to compare rates of decline.

RESULTS

No severe adverse reactions (uveitis, raised IOP, media opacity) occurred. The mean baseline PMV was 1.28 mm3(right), 1.27 mm3(left). 3 of the youngest patients exhibited bilateral progressive retinal thinning (p < 0.05), whereas retinal volume was stable in the remaining 5 patients. In the 3 patients undergoing retinal degeneration, the rate of PMV loss was slower in the treated vs. untreated eye (p = 0.000042, p = 0.0011, p = 0.00022).

CONCLUSIONS

Intravitreal rhTPP1 appears to be a safe and effective treatment for CLN2 related retinopathy however commencement of treatment early in the course of disease is more likely to be efficacious.

Ongoing retinal degeneration despite intraventricular enzyme replacement therapy with cerliponase alfa in late-infantile neuronal ceroid lipofuscinosis type 2 (CLN2 disease)

BACKGROUND/AIMS

Late-infantile neuronal ceroid lipofuscinosis type 2 (CLN2) is a neurodegenerative, blinding lysosomal storage disorder. The purpose of the current study was to characterise the progression of CLN2-associated retinal degeneration in patients under intraventricular enzyme replacement therapy (ERT) with cerliponase alfa.

METHODS

We analysed visual function, retinal morphology and neuropaediatric data using preferential looking test (PLT), Weill Cornell Batten Scale (WCBS), optical coherence tomography (OCT) imaging and the Hamburg Motor-Language late-infantile neuronal ceroid lipofuscinosis (LINCL) Scale (M-L scale).

RESULTS

Fifty-six eyes of 28 patients had baseline PLT, WCBS and OCT. 15 patients underwent serial examinations, resulting in a total of 132 OCT scans and WCBS results, 66 Hamburg M-L scores and 49 PLT results during a mean follow-up time of 18.2 months (range 5-40). A negative correlation (r=-0.69, p<0.001) was found between central retinal thickness (CRT) values and age at examination with a maximal annual decrease of 23 µm between 56 and 80 months of age. A significant correlation was observed between PLT results and the age at examination (r=0.46, p=0.001), the WCBS scores (r=0.62; p<0.001) and CRT values (r=-0.64; p<0.001). The M-L score correlated with the ocular measurements (CRT: r=0.58, p<0.001; WCBS r=-0.64, p<0.001; PLT score: r=-0.57, p<0.001).

CONCLUSION

Despite intraventricular ERT, retinal degeneration progressed in patients with CLN2 and was particularly pronounced between 56 and 80 months of age. Retina-directed therapies should therefore be initiated before or as early as possible during the phase of rapid retinal degeneration. PLT and WCBS were identified as valuable outcome measures to monitor disease progression.

TRIAL REGISTRATION NUMBER

NCT04613089.

Clinical management and diagnosis of CLN2 disease: consensus of the Brazilian experts group

Neuronal ceroid lipofuscinosis type 2 (CLN2) is a rare neurodegenerative genetic disease that affects children in early life. Its classic form is rapidly progressive, leading to death within the first 10 years. The urge for earlier diagnosis increases with the availability of enzyme replacement therapy. A panel of nine Brazilian child neurologists combined their expertise in CLN2 with evidence from the medical literature to establish a consensus to manage this disease in Brazil. They voted 92 questions including diagnosis, clinical manifestations, and treatment of the disease, considering the access to healthcare in this country. Clinicians should suspect CLN2 disease in any child, from 2 to 4 years old, with language delay and epilepsy. Even though the classic form is the most prevalent, atypical cases with different phenotypes can be found. Electroencephalogram, magnetic resonance imaging, molecular and biochemical testing are the main tools to investigate and confirm the diagnosis. However, we have limited access to molecular testing in Brazil, and rely on the support from the pharmaceutical industry. The management of CLN2 should involve a multidisciplinary team and focus on the quality of life of patients and on family support. Enzyme replacement therapy with Cerliponase α is an innovative treatment approved in Brazil since 2018; it delays functional decline and provides quality of life. Given the difficulties for the diagnosis and treatment of rare diseases in our public health system, the early diagnosis of CLN2 needs improvement as enzyme replacement therapy is available and modifies the prognosis of patients.

Visual perception and macular integrity in non-classical CLN2 disease

PURPOSE

Patients with CLN2 suffer from epileptic seizures, rapid psychomotor decline and vision loss in early childhood. The aim of the study was to provide longitudinal ophthalmic data of patients with confirmed genetic mutation and non-classical disease course, marked by later onset, protracted progression and prolonged life span.

METHODS

Prospective, observational study to assess visual acuity, retinal features (Weil Cornell Ophthalmic Score), central retinal thickness (CRT) measured by optical coherence tomography and general disease progression (Hamburg CLN2 motor language score) in non-classical CLN2 patients.

RESULTS

All patients received intracerebroventricular enzyme replacement therapy with cerliponase alfa. Mean age at last follow-up was 12.4 years; mean follow-up time 2.6 years. All cases demonstrated a stable Hamburg motor language CLN2 Score and Weill Cornell LINCL Ophthalmic Severity Score. Visual function remained stable in 4/6 patients, 2/6 patients showed a decrease, 4/6 cases had a stable CRT and 2/6 showed a reduction of CRT. One patient showed a massive macular thinning and low vision. A correlation with a specific mutation or age could not be verified.

DISCUSSION

The presented longitudinal study characterizes the variable ocular involvement in non-classical CLN2 disease and contributes to the natural history description. The functional and morphologic data outline the necessity of regular ophthalmic examination. Ocular phenotyping and description of retinal degeneration in non-classical CLN2 disease.

Contribution of Whole-Genome Sequencing and Transcript Analysis to Decipher Retinal Diseases Associated with MFSD8 Variants

Biallelic gene defects in MFSD8 are not only a cause of the late-infantile form of neuronal ceroid lipofuscinosis, but also of rare isolated retinal degeneration. We report clinical and genetic data of seven patients compound heterozygous or homozygous for variants in MFSD8, issued from a French cohort with inherited retinal degeneration, and two additional patients retrieved from a Swiss cohort. Next-generation sequencing of large panels combined with whole-genome sequencing allowed for the identification of twelve variants from which seven were novel. Among them were one deep intronic variant c.998+1669A>G, one large deletion encompassing exon 9 and 10, and a silent change c.750A>G. Transcript analysis performed on patients’ lymphoblastoid cell lines revealed the creation of a donor splice site by c.998+1669A>G, resulting in a 140 bp pseudoexon insertion in intron 10. Variant c.750A>G produced exon 8 skipping. In silico and in cellulo studies of these variants allowed us to assign the pathogenic effect, and showed that the combination of at least one severe variant with a moderate one leads to isolated retinal dystrophy, whereas the combination in trans of two severe variants is responsible for early onset severe retinal dystrophy in the context of late-infantile neuronal ceroid lipofuscinosis.

Natural History Studies in NCL and Their Expanding Role in Drug Development: Experiences From CLN2 Disease and Relevance for Clinical Trials

Conducting clinical trials in rare diseases is challenging. In trials that aim to use natural history control cohorts for evaluation of efficacy, lack of data on natural history of disease prolongs development of future therapies significantly. Therefore, collection of valid natural history data in clinical settings is needed to advance drug development. These data need to fulfill requirements on type of collection, quantifiable measures on the course of disease, verification and monitoring as well as compliance to strict data protection and sharing policies. Disease registries can be a source for patient data. Late-infantile CLN2 disease is characterized by rapid psychomotor decline and epilepsy. Natural-history data of 140 genotype-confirmed CLN2 patients from two independent, international cohorts were analyzed in a natural history study. Both datasets included quantitative ratings with disease-specific clinical scores. Among 41 patients for whom longitudinal assessments spanning an extended disease course were available within the DEM-CHILD DB (an international NCL disease patient database, NCT04613089), a rapid loss of motor and language abilities was documented in quantitative detail. Data showed that the course of disease in late-infantile CLN2 disease is highly predictable with regard to the loss of language and motor function and that the results were homogeneous across multiple and international sites. These data were accepted by EMA and FDA as valid natural-history controls for the evaluation of efficacy in experimental therapies for CLN2 disease and led to an expedited approval of intracerebroventricular enzyme replacement therapy with cerliponase alpha in May 2017.

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.

Automated Retinal Layer Segmentation in CLN2-Associated Disease: Commercially Available Software Characterizing a Progressive Maculopathy

Purpose

CLN2-associated disease is a hereditary, fatal lysosomal storage disorder characterized by progressive brain and retinal deterioration. Here, we characterize the inner and outer retinal degeneration using automated segmentation software in optical coherence tomography scans, providing an objective, quantifiable metric for monitoring subtle changes previously identified with a validated disease classification scale (the Weill Cornell Batten Scale).

Methods

This study is a retrospective, single-center cohort review of images from examinations under anesthesia in treatment-naïve patients with CLN2-associated disease. Automated segmentation software was used to delineate retinal nerve fiber, ganglion cell layer (GCL), and outer nuclear layer (ONL) thickness measurements in the fovea, parafovea, and perifovea based on age groups (months): 30 to 38, 39 to 45, 46 to 52, 53 to 59, 60 to 66, and 67 or older.

Results

Twenty-seven eyes from 14 patients were included, with 8 serial images yielding 36 interpretable optical coherence tomography scans. There was a significant difference in parafoveal ONL thickness between 39 to 45 and 46 to 52 months of age (P = 0.032) not seen in other regions or retinal layers. Perifoveal ONL demonstrated a difference in thickness between the 60 to 66 and greater than 67 months age cohorts (P = 0.047). There was strong symmetry between eyes, and high segmentation repeatability.

Conclusions

Parafoveal ONL thickness represents a sensitive, early age indicator of CLN2-associated degeneration. Outer retinal degeneration is apparent at younger ages than inner retinal changes though in treatment-naïve patients all retinal layers showed significant differences between 60 to 66 and more than 67 months of age.

Translational Relevance

This study establishes sensitive, quantitative biomarkers for assessing retinal degeneration in a large cohort natural history study in anticipation of future clinical trials.

Slowing late infantile Batten disease by direct brain parenchymal administration of a rh.10 adeno-associated virus expressing CLN2

Late infantile Batten disease (CLN2 disease) is an autosomal recessive, neurodegenerative lysosomal storage disease caused by mutations in the CLN2 gene encoding tripeptidyl peptidase 1 (TPP1). We tested intraparenchymal delivery of AAVrh.10hCLN2, a nonhuman serotype rh.10 adeno-associated virus vector encoding human CLN2, in a nonrandomized trial consisting of two arms assessed over 18 months: AAVrh.10hCLN2-treated cohort of 8 children with mild to moderate disease and an untreated, Weill Cornell natural history cohort consisting of 12 children. The treated cohort was also compared to an untreated European natural history cohort of CLN2 disease. The vector was administered through six burr holes directly to 12 sites in the brain without immunosuppression. In an additional safety assessment under a separate protocol, five children with severe CLN2 disease were treated with AAVrh.10hCLN2. The therapy was associated with a variety of expected adverse events, none causing long-term disability. Induction of systemic anti-AAVrh.10 immunity was mild. After therapy, the treated cohort had a 1.3- to 2.6-fold increase in cerebral spinal fluid TPP1. There was a slower loss of gray matter volume in four of seven children by MRI and a 42.4 and 47.5% reduction in the rate of decline of motor and language function, compared to Weill Cornell natural history cohort (P < 0.04) and European natural history cohort (P < 0.0001), respectively. Intraparenchymal brain administration of AAVrh.10hCLN2 slowed the progression of disease in children with CLN2 disease. However, improvements in vector design and delivery strategies will be necessary to halt disease progression using gene therapy.

Ocular Manifestations of Neuronal Ceroid Lipofuscinoses

Neuronal ceroid lipofuscinoses (NCLs) are a group of rare neurodegenerative storage disorders associated with devastating visual prognosis, with an incidence of 1/1,000,000 in the United States and comparatively higher incidence in European countries. The pathophysiological mechanisms causing NCLs occur due to enzymatic or transmembrane defects in various sub-cellular organelles including lysosomes, endoplasmic reticulum, and cytoplasmic vesicles. NCLs are categorized into different types depending upon the underlying cause i.e., soluble lysosomal enzyme deficiencies or non-enzymatic deficiencies (functions of identified proteins), which are sub-divided based on an axial classification system. In this review, we have evaluated the current evidence in the literature and reported the incidence rates, underlying mechanisms and currently available management protocols for these rare set of neuroophthalmological disorders. Additionally, we also highlighted the potential therapies under development that can expand the treatment of these rare disorders beyond symptomatic relief.

Presymptomatic treatment of classic late-infantile neuronal ceroid lipofuscinosis with cerliponase alfa

Background

Neuronal ceroid lipofuscinosis type 2 (CLN2 disease) is a rare rapidly progressive neurodegenerative disorder, resulting in early death. Intracerebroventricular enzyme replacement therapy (ERT) with cerliponase alfa is now available and has shown to delay disease progression in symptomatic patients. It is yet unknown if cerliponase alfa can prevent disease onset in presymptomatic patients.

Results

We evaluated the effect of 2 years of intracerebroventricular ERT in two siblings with CLN2 disease, one symptomatic (age 47 months) and one presymptomatic (age 23 months) at treatment start, using the CLN2 Clinical Rating Scale (CLN2 CRS), Gross Motor Function Measure-66 (GMFM-66) for motor function, Bayley Scales of Infant and Toddler Development, 3rd Edition, Dutch (BSID-III-NL) for neurocognitive development, brain MRI, and visual evoked potentials (VEP), electroretinogram (ERG) and retinoscopy for visual function. On the CLN2 CRS patient 1 showed a decline from 3 to 2 in the combined motor and language score due to regression in language use (CLN2 CRS total score after 2 years of treatment: 8), whereas a decline of 2 or more points in the combined motor and language score would be expected without treatment. Patient 2 retained the maximum score of 3 in all 4 subdomains (CLN2 CRS total score after 2 years of treatment: 12). The GMFM-66 total score declined from 46 to 39 in patient 1 and showed an age-appropriate increase from 66 to 84 in patient 2. Cognitive-developmental age decreased from 24 to 11 months in patient 1, whereas an increase in cognitive-developmental age from 21 to 39 months was seen in patient 2. Cerebral and cerebellar atrophy observed on MRI in patient 1 at age 42 months (before treatment) was not observed in patient 2 at age 48 months (after 2 years of treatment).

Conclusion

We show that cerliponase alfa is able to delay the onset of symptoms when treatment is started in a presymptomatic stage of CLN2 disease. Our results advocate the start of treatment at an early age before symptom onset, but should be confirmed in a larger cohort study.

Guidelines on the diagnosis, clinical assessments, treatment and management for CLN2 disease patients

Background

CLN2 disease (Neuronal Ceroid Lipofuscinosis Type 2) is an ultra-rare, neurodegenerative lysosomal storage disease, caused by an enzyme deficiency of tripeptidyl peptidase 1 (TPP1). Lack of disease awareness and the non-specificity of presenting symptoms often leads to delayed diagnosis. These guidelines provide robust evidence-based, expert-agreed recommendations on the risks/benefits of disease-modifying treatments and the medical interventions used to manage this condition.

Methods

An expert mapping tool process was developed ranking multidisciplinary professionals, with knowledge of CLN2 disease, diagnostic or management experience of CLN2 disease, or family support professionals. Individuals were sequentially approached to identify two chairs, ensuring that the process was transparent and unbiased. A systematic literature review of published evidence using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidance was independently and simultaneously conducted to develop key statements based upon the strength of the publications. Clinical care statements formed the basis of an international modified Delphi consensus determination process using the virtual meeting (Within3) online platform which requested experts to agree or disagree with any changes. Statements reaching the consensus mark became the guiding statements within this manuscript, which were subsequently assessed against the Appraisal of Guidelines for Research and Evaluation (AGREEII) criteria.

Results

Twenty-one international experts from 7 different specialities, including a patient advocate, were identified. Fifty-three guideline statements were developed covering 13 domains: General Description and Statements, Diagnostics, Clinical Recommendations and Management, Assessments, Interventions and Treatment, Additional Care Considerations, Social Care Considerations, Pain Management, Epilepsy / Seizures, Nutritional Care Interventions, Respiratory Health, Sleep and Rest, and End of Life Care. Consensus was reached after a single round of voting, with one exception which was revised, and agreed by 100% of the SC and achieved 80% consensus in the second voting round. The overall AGREE II assessment score obtained for the development of the guidelines was 5.7 (where 1 represents the lowest quality, and 7 represents the highest quality).

Conclusion

This program provides robust evidence- and consensus-driven guidelines that can be used by all healthcare professionals involved in the management of patients with CLN2 disease and other neurodegenerative disorders. This addresses the clinical need to complement other information available.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-01813-5.

Managing CLN2 disease: a treatable neurodegenerative condition among other treatable early childhood epilepsies

INTRODUCTION

Neuronal ceroid lipofuscinosis type 2 (CLN2 disease) is a rare pediatric neurodegenerative condition, which is usually fatal by mid-adolescence. Seizures are one of the most common early symptoms of CLN2 disease, but patients often experience language deficits, movement disorders, and behavioral problems. Diagnosis of CLN2 disease is challenging (particularly when differentiating between early-onset developmental, metabolic, or epileptic syndromes), and diagnostic delays often overlap with rapid disease progression. An enzyme replacement therapy (cerliponase alfa) is now available, adding CLN2 disease to the list of potentially treatable disorders requiring a prompt diagnosis.

AREAS COVERED

Although advances in enzymatic activity testing and genetic testing have facilitated diagnoses of CLN2 disease, our review highlights the presenting symptoms that are vital in directing clinicians to perform appropriate tests or seek expert opinion. We also describe common diagnostic challenges and some potential misdiagnoses that may occur during differential diagnosis.

EXPERT OPINION

An awareness of CLN2 disease as a potentially treatable disorder and increased understanding of the key presenting symptoms can support selection of appropriate tests and prompt diagnosis. The available enzyme replacement therapy heralds an even greater imperative for early diagnosis, and for clinicians to direct patients to appropriate diagnostic pathways.

[Ophthalmological manifestations of neuronal ceroid lipofuscinoses (NCL) : NCL as diseases of brain and retina-the role of ophthalmologists]

BACKGROUND

Neuronal ceroid lipofuscinoses are hereditary lysosomal storage diseases, which lead to a progressive neurodegeneration of the brain and retina. Visual loss can be the initial symptom but can also occur later in the course of the disease.

OBJECTIVE

The aim of this article is to provide ophthalmologists with an overview of the characteristic ocular alterations and the general disease course of the 13 currently known various forms of NCL.

MATERIAL AND METHODS

The findings from predominantly clinical articles are reviewed and summarized.

RESULTS AND CONCLUSION

Retinal degeneration plays a crucial role in this group of neurodegenerative diseases. In several forms visual decline is the initial clinical symptom in affected patients. Therefore, the ophthalmologist is the first medical expert consulted. An early diagnosis is crucial for the future personal and family planning but is also important regarding upcoming therapeutic strategies, which might be much more effective in patients with early stage disease. When the presence of retinal degeneration due to an NCL disease is suspected an immediate genetic diagnostic confirmation and collaboration with neuropediatricians is recommended.

"Real world effectiveness of cerliponase alfa in classical and atypical patients. A case series"

Introduction

Late infantile neuronal ceroid lipofuscinosis is an autosomal recessive disease caused by mutations in the CLN2/TPP1 gene, with secondary enzyme deficiency. In classical phenotypes, initial symptoms include seizures and delayed language development between 2 and 4 years of age. This article describes the presentation of CLN2 disease in a cohort of Colombian patients, as well as the impact of treatment on the course and progression of the disease.

Methods

Case series report of 8 patients with a confirmed diagnosis of neuronal ceroid lipofuscinosis treated with cerliponase alfa who remained on clinical and paraclinical follow-up for up to 24 months before and after treatment.

Results

An atypical phenotype, associated with initial symptoms and late diagnosis, was present in 5/8 patients. The most frequent symptoms were seizures and developmental delay, with age of onset at 24 months (classical phenotype) and 48 months (atypical phenotype). A novel mutation (c.1438G > A) was found in two siblings. All of the patients received cerliponase alfa, and there were no serious adverse events. No decline in the clinical status greater than 2 points on Hamburg, Weill Cornell and CNL2 clinical assessment scale was observed during follow-up after treatment initiation.

Conclusion

This is the first case series reported for neuronal ceroid lipofuscinosis patients in Colombia. In contrast with other reports, the majority of cases reported here displayed an atypical phenotype. Our study highlights the importance of early diagnosis and timely initiation of therapy, which is a feasible therapy, well tolerated by patients and accepted by caregivers in this country, generating a positive impact in the quality of life of CLN2 patients and on disease outcome.

Neuronal ceroid lipofuscinosis type 2: an Australian case series

AIM

Late infantile neuronal ceroid lipofuscinosis type 2 (CLN2) disease is a rare neurodegenerative disorder presenting in children aged 2-4 years with seizures and loss of motor and language skills, followed by blindness and death in late childhood. Initial presenting features are similar to a range of common epilepsies. We aim to highlight typical clinical and radiological features that may prompt diagnosis of CLN2 disease in early disease stages.

METHODS

We present a series of 13 Australian patients with CLN2 disease, describing clinical features, disease evolution, neuroimaging, electroencephalogram, biochemical and genetic results. Expert neuroradiological magnetic resonance imaging (MRI) analysis was retrospectively performed on 10 cases.

RESULTS

Twelve patients presented with seizures, with initial seizures being focal (n = 4), generalised tonic-clonic (n = 3), absence (n = 3) and febrile (n = 2). Eleven patients (85%) had a language delay before the onset of seizures. Cerebellar or cerebral atrophy was noted in all patients on centralised MRI review, with abnormalities of the brain-stem, ventricles, corpus callosum and hippocampi.

CONCLUSIONS

Early language delay with the onset of seizures at 2-4 years of age is the hallmark of CLN2 disease. MRI findings of early subtle atrophy in the cerebellum or posterior cortical regions should hasten testing for CLN2 disease to enable early initiation of enzyme replacement therapy.

Changing Times for CLN2 Disease: The Era of Enzyme Replacement Therapy

Neuronal ceroid lipofuscinosis type 2 (CLN2 disease) is a progressive neurodegenerative disease that results in early-onset, severe, progressive, neurological disabilities, leading to death in late childhood or early adolescence. Management has relied on symptomatic care, and supportive and palliative strategies, but the approval of the enzyme replacement therapy cerliponase alfa in the USA and Europe in 2017 brought different treatment opportunities. We describe the natural history of CLN2 disease, its diagnosis and management, and the preclinical and clinical development of cerliponase alfa. A PubMed search was undertaken for cerliponase alfa and rhTPP1 to identify preclinical and clinical studies. The hallmark-presenting symptoms of CLN2 disease are unprovoked seizures and a history of language delay, and progression involves motor dysfunction, and cognitive and visual decline. Cerliponase alfa has shown efficacy and tolerability in mouse and canine models of CLN2 disease when delivered intracerebroventricularly. Administration of cerliponase alfa in patients with CLN2 disease has led to significant reductions in the rate of decline of motor and language functions in comparison with a natural history population. The approval of cerliponase alfa has brought a new era for CLN2 disease, highlighting the need to understand different patterns of disease progression and clinical needs in treated patients.

Symmetric Age Association of Retinal Degeneration in Patients with CLN2-Associated Batten Disease

PURPOSE

Mutations in the CLN2 gene lead to a neurodegenerative and blinding lysosomal storage disorder: late infantile neuronal ceroid lipofucinosis, also known as "CLN2 disease." The purpose of the current study was to characterize the evolution of CLN2-associated retinal manifestations using the Weill Cornell Batten Scale (WCBS) and the age association of the retinal degeneration using central subfield thickness (CST) measurements and then correlate these findings with fundus photography and OCT to determine a critical period for retinal intervention.

DESIGN

Retrospective, single-center cohort.

PARTICIPANTS

Eighty-four eyes of 42 treatment-naïve patients with CLN2 disease.

METHODS

Clinical records, fundus photographs, and OCT imaging for patients with CLN2 disease collected during examinations under anesthesia were reviewed. Imaging was categorized per WCBS criteria by 3 masked graders.

MAIN OUTCOME MEASURES

CLN2-associated retinopathy assessed using WCBS scores, fundus photographs, and OCT imaging, correlated with patient age.

RESULTS

Eighty-four eyes of 42 patients had baseline fundus photographs, with baseline OCT in 31 eyes of 16 patients. Fundus photographs were obtained serially for 26 eyes of 13 patients, and serial OCT scans were obtained in 10 eyes of 5 patients. At baseline, bilateral WCBS scores were highly correlated for OCT and fundus photographs (r = 0.96 and 0.82, respectively). Central subfield thickness was negatively correlated with left and right eye WCBS OCT scores (r = -0.92 and -0.83, respectively; P < 0.001) and fundus photograph scores (r = -0.80 and -0.83, respectively; P < 0.001). OCT thickness was symmetrical between each eye. Baseline OCT data with age fit using a sigmoid function demonstrated a period of accelerated loss between 48 and 72 months of age.

CONCLUSIONS

Retinal degeneration associated with CLN2 disease manifests as a progressive, symmetrical decline, which appears to accelerate during a critical period at 48 to 72 months of age, suggesting intervention with retina-specific CLN2 gene therapy should occur ideally before or as early as possible within this critical period. The WCBS is a valuable tool and is highly correlated with the extent of retinal degeneration observed in OCT or fundus photographs; by using the fellow eye as a control, this grading scale can be used to monitor the effect of CLN2 gene therapy in future trials.

Management Strategies for CLN2 Disease

CLN2 disease (neuronal ceroid lipofuscinosis type 2) is a rare, autosomal recessive, pediatric-onset, rapidly progressive neurodegenerative lysosomal storage disorder caused by tripeptidyl peptidase 1 (TPP1) enzyme deficiency, and is characterized by language delay, seizures, rapid cognitive and motor decline, blindness, and early death. No management guidelines exist and there is a paucity of published disease-specific evidence to inform clinical practice, which currently draws upon experience from the field of childhood neurodisability. Twenty-four disease experts were surveyed on CLN2 disease management and a subset met to discuss current practice. Management goals and strategies are consistent among experts globally and are guided by the principles of pediatric palliative care. Goals and interventions evolve as the disease progresses, with a shift in focus from maintenance of function early in the disease to maintenance of quality of life. A multidisciplinary approach is critical for optimal patient care. This work represents an initial step toward the development of consensus-based management guidelines for CLN2 disease.

Diagnosis of neuronal ceroid lipofuscinosis type 2 (CLN2 disease): Expert recommendations for early detection and laboratory diagnosis

Neuronal ceroid lipofuscinoses (NCLs) are a heterogeneous group of lysosomal storage disorders. NCLs include the rare autosomal recessive neurodegenerative disorder neuronal ceroid lipofuscinosis type 2 (CLN2) disease, caused by mutations in the tripeptidyl peptidase 1 (TPP1)/CLN2 gene and the resulting TPP1 enzyme deficiency. CLN2 disease most commonly presents with seizures and/or ataxia in the late-infantile period (ages 2-4), often in combination with a history of language delay, followed by progressive childhood dementia, motor and visual deterioration, and early death. Atypical phenotypes are characterized by later onset and, in some instances, longer life expectancies. Early diagnosis is important to optimize clinical care and improve outcomes; however, currently, delays in diagnosis are common due to low disease awareness, nonspecific clinical presentation, and limited access to diagnostic testing in some regions. In May 2015, international experts met to recommend best laboratory practices for early diagnosis of CLN2 disease. When clinical signs suggest an NCL, TPP1 enzyme activity should be among the first tests performed (together with the palmitoyl-protein thioesterase enzyme activity assay to rule out CLN1 disease). However, reaching an initial suspicion of an NCL or CLN2 disease can be challenging; thus, use of an epilepsy gene panel for investigation of unexplained seizures in the late-infantile/childhood ages is encouraged. To confirm clinical suspicion of CLN2 disease, the recommended gold standard for laboratory diagnosis is demonstration of deficient TPP1 enzyme activity (in leukocytes, fibroblasts, or dried blood spots) and the identification of causative mutations in each allele of the TPP1/CLN2 gene. When it is not possible to perform both analyses, either demonstration of a) deficient TPP1 enzyme activity in leukocytes or fibroblasts, or b) detection of two pathogenic mutations in trans is diagnostic for CLN2 disease.

Brain Region-Specific Degeneration with Disease Progression in Late Infantile Neuronal Ceroid Lipofuscinosis (CLN2 Disease)

BACKGROUND AND PURPOSE

Late infantile neuronal ceroid lipofuscinosis (CLN2 disease) is a uniformly fatal lysosomal storage disease resulting from mutations in the CLN2 gene. Our hypothesis was that regional analysis of cortical brain degeneration may identify brain regions that are affected earliest and most severely by the disease.

MATERIALS AND METHODS

Fifty-two high-resolution 3T MR imaging datasets were prospectively acquired on 38 subjects with CLN2. A retrospective cohort of 52 disease-free children served as a control population. The FreeSurfer software suite was used for calculation of cortical thickness.

RESULTS

An increased rate of global cortical thinning in CLN2 versus control subjects was the primary finding in this study. Three distinct patterns were observed across brain regions. In the first, subjects with CLN2 exhibited differing rates of cortical thinning versus age. This was true in 22 and 26 of 34 regions in the left and right hemispheres, respectively, and was also clearly discernable when considering brain lobes as a whole and Brodmann regions. The second pattern exhibited a difference in thickness from healthy controls but with no discernable change with age (9 left hemispheres, 5 right hemispheres). In the third pattern, there was no difference in either the rate of cortical thinning or the mean cortical thickness between groups (3 left hemispheres, 3 right hemispheres).

CONCLUSIONS

This study demonstrates that CLN2 causes differential rates of degeneration across the brain. Anatomic and functional regions that degenerate sooner and more severely than others compared with those in healthy controls may offer targets for directed therapies. The information gained may also provide neurobiologic insights regarding the mechanisms underlying disease progression.

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.

Applications of optical coherence tomography in pediatric clinical neuroscience

For nearly two centuries, the ophthalmoscope has permitted examination of the retina and optic nerve-the only axons directly visualized by the physician. The retinal ganglion cells project their axons, which travel along the innermost retina to form the optic nerve, marking the beginning of the anterior visual pathway. Both the structure and function of the visual pathway are essential components of the neurologic examination as it can be involved in numerous acquired, congenital and genetic central nervous system conditions. The development of optical coherence tomography now permits the pediatric neuroscientist to visualize and quantify the optic nerve and retinal layers with unprecedented resolution. As optical coherence tomography becomes more accessible and integrated into research and clinical care, the pediatric neuroscientist may have the opportunity to utilize and/or interpret results from this device. This review describes the basic technical features of optical coherence tomography and highlights its potential clinical and research applications in pediatric clinical neuroscience including optic nerve swelling, optic neuritis, tumors of the visual pathway, vigabatrin toxicity, nystagmus, and neurodegenerative conditions.

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.