Senior-Løken syndrome and intracranial hypertension.

BACKGROUND: Senior-Løken syndrome (SLS) is a rare autosomal recessive disease characterised by nephronophthisis and retinal degeneration, and belongs to a group of genetically heterogeneous disorders known as the ciliopathies. MATERIALS AND METHODS: Case report of a  patient with genetically proven SLS presenting with headaches and swollen optic nerve heads, review of medical notes and ophthalmic imaging, with retinal photography, fundus autofluorescence, and OCT retinal nerve fibre layer analysis. RESULTS: We present findings in a 15 year old girl with Senior-Løken syndrome associated with compound heterozygous mutations in the SDCCAG8 gene,  who initially presented with a retinal dystrophy, and subsequent renal failure requiring renal transplantation and immunosuppression. Four and a half years later, she presented with headaches, reduced vision and clinical findings of papilloedema.  Cerebrospinal fluid analysis revealed a high opening pressure of 37cmH20 and neuroimaging was otherwise unremarkable.  Treatment with a reduced dose of oral acetazolamide resulted in symptomatic relief of headaches, and resolution of optic nerve swelling. CONCLUSION: The association of intracranial hypertension in a ciliopathy is a rare occurrence.  The aetiology of intracranial hypertension in this case is likely multi-factorial, due to renal transplantation, post-renal transplant medications and/ or weight gain.  With evidence of cilia involvement in the central nervous system, ciliary dysfunction may contribute to intracranial hypertension, and should be considered in these patients presenting with headaches. Diagnosis may be difficult with advanced retinal degeneration and baseline retinal nerve fibre layer thinning. Treatment requires careful monitoring of renal function.

Interventions to Reduce Myopia Progression in Children.

Efforts to reduce the progression of myopia in childhood are on the rise, due to an increasing incidence of myopia worldwide and its associated sight-threatening complications. Interventions are aimed at reducing myopia in childhood and include environmental considerations, spectacles, contact lenses, and pharmacological agents. We reviewed recent literature with interventions aimed at reducing myopia progression in children and found that a number of interventions were significant in reducing the progression of myopia. Of these interventions, atropine showed the largest dose-related effect on myopia progression control. Although higher doses are associated with side effects of pupil dilatation, loss of accommodation, near vision blur, and rebound phenomenon, low-dose atropine has also been shown to provide effective myopia control with minimal side effects and rebound. To a lesser degree, bifocal soft contact lenses have also been shown to be effective in reducing the progression of myopia, though compliance is an issue. Similarly, orthokeratology lenses have also been shown to be effective in reducing axial length elongation and myopia progression, though long-term data on its rebound effects are unavailable.

Topical Atropine in the Control of Myopia.

Efforts to reduce myopia progression in childhood are driven by the increasing incidence of high myopia and its attendant health risks. Interventional approaches to reduce myopia progression in childhood have included the use of spectacles, contact lens, and pharmacological methods, of which the latter appear to be most promising. We review the use of topical atropine eye drops in the retardation of myopia progression in children and discuss the efficacy and safety profiles when used at different concentrations (1.0%, 0.5%, 0.1%, and 0.01%). Topical atropine reduces myopia progression and axial elongation in children in a dose-related manner, but a rebound phenomenon occurs with higher doses. Its use has been shown to be safe, but higher doses cause pupil dilation, loss of accommodation and near vision. Atropine 0.01% has the best therapeutic index, with clinically insignificant amounts of pupil dilation, near vision, and accommodation loss but remains as effective as higher doses.

Electrophysiological abnormalities associated with extensive myelinated retinal nerve fibers.

An observational case report of electrophysiological abnormalities in a patient with anisomyopic amblyopia as a result of unilateral extensive myelinated retinal nerve fibers (MNFs) is illustrated. The electrophysiological readings revealed an abnormal pattern electroretinogram (PERG) but normal full-field electroretinogram readings in the affected eye. The visual-evoked potential was also undetectable in that eye. Our findings suggest that extensive MNFs can be associated with electrophysiological abnormalities, in particular the PERG, which can aid in diagnosing the cause of impaired vision when associated with amblyopia.