Novel pathogenic SLC25A46 splice-site mutation causes an optic atrophy spectrum disorder.

The inherited optic neuropathies comprise a group of genetically heterogeneous disorders causing optic nerve dysfunction. In some cases, optic neuropathies are associated with cerebellar atrophy which mainly affects the vermis. Here, we describe a Moroccan girl of consanguineous parents with optic atrophy and cerebellar atrophy. Exome sequencing revealed a novel homozygous mutation (c.283+3G>T) in the donor splice site for exon 1 of SLC25A46. RNA analysis revealed that an alternative splice site within exon 1 was used leading to a premature termination codon within exon 2. SLC25A46 mRNA expression showed there is no wild-type transcript present in the patient and the mutant transcript does not undergo nonsense-mediated mRNA decay. Futhermore, we observed c.283+3G>T SLC25A46 mutation induces mitochondrial fragmentation. An additional 10 patients with optic atrophy and cerebellar atrophy, which were negative for mtDNA and OPA1 variants, were tested for pathogenic mutations in the SLC25A46 gene. However, no additional variants were identified. Our findings confirm the recent report of pathogenic SLC25A46 mutations as a novel cause for optic atrophy spectrum disorder.

Comparison of the Storz bifocal zonal and the 3M diffractive multifocal intraocular lenses.

Visual acuity and contrast sensitivity after cataract surgery were evaluated in best-case eyes that received a Storz bifocal zonal intraocular lens (IOL) or a 3M diffractive multifocal IOL. A group of eyes with a monofocal IOL was used as a control. Postoperatively, all eyes had a best corrected visual acuity of 20/40 or better. At near, wearing the best distance correction, 86.0% of the Storz group and 94.5% of the 3M group had a visual acuity of 20/40 or better. Both the Storz and 3M groups had a significantly greater loss in visual acuity in dim light at the lowest contrast levels than the monofocal group. Under bright light, the Storz group's contrast sensitivity was not significantly different from that of the monofocal groups; however, the 3M group's contrast sensitivity decreased at all levels of contrast. The Storz lens performed slightly but significantly better than the 3M lens in bright light (96% and 25% Regan levels), perhaps because of the difference in IOL optics or small differences in the incidence of posterior capsule opacification, for which this study was not controlled. In the Storz and 3M groups, distance visual acuity was better than distance visual acuity using a minus addition, which makes the patient use the near portion of the optic.

Corneal astigmatism after clear corneal and corneoscleral incisions for cataract surgery.

PURPOSE: To compare the astigmatism induced by clear corneal incisions (CCIs) and corneoscleral tunnel incisions (CSIs) for cataract surgery over 6 months. SETTING: Rotterdam Eye Hospital, rotterdam, The Netherlands. METHODS: Thirty-five patients having phacoemulsification were recruited prospectively; 15 had CCIs and 20, CSIs. Corneal topography was performed by computerized videokeratoscopy preoperatively and 6 months postoperatively. The change in keratometric astigmatism was calculated using the absolute magnitude and vector analysis methods. RESULTS: There was no significant difference between the change in astigmatism produced by the two incisions (Student's t-test). CONCLUSION: The CCI for cataract surgery did not produce significantly greater astigmatism than the CSI. Concern over CCIs having a greater risk of increasing corneal astigmatism is unfounded and does not justify withholding the technique from patients it could benefit.