Additional multifocal sulcus-based intraocular lens: alternative to multifocal intraocular lens in the capsular bag.

PURPOSE: To compare the visual outcomes of additional multifocal intraocular lenses (IOLs) for sulcus fixation with those of standard multifocal IOLs in the capsular bag. SETTING: Department of Ophthalmology, Rudolf-Virchow-Klinikum Glauchau, Glauchau, Germany. DESIGN: Prospective controlled clinical trial. METHODS: Eyes had phacoemulsification and implantation of a monofocal IOL in the capsular bag and an additional aberration-free diffractive IOL in the ciliary sulcus (multifocal add-on IOL group). Measurements of uncorrected and distance-corrected distance, intermediate, and near visual acuities; contrast sensitivity; and defocus curve were performed 3 months postoperatively. Results were compared with those in eyes with an aberration-correcting diffractive posterior chamber IOL (multifocal PC IOL group). RESULTS: The multifocal add-on IOL group comprised 34 eyes of 20 patients and the multifocal PC IOL group, 31 eyes of 17 patients. Cataract surgery, IOL implantation, and the postoperative course were uneventful in all cases. There were no statistically significant differences in uncorrected and distance-corrected distance, intermediate, or near visual acuities between the 2 groups. The median uncorrected distance visual acuity was 0.00 logMAR in both groups, and the median uncorrected near visual acuity was 0.10 logMAR in both groups. Contrast sensitivity testing yielded significantly better results in the multifocal add-on IOL group, especially at spatial frequencies over 1.5 cycles per degree. Defocus curves were similar in the 2 groups. CONCLUSION: Visual performance with a multifocal diffractive add-on IOL was equivalent to that achieved with a commonly used multifocal diffractive PC IOL.

The ABNORMAL GAMETOPHYTES (AGM) gene product of Arabidopsis demonstrates a role in mitosis during gamete development.

Screening a T-DNA mutagenized population of Arabidopsis thaliana for reduced seed set and segregation distortion led to the isolation of the ABNORMAL GAMETOPHYTES (AGM) mutant. Homozygous plants were never recovered, but heterozygous plants showed mitotic defects during gametogenesis resulting in approximately 50% abortion of both the male and female gametes. Isolation of the genomic sequence flanking the co-segregating T-DNA element led to the identification of a gene located on chromosome 5, predicted to encode a transmembrane protein. BLAST homology searches identified two homologous proteins that are not redundant, as is clear from the existence of the agm mutant. Unexpectedly, expression studies using the beta-glucuronidase reporter gene suggest that AGM and its closest Arabidopsis homolog are mostly expressed in cells undergoing mitosis. Thus, AGM is not a gametophytic gene as originally speculated on the basis of segregation distortion, but rather classified as an essential gene crucial to the process of mitosis in plants.