Enhancing the Functional Performance of Patients with Late-Stage Age-Related Macular Degeneration Implanted with a Miniature Telescope using Rehabilitation Training

INTRODUCTION

In this work, our aim is to report the functional outcomes of cataract surgery with smaller-incision new-generation miniature telescope (SING IMT) implantation followed by rehabilitation training in patients with central visual loss due to late-stage age-related macular degeneration (AMD).

METHODS

This retrospective study included patients who were monocularly implanted with SING IMT and then followed a rehabilitation program based on 6 biweekly sessions focused on visual abilities, reading, writing, visual motor integration and mobility. A total of 11 participants were included in this study. Reading acuity (RA), reading speed (RS), and fixation stability (FS) were assessed biweekly at 6-, 8-, 10-, 12-, 14-, and 16-week follow-up visits after SING IMT implantation and at a final assessment at 24 weeks. Best-corrected distance visual acuity (BCDVA) was also measured at baseline and at the same postoperative timepoints.

RESULTS

Mean baseline BCDVA was 12.5 ± 8.6 letter score. Both RA and RS were found to be significantly improved from the first rehabilitation session (6 weeks after surgery) to the last session (24 weeks after surgery). At the end of the rehabilitation program, mean RA was 0.45 ± 0.19 LogMAR and mean RS was 30.9 ± 17.6 words per minute. Moreover, all patients achieved a FS of 15 s or more after the last rehabilitation session. Most patients (55%) achieved an improvement of 15 letters in BCDVA at the end of the study.

CONCLUSIONS

This study suggests that rehabilitation training can improve visual functions of patients with late-stage AMD implanted with SING IMT in real-world tasks such as reading skills.

Optical-Quality Assessment of a Miniaturized Intraocular Telescope

Age-related macular degeneration (AMD) causes severe vision impairments, including blindness. An option to improve vision in AMD patients is through intraocular lenses and optics. Among others, implantable miniaturized telescopes, which direct light to healthy lateral regions of the retina, can be highly effective in improving vision in AMD patients. Yet, the quality of the restored vision might be sensitive to the optical transmission and aberrations of the telescope. To shed light on these points, we studied the in vitro optical performance of an implantable miniaturized telescope, namely, the SING IMT™ (Samsara Vision Ltd., Far Hills, NJ, USA) designed to improve vision in patients affected by late-stage AMD. Specifically, we measured the optical transmission in the spectral range 350-750 nm of the implantable telescope with a fiber-optic spectrometer. Wavefront aberrations were studied by measuring the wavefront of a laser beam after passing through the telescope and expanding the measured wavefront into a Zernike polynomial basis. Wavefront concavity indicated that the SING IMT™ behaves as a diverging lens with a focal length of -111 mm. The device exhibited even optical transmission in the whole visible spectrum and effective curvature suitable for retinal images magnification with negligible geometrical aberrations. Optical spectrometry and in vitro wavefront analysis provide evidence supporting the feasibility of miniaturized telescopes as high-quality optical elements and a favorable option for AMD visual impairment treatments.

A shotgun antisense approach to the identification of novel essential genes in Pseudomonas aeruginosa

Background

Antibiotics in current use target a surprisingly small number of cellular functions: cell wall, DNA, RNA, and protein biosynthesis. Targeting of novel essential pathways is expected to play an important role in the discovery of new antibacterial agents against bacterial pathogens, such as Pseudomonas aeruginosa, that are difficult to control because of their ability to develop resistance, often multiple, to all current classes of clinical antibiotics.

Results

We aimed to identify novel essential genes in P. aeruginosa by shotgun antisense screening. This technique was developed in Staphylococcus aureus and, following a period of limited success in Gram-negative bacteria, has recently been used effectively in Escherichia coli. To also target low expressed essential genes, we included some variant steps that were expected to overcome the non-stringent regulation of the promoter carried by the expression vector used for the shotgun antisense libraries. Our antisense screenings identified 33 growth-impairing single-locus genomic inserts that allowed us to generate a list of 28 “essential-for-growth” genes: five were “classical” essential genes involved in DNA replication, transcription, translation, and cell division; seven were already reported as essential in other bacteria; and 16 were “novel” essential genes with no homologs reported to have an essential role in other bacterial species. Interestingly, the essential genes in our panel were suggested to take part in a broader range of cellular functions than those currently targeted by extant antibiotics, namely protein secretion, biosynthesis of cofactors, prosthetic groups and carriers, energy metabolism, central intermediary metabolism, transport of small molecules, translation, post-translational modification, non-ribosomal peptide synthesis, lipopolysaccharide synthesis/modification, and transcription regulation. This study also identified 43 growth-impairing inserts carrying multiple loci targeting 105 genes, of which 25 have homologs reported as essential in other bacteria. Finally, four multigenic growth-impairing inserts belonged to operons that have never been reported to play an essential role.

Conclusions

For the first time in P. aeruginosa, we applied regulated antisense RNA expression and showed the feasibility of this technology for the identification of novel essential genes.