33 research outputs found
One-year multicenter evaluation of a new hydrophobic acrylic intraocular lens with hydroxyethyl methacrylate in an automated preloaded delivery system
journal articl
A minimum specification dataset for liquid ocular endotamponades: recommendations by a European expert panel
\ua9 2023, The Author(s). Purpose: To propose a minimum specification dataset to characterize liquid ocular endotamponades (OEs), namely silicone oil (SO), heavy SO (HSO), perfluorodecalin (PFD), and perfluoro-octane (PFO), in terms of physicochemical properties, purity and available evidence of safety, in line with ISO16672:2020. Methods: An evidence-based consensus using the expert panel technique was conducted. Two facilitators led a committee of 11 European experts. Facilitators prepared a dataset for each compound including the list of specifications relevant for the safety, identified by the group members on the basis of expertise and a comprehensive literature review. Each item was ranked by each member using a 9-point scale from 1 “absolutely to not include” to 9 “absolutely to include” in two rounds followed by discussion. Only items reaching consensus (score ≥ 7 from ≥ 75% of members) were included in the final datasets. Results: For all OEs, consensus was reached to include manufacturer, density, refractive index, chemical composition, dynamic viscosity, interfacial and surface tension, endotoxins, in vitro cytotoxicity assessment, and any evidence from ex vivo and/or in vivo tests for safety assessment. Additional specifications were added for SO (molecular weight distribution, content of oligosiloxanes with MW ≤ 1000 g/mol, spectral transmittance) and PFD/PFO (% of pure PFD/PFO in the final product, vapor pressure, chemical analyses performed for safety assessment). Conclusion: The proposed evidence-based minimum specification datasets for SO, HSO, PFD, and PFO have the potential to provide surgeons and health service purchasers with an easily available overview of the most relevant information for the safety assessment of OEs. [Figure not available: see fulltext.
Spontaneous Rotation of a Toric Implantable Collamer Lens
We present a case of toric implantable collamer lens (TICL) spontaneous rotation in a patient with myopic astigmatism. A 23-year-old female underwent TICL implantation. Preoperative uncorrected visual acuity (UCVA) was 20/800 and 20/1200, respectively, with −7.75 −4.25 × 0° and −8.25 −5.25 × 180°. The left eye achieved an UCVA of 20/30. After 3 months of successful implantation of TICL in the left eye, the patient presented with a sudden decrease in visual acuity in the left eye. UCVA was 20/100 with a refraction of +2.50 −4.50 × 165°. We observed the toric marks with a 30° rotation from the original position and decided to reposition the TICL, obtaining a final UCVA of 20/25, which remained stable at 6 months' follow-up. TICL can present a considerable rotation that compromises visual acuity. The relocation of TICL is a safe and effective procedure to recover visual acuity due to significant spontaneous TICL rotation
Математические аспекты течения внутриглазной жидкости
It is shown that the process of establishing the equilibrium concentration of ions is exponential. But very small value of exponent leads to the fact that the ion concentration practically does not change at all reasonable times the values of diffusion, the possible changes as it lies within the experimental error of measurement.В работе показано, что процесс установления равновесной концентрации ионов носит экспоненциальный характер. Однако очень малое значение показателя экспоненты приводит к тому, что концентрация ионов практически не меняется при всех разумных значениях времен диффузии, возможные же ее изменения лежат в пределах экспериментальной погрешности измерения
The Optical Functional Advantages of an Intraocular Low-Vision Telescope
An implantable miniaturized telescope (IMT) for low vision has recently been developed. Surgically inserted into only one eye of patients with bilateral central visual loss, the IMT provides a nominal magnification of 3.0# and a field-of-view of 6.6 (9.2 for the 2.2# magnification version). Theoretical concerns have been raised regarding the ability of patients to function with a large interocular magnification difference, the impact of the monocular restriction of the field-of-view, and the impact of this design on depth perception. This article addresses these concerns regarding the design of the IMT in comparison with spectacle-mounted telescopes and combined intraocular lens/spectacle (or combined contact lens/spectacle) telescopic systems. The effective field-of-view (as determined by the combination of both the field-of-view and the field-of-fixation), the effects of head motion and the vestibular reflex, and the disruption of stereo depth perception with a monocular device are considered here. Physiological optics considerations of these issues show that the IMT may have important advantages over other designs of magnification devices for patients with age-related macular degeneration. (Optom Vis Sci 2002;79:225--233) Key Words: macular degeneration, adaptation, rehabilitation, binocular vision T he population profile of the U.S. and of other industrialized nations is aging. Low vision or vision disability affects mostly the elderly. Consequently, both the absolute number of people with visual impairment and the proportion of the population that is visually impaired are expected to increase rapidly in the next two decades. Prevent Blindness America reported that approximately 2.5 million Americans over the age of 40 had moderate visual impairment and an a..
