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Nepita, I.

Publications and source records attributed to Nepita, I..

2 recordsLinked to original sources

The role of eye movements in the process of silicone oil emulsification after vitreoretinal surgery

BackgroundEmulsification of silicone oil (SO) is a feared and common complication of SO tamponade as potentially associated with significant risks to ocular health, including elevated intraocular pressure (IOP), glaucoma, corneal and retinal changes. The aim of this study was to investigate the role and interplay of major factors on the formation of SO emulsion, such as eye rotations and albumin, a blood serum protein known to affect interfacial properties. MethodsExperiments were conducted in a realistic model of the vitreous chamber, filled with SO and an aqueous solution containing different concentrations of albumin. The model was subjected to harmonic and saccadic rotations, at body temperature. ResultsNo emulsions were detected in the absence of endogenous proteins in the aqueous solution. The presence of albumin significantly influenced emulsion formation, acting as a surfactant. Mechanical energy from eye movements was also found to contribute to emulsification, with higher mechanical energy provided to the system leading to smaller droplet sizes. The emulsions formed were stable over extended times. ConclusionsThis study highlights the complex interplay of factors influencing SO emulsification in the vitreous chamber. A better understanding of the mechanisms underlying SO emulsification is crucial for developing strategies to mitigate SO emulsion and the related complications.

biophysics↗

Optical-quality assessment of a miniaturized intraocular telescope

PurposeEvaluating the optical transmission and geometrical aberrations of an intraocular device, namely, the Small-Incision New Generation Implantable Miniature Telescope (SING IMT, Samsara Vision), designed to correct age-related macular degeneration. MethodsOptical transmission in the spectral range 350-750 nm of the implantable optics was recorded with a fiber-optic spectrometer. Geometrical aberrations were studied by measuring the wavefront of a laser beam after passing through the implantable optics and performing an expansion of the measured wavefront into a Zernike polynomial basis. The study was conducted under in-vitro experimental conditions. A second monofocal intraocular lens (SY60WF, Alcon) was tested and used as reference for assessing the optical quality of the SING IMT device. ResultsSpectroscopy measurements revealed that the SING IMT and monofocal IOL element feature UV-rejection and blue-rejection capabilities, respectively. Wavefront concavity indicated that the SING IMT behaves as a diverging lens with a focal length of approximately -100 mm; Zernike analysis showed that SING IMT has negligible coma, trefoil, astigmatism, and spherical aberrations of any order and along any direction. ConclusionsThe SING IMT exhibited even optical transmission in the whole visible spectrum and curvature capable of magnifying the retinal images without introducing geometrical aberrations, which proves the feasibility of this device as high-quality optical element for imaging. The rigidity of the compound lens of the SING IMT prevents mechanically-induced distortions, an issue encountered with polymeric lenses. Translational RelevanceSpectrometry and in vitro wavefront analysis provide evidence supporting the new generation miniaturized telescopic intraocular lens as a favorable option to intraocular implant in age-related macular degeneration.

biophysics↗