Search results for "Intraocular"

Efficacy and safety study of an eyelid gel after repeated nocturnal application in healthy contact lens users and non-users

2020

Purpose: To evaluate skin biocompatibility of a nighttime hydrating eyelid gel and possible ocular surface effects in contact lens users (CLU) and non-contact lens users (NCLU). The formulation is registered as a medical device as Tridocosahexaenoine-AOX® (TDHA-AOX) (a concentrated DHA triglyceride), containing also hyaluronic acid (HA). Methods: A prospective, randomized, masked clinical trial was performed with 62 participants of both sexes, aged 20–70 years, split into: (1) CLU (n = 30) and (2) NCLU (n = 32). All participants were instructed to apply a single dose of the moisturizing gel (containing TDHA-AOX and HA) nightly to the upper and inner eyelids of their right eye (RE) only, and…

Management of Descemet's membrane haemorrhage after canaloplasty

2019

Agreement among 3 optical imaging methods for the assessment of optic disc topography.

2005

Purpose To assess the agreement of disc topography measurements between the Heidelberg Retina Tomograph (HRT II), Retinal Thickness Analyzer (RTA), and Optical Coherence Tomograph (StratusOCT). Design Observational cross-sectional study. Participants Forty-two randomly chosen eyes of 42 subjects. Methods Each subject underwent HRT II, RTA, and StratusOCT examination. Two experienced examiners drew the contour lines for the HRT II and RTA. Bland and Altman plots were used to evaluate agreement for each topographic parameter among the instruments. The Spearman coefficient of rank correlation was evaluated for each topographic parameter. Main Outcome Measures Agreement in the measurement of op…

Proposal of a new diffractive corneal inlay to improve near vision in a presbyopic eye

2020

[EN] A new class of diffraction-based corneal inlays for treatment of presbyopia is described. The inlay is intended to achieve an improvement of the near focus quality over previous designs. Our proposal is a two-zone hybrid device with separated amplitude and phase areas having a central aperture and no refractive power. An array of micro-holes is distributed on the surface of the inlay conforming a binary photon sieve. In this way, the central hole of the disk contributes to the zero order of diffraction, and the light diffracted by the micro-holes in the peripheral photon sieve produces a real focus for near vision. We employed ray-tracing software to study the performance of the new in…

Fractal-structured multifocal intraocular lens

2017

[EN] In this work, we present a new concept of IOL design inspired by the demonstrated properties of reduced chromatic aberration and extended depth of focus of Fractal zone plates. A detailed description of a proof of concept IOL is provided. The result was numerically characterized, and fabricated by lathe turning. The prototype was tested in vitro using dedicated optical system and software. The theoretical Point Spread Function along the optical axis, computed for several wavelengths, showed that for each wavelength, the IOL produces two main foci surrounded by numerous secondary foci that partially overlap each other for different wavelengths. The result is that both, the near focus an…

Ophthalmic: Laboratorio virtual para el diseño de nuevas lentes oftálmicas

2013

This work presents a new virtual laboratory, OPHTALMIC, developed with MATLAB GUI for using in Optics and Optometry courses as a computer tool for studying the focusing properties of multifocal diffractive both on unconventional structures both periodic and aperiodic. This virtual laboratory enables students to quickly and easily analyze the influence of the different parameters of construction and find the best solution for a user.

Material properties of various intraocular lenses in an experimental study.

2002

<i>Introduction:</i> With the recent introduction of small-incision cataract surgery, requirements for intraocular lens (IOL) flexibility, strength and hydrophilicity have rapidly evolved. The IOL surface, however, remains a critical factor influencing uveal biocompatibility. <i>Purpose:</i> To objectively quantify factors of material properties of various IOLs using contact angle measurements, differential scanning calorimetry, dynamic-mechanical measurements and scanning electron microscopy. <i>Material and Methods:</i> In our study, 17 currently available IOLs were investigated using contact angle measurements to assess hydrophilicity and biocompatibil…

Tilted discs and central retinal vein occlusion.

1993

Strategies to Reduce Oxidative Stress in Glaucoma Patients

2018

Background Primary open-angle glaucoma (POAG) is a multifactorial pathology involving a variety of pathogenic mechanisms, including oxidative/nitrosative stress. This latter is the consequence of the imbalance between excessive formation and insufficient protection against reactive oxygen/nitrogen species. Objective Our main goal is to gather molecular information to better managing pathologic variants that may determine the individual susceptibility to oxidative/nitrosative stress (OS/NS) and POAG. Method An extensive search of the scientific literature was conducted using PUBMED, the Web of Science, the Cochrane Library, and other references on the topic of POAG and OS/NS from human and a…

Valutazione tonometrica in due posizioni di sguardo nell'orbitopatia di Graves

2006

Aim.To asses effective role of thickness of superior rectus muscle in the variation of intraocular pression (IOP) in the patients with Graves' ophthalmopathy.Methods.IOP was measured in 76 eyes of 38 patients(mean age,42.4 years;range 19 to 58 years)with Graves' ophthalmopathy in primary and in upgaze position(Elevation with divergence of 23°).Results.IOP in 52 of the 76 eyes was 17.5 +/-2.12 mm Hgin primary position and 21.2 +/-2.75 mm Hg in upgaze position.In the eyes (28)with thickness of the superior rectus muscle >4.6 mm,IOP was 22.7+/-1.48 mm Hg in primary position and 27.1 +/-1.92 mm Hg in upgaze position.The difference in the values in this group is statistically significant ( the p…