Search results for "ophthalmology"

Response to Letter to the Editor: Outcome of Bleb Revision With Autologous Conjunctival Graft Alone or Combined With Donor Scleral Graft for Late-ons…

2021

Fulminant bilateral Haemophilus influenzae keratitis in a patient with hypovitaminosis A treated with contaminated autologous serum

2011

We report on a patient with hypovitaminosis A treated with autologous serum (AS) who had bilateral infectious ulcers positive for Haemophilus influenzae. The patient suffered a perforation of his right eye and total healing of his left eye with a residual leukoma. In cases of severe malnutrition, serum levels of vitamins and bacteriostatic and growth factors are reduced, so AS would not only be ineffective but also increase the risk of secondary corneal infection. The prophylactic use of a topical antibiotic would be useful in treatment with AS, especially in patients who do not use and adequately store the eye drops, as in our patient.

Oxidative tissue damage after phacoemulsification: influence of ophthalmic viscosurgical devices.

2003

To quantify the oxidative tissue damage after phacoemulsification, correlate the damage to the energy applied, and investigate the influence of ophthalmic viscosurgical devices (OVDs).Department of Ophthalmology, University of Mainz, Mainz, Germany.The study comprised 130 eyes operated on by 1 surgeon using the same phacoemulsification machine. Some eyes received an OVD before phacoemulsification and some did not. Energy values were expressed as phaco time; that is, ultrasound (US) time (seconds) after conversion to 100% phaco power. Patients were grouped as follows: Group 1, phaco time less than 20 seconds and no OVD; Group 2, phaco time 20 to 40 seconds and no OVD; Group 3, phaco time mor…

Effect of different antioxidants in experimental alcoholic optic neuropathy

2008

Purpose To establish the possible beneficial effects of three synthetic antioxidants: S-adenosil-L-methionine (SAMe), N-acetyl-L-cysteine (NAC) and Ebselen in optic nerve damage following chronic ethanol feeding in adult rats. Methods Twenty male Sprague-Dawley rats (five groups of four animals each) were fed a liquid, ethanol-containing diet with littermates given isocaloric amounts of ethanol-free diet serving as controls. Antioxidants were administered by dissolving them in the liquid diet at 0.4 mg/ml (SAMe), 0.163 mg/ml (NAC) and 5.33 mg/ml (Ebselen). After 6 weeks, optic nerves were obtained and parameters that are relevant for the modulation of oxidative stress, such as antioxidants …

Do nutritional supplements have a role in age macular degeneration prevention?

2013

Purpose. To review the proposed pathogenic mechanisms of age macular degeneration (AMD), as well as the role of antioxidants (AOX) and omega-3 fatty acids (ω-3) supplements in AMD prevention.Materials and Methods. Current knowledge on the cellular/molecular mechanisms of AMD and the epidemiologic/experimental studies on the effects of AOX andω-3 were addressed all together with the scientific evidence and the personal opinion of professionals involved in the Retina Group of the OFTARED (Spain).Results. High dietary intakes ofω-3 and macular pigments lutein/zeaxanthin are associated with lower risk of prevalence and incidence in AMD. The Age-Related Eye Disease study (AREDS) showed a benefic…

Spring constants of capsular tension rings.

2004

Purpose To determine the spring constants of several types of capsular tension rings (CTRs). Setting Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany. Methods Fourteen models of CTRs provided by 9 companies were tested; all were 11.0 mm in diameter. The CTRs were positioned in a special retainer of a material-testing machine and compressed at a constant speed of 10.0 mm per minute. The distance and force values were recorded, and each CTR model was tested 3 times using a new specimen each time. The resulting measurements were used to calculate a mean spring constant for each CTR model. Results All tested CTRs showed linear proportionality between force and compress…

Healon5 viscoadaptive formulation: Comparison to Healon and Healon GV

2001

Abstract Purpose To compare the rheological characteristics of a viscoadaptive viscoelastic formulation with those of 2 standard ophthalmic viscosurgical devices (OVDs). Setting Department of Ophthalmology, Johannes Gutenberg-University, and Max Planck-Institute for Polymer Research, Mainz, Germany. Methods An independent comparative study of 3 OVDs of sodium hyaluronate (Healon®, Healon GV®, and Healon®5) was performed using the Advanced Rheometric Expansion System to analyze rheologic behavior (eg, dynamic frequency dependence of the complex viscosity) as well as rheological parameters (eg, viscosity at zero shear rate, pseudoplasticity, relaxation time, elastic and viscous modulus). Resu…

Application principles of excimer lasers in ophthalmology

2010

Abstract Excimer lasers (193 nm) can be used for photoablation of the human cornea due to their specific physical characteristics. This laser is applied in corneal refractive surgery for the targeted removal of corneal tissue for the purpose of correcting refractive errors. This article provides a short overview of the scientific development of excimer lasers for use in ophthalmic surgery and of the range of applications of these tools.

Optical quality of intraocular lenses after several years in the human eye

2013

The optical quality of explanted intraocular lenses (IOLs) was analysed to verify if their quality is maintained after having been in the human eye for several years. Twenty-five explanted IOLs were studied, 10 because of intraocular luxation and 15 from corneal donors. The dioptric power and modulation transfer function (MTF) were determined to discover the image quality of the IOLs. The spectral transmission was also established to ascertain whether the filter against ultraviolet (UV) radiation was still effective. The results show that the MTF of implanted IOLs is maintained and therefore so is the image quality they provide. Only decay in the MTF of some of the explanted IOLs was observ…

Irregularity of the posterior corneal surface during applanation using a curved femtosecond laser interface and microkeratome cutting head.

2012

PURPOSE: To evaluate the irregularity of the posterior corneal surface and intrastromal dissection during the preparation of donor tissue for Descemet stripping automated endothelial keratoplasty (DSAEK) using a curved interface femtosecond laser and microkeratome. METHODS: Sixteen human donor corneas unsuitable for transplantation were divided into two groups: a femtosecond (FS) laser group (n=7) using the VisuMax femtosecond laser (Carl Zeiss Meditec) and a microkeratome group (n=9) using the Amadeus II microkeratome (Ziemer Ophthalmic Group). The corneas were fixed on artificial anterior chambers. Horizontal cross-sections were obtained using spectral-domain optical coherence tomography…