Addressing electronic and dynamical evolution of molecules and molecular clusters: DFTB simulations of energy relaxation in polycyclic aromatic hydrocarbons.

We present a review of the capabilities of the density functional based Tight Binding (DFTB) scheme to address the electronic relaxation and dynamical evolution of molecules and molecular clusters following energy deposition either collision or photoabsorption. The basics and extensions of DFTB for addressing these systems and in particular their electronic states and their dynamical evolution are reviewed. Applications to PAH molecules and clusters, carbonaceous systems of major interest in astrochemical/astrophysical context, are reported.

Characterization and Prediction of the Clinical Outcome of Intense Pulsed Light-Based Treatment in Dry Eye Associated to Meibomian Gland Dysfunction.

This non-comparative prospective case series was conducted to characterize the clinical impact of intense pulsed light (IPL)-based treatment in dry eyes associated to Meibomian gland dysfunction (MGD), defining the predicting factors for a successful outcome with this therapy in a large case series. A total of 390 eyes (195 patients, range: 23-93 years) received four sessions of Optima IPL system (Lumenis, Yokneam, Israel). Significant changes were observed in tear film osmolarity in both eyes ( < 0.

An Update on Corneal Biomechanics and Architecture in Diabetes.

In the last decade, we have witnessed substantial progress in our understanding of corneal biomechanics and architecture. It is well known that diabetes is a systemic metabolic disease that causes chronic progressive damage in the main organs of the human body, including the eyeball. Although the main and most widely recognized ocular effect of diabetes is on the retina, the structure of the cornea (the outermost and transparent tissue of the eye) can also be affected by the poor glycemic control characterizing diabetes.

Keratitis Due to Achromobacter xylosoxidans in a Contact Lens User.

Objectives: Ocular infections due to Achromobacter xylosoxidans are extremely uncommon; their diagnosis is a challenge and the optimal treatment remains controversial. We present a case of A. xylosoxidans in a contact lens user and a review of the literature to facilitate diagnostic suspicion and empirical therapeutic management.

Computational Simulation of Scleral Buckling Surgery for Rhegmatogenous Retinal Detachment: On the Effect of the Band Size on the Myopization.

A finite element model (FE) of the eye including cornea, sclera, crystalline lens, and ciliary body was created to analyze the influence of the silicone encircling bandwidth and the tightness degree on the myopia induced by scleral buckling (SB) procedure for rhegmatogenous retinal detachment. Intraocular pressure (IOP) was applied to the reference geometry of the FE model and then SB surgery was simulated with encircling bandwidths of 1, 2, and 2.5 mm.

Assessment of corneal biomechanical properties and intraocular pressure in myopic spanish healthy population.

Purpose. To examine biomechanical parameters of the cornea in myopic eyes and their relationship with the degree of myopia in a western healthy population. Methods.

Two cases of accidental dislocation of the silicone sleeve of an extrusion cannula into the vitreous cavity.

Background: Fluid-air exchange during vitreoretinal surgery is often used as a tool for subretinal fluid endodrainage. Soft-tipped flexible extrusion cannulas are commonly used to aspirate the posterior subretinal fluid.

Methods: This is an observational two-case series describing two patients who underwent 20-G pars plana vitrectomy complicated by the accidental fall of the silicone sleeve of a soft-tipped extrusion cannula into the vitreous cavity.

[Effects of encircling scleral buckling on the morphology and biomechanical properties of the cornea].

Objective: To investigate the effects of encircling scleral buckle (SB) on corneal biomechanical properties of the cornea and its morphological parameters.

Methods: We prospectively examined twelve eyes diagnosed with vitreous haemorrhage undergoing pars plana vitrectomy (PPV), and fifteen eyes undergoing combined PPV and scleral buckle (PPV/SB) for repair of rhegmatogenous retinal detachment (RRD). Corneal biomechanical properties, including corneal hysteresis (CH) and corneal resistance factor (CRF), were measured with an Ocular Response Analyser (ORA) before and 1-month postoperatively.

Evaluation of in vitro efficacy of combined riboflavin and ultraviolet a for Acanthamoeba isolates.

Purpose: To evaluate in vitro the amoebicidal effects of riboflavin and ultraviolet A (UVA) collagen cross-linking.

Design: Experimental study, laboratory investigation.

Methods: Two different strains of Acanthamoeba species were tested identically.

Biomechanical property analysis after corneal collagen cross-linking in relation to ultraviolet A irradiation time.

Purpose: To study the biomechanical effect of riboflavin-ultraviolet A irradiation (UVA)-induced collagen cross-linking (CXL) in porcine corneas using two different exposure times of 30 and 60 min.

Methods: Seventeen enucleated porcine eyes were divided into three groups: group A, six eyes without any treatment, group B, six eyes treated by UVA CXL for 30 min, and group C, five eyes treated by UVA CXL for 60 min. Riboflavin (vitamin B2) was used as a photosensitizer in both groups of treatment.

Multifocal intraocular lenses for unilateral cataract in children.

Purpose: To evaluate the implantation of apodized diffractive multifocal intraocular lenses (IOLs) in children with unilateral cataract.

Setting: Ophthalmology Service, Hospital Clínico Lozano Blesa, Zaragoza, Spain.

Design: Prospective clinical study.

An unusual case of cocaine-induced maculopathy.

Purpose: Cocaine is one of the most common substances of abuse. When used intranasally, cocaine is cut with a variety of agents, which may increase local and systemic toxic reactions.

Methods: We examined a 34-year-old man who complained of color disturbance.

Effect of limbal relaxing incisions during phacoemulsification surgery based on nomogram review and numerical simulation.

Purpose: To determine the effect of the parameters related to limbal incisions (length, depth, optical zone, and so on) by revision of different nomograms and analyzing the outcomes of numerical simulation of incisions with a biomechanical model of the cornea.

Methods: The Cristóbal nomogram was developed based on our experience on the performance of relaxing incisions to correct astigmatism. A numerical model of the eye was used to analyze the effect induced by variation of each parameter compiled in nomograms.

Biomechanical properties of the cornea in Fuchs' corneal dystrophy.

Purpose: To investigate the effects of Fuchs' corneal dystrophy (FCD) on corneal biomechanical properties and the results of IOP readings in relation to changes in corneal hysteresis (CH) and central corneal thickness (CCT).

Methods: Corneal biomechanical properties, including CH, corneal resistance factor (CRF), and CCT, were measured with the ocular response analyzer (ORA) in 11 eyes of 11 patients with clinically confirmed FCD and 12 eyes of 12 healthy subjects. The ORA was also used to determine the values of intraocular pressure (IOP(g)) and corneal compensated IOP (IOP(cc)).

[Eyelid contact allergic eczema caused by topical ketorolac tromethamine 0.5%].

Clinical Case: A 65-year-old man had been treated with eye-drops containing NSAIDs (Ketorolac). He developed conjunctival injection, edematous swelling of the eyelids and periorbital dermatitis due to a contact allergy. Allergy to NSAIDs is uncommon.

Posttraumatic reaction in a case of fundus flavimaculatus with atrophic macular degeneration.

We report the case of a 13-year-old girl who had fundus flavimaculatus with atrophic macular degeneration. At the age of 14 years, she suffered mild trauma OD, subsequently developing a fibroglial reaction of the retina and pigmentary migration. The coexistence of both phenomena could be explained by the liberation of growth factors by the damaged retinal pigment epithelial (RPE) cells as a reaction to the injury and/or by the passage of chemoattractants from the serum through the damaged RPE cell barrier.

Noonan's syndrome with keratoconus and optic disc coloboma.

We report the case of a 14-year-old girl with multiple findings characteristic of Noonan's syndrome, including short stature, mild mental retardation, facial, skeletal and renal abnormalities. In addition, ophthalmic examination revealed a keratoconus in the left eye and a right optic disc coloboma. To date, only two cases of Noonan's syndrome with keratoconus have been reported, and this is the second case of this syndrome with optic disc coloboma.

Levels of vancomycin in aqueous humor after topical eye drops administration.

Vancomycin is an antibiotic which is especially active against Gram positive bacteria. At present, numerous infections of the anterior segment of the eye are caused by the Staphilococcus aureus and epidermis. Strains which are resistant to methicilin are more and more frequent and for this reason Vancomycin is becoming the antibiotic of choice to combat these infections since no resistance of the Staphilococcus to it has been demonstrated.