Optical coherence tomography evaluation of idiopathic macular hole treatment by gas-assisted posterior vitreous detachment

PURPOSE: To report a case of idiopathic macular hole, with vitreoretinal traction confirmed by optical coherence tomography that was successfully treated by a single intravitreous perfluoropropane (C3F8) gas bubble injection.METHODS: Case report. A 65-year-old patient with idiopathic macular hole (stage 2, one eye) received an intravitreous gas injection and was prospectively followed with optical coherence tomography.RESULTS: A complete posterior vitreous detachment was achieved within 6 weeks after gas injection. Visual acuity improved from 20/80 to 20/25 by 10 months of followup. Optical coherence tomography disclosed vitreoretinal traction release and macular hole closure. No complications were related to the procedure.CONCLUSION: This simple procedure can assist a complete posterior vitreous detachment with relief of the hyaloid-foveolar traction, facilitating macular hole closure. (C) 2001 by Elsevier Science Inc. All rights reserved.

Intravitreal injection versus sub-Tenon's infusion of triamcinolone acetonide for refractory diabetic macular edema: A randomized clinical trial

PURPOSE. To compare the effectiveness of posterior sub-Tenon's infusion (STi) and intravitreal injection (IVI) of triamcinolone acetonide (TA) for treatment of refractory diffuse diabetic macular edema.METHODS. Thirty-six phakic diabetic patients with refractory diffuse diabetic macular edema were prospectively enrolled. Patients randomly received either 40 mg STi or 4 mg IVI of TA. Comprehensive ophthalmic evaluation was performed at baseline and 1, 2, 4, 8 +/- 1, 12 +/- 2 and 24 +/- 2 weeks after treatment. Macular morphologic changes detected by optical coherence tomography and visual acuity, intraocular pressure, and lens status were evaluated.RESULTS. Twenty-eight patients (28 eyes) completed the 24-week study. Central macular thickness was significantly reduced in the IVI group when compared with the STi group at 2, 4, 8, 12, and 24 weeks after treatment (P < 0.01). Mean visual acuities (in logarithm of the minimum angle of resolution [logMAR]) at week-4, -8, and -12 follow-up examinations were significantly higher in the IVI group (0.74, 0.75, and 0.82, respectively) when compared with the STi group (0.88, 0.88, and 0.90, respectively; P < 0.01). A significant change from baseline in mean intraocular pressure (mm Hg) was seen at weeks 4 (+/- 3.21) and 8 (+/- 3.35) in STi the group (P < 0.01), and at week 8 (+/- 2.78) in the IVI group (P < 0.05). No patient had cataract progression during the study.CONCLUSIONS. Although the number of patients and length of follow-up in this preliminary study were limited, the changes in central macular thickness and visual acuity observed after treatment suggest that IVI TA may be more effective than STi for the management of refractory diffuse diabetic macular edema. Further studies are needed to confirm these preliminary findings.

Intravitreal triamcinolone versus bevacizumab for treatment of refractory diabetic macular oedema (IBEME study)

Background/aims: The aim of this study was to compare the morphological and visual acuity outcomes associated with a single intravitreal injection of triamcinolone acetonide versus bevacizumab for the treatment of refractory diffuse diabetic macular oedema.Methods: Twenty-eight patients were randomly assigned to receive a single intravitreal injection of either 4 mg/0.1 ml triamcinolone acetonide or 1.5 mg/0.06 ml bevacizumab. Comprehensive ophthalmic evaluation was performed at baseline and at weeks 1, 4, 8 (+/- 1), 12 (+/- 2) and 24 (+/- 2) after treatment. Main outcome measures included central macular thickness measured with optical coherence tomography (OCT) and best corrected Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity.Results: Twenty-six patients (26 eyes) completed all study visits (two patients missed two consecutive study visits). Central macular thickness was significantly reduced in the intravitreal triamcinolone group compared with the bevacizumab group at weeks 4, 8, 12 and 24 (p<0.05). Logarithm of the minimum angle of resolution (LogMAR) best-corrected visual acuity was significantly higher at weeks 8 (0.69; similar to 20/100(+1)) and 12 (0.74; 20/100(-2)) in the intravitreal triamcinolone group compared with the bevacizumab group (weeks 8 (0.83; similar to 20/125(-1)) and 12 (0.86; 20/ 160(+2))) (p<0.05). Significant change from baseline in mean intraocular pressure (mmHg) was seen at week 4 (+2.25) only in the intravitreal triamcinolone group (p<0.0001). No patient had observed cataract progression during the study.Conclusions: One single intravitreal injection of triamcinolone may offer certain advantages over bevacizumab in the short-term management of refractory diabetic macular oedema, specifically with regard to changes in central macular thickness. The actual clinical relevance of our preliminary findings, however, remains to be determined in future larger studies.

Interação da pele humana com fenol: determinação do mecanismo e caracterização do efeito de peeling

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Permeabilidade dentinária e erosão dentário: Avaliação de diferentes substâncias ácidas e agentes dessensibilizantes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Mean-field model for Josephson oscillation in a Bose-Einstein condensate on an one-dimensional optical trap

Using the axially-symmetric time-dependent Gross-Pitaevskii equation we study the phase coherence in a repulsive Bose-Einstein condensate (BEC) trapped by a harmonic and an one-dimensional optical lattice potential to describe the experiment by Cataliotti et al. on atomic Josephson oscillation [Science 293, 843 (2001)]. The phase coherence is maintained after the BEC is set into oscillation by a small displacement of the magnetic trap along the optical lattice. The phase coherence in the presence of oscillating neutral current across an array of Josephson junctions manifests in an interference pattern formed upon free expansion of the BEC. The numerical response of the system to a large displacement of the magnetic trap is a classical transition from a coherent superfluid to an insulator regime and a subsequent destruction of the interference pattern in agreement With the more recent experiment by Cataliotti et al. [New J. Phys. 5, 71 (2003)].

Dynamical classical superfluid-insulator transition in a Bose-Einstein condensate on an optical lattice

We predict a dynamical: classical superfluid-insulator transition in a Bose-Einstein condensate (BEC) trapped in combined optical and axially symmetrical harmonic potentials initiated by the periodic modulation of the radial trapping potential. The transition is marked by a loss of phase coherence in the BEC and a subsequent destruction of the interference pattern upon free:expansion. For a weak modulation of the radial potential the phase coherence is maintained. For a stronger modulation and a longer holding time in the modulated trap, the phase coherence is destroyed thus signalling a classical superfluid-insulator transition. The results are illustrated by a complete numerical solution of the axially symmetrical mean-field Gross-Pitaevskii equation for a repulsive BEC. Suggestions for future experimentation are-made.

Progressive power lens measurement by low coherence speckle interferometry

This work proposes a method for dioptric power mapping of progressive lenses through dual wavelength, low-coherence digital speckle pattern interferometry. Lens characterization finds several applications and is extremely useful in the fields of ophthalmology and astronomy, among others. The optical setup employs two red diode lasers which are conveniently aligned and tuned in order to generate a synthetic wavelength. The resulting speckle image formed onto a diffusive glass plate positioned behind the test lens appears covered of contour interference fringes describing the deformation on the light wavefront due to the analyzed lens. By employing phase stepping and phase unwrapping methods the wavefront phase was retrieved and then expressed in terms of a Zernike series. From this series, expressions for the dioptric power and astigmatic power were derived as a function of the x- and y-coordinates of the lens aperture. One spherical and two progressive lenses were measured. The experimental results presented a good agreement with those obtained through a commercial lensometer, showing the potentialities of the method. © 2013 Elsevier Ltd.