884 resultados para Undergraduate Ophthalmology


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The divided visual field technique was used to investigate the pattern of brain asymmetry in the perception of positive/approach and negative/withdrawal facial expressions. A total of 80 undergraduate students (65 female, 15 male) were distributed in five experimental groups in order to investigate separately the perception of expressions of happiness, surprise, fear, sadness, and the neutral face. In each trial a target and a distractor expression were presented simultaneously in a computer screen for 150 ms and participants had to determine the side (left or right) on which the target expression was presented. Results indicated that expressions of happiness and fear were identified faster when presented in the left visual field, suggesting an advantage of the right hemisphere in the perception of these expressions. Fewer judgement errors and faster reaction times were also observed for the matching condition in which emotional faces were presented in the left visual field and neutral faces in the right visual field. Other results indicated that positive expressions (happiness and surprise) were perceived faster and more accurately than negative ones (sadness and fear). Main results tend to support the right hemisphere hypothesis, which predicts a better performance of the right hemisphere to perceive emotions, as opposed to the approach-withdrawal hypothesis.

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PURPOSE. To evaluate the change in vision after 3 monthly consecutive intravitreal injections of 1.25 mg of bevacizumab for neovascular age-related macular degeneration (AMD). METHODS. A retrospective analysis of 35 eyes was performed. Visual acuity (VA) at initial visit and at each follow-up visit was compared. The injection of bevacizumab was performed at 30-day intervals and patients were observed for 5 months after the last injection. RESULTS. Of the 35 eyes, 9 had received previous treatment with photodynamic therapy with or without 4 mg of intravitreal triamcinolone. VA was measured in Snellen table and transformed into logMAR for statistical purposes. Mean age was 76.66 years (range, 49-90 years). There were 24(69%) women and 11(31%) men. Mean VA at the initial visit was 0.92 +/- 0.50. At month 1, mean VA was 0.84 +/- 0.51 and at month 2 was 0.74 +/- 0.51. At month 3, mean VA remained 0.74 +/- 0.49. Six and 8 months after the initial visit, VA was 0.79 +/- 0.49 and 0.77 +/- 0.50, respectively. The improvement in VA was statistically significant at month 2 and at the end of the follow-up (8 months) compared with the baseline VA. CONCLUSIONS. Three consecutive monthly injections of intravitreal bevacizumab to treat neovascular AMD is effective in improving VA in the short term. Longer prospective studies should be performed to confirm VA stability after the third injection. (Eur J Ophthalmol 2010; 20: 740-4)

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PURPOSE: To compare changes in corneal hysteresis (CH) and the corneal resistance factor (CRF) in myopic and hyperopic laser in situ keratomileusis (LASIK) and evaluate their relationship to the number of photoablative pulses delivered, a surrogate for ablation volume. SETTING: Cleveland Clinic Cole Eye Institute, Cleveland, Ohio, USA. METHODS: Preoperative and 1-week postoperative Ocular Response Analyzer measurements in eyes that had femtosecond-assisted LASIK were studied retrospectively. Changes in CH and CRF were compared and tested for correlation with the number of excimer laser pulses. RESULTS: Thirteen myopic eyes and 11 hyperopic eyes were evaluated. Preoperative corneal thickness, CH, CRF, programmed correction magnitude, flap thickness, and total number of fixed spotsize photoablative pulses were similar in the 2 groups (P>.1). Decreases in CH and CRF were greater after myopic LASIK than after hyperopic LASIK (P<.005), and changes in CRF were correlated with the number of excimer laser pulses in the myopic group only (r = -0.63, P = .02). Regardless of ablation profile, changes in CH were more strongly correlated with preoperative CH values than with attempted ablation volume. CONCLUSIONS: With comparable flap thickness and attempted ablation volumes, myopic photoablation profiles were associated with greater decreases in CRF and CH than hyperopic profiles. Results indicate that preoperative corneal biomechanical status, ablation volume, and the spatial distribution of ablation are important factors that affect corneal resistance and viscous dissipative properties differently. Preferential tissue removal in the natively thicker paracentral cornea in hyperopia may partially account for the rarity of ectasia after hyperopic LASIK.

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Purpose: To evaluate wavefront performance and modulation transfer function (MTF) in the human eye aft er the implantation of diffractive or refractive multifocal intraocular lenses (IOLs). Materials and Methods: This was a prospective, interventional, comparative, nonrandomized clinical study. Uncorrected distance and near visual acuity, and wavefront analysis including MTF curves (iTrace aberrometer, Tracey Technologies, Houston, TX, USA) were measured in 60 patients aft er bilateral IOL implantation with 6 months of follow-up. Forty eyes received the diffractive ReSTOR (Alcon), 40 eyes received the refractive ReZoom (Advanced Medical Optics) and 40 eyes, the Tecnis ZM900 (Advanced Medical Optics). The comparison of MTF and aberration between the intraocular lenses was performed using analysis of variance (ANOVA), followed by the Dunn test when necessary. Results: The mean uncorrected distance visual acuity was similar in all three groups of multifocal IOLs. The ReSTOR group provided better uncorrected near visual acuity than the ReZoom group (P < 0.001), but similar to the Tecnis group. Spherical aberration was significantly higher in the ReZoom group (P = 0.007). Similar MTF curves were found for the aspheric multifocal IOL Tecnis and the spheric multifocal IOL ReSTOR, and both performed better than the multifocal IOL ReZoom in a 5 mm pupil (P < 0.001 at all spatial frequencies). Conclusions: Diffractive IOLs studied presented similar MTF curves for a 5 mm pupil diameter. Both diffractive IOLs showed similar spherical aberration, which was significantly better with the full-diffractive IOL Tecnis than with the refractive IOL ReZoom.

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PURPOSE: To determine whether implantation of an aspherical intraocular lens (IOL) results in reduced ocular aberrations and improved contrast sensitivity after cataract surgery without critical reduction of depth of focus. DESIGN: Double-blinded, randomized, prospective study. METHODS: In an intraindividual study of 25 patients with bilateral cataract, an aspherical IOL (Akreos Advanced Optic [AO]; Bausch & Lomb, Inc., Rochester, New York, USA) was implanted in one eye and a spherical IOL (Akreos Fit; Bausch & Lomb, Inc) in the fellow eye. Higher-order aberrations with a 5- and 6-mm pupil were measured with a dynamic retinoscopy aberrometer at 1 and 3 months after surgery. Uncorrected and best-corrected visual acuity and contrast sensitivity under mesopic and photopic conditions also were measured. Distance-corrected near and intermediate visual acuity were studied as a measurement of depth of focus. RESULTS: There was no statistically significant difference between eyes in uncorrected and best-corrected visual acuity at I and 3 months after surgery. There was a statistically significant between-group difference in contrast sensitivity under photopic conditions at 12 cycles per degree and under mesopic conditions at all spatial frequencies. The Akreos AO group obtained statistically significant lower values of higher-order aberrations and spherical aberration with 5- and 6-mm pupils compared with the Akreos Fit group (P < .05). There was no significant difference in distance-corrected near and intermediate visual acuity between both groups. CONCLUSIONS: Aspherical aberration-free Akreos AO IOL induced significantly less higher-order aberrations and spherical aberration than the Akreos Fit. Contrast sensitivity was better under mesopic conditions with the Akreos AO with similar results of depth of focus. (Am J Ophthalmol 2010;149:383-389. (C) 2010 by Elsevier Inc. All rights reserved.)

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Purpose: To study the oculometric parameters of hyperopia in children with esotropic amblyopia, comparing amblyopic eyes with fellow eyes. Methods: Thirty-seven patients (5-8 years old) with bilateral hyperopia and esotropic amblyopia underwent a comprehensive ophthalmic examination, including cycloplegic refraction, keratometry and A-scan ultrasonography. Anterior chamber depth, lens thickness, vitreous chamber depth and total axial length were recorded. The refractive power of the crystalline lens was calculated using Bennett`s equations. Paired Student`s t-tests were used to compare ocular biometric measurements between amblyopic eyes and their fellow eyes. The associations of biometric parameters with refractive errors were assessed using Pearson correlation coefficients and linear regression. Multivariable models including axial length, corneal power and lens power were also constructed. Results: Amblyopic eyes were found to have significantly more hyperopic refraction, less corneal power, greater lens power, shorter vitreous chamber depth and shorter axial length, despite similar anterior chamber depth and lens thickness. The strongest correlation with refractive error was observed for the axial length/corneal radius ratio (r(36) = -0.92, p < 0.001 for amblyopic and r(36) = 0.87, p < 0.001 for fellow eyes). Axial length accounted for 39.2% (R(2)) of the refractive error variance in amblyopic eyes and 35.5% in fellow eyes. Adding corneal power to the model increased R(2) to 85.7% and 79.6%, respectively. A statistically significant correlation was found between axial length and corneal power, indicating decreasing corneal power with increasing axial length, and they were similar for amblyopic eyes (r(36) = 0.53,p < 0.001) and fellow eyes (r(36) = -0.57, p < 0.001). A statistically significant correlation was also found between axial length and lens power, indicating decreasing lens power with increasing axial length (r(36) = -0.72, p < 0.001 for amblyopic eyes and r(36) = -0.69, p < 0.001 for fellow eyes). Conclusions: We observed that the correlation among the major oculometric parameters and their individual contribution to hyperopia in esotropic children were similar in amblyopic and non-amblyopic eyes. This finding suggests that the counterbalancing effect of greater corneal and lens power associated with shorter axial length is similar in both eyes of patients with esotropic amblyopia.

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PURPOSE: To evaluate laser combined with intravitreal triamcinolone acetonide (IVTA) for the management of patients with proliferative diabetic retinopathy (PDR) and clinically significant macular edema (CSME). DESIGN: Randomized clinical trial. METHODS: SETTINGS: Single center. STUDY POPULATION: Twenty-two patients with bilateral treatment,naive moderate PDR and CSME. INTERVENTION: Laser (panretinal and macular) photocoagulation was performed in each eye, followed by IVTA in one randomly assigned eye. Best,corrected visual acuity (BCVA), fundus photography, and optical coherence tomography were performed at baseline and at months 1, 3, 6, 9, and 12. MAIN OUTCOME MEASURES:. Changes in BCVA, central macular thickness (CMT), and total macular volume (TMV). RESULTS: The mean logarithm of the minimal angle of resolution (logMAR) BCVA improved significantly, and mean CMT and TMV were significantly reduced in the IVTA group compared with the laser,only group (controls) at all study follow-up visits (P < .001). The mean logMAR BCVA (Snellen equivalent) was 0.44 (20/50(-2)) for the IVTA group and 0.38 (20/50(+1)) for the controls at baseline, and 0.12 (20/25(-1)) for the IVTA group and 0.32 (20/40(-1)) for the controls at 12 months (P < .001.). The mean CMT and TMV were, respectively, 360 mu m and 8.59 mm(3) for the IVTA group and 331 mu m and 8.44 mm(3) for the controls at baseline, and 236 mu m and 7.32 mm(3) for the IVTA group and 266 mu m and 7.78 mm(3) for the controls at 12 months (P < .001). CONCLUSIONS: The combination of laser photocoagulation with IVTA was associated with improved BCVA and decreased CMT and TMV when compared with laser photocoagulation alone for the treatment of moderate PDR with CSME. (Am J Ophthalmol 2009;147:291-297. (C) 2009 by Elsevier Inc. All rights reserved.)

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Background: Retinitis pigmentosa (RP) is a group of genetically heterogeneous diseases with progressive degeneration of the retina. The condition can be inherited as an autosomal dominant, autosomal recessive, and X-linked trait. Methods: We report on two female twin pairs. One twin of each pair is affected with RP, the other twin is unaffected, both clinically and functionally. Molecular analysis in both twins included zygosity determination, arrayed primer extension chip analysis for autosomal recessive and dominant RP, sequencing of the entire RPGR gene, and analysis of X-chromosome inactivation status. Results: Both unrelated twin pairs were genetically identical. Of the potential pathogenetic mechanisms, skewed X-inactivation was excluded on leukocytes. Autosomal recessive RP and autosomal dominant RP arrayed primer extension chip analysis result was completely normal, excluding known mutations in known genes as the cause of disease in the affected twins. Sequencing excluded mutations in RPGR. A postzygotic recessive or dominant genetic mutation of an RP gene is not impossible. A postfertilization error as a potential cause of uniparental isodisomy is unlikely albeit not entirely impossible. Conclusion: The authors report on the second and third unrelated identical twin pair discordant for RP. The exact cause of the condition and the explanation of the clinical discordance remain elusive. RETINA 31:1164-1169, 2011

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Purpose To evaluate the ocular toxicity of escalating doses of intravitreous adalimumab (Humira) in the rabbit eye. Methods Twelve New Zealand albino rabbits received unilateral intravitreous injections of 0.1 ml of adalimumab 0.25 mg (three eyes), 0.50 mg (three eyes), 1.0 mg (three eyes) or 0.1 ml balanced salt solution (BSS, threeeyes). Slit-lamp biomicroscopy and fundoscopy were carried out at baseline, day 1, 7 and 14 following intravitreous injection, while electroretinography (ERG) was carried out at baseline and day 14. Animals were euthanized on day 14, and histopathological examination of the eyes was performed. Results Slit-lamp biomicroscopy and fundoscopy were normal in eyes having received BSS, 0.25 mg or 0.50 mg adalimumab; however, inflammation was present in two of three eyes having received 1.0 mg adalimumab. Similarly, comparison of scotopic and photopic ERG light at baseline and day 14 demonstrated no changes in eyes receiving BSS, 0.25 mg or 0.50 mg adalimumab, but two of three eyes having received 1.0 mg adalimumab showed a greater than 30% reduction in a and b wave. Finally, histopathology demonstrated no differences between eyes receiving BSS, 0.25 mg or 0.50 mg of adalimumab, but two of three eyes injected with 1.0 mg demonstrated inflammatory cell infiltration of the vitreous and anterior chamber, with one of these eyes demonstrating retinal necrosis. Conclusions Escalating doses of intravitreous adalimumab in rabbit eyes caused no detectable functional or structural ocular toxicity up to a dose of 0.50 mg. Administration of 1.0 mg in 0.1 ml was associated with an inflammatory reaction and retinal necrosis.

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PURPOSE: To determine whether implantation of an intraocular lens (IOL) with an aspheric surface (Akreos AO, Bausch & Lomb Inc) results in reduced ocular aberrations (spherical aberration) and improved Strehl ratio and modulation transfer function (MTF) after cataract surgery. METHODS: In an intraindividual, randomized, double-masked, prospective study of 50 eyes (25 patients) with bilateral cataract, an IOL with modified anterior and posterior surfaces (Akreos AO) was implanted in one eye and a biconvex IOL with spherical surfaces (Akreos Fit, Bausch & Lomb Inc) implanted in the fellow eye. Ocular aberrations, Strehl ratio, and MTF curve with 4.5-, 5.0-, and 6.0-mm pupils were measured with a NIDEK OPD-Scan dynamic retinoscopy aberrometer 3 months after surgery. Uncorrected and corrected distance visual acuity (UDVA and CDVA, respectively) were also measured. RESULTS: No statistically significant difference was noted between eyes in postoperative UDVA and CDVA at 1 month. At 3 months, the Akreos AO IOL group obtained statistically significant lower values of higher order and spherical aberrations with 4.5-, 5.0-, and 6.0-mm pupil diameters than the Akreos Fit IOL group (P<.05). The value of Strehl ratio was statistically significantly higher in eyes with the Akreos AO IOL for 4.5- and 6.0-mm pupils (P<.05). The MTF curve was better in the Akreos AO IOL group in 4.5-, 5.0-, and 6.0-mm pupils (P<.05). CONCLUSIONS: The aspheric Akreos AO IOL induced significantly less spherical aberration than the Akreos Fit IOL for 4.5-, 5.0-, and 6.0-mm pupils. Modulation transfer function and Strehl ratio were also better in eyes implanted with the Akreos AO IOL than the Akreos Fit. [J Refract Surg. 2011;27(4):287-292.] doi:10.3928/1081597X-20100714-01

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Purpose: To compare the central corneal thickness (CCT) of patients with systemic sclerosis (SSc) and control subjects. Methods: The study group comprised 37 consecutive patients with SSc, and the control group comprised 23 healthy individuals similar in age and sex. CCT value was measured by ultrasound pachymetry. Results: In the SSc group, the mean CCT in the right eye was 534.9 +/- 33.5 mu m and 536.9 +/- 32.4 mu m in the left eye. In the control group, the mean CCT was 533.0 +/- 32.9 mu m in the right eye and 533.1 +/- 33.6 mu m in the left eye. The mean CCT was not significantly different in the SSc group compared with the control group for both the right (P = 0.83) and left (P = 0.67) eyes. Conclusions: CCT measurements do not significantly differ in patients with SSc compared with healthy control subjects.

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PURPOSE To compare reading ability after cataract surgery and bilateral implantation of multifocal intraocular lenses (IOLs) with a +3 00 diopter (D) addition (add) or a +4 00 D add SETTING Department of Ophthalmology, University of Sao Paulo, Sao Paulo, Brazil DESIGN Prospective comparative study METHODS Patients scheduled for cataract surgery were randomly assigned to bilateral implantation of an aspheric AcrySof ReSTOR multifocal IOL with a +3 00 diopter (D) addition (add) or a +4 00 D add The reading speed, critical print size, and reading acuity were measured binocularly with best correction using MNREAD acuity charts 6 months after surgery Patients were tested with the chart at the best patient-preferred reading distance and at 40 cm Binocular uncorrected and best distance-corrected visual acuities at far and near were also measured RESULTS The study enrolled 32 patients At the best reading distance the results were similar between the 2 IOL groups in all reading parameters When tested at 40 cm, reading speed at all print sizes from 03 to 00 (all P< 001), critical print size (P< 001) and reading acuity (P = 014) were statistically significantly better in the +3 00 D IOL group than in the +4 00 DIOL group Uncorrected and corrected visual acuities at far and near were similar between the 2 groups CONCLUSION Although the 2 IOL groups had similar performance in reading parameters, patients had to adjust to their best reading distance The +3 00 D IOL performed better than the +4 00 D IOL at 40 cm

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Purpose The aim of this study was to test the correlation between Fourier-domain (FD) optical coherence tomography (OCT) macular and retinal nerve fibre layer (RNFL) thickness and visual field (VF) loss on standard automated perimetry (SAP) in chiasmal compression. Methods A total of 35 eyes with permanent temporal VF defects and 35 controls underwent SAP and FD-OCT (3D OCT-1000; Topcon Corp.) examinations. Macular thickness measurements were averaged for the central area and for each quadrant and half of that area, whereas RNFL thickness was determined for six sectors around the optic disc. VF loss was estimated in six sectors of the VF and in the central 16 test points in the VF. The correlation between VF loss and OCT measurements was tested with Spearman`s correlation coefficients and with linear regression analysis. Results Macular and RNFL thickness parameters correlated strongly with SAP VF loss. Correlations were generally stronger between VF loss and quadrantic or hemianopic macular thickness than with sectoral RNFL thickness. For the macular parameters, we observed the strongest correlation between macular thickness in the inferonasal quadrant and VF loss in the superior temporal central quadrant (rho=0.78; P<0.001) whereas for the RNFL parameters the strongest correlation was observed between the superonasal optic disc sector and the central temporal VF defect (rho=0.60; P<0.001).

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Purpose: Animal models of diseases are extremely important in the study of the physiopathogenesis of human diseases and for testing novel therapeutic interventions. The present study aimed to develop an animal model that simulates human allergic conjunctivitis and to study how allergic response may be influenced by the allergen dose used for immunization and by genetic factors. Methods: Sixty C57Bl/6 mice and 60 BALB/c mice were immunized with placebo, or 5 mu g or 500 mu g of allergen derived from Dermatophagoides pteronyssinus. After ocular challenge, the mice were examined in order to clinically verify the occurrence or not of conjunctivitis. Material obtained from animals was used for total and specific IgE and IgG1 dosage, for assays of Der p-specific lymphocyte proliferation and supernatant cytokine dosage, and for histopathological evaluation of conjunctiva. Results: We developed a murine model of allergic conjunctivitis induced by D. pteronyssinus. The model is similar to human disease both clinically and according to laboratory findings. In mouse, conjunctivitis was associated with a Th2 cytokine profile. However, IL-10 appeared to be involved with disease blockade. Mice of different strains have distinct immune responses, depending on the sensitization dose. Conclusions: The murine model developed is suitable for the study of immunopathogenesis and as a template for future therapies. Using BALB/c and C57BL/6 mice, we demonstrated that genetic factors play a role in determining susceptibility and resistance, as well as in establishing the allergen concentration needed to induce or to block disease development.

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This paper reports on an investigation into the teaching of medical ethics and related areas in the medical undergraduate course at the University of Queensland. The project was designed in the context of a major curriculum change to replace the current 6 year course by an integrated, problem-based, 4 year graduate medical course, which began in 1997. A survey of clinical students, observations of clinical teaching sessions, and interviews with clinical teachers were conducted. Data obtained have contributed to curriculum development and will provide a baseline for comparison and evaluation of the graduate course in this field. A view of integrated ethics teaching is advanced in the light of the data obtained.