ABSTRACT
PURPOSE: The present study aimed to compare the postoperative contrast sensitivity functions between wavefront-guided LASIK eyes and their contralateral wavefront-guided PRK eyes. METHODS: The participants were 11 healthy subjects (mean age=32.4 ± 6.2 years) who had myopic astigmatism. The spatial contrast sensitivity functions were measured before and three times after the surgery. Psycho and a Cambridge graphic board (VSG 2/4) were used to measure luminance, red-green, and blue-yellow spatial contrast sensitivity functions (from 0.85 to 13.1 cycles/degree). Longitudinal analysis and comparison between surgeries were performed. RESULTS: There was no significant contrast sensitivity change during the one-year follow-up measurements neither for LASIK nor for PRK eyes. The comparison between procedures showed no differences at 12 months postoperative. CONCLUSIONS: The present data showed similar contrast sensitivities during one-year follow-up of wave-front guided refractive surgeries. Moreover, one year postoperative data showed no differences in the effects of either wavefront-guided LASIK or wavefront-guided PRK on the luminance and chromatic spatial contrast sensitivity functions.
OBJETIVO: A proposta do presente estudo é comparar funções de sensibilidade ao contraste obtidas após wavefront-LASIK e wavefront-PRK no olho contralateral. MÉTODOS: Os participantes foram 11 sujeitos saudáveis (idade média=32,4 ± 6,2 anos) com astigmatismo miópico. As funções de sensibilidade ao contraste espacial foram obtidas antes e três vezes após a cirurgia. O programa Psycho e uma placa gráfica da Cambridge Research Systems (VSG 2/4) permitiram gerar os estímulos com contraste espacial de luminância e cromático (verde-vermelho e azul-amarelo) de 0,85 até 13,1 ciclos/grau. Análises longitudinais e comparações entre as cirurgias foram realizadas. RESULTADOS: Não houve mudança significativa da sensibilidade ao contraste durante o primeiro ano após a cirurgia para o olho que recebeu o LASIK ou para o olho que recebeu o PRK. A comparação entre as cirurgias também foi semelhante no pós-operatório de um ano. CONCLUSÕES: Os resultados apresentados mostraram sensibilidade ao contraste semelhante durante o primeiro ano após a cirurgia refrativa com o wavefront. Além disso, no pós-operatório de um ano não houve diferença nas funções de sensibilidade ao contraste de luminância e cromático entre os olhos que receberam LASIK e os que receberam PRK.
Subject(s)
Adult , Female , Humans , Male , Astigmatism/surgery , Contrast Sensitivity/physiology , Keratomileusis, Laser In Situ/methods , Myopia/surgery , Photorefractive Keratectomy/methods , Light , Prospective Studies , Refractive Surgical Procedures/methods , Treatment OutcomeABSTRACT
In children with Duchenne muscular dystrophy, color vision losses have been related to dystrophin deletions downstream of exon 30, which affect a dystrophin isoform, Dp260, present in the retina. To further evaluate visual function in DMD children, we measured spatial, temporal, and chromatic red-green and blue-yellow contrast sensitivity in two groups of DMD children with gene deletion downstream and upstream of exon 30. Psychophysical spatial contrast sensitivity was measured for low, middle, and high spatial frequencies with achromatic gratings and for low and middle frequencies with red-green and blue-yellow chromatic gratings. Temporal contrast sensitivity was also measured with achromatic stimuli. A reduction in sensitivity at all spatial luminance contrasts was found for the DMD patients with deletion downstream of exon 30. Similar results were found for temporal luminance contrast sensitivity. Red-green chromatic contrast sensitivity was reduced in DMD children with deletion downstream of exon 30, whereas blue-yellow chromatic contrast sensitivity showed no significant differences. We conclude that visual function is impaired in DMD children. Furthermore, we report a genotype-phenotype relationship because the visual impairment occurred in children with deletion downstream but not upstream of exon 30, affecting the retinal isoform of dystrophin Dp260.
Subject(s)
Humans , Male , Child , Adolescent , Adult , Color Vision , Contrast Sensitivity , Muscular Dystrophy, Duchenne , PsychophysicsABSTRACT
Electrophysiological retinal alterations were evaluated in a group of odontologists contaminated with mercury vapor. The group consisted of 20 odontologists exposed to mercury vapor during the professional activities. The multifocal electroretinogram showed significant statistical differences for the values of the amplitudes of Ni and P1 in all of the rings: ring 1 (p=0.002) for amplitude Ni and (p < 0.00i) for amplitude P1; ring 2(p < O.001) for amplitudes Ni and P1; ring 3(p < O.00i) for amplitude Ni and (p=0.002) for amplitude Pi; ring 4 (p < 0.00i) for amplitudes Ni and Pi; ring 5 (p < 0.001)for amplitude Ni and (p=0.001 ) for amplitude P1; ring 6 (p < 0.001 ) for amplitudes Ni and P1. Increases of the latency P1 for ring1 (p=0.013), ring 5 (p=0.038) and ring 6 (p=0.038) were also found. We conclude that mercurial contamination causes important alterations in cone and rod photoreceptors and also in bipolar cells.
Fueron evaluadas alteraciones electrofisiológicas de la retina en un grupo de odontólogos contaminados con el vapor de mercurio. El grupo estaba formado por 20 odontologos expuestos al vapor de mercurio durante la actividad profesional. El electrorretinograma multifocal señalo diferencias estadísticas significativas para los valores de amplitud N1 y P1 en todos los anillos: anillo 1 (p=0,002) para la amplitud N1 y (p<0,001) para la amplitud P1; anillo 2 (p<0,001) para las amplitudes N1 y P1; anillo 3 (p<0,001) para la amplitud N1 y ( p=0,002) para la amplitud P1; anillo 4 (p<0,001) para la amplitud N1 y P1; anillo 5 (p<0,001) para la amplitud N1 y (p=0,001) para la amplitud P1; anillo 6 (p<0,001) para las amplitudes N1 y P1. El aumento de la latencia P1 para el anillo 1 (p=0,013), el anillo 5 (p=0,038) y el anillo 6 (p=0, 038) también fueron encontrados. Se concluye que la contaminación por mercurio causa importantes alteraciones en los conos y bastoncillos, fotorreceptores y también en las células bipolares.