Assuntos
Acomodação Ocular/fisiologia , Traumatismos Craniocerebrais/complicações , Miopia/etiologia , Espasmo/etiologia , Adulto , Encéfalo/patologia , Coma Pós-Traumatismo da Cabeça/complicações , Traumatismos Craniocerebrais/diagnóstico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Miopia/diagnósticoAssuntos
Opacidade da Córnea/virologia , Infecções Oculares Virais/virologia , Infecções por HTLV-I/virologia , Ceratite/virologia , Paraparesia Espástica Tropical/virologia , Opacidade da Córnea/diagnóstico , Substância Própria/virologia , Infecções Oculares Virais/diagnóstico , Anticorpos Anti-HTLV-I/análise , Infecções por HTLV-I/diagnóstico , Vírus Linfotrópico T Tipo 1 Humano/isolamento & purificação , Humanos , Ceratite/diagnóstico , Paraparesia Espástica Tropical/diagnósticoRESUMO
OBJECTIVE: To evaluate clinical and refractive results of myopic angle-supported intraocular lenses (IOLs). DESIGN: Prospective, noncomparative case series. PARTICIPANTS: Twenty-one eyes of 12 patients (7 female) with a mean age of 29.5 years and a follow-up of 24 months. The prospective study included highly myopic eyes (more than -11.00 diopters [D]) with spectacle-corrected visual acuity better than 20/200. METHODS: Twenty-one eyes underwent implantation of a single-piece IOL with Z-shaped haptics for angle support (each haptic with two footplates) and an optical zone of 4.5 mm (NuVita, Bausch & Lomb Surgical, Irvine, CA). The dioptric power of the IOL was calculated considering refraction, keratometry, and anterior chamber depth (specific nomogram), and its diameter was determined by adding 0.5 mm to the corneal diameter. MAIN OUTCOME MEASURES: We evaluated the following clinical and refractive data: visual acuity without and with correction (VAsc and VAcc), spherical equivalent (SE) obtained under cycloplegia, slit-lamp biomicroscopy, keratometry, applanation tonometry, endothelial cell count, ultrasound pachymetry, gonioscopy, indirect ophthalmoscopy, subjective complaints, and descriptions of complications. RESULTS: Mean postoperative VAsc was 20/74. Mean preoperative VAcc (20/50) increased to 20/30; 65% gained at least two lines of VAcc, and no eye had a decrease in VAcc. Preoperative SE (-18.95 D) evolved to -2. 06 D, stabilizing after one month. Iris retraction (pupil ovalization) more than 0.5 mm was noted in eight eyes (40%). Mean keratometry, corneal astigmatism, and ultrasound pachymetry were stable during the study (P > 0.01). Significant endothelial cell loss was demonstrated in the second year. Gonioscopy showed 70 (87. 5%) footplates ideally positioned with no iris depression. Reports of glare and haloes in dark environment were considered light in 80% and not referred in 20%, and spectacles were used for residual refraction in 75%. Intraocular lens exchange was needed in one eye because of undersizing, and the IOL was removed in one eye because of chronic inflammatory reaction associated with ocular hypertension (this patient was excluded from the statistical analysis). CONCLUSIONS: This report demonstrates good efficacy for correction of high myopia by the phakic IOL used during the two years of follow-up. Long-term complications (safety) such as iris retraction and endothelial cell loss remain a concern.
Assuntos
Câmara Anterior/cirurgia , Lentes Intraoculares , Miopia/cirurgia , Adulto , Contagem de Células , Endotélio Corneano/patologia , Feminino , Seguimentos , Gonioscopia , Humanos , Pressão Intraocular , Implante de Lente Intraocular , Masculino , Estudos Prospectivos , Tonometria Ocular , Acuidade VisualRESUMO
Objetivo: Resumir o desenvolvimento de um Videoceratógrafo (ou menos precisamente, Topógrafo de Córnea) projetado e fabricado no Brasil. Métodos: Discos de Plácido pintados num anteparo em forma de cone säo refletidos pela córnea. As imagens passam por um sistema óptico de aumento e säo focalizadas num CCD ('' Charge Coupled Device ''; nada mais do que uma abreviaçäo para câmeras fabricadas com a tecnologia de semicondutores) atrás do cone. O sinal do CCD é enviado para uma placa de captura de imagens ('' frame grabber '')intalada em um PC-IBM compatível. Por meio de algoritmos de processamento de imagens, extraem-se das imagens digitalizadas distâncias de borda dos Discos de Plácido. Estes valores säo inseridos em algoritmos com modelos matemáticos de curvatura da córnea, resultando no cálculo da dioptria de aproximadamente 5.760 pontos. Resultados: Assim como em outros aparelhos importados, imprime-se na tela do computador um mapa colorido plano com código de cores relativo aos valores de dioptria. Para um conjunto de 9 esferas de raios: 5.50; 5.75; 6.00; 6.25; 6.75; 7.00; 7.25; 7.50; 7.75 mm obteve-se um desvio médio de 0.1 para dioptria e 0.02 mm para o raio. Foram analizados computacionalmente 5.760 pontos para cada esfera. Em uma amostra de 20 córneas obteve-se desvio médio de 0.2 dioptrias com relaçäo ao topógrafo EyeSys. Conclusöes: Podemos afirmar que o instrumento contruído obtém resultados equivalentes àqueles do intrumento importado.
Assuntos
Desenvolvimento Tecnológico , Topografia da Córnea/instrumentaçãoRESUMO
PURPOSE: To study two cases of corneal scarring due to trauma (one case) and infection (one case) unrelated to a previous photorefractive keratectomy (PRK) for the correction of myopia. METHODS: The patients are part of an Institutional Review Board-approved study of the safety and efficacy of PRK. Both patients underwent bilateral, nonsimultaneous corneal ablation based on preoperative spherical equivalent. RESULTS: Seven months after PRK, the first patient sustained an alkali burn in one eye that caused severe corneal scarring and myopic regression. The other patient developed bilateral keratoconjunctivitis, more intense in the right eye (1 month after the operation) than in the left eye (4 months after the operation). This right eye subsequently developed diffuse scarring and loss of visual acuity. CONCLUSION: Patients who have undergone PRK may develop severe corneal scarring after relatively mild ocular traumas or infections.
Assuntos
Infecções por Adenovirus Humanos/complicações , Queimaduras Químicas/complicações , Opacidade da Córnea/etiologia , Queimaduras Oculares/induzido quimicamente , Infecções Oculares Virais/complicações , Ceratoconjuntivite/complicações , Ceratectomia Fotorrefrativa , Infecções por Adenovirus Humanos/tratamento farmacológico , Infecções por Adenovirus Humanos/patologia , Adulto , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/uso terapêutico , Queimaduras Químicas/tratamento farmacológico , Compostos de Cálcio/efeitos adversos , Opacidade da Córnea/patologia , Opacidade da Córnea/cirurgia , Queimaduras Oculares/tratamento farmacológico , Infecções Oculares Virais/tratamento farmacológico , Infecções Oculares Virais/patologia , Seguimentos , Humanos , Ceratoconjuntivite/tratamento farmacológico , Ceratoconjuntivite/patologia , Lasers de Excimer , Masculino , Soluções Oftálmicas , Óxidos/efeitos adversos , Estudos Prospectivos , Acuidade VisualAssuntos
Córnea/cirurgia , Substância Própria/patologia , Transplante de Córnea/efeitos adversos , Miopia/cirurgia , Transtornos da Visão/etiologia , Adulto , Córnea/fisiopatologia , Doenças da Córnea/etiologia , Doenças da Córnea/patologia , Humanos , Masculino , Miopia/fisiopatologia , Transtornos da Visão/patologia , Acuidade VisualRESUMO
The purpose of this study was to evaluate corneal reepithelialization and wound healing following annular excimer keratectomy. Two sets of experiments were performed on 35 rabbit eyes. In the first set of experiments, experiment I, deep Fresnel excimer keratectomy was performed, with a 6-mm outer and 3-mm inner diameter. Animals were sacrificed at 1, 5, 12, and 16 weeks, and corneas were examined by light and electron microscopy. In experiment II, the central epithelium was left intact, and superficial and deep mid-peripheral excimer annular keratectomies were performed measuring 6 mm in outer and 3 mm in inner diameter. Animals were sacrificed at 1 week, and corneas were examined by light microscopy. Following deep Fresnel excimer keratectomy (experiment I), corneas showed stromal edema in the central 3-mm zone. Intrastromal islands of epithelial cells with PAS positive basement membrane-like structures were seen histologically at 1 week. Electron microscopy showed loss of stromal collagen in areas adjacent to epithelial islands; in areas distant from the epithelial islands, the stromal collagen appeared normal. The overlying central stroma sloughed after 5 weeks. Anterior stromal scarring was observed. In experiment II (mid-peripheral annular keratectomy), intrastromal epithelial accretion was present in corneas with deep annular keratectomy but not in superficial annular keratectomy. Intrastromal epithelial accretion follows deep excimer annular keratectomy and is associated with adjacent stromal degradation.
Assuntos
Córnea/patologia , Córnea/cirurgia , Terapia a Laser/métodos , Animais , Substância Própria/patologia , Endotélio Corneano/patologia , Período Pós-Operatório , CoelhosRESUMO
PURPOSE: To compare corneal light scattering after laser in situ keratomileusis and photorefractive keratectomy in rabbit eyes. METHODS: For laser in situ keratomileusis, a 5-mm, -10-diopter spherorefractive resection was performed on the stromal bed under a corneal flap. Corneal light scattering was objectively measured for 12 weeks, and compared to corneal light scattering after photorefractive keratectomy (5 mm, -10 diopters). RESULTS: Corneal light scattering was significantly lower in the laser in situ keratomileusis group than in the photorefractive keratectomy group at all time points after surgery (P < .01 at weeks 1 through 6, and P = .03 at week 12). CONCLUSIONS: In this experimental study, laser in situ keratomileusis resulted in significantly less corneal light scattering than photorefractive keratectomy.
Assuntos
Córnea/fisiologia , Ceratectomia Fotorrefrativa , Espalhamento de Radiação , Animais , Córnea/cirurgia , Substância Própria/cirurgia , Lasers de Excimer , Luz , Estudos Prospectivos , CoelhosRESUMO
The authors reviewed the charts of 22 patients with Peters' anomaly. Various surgical procedures were performed on 30 eyes of 18 patients (mean number of procedures = 3.3 per eye). Follow-up averaged six years. Visual acuity varied widely, with six eyes having an acuity of 20/400 or better, and 11 eyes with no light perception. Concomitant or secondary glaucoma required a greater number of surgical procedures (4.1 vs 3.4) per eye and was associated with a poorer visual outcome. No eyes with glaucoma had visual acuity better than 20/400. In bilaterally operated patients, visual results in one eye were independent of the outcome of the fellow eye. The range of visual acuity in bilaterally operated patients was similar to the vision in those operated unilaterally. Visual outcome in patients with Peters' anomaly remains guarded. With modern surgical techniques and aggressive attempts at visual rehabilitation, many patients may benefit from surgery. Some patients may have moderately good visual acuity for months or years before vision is lost. In the interim they may learn tasks they may not have otherwise acquired.
Assuntos
Córnea/cirurgia , Opacidade da Córnea/congênito , Opacidade da Córnea/cirurgia , Acuidade Visual , Extração de Catarata , Opacidade da Córnea/fisiopatologia , Seguimentos , Glaucoma/complicações , Glaucoma/cirurgia , Humanos , Lactente , Ceratoplastia Penetrante , VitrectomiaRESUMO
OBJECTIVE: To report objective grading and analysis of excimer laser-induced scarring using high-frequency ultrasound. METHODS: High-frequency ultrasound (50 MHz) corneal examination was performed on eight New Zealand white rabbits at different time points (10, 17, 24, and 74 days following phototherapeutic keratectomy). We used biometry and signal-processing techniques to determine corneal, epithelial, and scar thicknesses and to quantify the acoustic backscatter. RESULTS: Excimer laser-induced scarring showed an irregularly distributed acoustic hyperreflectivity that decreased through day 74. Corneal thickness remained reduced after ablation (mean, 318 microns compared with 419 microns for controls). Epithelial thickness averaged 62 microns and scar thickness, 87 microns. Scar peak and average anterior stroma acoustic backscatter ratios decreased from day 10 to day 74 (19.65 to 2.76, and 6.42 to 1.32, respectively). Histopathologic study showed increased keratocyte activity at early time points that correlated with acoustic backscatter ratios and imaging pattern. CONCLUSIONS: High-frequency ultrasound signal processing is a noninvasive method that quantitatively grades excimer laser-induced corneal scarring.
Assuntos
Córnea/cirurgia , Doenças da Córnea/diagnóstico por imagem , Doenças da Córnea/etiologia , Terapia a Laser/efeitos adversos , Animais , Antropometria , Cicatriz/patologia , Córnea/diagnóstico por imagem , Córnea/patologia , Doenças da Córnea/patologia , Seguimentos , Coelhos , UltrassonografiaRESUMO
The excimer laser has been undergoing rapid development for clinical use since the early 1980s. The authors report 2-year follow-up results from studies in 31 eyes (15 women and 14 men) to evaluate the excimer laser in performing photokeratectomy. Patients were divided into two groups: 27 eyes (group 1) underwent phototherapeutic keratectomy, and 4 eyes (group 2) underwent photorefractive keratectomy. Visual function improved in 21 of 27 eyes in group 1 and in 2 of 4 eyes in group 2. Complications were minimal and manageable. The authors describe a procedure to minimize induced hyperopia in phototherapeutic keratectomy patients, and, although not statistically significant, less induced hyperopia was noted in these patients. Photokeratectomy may be an alternative to penetrating or lamellar keratoplasty and more invasive refractive procedures, but the long-term effects must be carefully observed.