Diogo Leitão Caldas

Evaluation of corneal shape and biomechanics before LASIK.

The preoperative evaluation is of critical importance for success in laser in situ keratomileusis (LASIK). This examination should fulfill 3 main purposes: counseling and educating the candidates, surgery planning, and screening for cases at higher risk for complications. It is critical to interview each refractive patient to assess their individual needs and to provide realistic expectations. A thorough ophthalmologic examination is mandatory, including specific complementary examinations to characterize many aspects of the cornea and the optics of the eye. In fact, it is notable that refractive surgery has motivated tremendous development for advanced diagnostic methods, among many others advancements and innovations in Ophthalmology. One of the most important aspects of the preoperative examination of LASIK candidates is to screen cases at risk for progressive ectasia.

Impact of the wavefront analysis in refraction of keratoconus patients

OBJETIVO: Verificar se a aberrometria ocular total (analise da frente de onda ou wavefront) possibilita a melhora na acuidade visual corrigida (AVc) com lentes esfero-cilindricas, obtida com a refratometria manifesta em casos de ceratocone com algum grau de intolerância ao uso de lentes de contato. METODOS: Os prontuarios de 46 pacientes (89 olhos) referidos com diagnostico de ceratocone e intolerantes ao uso de lentes de contato, submetidos ao exame de aberrometria ocular total seguido de refracao manifesta, foram estudados de forma retrospectiva. A AVc (logMAR) com a correcao existente antes do exame foi comparada com a obtida com a nova refracao manifesta, realizada, considerando-se os dados objetivos da aberrometria. O teste nao-parametrico de Wilcoxon para amostras pareadas foi utilizado para verificacao de diferencas estatisticamente significantes na AVc. RESULTADOS: Houve uma melhora estatisticamente significante na AVc com a nova refracao manifesta (p OBJECTIVE: To verify if the total ocular aberrometry (wavefront analysis) facilitates manifest refraction and improvement in best spectacle distance corrected visual acuity (BSCDVA) with sphero-cylindrical lenses, in keratoconus cases with some degree of contact lenses intolerance. METHODS: Retrospective chart review of 46 patients (89 eyes) referred with keratoconus and contact lenses intolerance was performed. Ocular aberrometry with ray tracing was followed by manifest refraction. BSCDVA (logMAR) with the previous correction was compared with the one obtained based on the wavefront auto-refraction. The nonparametric test of Wilcoxon for paired samples was used to test statistically significant differences in BSCDVA. RESULTS: There was a statistically significant improvement in BSCDVA with the new manifest refraction (p

Ceratoplastia em crianças: indicações e resultados

PURPOSE: To evaluate the indications and results after penetrating keratoplasty in children at Altino Ventura Foundation (FAV). METHODS: A retrospective study was performed in 33 patients (34 eyes), with ages equal or less than 12 years, they underwent a penetrating keratoplasty at FAV, from 2000 to 2009. The mean follow up time was 32.5 ± 23.1 months. Surgery indication, best corrected visual acuity (BCVA) before and after surgery, spherical equivalent (SE) pos surgical and complications were analyzed. The qualitative results were expressed by their frequencies and the quantitative by their means and standard deviations. The t-Student test was used to verify possible differences between means. The level of significance was 95.0% (p<0.05). RESULTS: Mean age at surgery was 7.5 ± 3.3 years. Twenty seven (79.4%) grafts had optical indication and seven (20.6%) therapeutic or tectonic. Among the optical transplants, the most frequent indication was cornea opacity after ocular trauma in 18 (52.9%) eyes. The visual acuity was better in 21 (61.7%) eyes and worse in eight (23.5%). In the optical transplants, rejection was present in four (14.8%) eyes, and four (11.8%) developed glaucoma. CONCLUSION: In FAV opacity after ocular trauma was the most common indication for pediatric keratoplasty. This may be the result of the low income and violent society, among the citizens from the studied population. Many blind children due to cornea disease may achieve improvement in visual acuity if an appropriate surgical and good postoperative management is performed.

Novel use of trypan blue in ocular surface staining: redefining implications for this vital dye

Different applications of trypan blue (TB) for intraocular surgery have been reported, with very high levels of safety and efficacy. We describe the use of TB as an alternative vital dye for staining the ocular surface to assess the integrity of superficial cell layers of the cornea and the surface environment. This facilitates the diagnosis of various ocular surface disorders, including screening for dry eye disease (DED) among refractive and cataract patients. TB staining properties are different from fluorescein and both are stable in a solution, so that a double staining technique is introduced.

Impacto da análise do "wavefront" na refratometria de pacientes com ceratocone

OBJETIVO: Verificar se a aberrometria ocular total (analise da frente de onda ou wavefront) possibilita a melhora na acuidade visual corrigida (AVc) com lentes esfero-cilindricas, obtida com a refratometria manifesta em casos de ceratocone com algum grau de intolerância ao uso de lentes de contato. METODOS: Os prontuarios de 46 pacientes (89 olhos) referidos com diagnostico de ceratocone e intolerantes ao uso de lentes de contato, submetidos ao exame de aberrometria ocular total seguido de refracao manifesta, foram estudados de forma retrospectiva. A AVc (logMAR) com a correcao existente antes do exame foi comparada com a obtida com a nova refracao manifesta, realizada, considerando-se os dados objetivos da aberrometria. O teste nao-parametrico de Wilcoxon para amostras pareadas foi utilizado para verificacao de diferencas estatisticamente significantes na AVc. RESULTADOS: Houve uma melhora estatisticamente significante na AVc com a nova refracao manifesta (p<0,0001). A AVc media passou de 0,37 ou 20/47 (variando entre 1,3 e 0; desvio padrao[DP]=0,25) com a refracao previa para 0,23 ou 20/34 (variando entre 1 e 0,1; DP=0,21). 52 olhos (58,4%) de 28 pacientes apresentaram melhora na AVc com a nova refracao. A melhora media foi de 0,13 logMAR (1,3 linhas na tabela de Snellen), variando entre nula e 0,6 (6 linhas), com desvio padrao de 0,16. Oito pacientes apresentaram anisometropia significativa que limitou a prescricao de oculos em um dos olhos. CONCLUSAO: A aberrometria facilitou a refratometria, determinando melhora significativa na acuidade visual corrigida com as lentes esfero-cilindricas de pacientes com ceratocone intolerantes ao uso de lentes de contato. A anisometropia foi um fator limitante na prescricao de oculos.