Aberrometría corneal en el queratocono subclínico / Corneal Aberrometry in Subclinical Keratoconus

Objetivo: Determinar parámetros aberrométricos de la córnea para la detección del queratocono subclínico. Métodos: Se realizó un estudio observacional, analítico de corte transversal que incluyó 36 pacientes con queratocono subclínico (grupo de estudio) y 36 estudiantes con córneas aparentemente sanas (grupo control), que asistieron a la consulta de córnea del Instituto Cubano de Oftalmología Ramón Pando Ferrer, entre mayo de 2018 y junio de 2022. Se analizaron topografía y aberrometría corneal con el tomógrafo corneal Pentacam AXL. Resultados: El grupo queratocono subclínico mostró valores similares para la queratometría, asfericidad corneal, paquimetría y el valor total de desviación en comparación con el grupo normal. Hubo diferencias estadísticamente significativas en los parámetros aberrométricos, como el coma a 90º (Z3 -1), y la raíz cuadrada media de las aberraciones de alto orden, de cara anterior, posterior y total corneal, en queratocono subclínico en comparación con el grupo normal. El coma posterior a 90º presentó un área bajo la curva (0,894) mayor dentro de las aberrometrías, con un punto de corte de -0,013 µm, con sensibilidad del 86,1 por ciento y especificidad del 88,9 por ciento. Conclusiones: El coma posterior a 90º (parámetro aberrométrico) presenta una alta sensibilidad y especificidad para el diagnóstico de queratocono subclínico, mediante el análisis tomográfico Pentacam AXL(AU)

Objective: To determine corneal aberrometric parameters for the detection of subclinical keratoconus. Methods: An observational, analytical, cross-sectional study was performed including 36 patients with subclinical keratoconus (study group) and 36 students with apparently healthy corneas (control group), who attended the cornea consultation at the Cuban Institute of Ophthalmology Ramón Pando Ferrer, between May 2018 and June 2022. Corneal topography and aberrometry were analyzed with the Pentacam AXL corneal tomographer. Results: The subclinical keratoconus group showed similar values for keratometry, corneal asphericity, pachymetry and total deviation value compared to the normal group. There were statistically significant differences in aberrometric parameters, such as coma at 90° (Z3-1), and root mean square of high-order anterior, posterior and total corneal aberrations in subclinical keratoconus compared to the normal group. The 90° posterior coma presented a higher area under the curve (0.894) within the aberrometries, with a cutoff point of -0.013 µm, with sensitivity of 86.1 percent and specificity of 88.9 percent. Conclusions: Coma posterior to 90º (aberrometric parameter) presents high sensitivity and specificity for the diagnosis of subclinical keratoconus, using Pentacam AXL tomographic analysis(AU)

Avaliação das aberrações de alta ordem em pacientes com ceratocone inicial / Assessment of high-order aberrations in patients with early keratoconus

RESUMO Objetivo Identificar alterações de aberrometria de alta ordem em diferentes graus de ceratocone. Métodos Estudo transversal, retrospectivo, observacional. Foram analisados 54 pacientes (108 olhos) diagnosticados com ceratocone pelo mesmo especialista em córnea por meio dos critérios ABCD de Belin/Ambrósio Enhanced Ectasia, utilizando-se o tomógrafo Pentacam® HR 70900 (Oculus Wetzlar, Alemanha). Além disso, foram feitas análises qualitativa e quantitativa das aberrações de alta ordem desses mesmos pacientes por meio do OPD-Scan III-NIDEK. Resultados Por meio da avaliação de ambos os olhos dos pacientes com os critérios de Belin-Ambrósio, constatou-se presença de ceratocone em 34 pacientes. Ademais, por meio da análise estatística, constatou-se relação direta entre a asfericidade posterior e o desenvolvimento do ceratocone, com p<0,001 (referência: p<0,05). Por meio da análise do OPD-Scan III-NIDEK, as principais aberrações de alta ordem encontradas nos pacientes com ceratocone foram coma, trefoil e aberração esférica. Conclusão O raio da curvatura posterior é a primeira variável a se alterar com o desenvolvimento do ceratocone, o que se faz perceptível na análise da asfericidade posterior por meio o Pentacam®. Além disso, a alteração da paquimetria e da asfericidade posterior influencia diretamente o desenvolvimento de aberrações de alta ordem em pacientes com ceratocone.

ABSTRACT Objective To identify higher order aberrometry changes in different degrees of keratoconus. Methods Cross-sectional, retrospective, observational study. Fifty-four patients (108 eyes) diagnosed with keratoconus by the same corneal specialist using the Belin/Ambrósio Enhanced Ectasia ABCD criteria were analyzed, using the Pentacam® HR 70900 tomograph (Oculus Wetzlar, Germany). In addition, qualitative and quantitative analysis of higher order aberrations in these patients was performed using the OPD-Scan III-NIDEK. Results Through the evaluation of both eyes of the patients according to the criteria of Benin Ambrósio, the presence of KCN was verified in 34 patients. Furthermore, through statistical analysis, a direct relationship was found between posterior asphericity and the development of KCN; p<0.001 (reference: p<0.05). Through the analysis of the OPD scan, the main higher order aberrations found in patients with KCN were Coma, Trefoil and Spherical Aberration (AE). Conclusion The posterior curvature radius is the first variable to change with the development of the KCN, which is noticeable in the analysis of posterior asphericity in Pentacam. In addition, alterations in pachymetry and posterior asphericity directly influence the development of higher order aberrations in patients with KCN.

Anterior chamber characteristics assessed by rotating Scheimpflug imaging in patients with retinitis pigmentosa / Características da câmara anterior avaliadas por um dispositivo de imagem rotativo Scheimpflug em pacientes com retinite pigmentosa

ABSTRACT Purpose: The aim of this study was to evaluate anterior segment parameters and corneal aberrations in patients with retinitis pigmentosa using Scheimpflug imaging and to compare the findings with those for healthy controls. Methods: This single-center, case-control study included patients diagnosed with retinitis pigmentosa who were followed up at the Department of Ophthalmology of Kayseri Training and Research Hospital between February and June 2018. Age- and sex-matched healthy individuals with no known ophthalmologic disease formed the control group. Both patients with retinitis pigmentosa and controls underwent comprehensive ophthalmic assessments, including the measurement of the best-corrected visual acuity calculation of the spherical equivalent, slit-lamp examination, stereoscopic fundus examination, computerized visual field test, and electroretinography. Topographic and aberrometric values were measured using Scheimpflug-based tomography. Results: This study was performed on 52 eyes of 26 patients with retinitis pigmentosa (14 men) and 52 eyes of 26 healthy controls (11 men). The average keratometry (K avg) values for the patient and control groups were similar (43.87 ± 2.23 versus 43.61 ± 1.68; p=0.546), but the maximum keratometry (K max) value was significantly higher in the patient group (45.85 ± 2.35 and 44.69 ± 1.86; p=0.015). Patients with retinitis pigmentosa had a significantly lower central corneal thickness (518.5 ± 42.3 versus 534.1 ± 24.5, respectively; p=0.042) and maximal corneal thickness (509.1 ± 50.5 versus 530.5 ± 24.1, respectively; p=0.015). Additionally, the iridocorneal angle for the patients was significantly lower (31.6 ± 9.2 versus 35.9 ± 7.7, p=0.025). The aberrometric findings indicated that patients with retinitis pigmentosa had significantly more higher-order aberrations than those in the healthy controls (0.794 ± 51 and 0.398 ± 08, respectively; p<0.001). Conclusions: The results of the present study demonstrated that patients with retinitis pigmentosa have different anterior segment parameters and corneal aberrations compared to healthy controls. These results should be supported by further studies.

RESUMO Objetivo: Este estudo visou avaliar parâmetros do segmento anterior e aberrações corneanas em pacientes com retinite pigmentosa através de imagens de Scheimpflug e comparar os achados com os de controles saudáveis. Métodos: Este foi um estudo caso-controle unicêntrico que incluiu pacientes com o diagnóstico de retinite pigmentosa em acompanhamento no Departamento de Oftalmologia do Hospital de Treinamento e Pesquisa de Kayseri, entre fevereiro e junho de 2018. Indivíduos saudáveis pareados por idade e sexo, sem nenhum conhecimento da doença oftalmológica formou o grupo controle. Ambos os pacientes com retinite pigmentosa quanto os controles foram submetidos a avaliações oftalmológicas abrangentes, incluindo a medição do cálculo da acuidade visual melhor corrigida, o cálculo do equivalente esférico, biomicroscopia, fundoscopia estereoscópica, campimetria computadorizada e eletrorretinografia. Os valores topográficos e de aberrometria foram medidos através de tomografia baseada no sistema Scheimpflug. Resultados: O estudo incluiu 52 olhos de 26 pacientes com retinite pigmentosa (14 homens) e 52 olhos de 26 controles saudáveis (11 homens). Os valores médios da ceratometria (K avg) para grupos dos pacientes e controle foram semelhantes (43,87 ± 2,23 versus 43,61 ± 1,68, p=0,546), mas o valor máximo da ceratometria (K max) foi significativamente maior no grupo de pacientes (45,85 ± 2,35 e 44,69 ± 1,86; p=0,015). Pacientes com retinite pigmentosa apresentaram uma espessura corneana central significativamente menor (518,5 ± 42,3 versus 534,1 ± 24,5, respectivamente; p=0,042) e espessura corneana máxima (509,1 ± 50,5 verus 530,5 ± 24,1, respectivamente; p=0,015). Além disso, o ângulo iridocorneano para os pacientes foi significativamente menor (31,6 ± 9,2 versus 35,9 ± 7,7; p=0,025). Os achados da aberrometria indicaram que os pacientes com retinite pigmentosa apresentaram significativamente mais aberrações de ordem superior em comparação com os controles saudáveis (respectivamente 0,794 ± 51 e 0,398 ± 08, respectivamente; p<0,001). Conclusões: Os resultados do presente estudo demonstraram que pacientes com retinite pigmentosa têm diferentes parâmetros do segmento anterior e aberrações corneanas em comparação com controles saudáveis. Estes resultados precisam ser confirmados por novos estudos.

Topoaberrometría en pacientes con queratocono / Topoaberrometry in patients with keratoconus

RESUMEN Objetivo: Determinar las características topoaberrométricas del queratocono. Métodos: Se realizó un estudio observacional descriptivo de corte transversal que comprendió 101 topografías corneales de pacientes diagnosticados de queratocono con el topógrafo corneal Magellan Plug and Play (n= 101 ojos), en el Instituto Cubano de Oftalmología Ramón Pando Ferrer, en el período 2016-2017. Resultados: Los grupos de edades más representados en la muestra fueron de 20-29 y de 30-39 años, con una proporción similar de pacientes en uno y otro sexo. Predominaron los pacientes con queratocono clínico por índice de severidad y con clasificación patológica según índice de predicción con correlación ascendente entre ambos índices. La localización central del cono fue la más frecuente en esta muestra, donde predominaron los valores más elevados de los índices anteriores. Predominó la aberración de alto orden coma en cuanto al valor medio de raíz cuadrática media y la aberración esférica en el valor máximo. Conclusiones: El grupo de edades más representado según la muestra analizada es el de 20 a 39 años, con proporción similar de pacientes en uno y otro sexo. Predominan los pacientes con queratocono clínico por índice de severidad y con clasificación patológica según índice de predicción con correlación ascendente entre ambos índices. La localización central del cono es la más frecuente y es donde existen los valores más elevados de los índices anteriores. Predomina la aberración de alto orden coma en cuanto al valor medio de la raíz cuadrática media y la aberración esférica en el valor máximo de esta(AU)

ABSTRACT Objective: Determine the topoaberrometric characteristics of keratoconus. Methods: A cross-sectional observational descriptive study was conducted of 101 corneal topograms of patients diagnosed with keratoconus obtained with the corneal topograph Magellan Plug and Play (n= 101 eyes) at Ramón Pando Ferrer Cuban Institute of Ophthalmology in the period 2016-2017. Results: The age groups best represented in the sample were 20-29 and 30-39 years, with a similar proportion of male and female patients. A predominance was found of patients with clinical keratoconus by the severity index and with pathological classification by the prediction index, with an ascending correlation between the two indices. Central cone location was the most frequent in the sample, with a prevalence of the highest levels of the aforementioned indices. A high frequency was found of coma higher-order aberration, according to root mean square and maximum spherical aberration values. Conclusions: The age group best represented in the study sample is 20-39 years, with a similar proportion of male and female patients. A predominance is found of patients with clinical keratoconus by the severity index and with pathological classification by the prediction index, with an ascending correlation between the two indices. Central cone location is the most frequent, with a prevalence of the highest levels of the aforementioned indices. A high frequency is found of coma higher-order aberration, according to root mean square and maximum spherical aberration values(AU)

Relación entre la clasificación subjetiva de la opacidad del cristalino y la calidad visual / Relationship between subjective lens opacity classification and visual quality

RESUMEN Objetivo: Determinar la relación entre la clasificación subjetiva de la opacidad del cristalino por LOCS III, la agudeza visual mejor corregida y el análisis objetivo de la calidad visual por aberrometría. Métodos: En este estudio observacional, descriptivo y transversal se realizó la categorización con LOCS III de cataratas seniles en paciente con agudeza visual mayor a 0,7 y una medición objetiva de la calidad visual por análisis de frente de onda en pacientes que asistieron al Centro de Microcirugía Ocular del Instituto Cubano de Oftalmología "Ramón Pando Ferrer" entre junio del año 2016 y diciembre de 2017. Resultados: Las cataratas corticales estuvieron relacionadas con una gran magnitud de aberraciones ópticas de alto orden, principalmente coma y trefoil. También se encontró un valor significativo de la aberración esférica en el grupo de cataratas nucleares. Las cataratas del grupo subcapsular posterior no mostraron un tipo de aberración predominante. No se pudo obtener la relación entre la magnitud de la catarata catalogada por LOCS III y los indicadores de calidad visual o la agudeza visual mejor corregida porque el tamaño de la muestra fue insuficiente para relacionarlo con el gran número de categorías en LOCS III. Conclusiones: En los pacientes con catarata senil y buena agudeza visual, el tipo y el grado de opacidad categorizada por LOCS III condiciona el tipo y la magnitud de las aberraciones, y por tanto el deterioro de la calidad visual(AU)

ABSTRACT Objective: Determine the relationship between subjective lens opacity classification by LOCS III, best corrected visual acuity and objective visual quality analysis by aberrometry. Methods: A cross-sectional observational descriptive study was conducted based on LOCS III to classify senile cataracts in patients with visual acuity above 0.7 and objective visual quality measurement by wavefront analysis attending the Ocular Microsurgery Center of Ramón Pando Ferrer Cuban Institute of Ophthalmology from June 2016 to December 2017. Results: Cortical cataracts were associated to a large number of higher-order ocular aberrations, mainly coma and trefoil. Significant spherical aberration values were also found in the nuclear cataract group. Cataracts in the posterior subcapsular group did not display a prevailing aberration type. It was not possible to determine the relationship between the magnitude of the cataract as classified by LOCS III and visual quality indicators or best corrected visual acuity, because sample size was insufficient to be related to the large number of categories in LOCS III. Conclusions: In patients with senile cataract and good visual acuity, the type and degree of opacity as classified by LOCS III determines the type and magnitude of the aberrations, and thus the deterioration of visual quality(AU)

Analysis of Positional Relationships of Various Centers in Cataract Surgery

PURPOSE: To analyze the positional relationships of various centers in patients undergoing femtosecond laser-assisted cataract surgery (FLACS). METHODS: The locations of the pupil center (PC), limbal center (LC) and lens center were analyzed in each patient using optical coherence tomography during FLACS in 35 eyes of 35 patients. Using the preoperative corneal aberrometry device, angle kappa and the location of the visual axis (VA) were calculated. After acquiring the relative horizontal and vertical coordinates of each center, the distance and location among each center were compared. The relative location and distance of each center were statistically evaluated. RESULTS: The distance from the PC to the lens center was 0.147 ± 0.103 mm, that from the LC to the lens center was 0.205 ± 0.104 mm, and that from the VA to the lens center was 0.296 ± 0.198 mm. The distance from the PC to the VA was 0.283 ± 0.161 mm, that from the LC to the VA was 0.362 ± 0.153 mm, and that from the lens center to the VA was 0.296 ± 0.198 mm. Among the various centers, the PC was the closest to the lens center, whereas the LC and VA were the farthest. Based on the location of the lens center, the PC, LC, and VA exhibited differences in the X and Y coordinate positions (vertical p = 0.004, horizontal p < 0.001). Among them, the LC was significantly inferior and temporal compared to the PC (vertical p = 0.026, horizontal p = 0.023). Based on the location of the VA, the respective locations of the PC, LC and lens center in two dimensions did not significantly differ (vertical p = 0.310, horizontal p = 0.926). CONCLUSIONS: This study demonstrated the positional and locational relationships between the centers regarding FLACS. The locations of the PC, LC, and VA were different from the lens center with the PC being the closest. Surgeons should be aware of these positional relationships, especially in FLACS.

Manejo do astigmatismo residual após implante de lente intraocular / Management of residual astigmatism after intraocular lens implantation

RESUMO Relatamos um caso de astigmatismo residual, após cirurgia de catarata com implante de lente intra-ocular (LIO) tórica (Acrysof Toric, Alcon, Frot Worth TX). A refração residual (+1,25 -2,50 x 105º) e o posicionamento da LIO implantada neste olho, foram correlacionados com a aberrometria total obtida por ray tracing de pontos individuais integrada à da face anterior da córnea obtida por topografia de Plácido, para cálculo das aberrações internas (iTrace, Tracey, Technologies, Houston TX). O cálculo do eixo ideal da LIO, para minimizar a refração residual foi realizado de acordo com Berdahl & Hardten (astigmatismfix.com). A rotação da LIO foi realizada com sucesso 5 meses após a cirurgia inicial para o eixo indicado, reduzindo o erro residual para +0,25 -0,25 x 61º e promovendo reabilitação visual sem correção de 20/20.

ABSTRACT We report a case of residual astigmatism after cataract surgery with toric intraocular lens (IOL) implantation (Acrysof Toric, Alcon, Frot Worth TX). Residual refraction (+1,25 -2,50 x 105º) and IOL positioning were correlated with total ray-tracing wavefront aberrometry integrated with anterior corneal surface Placido-based topography to calculate internal aberrations (iTrace, Tracey Technologies, Houston TX). The ideal IOL axis to minimize residual refraction was calculated with Berdahl & Hardten (astigmatismfix.com). IOL rotation to the indicated axis was successfully performed 5 months after initial surgery, reducing residual error to +0,25 -0,25 x 61º, promoting visual reabilitation, with final uncorrected distance visual acuity 20/20.

Assessing the accommodation response after near visual tasks using different handheld electronic devices / Avaliação da resposta de acomodação após tarefas visuais próximas usando diferentes dispositivos eletrônicos portáteis

ABSTRACT Purpose: To assess the accommodation response after short reading periods using a tablet and a smartphone as well as determine potential differences in the accommodation response at various stimulus vergences using a Hartmann- Shack aberrometer. Methods: Eighteen healthy subjects with astigmatism of less than 1 D, corrected visual acuity of 20/20 or better, and normal findings in an ophthalmic examination were enrolled. Accommodation responses were obtained under three different conditions: accommodation system of the eye relaxed and visually stressed with a tablet and an smartphone for 10 min, at a distance of 0.25 m from the subject's eyes. Three measurements of accommodation response were monocularly acquired at stimulus vergences ranging from 0 to 4 D (1-D step). Results: No statistically significant differences were found in the accommodation responses among the conditions. A moderate but gradually increasing root mean square, coma-like aberration was found for every condition. Conversely, the spherical aberration decreased as stimulus vergences increased. These outcomes were identified in comparison to the one-to-one ideal accommodation response, implying that a certain lag value was present in all stimulus vergences different from 0 D. Conclusions: The results support the hypothesis that the difference between the ideal and real accommodation responses is mainly attributed to parameters associated with the accommodation process, such as the near visual acuity, depth of focus, pupil diameter, and wavefront aberrations. The wavefront aberrations were dependent on the 3-mm pupil size selected in this study. The accommoda tion response was not dependent on the electronic device employed in each condition, and it was mainly associated with young age and level of amplitude of accommodation of the subjects.

RESUMO Objetivo: Avaliar a resposta de acomodação após períodos de leitura curtos usando um tablet e um smartphone, bem como para determinar potenciais diferenças na resposta de acomodação em estímulos de várias vergências com uma aberrômetro Hartmann-Shack. Método: Dezoito indivíduos saudáveis com astigmatismo inferior a 1 D, apresentando acuidade visual corrigida de 20/20 ou melhor com exame oftalmológico normal foram avaliados. As respostas acomodativas foram obtidas em três condições diferentes: sistema de acomodação com o olho relaxado, e visualmente estressado com um tablet e um smartphone por 10 min, a uma distância de 0,25 m dos olhos dos sujeitos. Três medidas de resposta acomodativa foram obtidas monocularmente com estímulos cujas vergências variaram de 0 a 4 D (intervalos de 1 D). Resultados: Não houve diferença estatisticamente significativa entre as respostas acomodativas em todas as condições. Foi observada moderada aberração do tipo coma com aumento progressivo para cada condição, enquanto houve diminuição da aberração esférica com o aumento das vergências do estímulo. Estes resultados foram identificados em comparação com a resposta acomodativa de um-para-um ideal, o que implica que um certo valor de desfasagem estava presente em todos os estímulos com vergências diferentes de 0 D. Conclusões: Os resultados apoiam a hipótese de que a diferença entre as respostas acomodativas ideal e real é atribuída principalmente a parâmetros tais como a acuidade visual para perto, profundidade de foco, diâmetro pupilar e aberrações de frente de onda, associados ao processo acomodativo. As aberrações de frente de onda foram dependentes do tamanho da pupila de 3 mm, selecionado neste estudo. A resposta acomodativa não foi dependente do dispositivo eletrônico empregue em cada condição e foi associada principalmente à idade jovem e ao nível da amplitude de acomodação dos sujeitos avaliados.

Comparative study on optical performance and visual outcomes between two diffractive multifocal lenses: AMO Tecnis ® ZMB00 and AcrySof ® IQ ReSTOR ® Multifocal IOL SN6AD1 / Estudo comparativo de desempenho óptico e resultado visual entre duas lentes multifocais difrativas: Tecnis ZMB00 e AcrySof SN6AD1

ABSTRACT Purpose: To compare the optical performance and visual outcomes between two diffractive multifocal lenses: AMO Tecnis® ZMB00 and AcrySof® ReSTOR® SN6AD1. Methods: This prospective, non-randomized comparative study included the assessment of 74 eyes in 37 patients referred for cataract surgery and candidates for multifocal intraocular lens implants. Exclusion criteria included existence of any other eye disease, previous eye surgery, high axial myopia, preoperative corneal astigmatism of >1.00 cylindrical diopter (D), and intraoperative or postoperative complications. Ophthalmological evaluation included the measurement of uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), distance-corrected near visual acuity (DCNVA), and distance-corrected intermediate visual acuity (DCIVA), with analysis of contrast sensitivity (CS), wavefront, and visual defocus curve. Results: Postoperative UDVA was 0.09 and 0.08 logMAR in the SN6AD1 and ZMB00 groups, respectively (p=0.868); postoperative CDVA was 0.04 and 0.02 logMAR in the SN6AD1 and ZMB00 groups, respectively (p=0.68); DCIVA was 0.17 and 0.54 logMAR in the SN6AD1 and ZMB00 groups, respectively (p=0.000); and DCNVA was 0.04 and 0.09 logMAR in the SN6AD1 and ZMB00 groups, respectively (p=0.001). In both cases, there was an improvement in the spherical equivalent and UDVA (p<0.05). Under photopic conditions, the SN6AD1 group had better CS at low frequencies without glare (p=0.04); however, the ZMB00 group achieved better sensitivity at high frequencies with glare (p=0.003). The SN6AD1 and ZMB00 lenses exhibited similar behavior for intermediate vision, according to the defocus curve; however, the ZMB00 group showed a shorter reading distance than the SN6AD1 group. There were no significant differences regarding aberrometry between the two groups. Conclusion: Both lenses promoted better quality of vision for both long and short distances and exhibited a similar behavior for intermediate vision. The SN6AD1 and ZMB00 groups showed better results for CS under photopic conditions at low and high spatial frequencies, respectively.

RESUMO Objetivo: Comparar o desempenho óptico e resultado visual entre duas lentes multifocais difrativas: AMO Tecnis® ZMB00 e AcrySof® ReSTOR® SN6AD1. Métodos: O estudo prospectivo, comparativo não randomizado incluiu avaliação de 74 olhos em 37 pacientes com indicação de facectomia e candidatos a implante de lente multifocal. Critérios de exclusão foram: presença de outras doenças oculares; cirurgia ocular prévia; alta miopia axial; astigmatismo cornenano maior que 1,00 D cilíndrica; complicações intraoperatórias ou pós-operatórias. A avaliação oftalmológica contou com medida da acuidade visual para longe corrigida (CDVA) e não corrigida (UDVA), intermediária (DCIVA) e curta distância (DCNVA) com melhor correção óptica para longe; teste de sensibilidade ao contraste; análise de frente de onda e curva visual de Defocus. Resultados: A UDVA foi de 0,09 logMAR para o grupo SN6AD1 e 0,08 logMAR para o grupo ZMB00; com correção foi de 0,04 logMAR para SN6AD1 e 0,02 para o grupo ZMB00 (p>0,05). O grupo SN6AD1 obteve valor de 0,04 logMAR e o grupo ZMB00 de 0,09 logMAR para DCNVA (p<0,05) e DCIVA de 0,17 logMAR para SN6AD1 e 0,54 logMAR para ZMB00 (p=0,000). Houve melhora do equivalente esférico e da UDVA em ambos os grupos (p<0,05). Em condições fotópicas, o grupo SN6AD1 teve melhor sensibilidade ao contraste em baixas frequências sem ofuscamento (p<0,05), contudo grupo ZMB00 obteve melhor sensibilidade em altas frequências (p<0,05) com ofuscamento. As lentes SN6AD1 e ZMB00 obtiveram comportamento semelhantes para visão intermediária na curva de Defocus, porém, o grupo ZMB00 mostrou menor distância de leitura que o grupo SN6AD1. Não houve diferença com significância estatística relacionada à aberrometria na comparação dos dois grupos. Conclusão: As duas lentes promoveram melhor qualidade de visão para longe e perto e comportamento semelhante para visão intermediária. O grupo ZMB00 exibiu melhores resultados para sensibilidade ao contraste em condições fotópicas em alta frequência espacial e SN6AD1 em baixa frequência espacial.

Higher Order Aberration and Astigmatism in Children with Hyperopic Amblyopia

PURPOSE: To investigate the changes in corneal higher-order aberration (HOA) during amblyopia treatment and the correlation between HOA and astigmatism in hyperopic amblyopia children. METHODS: In this retrospective study, a total of 72 eyes from 72 patients ranging in age from 38 to 161 months were included. Patients were divided into two groups based on the degree of astigmatism. Corneal HOA was measured using a KR-1W aberrometer at the initial visit and at 3-, 6-, and 12-month follow-ups. Correlation analysis was performed to assess the association between HOA and astigmatism. RESULTS: A total of 72 patients were enrolled in this study, 37 of which were classified as belonging to the higher astigmatism group, while 35 were assigned to the lower astigmatism group. There was a statistically significant difference in success rate between the higher and lower astigmatism groups. In both groups, all corneal HOAs were significantly reduced during amblyopia treatment. When comparing the two groups, a significant difference in coma HOA at the 12-month follow-up was detected (p = 0.043). In the Pearson correlation test, coma HOA at the 12-month follow-up demonstrated a statistically significant correlation with astigmatism and a stronger correlation with astigmatism in the higher astigmatism group than in the lower astigmatism group (coefficient values, 0.383 and 0.284 as well as p = 0.021 and p = 0.038, respectively). CONCLUSIONS: HOA, particularly coma HOA, correlated with astigmatism and could exert effects in cases involving hyperopic amblyopia.

Comparison of the Clinical Outcomes of Two Types of Toric Intraocular Lens

PURPOSE: In this study evaluated clinical outcomes and higher-order aberrations in patients with implanted Tecnis ZCT toric intraocular lens (IOL) (Abbott Medical Optics Inc., Santa Ana, CA, USA) and the Zeiss AT TORBI toric IOL (Carl Zeiss Meditec AG, Jena, Germany) in eyes with low to moderate corneal astigmatism. METHODS: We conducted a retrospective study of 32 consecutive eyes of 26 patients with a visually significant cataract and moderate corneal astigmatism (higher than 1.25 diopter [D] and lower than 4.5 D) undergoing cataract surgery with implantation of the aspheric Tecnis ZCT toric IOL (Abbott Medical Optics Inc.) and the Zeiss AT TORBI toric IOL (Carl Zeiss Meditec AG). Phacoemulsification was performed by the same experienced surgeon using 2.2 mm temporal incision. Visual, refractive and aberrometric changes were evaluated during a 3-month follow-up. Power vector analysis of Cartesian astigmatism (J0) and oblique astigmatism (J45) was performed. RESULTS: At the 3-month follow-up, corrected distance visual acuity (CDVA) and residual astigmatism showed no statistically significant differences between groups (p = 0.203 and p = 0.364, respectively). Pre- and postoperative J0 were 0.71 +/- 0.84 and 0.05 +/- 0.39 in the Tecnis Toric group and, 0.88 +/- 1.27 and -0.02 +/- 0.16 in the AT TORBI group, respectively, which showed statistically significant differences (p = 0.029 and p = 0.032, respectively). Pre- and post-operative differences of J0 and J45 were not statistically significant (p = 0.234 and p = 0.603, respectively). No eye had IOL rotation > or =10degrees. Ocular aberrometry values were statistically significantly differenct between the groups, except for spherical aberration, which was higher in the AT TORBI group (p = 0.0047). CONCLUSIONS: Both IOLs showed good postoperative uncorrected distance visual acuity, CDVA and refractive results in this study. Rotational stability was excellent for both IOLs until the 3-month follow-up.

Comparison of the Astigmatic Power of Toric Intraocular Lenses Using Three Toric Calculators

PURPOSE: To compare the astigmatic power of toric intraocular lenses (IOLs) obtained from the AcrySof, TECNIS, and iTrace toric calculator in patients with preoperative with-the-rule (WTR) or against-the-rule (ATR) corneal astigmatism. MATERIALS AND METHODS: Fifty eyes with cataract and corneal astigmatism greater than 0.75 diopters were enrolled in each group (WTR and ATR). Keratometric values were measured using autokeratometry, an IOLMaster, and an iTrace, which incorporated corneal topography and ray-tracing aberrometry. Based on measured keratometric values, the astigmatic power of each toric IOL was calculated using three toric calculators. RESULTS: Bland-Altman plots showed good agreement between six pairwise corneal astigmatism values in both groups. The TECNIS calculator tended to suggest a higher astigmatic power of the toric IOL than the AcrySof calculator. With the higher astigmatism and keratometric values from the IOLMaster, in both groups, calculations from the AcrySof and TECNIS calculators resulted in higher calculated astigmatic powers than those from same calculators with autokeratometry-measured values, demonstrating good agreement. With the higher calculated astigmatic power values, the values from the iTrace toric calculator using keratometric values obtained from iTrace ray tracing wavefront aberrometry or iTrace simulated keratometry showed fair to moderate agreement with those from the other calculator-keratometry pairs in both groups. CONCLUSION: To achieve the best refractive outcome after toric IOL implantation, understanding the differences in keratometric values between instruments and in calculated astigmatic power among toric calculator programs is necessary. Moreover, systemic analysis of each toric calculator in conjunction with postoperative data is required.

Higher order aberrations in amblyopic children and their role in refractory amblyopia / Aberrações de alta ordem em crianças com ambliopia e seu papel na ambliopia refratária

Objective: Some studies have hypothesized that an unfavourable higher order aberrometric profile could act as an amblyogenic mechanism and may be responsible for some amblyopic cases that are refractory to conventional treatment or cases of “idiopathic” amblyopia. This study compared the aberrometric profile in amblyopic children to that of children with normal visual development and compared the aberrometric profile in corrected amblyopic eyes and refractory amblyopic eyes with that of healthy eyes. Methods: Cross-sectional study with three groups of children – the CA group (22 eyes of 11 children with unilateral corrected amblyopia), the RA group (24 eyes of 13 children with unilateral refractory amblyopia) and the C group (28 eyes of 14 children with normal visual development). Higher order aberrations were evaluated using an OPD-Scan III (NIDEK). Comparisons of the aberrometric profile were made between these groups as well as between the amblyopic and healthy eyes within the CA and RA groups. Results: Higher order aberrations with greater impact in visual quality were not significantly higher in the CA and RA groups when compared with the C group. Moreover, there were no statistically significant differences in the higher order aberrometric profile between the amblyopic and healthy eyes within the CA and RA groups. Conclusions: Contrary to lower order aberrations (e.g., myopia, hyperopia, primary astigmatism), higher order aberrations do not seem to be involved in the etiopathogenesis of amblyopia. Therefore, these are likely not the cause of most cases of refractory amblyopia. .

Objetivo: Alguns estudos levantaram a hipótese de que um perfil aberrométrico de alta ordem desfavorável poderia ser um fator ambliogênico, responsável por certos casos de ambliopia “idiopática” ou refratária ao tratamento convencional. Este trabalho tem como objetivos: 1) comparar o perfil aberrométrico de crianças amblíopes com o de crianças com desenvolvimento visual normal; 2) comparar a aberrometria de olhos amblíopes tratados com sucesso/curados e olhos amblíopes refratários ao tratamento convencional com a aberrometria de olhos saudáveis. Métodos: Estudo transversal com três grupos de crianças: grupo CA (22 olhos de 11 crianças com ambliopia unilateral curada), grupo RA (24 olhos de 13 crianças com ambliopia unilateral refratária) e grupo C (28 olhos de 14 crianças com desenvolvimento visual normal). Avaliou-se a aberrometria ocular total utilizando o OPD Scan-III (NIDEK). Comparou-se o perfil aberrométrico dos três grupos de estudo bem como dentro dos grupos CA e RA, o olho amblíope com o saudável. Resultados: As aberrações de alta ordem com maior impacto na qualidade visual não foram significativamente superiores nos grupos CA e RA, comparativamente ao grupo C. Por outro lado, não se encontraram diferenças estatisticamente significativas entre o perfil aberrométrico de alta ordem dos olhos amblíopes e dos olhos sãos dentro dos grupos CA e RA. Conclusão: Contrariamente às aberrações de baixa ordem (miopia, hipermetropia, astigmatismo primário), as de alta ordem não parecem relacionar-se com a etiopatogênese da ambliopia. É também pouco provável que estas sejam a causa da maioria dos casos de ambliopia refratária. .

Influence of aspheric intraocular lens on frequency doubling technology and contrast sensitivity: a fellow eye study / Influência da lente intraocular asférica na perimetria de frequência dupla e sensibilidade ao contraste: estudo contralateral

Purpose: To evaluate whether implantation of an aspheric intraocular lens (IOL) results in reduced ocular aberrations and improved contrast sensitivity after cataract surgery and, therefore, changes on frequency-doubling technology (FDT) testing. Methods: The present prospective clinical study enrolled 25 patients with bilateral cataract (50 eyes), who randomly received either an aspheric (Akreos AO) or a spherical (Akreos Fit) IOL in one eye and the other IOL in the second eye. Assessment 12 months postoperatively included photopic and mesopic contrast sensitivity testing. Higher-order aberrations (HOAs) were computed. FDT testing was divided into four areas to evaluate the variation of the values at different points. The median values of the local pattern thresholds (median area contrast sensitivity [MACS]) obtained with that division were calculated. Results: The Akreos AO group obtained statistically significantly lower values of HOAs and spherical aberration compared with the Akreos Fit group. There was a statistically significant between-group difference in contrast sensitivity under mesopic conditions at all spatial frequencies. No statistically significant differences were observed in mean deviation and pattern standard deviation. The aspheric IOL exhibited higher MACS in all areas, although a statistically significant difference was reached only in the 20-degree field area (P=0.043). Conclusion: Aspheric IOLs significantly reduced spherical aberration and HOAs, improving mesopic contrast sensitivity. Although there was a trend toward slightly improved FDT in the aspheric IOL group, it was not statistically significant. .

Objetivo: Avaliar se o implante de uma lente intraocular (LIO) asférica reduz a aberração ocular (alta ordem e esférica), melhora a sensibilidade ao contraste e consequentemente, provoca mudanças nos valores da perimetria de frequência dupla (FDT ). Métodos: Trata-se de um estudo prospectivo envolvendo 25 pacientes com catarata bilateral (50 olhos) que foram randomizados para receberem uma LIO asférica (Akreos AO) em um olho e uma LIO esfércia (Akreos Fit) no olho contralateral. Com 12 meses de pós-operatório a sensibilidade ao contraste (condições fotópicas e mesópicas) e a aberração de alta ordem foram computados. A FDT foi dividida em 4 áreas para análise da variação dos valores em diferentes localizações. Os valores médios dos limiares locais (área média de sensibilidade ao contraste [MACS]) obtidos com essa divisão foram calculados. Resultados: O grupo da Akreos AO apresentou menores valores de aberração de alta ordem e aberração esférica. Houve diferença estatisticamente significativa na sensibilidade ao contraste em condições mesópicas em todas frequências. Não houve diferença estatística nos valores do mean deviation e pattern standard deviation da FDT. A LIO asférica apresentou maiores MACS em todas as áreas, embora diferença estatística foi encontrada apenas na área de 20 graus de campo visual (P=0,043). Conclusões: A lente asférica reduziu significativamente a quantidade de aberração de alta ordem e esférica, melhorando a sensibilidade ao contraste em condições mesópicas. Embora houve uma melhora nos valores da FDT no grupo da LIO asférica, essa diferença não foi estatisticamente significativa. .

Implantable collamer lens and femtosecond laser for myopia: comparison using an adaptive optics visual simulator / Lente implantável de collamer e laser de femtosegundo para miopia: comparação usando um simulador visual de óptica adaptativa

Purpose: To compare optical and visual quality of implantable collamer lens (ICL) implantation and femtosecond laser in situ keratomileusis (F-LASIK) for myopia. Methods: The CRX1 adaptive optics visual simulator (Imagine Eyes, Orsay, France) was used to simulate the wavefront aberration pattern after the two surgical procedures for -3-diopter (D) and -6-D myopia. Visual acuity at different contrasts and contrast sensitivities at 10, 20, and 25 cycles/degree (cpd) were measured for 3-mm and 5-mm pupils. The modulation transfer function (MTF) and point spread function (PSF) were calculated for 5-mm pupils. Results: F-LASIK MTF was worse than ICL MTF, which was close to diffraction-limited MTF. ICL cases showed less spread out of PSF than F-LASIK cases. ICL cases showed better visual acuity values than F-LASIK cases for all pupils, contrasts, and myopic treatments (p<0.05). No statistically significant differences were found in contrast sensitivities between ICL and F-LASIK cases with -3-D myopia for both pupils for all evaluated spatial frequencies (p>0.05). For -6-D myopia, however, statistically significant differences in contrast sensitivities were found for both pupils for all evaluated spatial frequencies (p<0.05). Contrast sensitivities were better after ICL implantation than after F-LASIK. Conclusions: ICL implantation and F-LASIK provide good optical and visual quality, although the former provides better outcomes of MTF, PSF, visual acuity, and contrast sensitivity, especially for cases with large refractive errors and pupil sizes. These outcomes are related to the F-LASIK producing larger high-order aberrations. .

Objetivo: Comparar a qualidade óptica e visual da lente implantável de collamer (ICL) e da ceratomileuse in situ com laser de femtosegundo (F-LASIK) na correção de miopia. Métodos: O simulador visual de óptica adaptativa CRX1 (Imagine Eyes, Orsay, França) foi usado para simular o padrão de aberração de frentes de onda, depois de dois procedimentos cirúrgicos: implante de ICL e tratamento F-LASIK para -3 e -6 D. A acuidade visual em diferentes contrastes e sensibilidade ao contraste em 10, 20 e 25 ciclos/grau (cpd) foram medidos para pupilas de 3 e 5 mm. A função de transferência de modulação (MTF) e a função de espalhamento de ponto (PSF) foram calculados para a pupila de 5 mm. Resultados: A MTF do F-LASIK foi pior do que a do ICL, que estava perto da MTF do limite de difração. A ICL apresentou menor espalhamento do PSF do que o F-LASIK. ICL apresentou melhores valores da acuidade visual do que F-LASIK para todas as pupilas, contrastes e tratamentos miópicos (p<0,05). Não foram encontradas diferenças estatisticamente significantes na sensibilidade ao contraste entre ICL e F-LASIK de -3 D, para ambas as pupilas e quaisquer frequências espaciais avaliadas (p>0,05). Por outro lado, para -6 D, diferenças estatisticamente significativas na sensibilidade ao contraste foram encontrados para ambas as pupilas e todas as frequências espaciais avaliadas (p<0,05). Sensibilidade ao contraste foi melhor após o implante da ICL que após o F-LASIK. Conclusões: ICL e F-LASIK proporcionam uma boa qualidade óptica e visual, embora a ICL oferece melhores resultados de MTF, PSF, acuidade visual e sensibilidade ao contraste, especialmente para grandes erros de refração e tamanhos de pupila. Estes resultados estão relacionados ao procedimento F-LASIK que induz maiores aberrações ...

Intrastromal corneal ring segments: how successful is the surgical treatment of keratoconus?

This review evaluates the outcomes of intrastromal corneal ring segment [ICRS] implantation for the treatment of keratoconus considering a new grading system based on the preoperative visual impairment of the patient. Additionally, a five-year follow-up analysis of patients with stable and progressive keratoconus is performed in order to assess the long term stability of the surgical procedure. Corrected distance visual acuity decreased statistically significantly in patients with mild keratoconus [P < 0.01] but statistically significantly increased in all other grades [P< 0.05]. The improvement in visual acuity and the decrease of keratometric and aberrometric values were stable throughout a long period of time in patients with stable keratoconus. In patients with progressive form keratoconus, a significant improvement was found immediately after the procedure, however clinically relevant regression greater than 3 D was observed at the end of the follow up period

Comparison of ocular modulation transfer function determined by a ray-tracing aberrometer and a double-pass system in early cataract patients / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The evaluation of retinal image quality in cataract eyes has gained importance and the clinical modulation transfer functions (MTF) can obtained by aberrometer and double pass (DP) system. This study aimed to compare MTF derived from a ray tracing aberrometer and a DP system in early cataractous and normal eyes.</p><p><b>METHODS</b>There were 128 subjects with 61 control eyes and 67 eyes with early cataract defined according to the Lens Opacities Classification System III. A laser ray-tracing wavefront aberrometer (iTrace) and a double pass (DP) system (OQAS) assessed ocular MTF for 6.0 mm pupil diameters following dilation. Areas under the MTF (AUMTF) and their correlations were analyzed. Stepwise multiple regression analysis assessed factors affecting the differences between iTrace- and OQAS-derived AUMTF for the early cataract group.</p><p><b>RESULTS</b>For both early cataract and control groups, iTrace-derived MTFs were higher than OQAS-derived MTFs across a range of spatial frequencies (P < 0.01). No significant difference between the two groups occurred for iTrace-derived AUMTF, but the early cataract group had significantly smaller OQAS-derived AUMTF than did the control group (P < 0.01). AUMTF determined from both the techniques demonstrated significant correlations with nuclear opacities, higher-order aberrations (HOAs), visual acuity, and contrast sensitivity functions, while the OQAS-derived AUMTF also demonstrated significant correlations with age and cortical opacity grade. The factors significantly affecting the difference between iTrace and OQAS AUMTF were root-mean-squared HOAs (standardized beta coefficient = -0.63, P < 0.01) and age (standardized beta coefficient = 0.26, P < 0.01).</p><p><b>CONCLUSIONS</b>MTFs determined from a iTrace and a DP system (OQAS) differ significantly in early cataractous and normal subjects. Correlations with visual performance were higher for the DP system. OQAS-derived MTF may be useful as an indicator of visual performance in early cataract eyes.</p>

Quality of vision in refractive and cataract surgery, indirect measurers: review article / Qualidade visual em cirurgia refrativa e catarata, medidores indiretos: artigo de revisão

Visual acuity is the measurement of an individual's ability to recognize details of an object in a space. Visual function measurements in clinical ophthalmology are limited by factors such as maximum contrast and so it might not adequately reflect the real vision conditions at that moment as well as the subjective aspects of the world perception by the patient. The objective of a successful vision-restoring surgery lies not only in gaining visual acuity lines, but also in vision quality. Therefore, refractive and cataract surgeries have the responsibility of achieving quality results. It is difficult to define quality of vision by a single parameter, and the main functional-vision tests are: contrast sensitivity, disability glare, intraocular stray light and aberrometry. In the current review the different components of the visual function are explained and the several available methods to assess the vision quality are described.

Qualidade Visual é a medida da capacidade individual de reconhecer detalhes de um objeto no espaço. Medições de função visual na clínica oftalmológica são limitadas por vários fatores, tal como máximo contraste e assim podem não refletir adequadamente as condições visuais reais, bem como os aspectos subjetivos da percepção do mundo pelo paciente. O sucesso em uma cirurgia está não apenas em restaurar linhas de visão, mas sim qualidade visual. Portanto, as cirurgias refrativas e de catarata têm a responsabilidade de alcançar resultados de qualidade. É difícil definir qualidade visual por um único parâmetro, sendo os principais testes de função visual: sensibilidade ao contraste; glare; dispersão intraocular da luz e aberrometria. Nesta revisão os diferentes componentes da função visual são explicados e os diversos métodos disponíveis para se avaliar a qualidade de visão são descritos.

Correlações entre straylight, aberrometria, opacidade e densitometria do cristalino em pacientes com catarata / Correlations of straylight, aberrometry, and lens scattering in cataract patients

Objetico: Correlacionar os níveis de straylight, de scattering, de opacidade do cristalino (LOCS III) e das aberrações ópticas intraoculares em pacientes com catarata nuclear. Métodos: Estudo observacional, prospectivo envolvendo 30 olhos de 30 pacientes com diagnóstico de catarata nuclear. A avaliação do straylight (espalhamento de luz) através do Log(s) foi realizada pelo C-Quant (Oculus, Wetzlar, Germany). A densitometria do cristalino (scattering) através do PNS (Pentacam Nucleus Staging) foi realizada pela tomografia de córnea e segmento anterior (Pentacam® - Oculus, Wetzlar, Germany) e a análise do tipo e graduação da opacidade do cristalino foi feito pelo Lens Opacities Classification System (LOCS III). O Ray tracing (iTrace, Vista, Tracy Technologies) foi utilizado para avaliação da aberrometria total e intraocular onde foi calculado com a integração da Topografia de Plácido. Os critérios de exclusão foram: doença corneana, doenças da retina e/ou nervo óptico e cirurgia ocular prévia. O Teste de Kolmogorov-Smirnov foi utilizado para avaliar a distribuição normal e o Teste de Spearman (não paramétrico) utilizado para as correlações entre as variáveis Log(s) x PNS; Log(s) x LOCS III; LOCS III x PNS; RMS IO x PNS; RMS IO x LOCS III e RMS IO x Log(s). Foi considerado como estatisticamente significante p≤ 0,05%. RESULTADOS: A média de idade dos pacientes foi de 72,3 anos (±8,9). As médias do PNS, do LOCS III, do Log(s) e da RMS IO, foram 2,7 (±1,14), 3,7 (±1,15), 1,49 (±0,38) e 1,23 (±0,5), respectivamente. As correlações de Spearman e o seu coeficiente de correlação (rho) foram p=0,270 (rho 0,20) entre Log(s) x PNS, um p=0,717 (rho 0,06) entre Log(s) x LOCS III, um p=0 (rho 0,76) entre LOCS III x PNS, um p=0,41 (rho -0,15) entre RMS IO x PNS, um p=0,39 (rho -0,15) entre RMS IO x LOCS III e um p=0,83 (rho 0.03) entre RMS IO x Log(s). CONCLUSÃO:A perda da qualidade de....

Purpose: To correlate straylight levels, lens scattering, lens opacity and intraocular aberrometry in patients with nuclear cataract. Methods: This is a prospective study. Thirty consecutive patients (30 eyes) were including. Ocular Straylight was evaluated using the C-Quant. Lens scattering was evaluated using Scheimpflug anterior segment tomography, using the new software PNS. Dilated slip lamp evaluation was performed and lens opacity was classified according to LOCS III scale. Total wavefront was measured by ray tracing (iTrace); intraocular aberrations were calculated by the integration of the Placido topography (Vista, Tracy Technologies. Exclusion criteria: corneal disease, retinal or optic nerves disease or previous ocular surgery. This is study analyzed was Kolmogorov-Smirnov for Normality. Spearman correlation test was performed. Results: The mean age from patients was 72,3 y (±8,9). The mean PNS was 2,7 (±1,14), the mean LOCS III was 3,7 (±1,15) and the mean Log(s) was 1,49(±0,38). The correlations between Log(s) x PNS, Log(s) x LOCS III and LOCS III x PNS obtained respectively p=0,270 (rho 0,20), p=0,717 (rho 0,06) e p=0 (rho 0,76). The mean RMS IO was 1,23 (+/- 0,5). The correlations between RMS IO x PNS was p=0, 41 (rho -0,15) and RMS IO x LOCS III was p=0,39 (rho -0.15) and between RMS IO x Log(s) was p=0,83 (rho 0,03). CONCLUSION: There is an association between the ...

La prueba de Hartmann en ciencias de la visión / Hartmann test in vision science

En este artículo se muestran tres aplicaciones de la prueba de Hartmann en Ciencias de la Visión, desarrolladas en el laboratorio de diseño óptico del Departamento de Física de la Universidad Nacional de Colombia: lensómetro para lentes de adición progresiva, topógrafo corneal y aberrómetro tipo Hartmann-Shack. Primero se describe brevemente la prueba clásica de Hartmann para espejos astronómicos y luego se presentan tres variaciones de la prueba de Hartmann para optometría y oftalmología. En cada caso se describe el sistema óptico empleado y la geometría para deducir la aberración de frente de onda a partir de las aberraciones de rayo (patrones de Hartmann). En los tres casos se obtienen relaciones matemáticas similares, por lo que el frente de onda se puede determinar en cada caso empleando el mismo método de integración. Posteriormente, se calculan las cantidades de interés, a saber: en lensometría, los mapas de potencia refractiva cilíndrica y esférica; en topografía, el mapa de curvatura tangencial; y en aberrometría, el mapa de elevación de frente de onda y la psf. Finalmente, se hace un breve comentario sobre la implementación de la prueba de Hartmann por parte de algunas compañías comerciales.

In this paper, we present three applications of the Hartmann test in vision science, developed atthe optical design laboratory of the Physics Department at the National University of Colombia:lensmeter for progressive addition lenses, corneal topography, and Hartmann-Shack aberrometer.First we briefly describe the classical Hartmann test for astronomical mirrors, and later threevariations of the Hartmann test for optometry and ophthalmology are done. In each case the opticalsystem and geometry used to derive the wavefront aberration from ray aberrations (Hartmann patterns) are described. In all three cases similar mathematical relationships are obtained, so that the wavefront can be determined in each case using the same method of integration. Afterwards,the quantities of interest are calculated in order to find out: in lensometry, maps of cylindrical and spherical refractive power; in topography, the map of tangential curvature; and in aberrometry,the wavefront elevation map and psf. Finally, a brief comment is made on the implementation of the Hartmann test by some commercial companies.