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RESUMO Objetivo: Avaliar os resultados visuais, topográficos e refrativos do implante de segmentos assimétricos (AS) de anel intracorneano (ICRS) em olhos com ceratocone e astigmatismo irregular/assimétrico (fenótipos tipo 2 Duck e 3 Snowman pela classificação morfológica do ceratocone de Fernandez-Vega/Alfonso). Métodos: Estudo clínico prospectivo realizado com 60 pacientes (60 olhos) com ceratocone que tiveram segmentos assimétricos de Kearing selecionados e implantados de acordo com o nomograma Mediphacos (http://kearing.online) com laser femtosegundo. As avaliações pré-operatórias e pós-operatórias incluíram medida de acuidade visual não corrigida, melhor acuidade visual corrigida, astigmatismo refracional, equivalente esférico e astigmatismo topográfico, Kmax e coma, medidos com o Galilei (Ziemer, Port, Suíça). Todos os parâmetros foram avaliados no pré-operatório e aos 3 e 6 meses de pós-operatório. Resultados: A média de idade dos pacientes foi de 26,34±8,49 anos; 28 (56,7%) eram do sexo feminino, 34 olhos apresentavam ceratocone de fenótipo tipo 2 e outros 26 olhos de fenótipo tipo 3. Aos 6 meses de pós-operatório, os olhos de fenótipo tipo 2 obtiveram ganhos na acuidade visual não corrigida e melhor acuidade visual corrigida de 0,30 LogMAR e 0,15 LogMAR, respectivamente; e reduções de 2,45D no astigmatismo topográfico; 2,30D no Kmax; 0,32μm no coma; 1,63D no astigmatismo refracional e 1,88D no equivalente esférico. Aos 6 meses, os olhos de fenótipo tipo 3 obtiveram ganhos na acuidade visual não corrigida e na melhor acuidade visual corrigida de 0,50 logMAR e 0,10 LogMAR, respectivamente; e reduções de 3,00D no astigmatismo topográfico; 5,20 D no Kmax; 0,09μm no coma; 2,00D no astigmatismo refracional e 4,25D no equivalente esférico. Os resultados das comparações entre 3 e 6 meses de pós-operatório não foram estatisticamente significativos para nenhuma das variáveis avaliadas, o que denotou a estabilidade do procedimento nesse tempo de seguimento. Conclusão: O implante de segmentos assimétricos de Kearing em olhos com ceratocone e astigmatismo irregular/assimétrico (fenótipos tipo 2 e 3) melhoraram os parâmetros visuais, topográficos e refrativos com segurança e eficácia clínica.

Copyright of Arquivos Brasileiros de Oftalmologia is the property of Arquivos Brasileiros de Oftalmologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Arquivos Brasileiros de Oftalmologia is the property of Arquivos Brasileiros de Oftalmologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Arquivos Brasileiros de Oftalmologia is the property of Arquivos Brasileiros de Oftalmologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

RESUMO Objetivo: Analisar retrospectivamente as alterações na ceratometria e no astigmatismo corneano obtidas após cirurgia de implante de anel intraestromal, comparando o uso de um segmento de arco longo versus o implante de dois segmentos de comprimento de arco tradicional. Métodos: A partir de um estudo transversal, obtivemos os dados de 94 olhos de pacientes diagnosticados com ceratocone, que foram submetidos ao implante de anel corneano. Eles foram divididos em dois grupos, dependendo do tipo de implante recebido: Grupo A, um segmento de arco longo; Grupo B, dois segmentos tradicionais. Todos os segmentos implantados possuíam 250µ de espessura. Os dados do pré-operatório dos dois grupos foram comparados, para garantir que as amostras eram similares (as diferenças encontradas entre os dois grupos não eram estatisticamente significativas). As variáveis analisadas no pré e no pós-operatório foram acuidade visual com correção, ceratometria, astigmatismo corneano e refração. Resultados: A amostra que recebeu apenas um segmento de arco longo (Grupo A) obteve redução da ceratometria média de 4,42D (8,7%) e do astigmatismo corneano de 2,43D (40,4%). Já na amostra dos olhos que receberam dois segmentos de arco tradicional (Grupo B), houve redução média de 2,66D (5,1%) em relação à ceratometria média e redução média de 2,11D (34,8%) em relação ao astigmatismo corneano. A redução obtida na ceratometria média no Grupo A foi maior que a obtida no Grupo B (diferença estatisticamente significativa). A redução obtida no astigmatismo do Grupo A não foi estatisticamente significante, se comparada com o resultado obtido no Grupo B (considerando p≤0,05). Conclusão: Foi demonstrado que o uso de um segmento de arco longo possui maior capacidade de aplanação corneana, se comparado com o uso de dois segmentos com comprimento de arco tradicional. Em relação à redução do astigmatismo, os dois grupos mostraram resultados equivalentes.

Purpose: To retrospectively analyze the changes in corneal keratometry and astigmatism after intrastromal ring surgery, comparing the use of one long arch segment versus two traditional arc length segments. Methods: A cross-sectional study obtained data from 94 eyes of patients diagnosed with keratoconus that underwent surgical treatment with corneal ring implant. They were divided into two groups according to the type of implant received: one long-arch segment (Group A) or two traditional segments (Group B), both 250 microns thick. Preoperative data from the two groups were compared to ensure that the samples were similar (the differences between the two groups were not statistically significant). The variables (pre and post-operatively) analyzed were: best corrected visual acuity, keratometry, corneal astigmatism and refraction. Results: Group A, which received one long arch segment, showed a Km decrease of 4.42D (8.7%) and a corneal astigmatism reduction of 2.43D (40.4%). Group B, where the eyes acquired two traditional arch segments, showed an average Km decrease of 2.66D (5.1%) and corneal astigmatism reduction of 2.11D (34.8%). The mean keratometry (Km) reduction obtained was statistically significant (p≤0.05) when comparing both groups (A and B). The mean corneal astigmatism reduction was not statistically significant (p≤0.05) when comparing both groups (A and B). Conclusions: One long-arch segment has been demonstrated to have a greater capacity to reduce corneal curvature when compared to the use of two traditional-sized arch segments. No significant differences were found regarding the reduction of corneal astigmatism after comparing the results obtained in both groups. [ABSTRACT FROM AUTHOR]

LASIK is a refractive surgical procedure in which a corneal flap is created to expose the corneal stromal bed. Preoperative estimation of corneal flap thickness is necessary to calculate the percentage tissue altered in LASIK, an important quantitative risk factor for ectasia. The objective of this study was to assess flap thickness and calculate percentage tissue altered to check if unexpectedly thicker flaps and higher percentage tissue altered could pose as risk factors of ectasia. Four subjects (eight eyes) were submitted to mechanical LASIK in 2009 and 2010. Pre and postoperative clinical and tomographic data were reviewed. Mean preoperative estimated percentage tissue altered was 39.18±1.31%, which was borderline for increased ectasia risk when considering the limit of 40%. However, when considering the postoperatively measured flap thickness, the actual mean percentage tissue altered turned out to be 45.17 ± 4.13%, which was significantly higher than predicted preoperatively (p=0.002). Unexpectedly higher postoperative percentage tissue altered may be responsible for corneal ectasia after mechanical LASIK. [ABSTRACT FROM AUTHOR]

The accuracy of the intraocular lens calculation is not perfect, and postoperative refractive errors are common, especially in patients who have undergone previous refractive surgery or in presence of asymmetric corneas. Corneal power after refractive surgery can be more accurately measured using the total optical power map in the 4-mm central zone, by means of Orbscan II or equivalent keratometric reading map available on pentacam, with central measurements of 1.0, 2.0, 3.0 and 4.5 mm. The purpose of this case series is to demonstrate four approaches performed in special corneal conditions, using pentacam equivalent keratometric reading to measure corneal power and biometrics, and comparing with possible results obtained with other strategies. The four eyes were submitted to previous refractive procedures, and the intraocular lens chosen from the use of the corneal power calculated by equivalent keratometric reading showed excellent postoperative results. [ABSTRACT FROM AUTHOR]

RESUMO A acurácia do cálculo da lente intraocular não é perfeita, podendo ser comuns erros refrativos pós-operatórios, especialmente em pacientes submetidos à cirurgia refrativa prévia ou na presença de córneas assimétricas. O poder corneano após cirurgia refrativa pode ser medido com maior acurácia utilizando o mapa de poder óptico total na zona central de 4mm, com Orbscan II ou pelo mapa equivalent keratometric reading disponível no pentacam, com medidas centrais de 1,0, 2,0, 3,0 e 4,5mm. O objetivo desta série de casos é demonstrar a abordagem de quatro olhos em condições especiais corneanas, por meio do equivalent keratometric reading do pentacam para mensuração do poder corneano e o utilizando na biometria, em comparação com possíveis resultados obtidos com outras estratégias. Os quatro olhos foram submetidos a procedimentos refrativos prévios, e a lente intraocular escolhida a partir do uso do poder corneano calculado pelo equivalent keratometric reading mostrou excelentes resultados pós-operatórios.

RESUMO Objetivo: Avaliar sensibilidade do volume corneano, asfericidade e índice D para o diagnóstico precoce de ceratocone. Métodos: Estudo transversal analítico, realizado entre dezembro de 2018 e outubro de 2020, no qual foram analisados os prontuários de 39 pacientes (78 olhos) diagnosticados com ceratocone por um único subespecialista em córnea, por meio dos critérios de Belin/Ambrosio Enhanced Ectasia. Os dados coletados foram: asfericidade anterior, asfericidade posterior, índice D e suas frações (Da, Db, Dt, Dp e Df). Os dados foram digitados e manipulados em Excel, para posterior tratamento utilizando o programa Statistical Package for Social Science do Windows, versão 21.0. As variáveis categóricas foram apresentadas como valor absoluto e percentual. Variáveis contínuas foram apresentadas como média ± desvio-padrão e mediana (intervalo de confiança de 95%). Resultados: Foram analisados 78 olhos, com idade média de 28,2±5,8 anos e porcentagem entre o sexo feminino e masculino de 59,0% e 41,0%, respectivamente. O índice D apresentou estreita relação com sua fração Db nos casos iniciais de ceratocone, enquanto a fração Dt apresentou tal relação de forma reduzida. Conclusão: A correlação entre o índice D e sua fração Db sugere alterações precoces na elevação corneana posterior, colaborando para o diagnóstico de ceratocone subclínico.

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Objective: To assess sensitivity of corneal volume, corneal asphericity, and D index in early diagnosis of keratoconus. Methods: A cross-sectional analytical study, carried out between December 2018 and October 2020, which analyzed the medical records of 39 patients (78 eyes) diagnosed as keratoconus by a single corneal specialist, using the criteria of Belin-Ambrosio Enhanced Ectasia Display. The collected data were anterior asphericity, posterior asphericity, D index and its parameters (Da, Db, Dt, Dp and Df). The data were entered and handled in Excel, for later data treatment using the software Statistical Package for Social Science, version 21.0, for Windows. The categorical variables were presented as absolute value and percentages. The continuous variables were presented as mean±standard deviation, and median (95% of confidence interval). Results: We analyzed 78 eyes, mean age of 28.2±5.8 years, 59.0% of sample were female, and 41.0%, male. The D index showed a close relation to its Db parameter in the cases of keratoconus at early stage, while Dt parameter showed a reduced relation. Conclusion: The correlation between the D index and its Db parameter suggests early changes in the posterior corneal elevation, contributing to early diagnosis of subclinical keratoconus. [ABSTRACT FROM AUTHOR]

Copyright of Arquivos Brasileiros de Oftalmologia is the property of Arquivos Brasileiros de Oftalmologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Arquivos Brasileiros de Oftalmologia is the property of Arquivos Brasileiros de Oftalmologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective:To Perform a review on the diagnosis of keratoconus, focusing on the available propaedeutic methods. Methods:A search was performed in the PubMed database using the key words: Keratoconus, diagnosis, topography and tomography. As it is a review, there was no restriction regarding the publication period of the selected articles. Furthermore, both the preferred practice pattern(PPP) manual of the American Academy of Ophthalmology, as well as the website “eyewiki.aao.org” were used as reference. The project was submitted to the research ethics committee of the Federal University of São Paulo / UNIFESP / SP 2018 (# 2,568,770). Results: Out of the 641 papers found in PubMed, in adition to those used as a reference for PPP, 36 were selected while considered more relevant to the adopted theme. The website “eyewiki.aao.org” was used as a reference for the images. Conclusion: The diagnosis of keratoconus has evolved considerably since it was first described. It is desirable to diagnose it on the early stages due to its high potential of morbility. A possibility of an integration between the various diagnostic indices, genetic research, molecular biology and artificial intelligence is recommended for greater diagnostic accuracy. [ABSTRACT FROM AUTHOR]

Copyright of Arquivos Brasileiros de Oftalmologia is the property of Arquivos Brasileiros de Oftalmologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Arquivos Brasileiros de Oftalmologia is the property of Arquivos Brasileiros de Oftalmologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Arquivos Brasileiros de Oftalmologia is the property of Arquivos Brasileiros de Oftalmologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Arquivos Brasileiros de Oftalmologia is the property of Arquivos Brasileiros de Oftalmologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: In the presence of an irregular cornea, like in keratoconus, the corneal epithelium has a different profile "masking" the irregular corneal stroma surface. Topographical analysis without considering the epithelium effect can result in an incorrect assessment, affecting the accuracy of any topography guided treatment. The aim of this study was to evaluate the "masking" effect of the corneal epithelium on corneal curvature in patients with keratoconus, comparing topographical findings before and after removal of the epithelium during Crosslinking (CXL). Methods: Five eyes of 5 patients with progressive keratoconus submitted to CXL according to the original Dresden protocol. Corneal topography was performed before and during the procedure (immediately after epithelium removal) and values of keratometry: K1, K2, mean K (Km), maximum corneal apical curvature (Kmax), corneal thickness and corneal astigmatism were evaluated. Results: The average values of corneal curvature before and after epithelial remove were: K1: 43.50±2.54D and 44.32±2,64D (p=0.080); K2 46.64±2,35D and 49.38±2,86D (p=0.043); Km 45.48±2.42D and 46.72±2.60D (p=0.042). It was also observed a significant increase in the maximum values of corneal apical curvature after removal of the epithelium (p=0.043). In central corneal thickness there was seen a reduction of 26.8μm from 524.8±33.0µm to 498.2±37.7μm (p = 0.042). Conclusion: There was seen a significant increase in the values of Kmax, K2 and mean K. This study demonstrates the masking effect of corneal epithelium on corneal curvature in keratoconus. [ABSTRACT FROM AUTHOR]

Objective: In the presence of an irregular cornea, like in keratoconus, the corneal epithelium has a different profile "masking" the irregular corneal stroma surface. Topographical analysis without considering the epithelium effect can result in an incorrect assessment, affecting the accuracy of any topography guided treatment. The aim of this study was to evaluate the "masking" effect of the corneal epithelium on corneal curvature in patients with keratoconus, comparing topographical findings before and after removal of the epithelium during Crosslinking (CXL). Methods: Five eyes of 5 patients with progressive keratoconus submitted to CXL according to the original Dresden protocol. Corneal topography was performed before and during the procedure (immediately after epithelium removal) and values of keratometry: K1, K2, mean K (Km), maximum corneal apical curvature (Kmax), corneal thickness and corneal astigmatism were evaluated. Results: The average values of corneal curvature before and after epithelial remove were: K1: 43.50±2.54D and 44.32±2,64D (p=0.080); K2 46.64±2,35D and 49.38±2,86D (p=0.043); Km 45.48±2.42D and 46.72±2.60D (p=0.042). It was also observed a significant increase in the maximum values of corneal apical curvature after removal of the epithelium (p=0.043). In central corneal thickness there was seen a reduction of 26.8μm from 524.8±33.0µm to 498.2±37.7μm (p = 0.042). Conclusion: There was seen a significant increase in the values of Kmax, K2 and mean K. This study demonstrates the masking effect of corneal epithelium on corneal curvature in keratoconus. [ABSTRACT FROM AUTHOR]

Copyright of Arquivos Brasileiros de Oftalmologia is the property of Arquivos Brasileiros de Oftalmologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Pellucid marginal corneal degeneration (PMCD) is a rare bilateral noninflammatory ectatic peripheral corneal disorder, usually involving the inferior portion of the cornea, separated from limbus by an area of normal corneal thickness. There is protrusion of the cornea above the thinning area, resulting in high irregular astigmatism. Corneal Topography shows the characteristic, but not pathognomonic, image of a "butterfly wing". A patient with superior PMCD - an atypical presentation of the disease - is presented, highlighting the importance of the inclusion of PMCD as a diagnostic hypothesis, in cases of non-inflammatory peripheral corneal thinning that does not compromise only the inferior corneal area. [ABSTRACT FROM AUTHOR]

Pellucid marginal corneal degeneration (PMCD) is a rare bilateral noninflammatory ectatic peripheral corneal disorder, usually involving the inferior portion of the cornea, separated from limbus by an area of normal corneal thickness. There is protrusion of the cornea above the thinning area, resulting in high irregular astigmatism. Corneal Topography shows the characteristic, but not pathognomonic, image of a "butterfly wing". A patient with superior PMCD - an atypical presentation of the disease - is presented, highlighting the importance of the inclusion of PMCD as a diagnostic hypothesis, in cases of non-inflammatory peripheral corneal thinning that does not compromise only the inferior corneal area. [ABSTRACT FROM AUTHOR]

The determination of corneal power, after excimer laser refractive surgery, is difficult. Different alternatives with the use of corneal tomographs have been used for this measurement. Objective. To evaluate various methods of determination of corneal power in patients undergoing photorefractive surgery, including diagnostic tests with quantitative measurements. Methodology. This is a retrospective observational study. We included patients undergoing photorefractive surgery with refractive results and postoperative corneal tomography taken at least ten weeks after surgery. Results. In the myopic eyes significant differences were found in the value determined by the keratometry derived from the clinical history when compared with the average postoperative manual keratometry, the simulated keratometry and the Mean Pupil Power of the Sirius® tomograph. On the other hand, when averaging the average postoperative manual keratometry with the postoperative Mean Pupil Power (value called Kpop average 1) and comparing it with the keratometry derived by the clinical history method, no statistically significant differences were observed in the myopic patients. Likewise, when averaging the simulated postoperative keratometry of the Sirius® equipment with the postoperative Mean Pupil Power (value called "Kpop average 2") and comparing it with the keratometry derived by the method of the clinical history, no statistically significant differences were observed in the myopic patients. On the other hand, in hyperopic eyes and with mixed astigmatism, mean errors of the postoperative Mean Pupil Power, with respect to the keratometry derived by the clinical history method, were not significantly different from the errors when comparing the "Kpop average 1" and the "Kpop average 2" with the keratometry derived by the clinical history method. Conclusions. In myopic eyes the postoperative corneal power determinations with the "Kpop average 1" and "Kpop average 2" are closer to the keratometry derived by the clinical history method than to the measurements of the average postoperative manual keratometry, the postoperative simulated keratometry or the Mean Pupil Power of the Sirius® equipment. [Jaramillo LC, Galvis V., Tello A., Camacho PA, Castillo A., Pareja LA. Corneal power determination with corneal tomography after refractive surgery with excimer laser. [ABSTRACT FROM AUTHOR]

Purpose: To compare the ability to detect preoperative ectasia risk among LASIK candidates using classic ERSS (Ectasia Risk Score System) and Pentacam Belin-Ambrósio deviation index (BAD-D), and to test the benefit of a combined approach including BAD-D and clinical data. Methods: A retrospective nonrandomized study involved preoperative LASIK data from 23 post-LASIK ectasia cases and 266 stable-LASIK (follow up > 12 months). Preoperative clinical and Pentacam (Oculus; Wetzlar, Germany) data were obtained from all cases. Mann-Whitney's test was performed to assess differences between groups. Stepwise logistic regression was used for combining parameters.The areas under the Receiver Operating Characteristic (ROC) curves (AUC) were calculated for all parameters and combinations, with pairwise comparisons of AUC (DeLong's method). Results: Statistically significant differences were found for age, residual stromal bed (RSB), central corneal thickness and BAD-D (p0.05). ERSS was 3 or more on 12/23 eyes from the ectasia group (sensitivity = 52.17%) and 48/266 eyes from the stable LASIK group (18% false positive). BAD-D had AUC of 0.931 (95% CI: 0.895 to 0.957), with cut-off of 1.29 (sensitivity = 87%; specificity = 92.1%). Formula combining BAD-D, age and RSB provided 100% sensitivity and 94% specificity, with better AUC (0.989; 95% CI: 0.969 to 0.998) than all individual parameters (p>0.001). Conclusion: BAD-D is more accurate than ERSS. Combining clinical data and BAD-D improved ectasia susceptibility screening. Further validation is necessary. Novel combined functions using other topometric and tomographic parameters should be tested to further enhance accuracy.

Copyright of Arquivos Brasileiros de Oftalmologia is the property of Arquivos Brasileiros de Oftalmologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Arquivos Brasileiros de Oftalmologia is the property of Arquivos Brasileiros de Oftalmologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: To correlate the asphericity coefficient (Q) with longitudinal spherical aberration (LSA) of the corneal surface, also correlating each of these variables with the average keratometry Methods: An observational study was conducted by collecting preoperative data from the medical records of individuals candidate cataract surgery, i.e., patient sex and age, as well as Q, LSA of the corneal surface and mean keratometry (Km). Patients who had been subjected to any corneal surgical procedure who would alter Q, LSA and Km measuements were excluded. The corneanl topograph selected, fixedly, a 4.5 mm area of the anterior surface of the cornea for the measurement of Q and LSA, having the pupillary axis as the central point, since the occurrence of LSA is relevant in dim environments in individuals with a pupil wider than 3 mm Results: The sample consisted of 70 eyes of 35 individuals, 24 of them women (68.6%) and 11 men (31.4%) ranging in age from 48 to 89 years (mean: 69.97 ± 8.29). Km ranged from 41.00 to 46.50 D, with a mean of 43.94 ± 1.48D, and mean Q of the corneal surface was -0.15 ± 0.15. Six corneas showed a spherical design (Q= 0.0) and only one showed an aspheric design with Q = -0.50, generating an LSA of 0.0. Mean LSA of the corneal surface was +0.33 ± 0.14 µm. Only one eye showed an LSA equal to 0.0µm, and five showed an LSA of +0.10 to +0.30µm. No eye showed a negative LSA of the corneal surface. There was no correlation between Km and Q (r = -0.005 / p = 0.965) or between Km and LSA (r = 0.167 / p = 0.170). A correlation (r = 0.962 / p = 0.000) was observed between Q and LSA Conclusion: There was a correlation between Q and LSA of the corneal surface. There was no correlation between the sphericity coefficient or longitudinal spherical aberration with the average keratometry. [ABSTRACT FROM AUTHOR]

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Copyright of Investigaciones ANDINA is the property of Fundacion Universitaria del Area Andina and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

OBJECTIVE: To describe a novel technique for clinical characterization of corneal biomechanics using non-invasive dynamic imaging. METHODS: Corneal deformation response during non contact tonometry (NCT) is monitored by ultra-high-speed (UHS) photography. The Oculus Corvis ST (Scheimpflug Technology; Wetzlar, Germany) has a UHS Scheimpflug camera, taking over 4,300 frames per second and of a single 8mm horizontal slit, for monitoring corneal deformation response to NCT. The metered collimated air pulse or puff has a symmetrical configuration and fixed maximal internal pump pressure of 25 kPa. The bidirectional movement of the cornea in response to the air puff is monitored. RESULTS: Measurement time is 30ms, with 140 frames acquired. Advanced algorithms for edge detection of the front and back corneal contours are applied for every frame. IOP is calculated based on the first applanation moment. Deformation amplitude (DA) is determined as the highest displacement of the apex in the highest concavity (HC) moment. Applanation length (AL) and corneal velocity (CVel) are recorded during ingoing and outgoing phases. CONCLUSION: Corneal deformation can be monitored during non contact tonometry. The parameters generated provide clinical in vivo characterization of corneal biomechanical properties in two dimensions, which is relevant for different applications in Ophthalmology.

Este trabalho revisa e faz uma análise crítica da radiofrequência em oftalmologia. O aquecimento da córnea tem sido realizado desde 1889 com diferentes finalidades terapêuticas e cirúrgicas. O princípio do aquecimento da córnea causa um enrugamento do colágeno que muda a curvatura da córnea. Após a aprovação da FDA em 2004, iniciou-se um estudo multicêntrico no Brasil coordenado pela Faculdade de Medicina do ABC que resultou na análise de 258 pacientes. Como conclusão o estudo mostrou que o procedimento tem um resultado temporário e que os melhores resultados foram obtidos em pacientes entre 45 e 55 anos de idade sem correção óptica para longe. Acreditamos que o problema ainda não foi resolvido e que novas pesquisas devem ser realizadas.

Descrevemos a importância da tomografia de córnea e segmento anterior na propedêutica do exame complementar na avaliação de ectasia. Esta descrição da interpretação clínica dos índices da tomografia de córnea e segmento anterior (Pentacam - Oculus, Wetzlar, Germany) neste relato de caso, demonstra a relevância de uma nova tecnologia na avaliação da córnea e segmento anterior na suspeita de ceratocone. O diagnóstico de ceratocone foi excluído pela análise dos índices tomográficos de ectasia. Detectou-se assimetria entre os lados nasal e temporal por meio da avaliação do mapa de profundidade de câmara anterior. No exame biomicroscópico sob midríase foi constatado subluxação do cristalino, sendo assim devemos estar atentos não somente aos índices tomográficos corneanos na avaliação do exame complementar e sim analisarmos outros dados importantes oferecidos pela tomografia de córnea e segmento anterior.The methodology currently used for interpretation of the cornea and anterior segment tomography for the diagnosis of corneal ectasia. Description of the clinical interpretation of anterior segment tomography (Pentacam - Oculus, Wetzlar, Germany); case report of the ectopia lentis demonstrating the importance o evaluation of the cornea and anterior segment of the keratoconus. We excluded the disease, analyzing the tomographic analysis of rates of ectasia and observe an asymmetry between nasal and temporal sides in assessing the depth map of the anterior chamber. On the biomicroscopic examination in mydriasis, was found a ectopia lentis. We must be mindful not only to corneal tomography indices to evaluate a diagnostic test, but look at other important information provided by anterior segment tomography.

PURPOSE: To assess the repeatability of central corneal thickness measurement at the geometrical center (Central Corneal Thickness - CCT) given by the Pentacam High Resolution (HR) Comprehensive Eye Scanner (Oculus, Wetzlar, Germany) over time. METHODS: Prospective, single center, observational study. Two separate CCT measurements were taken by the Pentacam corneal tomography exam (CTm) 3 to 12 months apart, and compared. RESULTS: One hundred and sixteen eyes (n=116) of 62 health patients were included in this study. Average CCT in first and last visits was 541.6±37 µm and 543.6±36.9 µm respectively. Mean difference between both measurements was 9.2±6.4 µm, and there was no statistically significant difference in CCT measurement between visits, with good correlation between them (P = 0.057, r² = 0,9209). CONCLUSION: Pentacam (HR) CTm gives repeatable CCT measurements over time.

OBJETIVO: Correlacionar área do disco óptico com parâmetros geométricos e biomecânicos da córnea. MÉTODOS: Estudo retrospectivo nos arquivos de pacientes do Instituto de Olhos Renato Ambrósio a fim de se identificar os pacientes que realizaram exames HRT (Heidelberg Retina Tomography), Pentacam e ORA. A retinografia digital foi revisada de modo a se classificar na escala DDLS (Disc Damage Likelihood Scale). RESULTADOS: 244 olhos de 122 pacientes (75 mulheres) foram incluídos no estudo. A média de idade foi de 47,2 anos (de 8 a 97 anos, desvio padrão de 21,7). Não houve correlação significante entre área do disco e nenhuma das medidas de PIO (IOPg, IOPcc). Encontrou-se uma relação negativa significativa com CRF (r=-0,1337, p=0,0263). A relação com histerese foi também negativa (-0,1123), mas o valor p foi maior que 0,05 (0,0625). Não houve correlação significante entre área do disco e progressão paquimétrica mínima ou média. Entretanto, observou-se correlação significante e positiva entre a área do disco e astigmatismo corneano (Delta K), sendo de 1,15 (p=0,0129). CONCLUSÃO: Existe uma correlação negativa entre a área do disco óptico e os parâmetros biomecânicos e estruturais da córnea. Tal correlação pode ser parte da explicação da córnea ser um fator de risco para maior susceptibilidade do nervo óptico para neuropatia glaucomatosa.

OBJETIVO: Determinar a variação da ceratometria em olhos de pacientes portadores de espasmo hemifacial submetidos a tratamento com toxina botulínica. MÉTODOS: Foram incluídos 18 pacientes portadores de espasmo hemifacial que foram submetidos ao exame oftalmológico completo, além da topografia corneana e Orbscan previamente à aplicação de toxina botulínica tipo A e 1 mês após o procedimento. RESULTADOS: Não houve diferença estatisticamente significante entre a ceratometria encontrada pela topografia corneana ou diferença no BFS ("best fit sphere") anterior e posterior e índice de Roush avaliados pelo Orbscan nos olhos acometidos pelo espasmo em relação ao olho contralateral quando comparados antes e após o procedimento. CONCLUSÃO: Neste estudo, não encontramos diferença entre olhos com espasmo hemifacial e olhos sem essa condição quando avaliados a ceratometria, o índice de Roush e o BFS corneano antes e após tratamento.

OBJETIVO: Comparação da espessura central da córnea entre crianças com cristalino transparente (controle), catarata, pseudofácicas e afácicas. Estudo prospectivo, observacional. MÉTODOS: Noventa e quatro olhos de 47 crianças foram submetidos à medida da espessura central corneana (ECC) e comparou-se o grupo controle (cristalino transparente) aos pacientes que apresentavam catarata, afacia ou pseudofacia. Pacientes com Síndrome de Down, aniridia, Síndrome de Marfan, glaucoma, anormalidades do segmento anterior ou pressão intraocular maior que 30 mmHg foram excluídos do estudo. RESULTADOS: Dos 94 olhos estudados, 52 faziam parte do grupo controle com ECC média 533,6 µm. No grupo com catarata (n=27) a ECC média foi de 532,3 µm, enquanto no grupo de afácicos (n=8) e pseudofácicos (n=12) de 585,63 µ e 585,7 µ, respectivamente. CONCLUSÃO: A espessura central da córnea é semelhante em olhos com catarata congênita e olhos fácicos, sendo mais espessa após a cirurgia de catarata com ou sem implante de lente intraocular.PURPOSE: To evaluate central corneal thickness (CCT) in phakic children (controls) and in those with cataracts, pseudophakia and aphakia. Study prospective, observational METHODS: Central corneal thickness was measured in 94 eyes of 47 children. Subjects with Down Syndrome, aniridia, Marfan Syndrome, glaucoma, anterior segment abnormalities or intraocular pressure over 30 mmHg were excluded. Groups were compared for controls and for eyes with pediatric cataracts, pseudophakia and aphakia. RESULTS: Twenty-nine patients were male and eighteen female and the mean age was 5. 5 years (range, 1 month to 15 years). Of the 94 eyes, 52 were part of the control group and the CCT average was 533. 6 µm. The average measurement of the CCT for all patients with cataract was 532. 3 µm (n = 27). The average CCT aphakia the group was 585. 63 µm (n = 8) and pseudophakic was 585. 7 µm (n = 12). CONCLUSION: In the absence of factors known to affect CCT (Down syndrome, aniridia, and Marfan syndrome), CCT is similar in eyes with pediatric cataracts and normal controls and increases after cataracts surgery.

A córnea possui grande influência no processo visual. Porém é passível de deformação, tal como o aplanamento. Quando esse aplanamento é causado pelo uso de lentes de contato, chamamos de "corneal warpage". Neste caso, alguns sintomas podem ocorrer como visão embaçada com os óculos, hiperemia conjuntival, sensação de corpo estranho, etc. Pensava-se que a córnea era mais rígida e, com o tempo, percebeu-se que a córnea possui entidade viscoelástica. Podemos dizer que a córnea possui uma entidade biomecânica e que, quando sofre instabilidade, ocorrem algumas alterações, como no caso do ceratocone, onde ocorre uma degeneração progressiva corneana. Com o intuito de buscar a estabilização corneana, foi desenvolvida a técnica de "crosslink", que consiste em promover ligações covalentes entre as lamelas da córnea para torná-la mais firme e menos elástica. Outra alteração corneana pode ser induzida, de forma planejada, através do modelamento corneano com o uso de lentes de contato rígidas, com coeficiente de transmissibilidade de oxigênio (DK/L) maior. Elas são usadas somente durante o sono, não sendo necessário o seu uso diurno. Esta técnica é conhecida como Ortoceratologia e seus conceitos serão abordados neste estudo.The cornea has a great influence in the visual process. However, it is liable to distortion, such as flattening. When this flattening is caused by the use of contact lenses, we call "corneal warpage". In this case, some symptoms may occur as blurred vision with glasses, conjunctival hyperemia, foreign body sensation, etc… Used to think that the cornea was more rigid and, in time, realized that the cornea has viscoelastic properties. We can say that the cornea has a body biomechanics property and suffers instability when there are some changes, such as keratoconus, which is a progressive corneal degeneration. In order to preserve the cornea more stable, the cross-linking technique was developed to promote covalent bonds between the lamellae of the cornea to make it stronger and less elastic. Other corneal change that may occur is based on the induction in corneal reshaping by using rigid contact lenses (only during sleeping) with high oxygen transmissibility (DK / L). This technique is known as Orthokeratology and its concepts will be addressed in this study.

Relato de um caso de surpresa refracional pós-operatória não pretendida em paciente portador de distrofia corneana posterior amorfa submetida à facoemulsificação. A provável causa do erro, bem como a conduta tomada a partir do reconhecimento da mesma, são discutidas neste relato.One case of post-phacoemulsification refractive surprise in a posterior amorphous corneal dystrophy patient is reported herein. Its likely causative factor, as well as our approach once it was recognized are discussed in this report.

OBJETIVO: Este trabalho tem como objetivo relatar experiência com utilização do crosslinking após implante de anel intracorneano de Ferrara (Ferrara Ophtalmic) visando a melhora refrativa e estabilização corneana. MÉTODOS: Seis pacientes com idade entre 26 e 38 anos foram submetidos ao tratamento com crosslinking após implante de anel de Ferrara. Cinco pacientes receberam 2 segmentos de anel e um paciente recebeu um segmento. Depois de 4 a 55 meses os pacientes foram submetidos a aplicação do "crosslinking" com ultra-violeta de acordo com o protocolo estabelecido por Seiler & cols. RESULTADOS: Quatro olhos apresentaram alteração progressiva da refração e 2 apresentaram refração sem alteração progressiva. A topografia mostrou queda acentuada da curvatura e o estudo da lâmpada de fenda mostrou anel em boa profundidade durante um ano de pós-operatório em 100% dos olhos. A microscopia especular não mostrou alteração significativa e a acuidade visual se mostrou semelhante ao pré-operatório. CONCLUSÃO: O crosslinking poderá ajudar a manter ceratocones estáveis, não-somente nos casos de progressão, mas também nos cones evolutivos com implante de anel.PURPOSE: To describe our experience with crosslinking after Ferrara ring implant for better vision and corneal stabilization. METHODS: six patients with age of 26 - 38 years old had treatment with crosslinking after Ferrara ring implant. Five patients had 2 ring segments implanted and one patient had one segment implanted. After 4 to 55 months the patients were submitted to crosslinking with UVA light according to Seiler et al protocol. RESULTS: Four eyes had progressive alteration of refraction and 2 patients had no alteration of refraction. The topography showed flattener curvature and at the slip lamp 100% of the eyes had good depth after one year post operatively. The specular microscopy didn't show any significant alteration and the visual acuity was similar before the procedure. CONCLUSION: The crosslinking may help to maintain stable keratoconus, not only in progression cases, but also in evolutive keratoconus with ring implant.

OBJETIVO: Avaliar o efeito clínico e topográfico da reticulação do colágeno corneano (crosslinking) em pacientes com ceratocone pertencentes à população brasileira. MÉTODOS: Trinta e sete olhos de 37 pacientes (22 mulheres e 15 homens) com diagnóstico de ceratocone em progressão e com espessura mínima de 395 micra, foram submetidos à técnica de indução da reticulação do colágeno corneano através da aplicação durante 30 minutos de luz ultravioleta (370nm) associada à solução de riboflavina 0,1% (instilada a cada 5 minutos). Foram comparados os valores ceratométricos e a melhor acuidade visual corrigida antes e após o procedimento, com intervalos de 40 e 90 dias. RESULTADOS: Houve redução do poder dióptrico médio (PDM) nos 3mm centrais em 83,8% dos pacientes após três meses. O PDM reduziu em média 0,4D nos 3mm centrais (pPURPOSE: Assess the clinical and topographical effects of corneal collagen crosslinking in patients with keratoconus on Brazilian population. METHODS: Thirty seven eyes of 37 patients (22 female and 15 male) with diagnosis of progressive keratoconus and corneal paquimetry higher than 395 micra, were treated with riboflavin and ultraviolet A radiation, over 30 minutes, to induce corneal collagen crosslinking. Keratometric values were compared as well as the best corrected visual acuity, before and after the procedure, with ranges of 40 and 90 days. RESULTS: There was a reduction of mean dioptric power (PDM) in central 3mm in 83.8% of patients after three months.The PDM reduced 0.4D on average in central 3mm (p

OBJETIVO: Analisar a possível variação da pressão intra-ocular, obtida por diferentes tonômetros, com a espessura central da córnea. MÉTODOS: Após a medida da pressão intra-ocular com o ICare, instilou-se uma gota de colírio anestésico e fez-se a medida da espessura da córnea e, também, a medida da pressão intra-ocular com o tonômetro de contorno dinâmico de Pascal. Em seguida, instilou-se uma gota de colírio de fluoresceína e mediu-se a pressão intra-ocular o tonômetro de aplanação de Goldmann. RESULTADOS: 138 olhos de 71 pacientes foram examinados e divididos em 3 grupos de acordo com a espessura central da córnea. A análise da pressão intra-ocular mostrou valores concordantes quando se utilizou o ICare e o tonômetro de contorno dinâmico de Pascal, com média de diferença de -0,2. A pressão intra-ocular medida com o tonômetro de contorno dinâmico de Pascal apresentou valores maiores que os obtidos com o tonômetro de aplanação de Goldmann, com média de diferença de -3,1. Uma diferença estatisticamente significante foi obtida nas medidas com o ICare e tonômetro de aplanação de Goldmann. CONCLUSÃO: Existe uma diferença estatisticamente significante entre os valores da PIO obtidos com ICare, tonômetro de contorno dinâmico de Pascal e tonômetro de aplanação de Goldmann, quando relacionados com a espessura central da córnea.PURPOSE: Could the central corneal thickness (CCT) change the intraocular pressure (IOP) measured by ICARE (IC) GOLDMANN APPLANATION TONOMETER (GAT) and PASCAL DYNAMIC COUNTOUR TONOMETER (PDCT). METHODS: Before using the anesthesia we have measured the IOP with IC tonometer. After that we have used topical anesthesia to obtain the CCT using an ultrasound pachymeter (Mentor Co.) and the IOP measured by PCDT followed by a drop of fluorescein to measured IOP with GAT. RESULTS: 138 eyes of 71 patients were analyzed. Patients were divided into 3 groups according to CCT. Best correlation was observed with IC and PDCT, showing a mean average difference of -0.2. The intraocular pressure data obtained from PDCT showed higher values when compared with GAT, with a mean average difference of -3.1. There are also a statistical significant difference with the IOP measurements with IC and GAT. CONCLUSION: There are a significant difference in IOP measurements obtained by IC, GAT and PCDT when compared with CCT.

OBJETIVOS: Comparar a medida da espessura corneana central (ECC) obtida pelo paquímetro óptico Haag-Streit e a paquimetria ultrassônica DGH 500 (PachetteTM). MÉTODOS: Foram avaliados, 200 olhos de 100 pacientes utilizando-se o paquímetro óptico (PO) e o ultrassônico (PU). As medidas foram realizadas na área central da córnea, respeitando a área dos 3 mm, em pacientes com córneas normais, em olhos hipermétropes, emétropes e míopes, excluindo doenças oculares, usuários de lentes de contato ou submetidos às cirurgias. RESULTADOS: A média geral da ECC medida pelo PO foi 603,8± 32,6µm, e 568,2±40,5 µm pelo PU. As comparações entre as medidas dos dois aparelhos foram realizadas ao nível de 5% de significância e a diferença entre os dois aparelhos foi 35,7±26,4 µm (p=0,0000), indicando diferença significativa entre os métodos utilizados. Não houve diferença estatística entre olhos hipermétropes, emétropes e míopes usando o PU. CONCLUSÃO: A medida da ECC é superestimada pelo PO quando comparada com o PU.PURPOSE: To compare measurements of central corneal thickness obtained using a Haag-Streit optic pachymeter and a DGH 500 (Pachette Ttm ) ultrasonic pachymeter in normal patients. METHODS: An evaluation was made of 200 eyes of 100 patients using Optic (PO) and Ultrasonic (PU) pachymeters. Measurements were made in the area of the central cornea (ECC) respecting the 3.0 mm territory, in patients with normal corneas of hypermetropic, emetropic and myopic eyes. Patients with ocular diseases, ocular surgeries, and contact lens wearers, were excluded. A statistical analysis was performed using a Paired Student's t test to compare measurements between instruments at the 5% level of significance. RESULTS: The mean thickness of the ECC measured by the PO was 603.8±32.6µm and by the PU, 568.2±40.5µm. The difference between the two instruments was 35.7±26.4µm. Applying the t test with p =

Copyright of Arquivos Brasileiros de Oftalmologia is the property of Arquivos Brasileiros de Oftalmologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)