Mycobacterium abscessus keratitis after LASIK surgery / Ceratite por Mycobacterium abscessus após cirurgia LASIK

ABSTRACT A 33-year-old male presented with unilateral subacute infectious keratitis 4 weeks after surgery. Corneal inflammation was resistant to standard topical antibiotic regimens. During diagnostic flap lifting and sampling, the corneal flap melted and separated. Through flap lifting, corneal scraping, microbiological diagnosis of atypical mycobacteria, and treatment with topical fortified amikacin, clarithromycin, and systemic clarithromycin, clinical improvement was achieved.

RESUMO Paciente do sexo masculino, 33 anos, apresentou ceratite infecciosa subaguda unilateral 4 semanas após a cirurgia. A inflamação da córnea foi resistente aos regimes de antibióticos tópicos padrão. A aba da córnea foi derretida e seccionada durante o levantamento e amostragem para diagnóstico. A melhora clínica só foi alcançada após levantamento do retalho, raspagem e diagnóstico microbiológico de micobactérias atípicas e tratamento com amicacina fortificada tópica, claritromicina e claritromicina sistêmica.

Clinical experience with adjustable scleral lenses / Experiência clínica com lentes esclerais ajustáveis

ABSTRACT Purpose: The aim of this study was to evaluate the fitting process of a scleral lens that allows several parameter adjustments during trials and after the initial period of use. In addition, we verified which adjustments were needed and used the most, their indications, and how often these resources were used, and checked the results. Methods: Scleral contact lens fittings in a private clinic setting were prospectively analyzed in a sequential, non-randomized, and non-comparative manner. All the patients underwent a complete ophthalmic examination and had an indication for scleral lens use (Zenlens, Alden Optical). Results: Scleral fit was analyzed in 80 eyes of 45 patients. Regarding diagnosis, 72% of the patients had keratoconus; 12%, radial keratotomy; 5%, post-refractive surgery ectasia; 5%, dry eye; and 3%, high myopia. In 66 (82.5%) of the 80 eyes studied, parameters were modified when the lenses were ordered. The reasons that led to the modifications were apical touch or decreased sagittal height, increased sagittal height, cylindrical over-refraction, poor visual acuity, lens flexure, peripheral touch, 360° edge compression, horizontal edge compression, and vertical edge compression. Conclusion: In this study, the use of Zenlens scleral lenses was shown to be a promising corrective treatment for patients requiring the use of scleral lenses. Although the study suggests a learning curve, as many adjustments were allowed, the lens could be customized according to the patients' needs. This increased the success rates of fitting and wearing, and consequently, use of the lens became a great option for the visual rehabilitation of patients.

RESUMO Objetivo: Avaliar o processo de adaptação de uma lente escleral que permite vários ajustes de parâmetros durante os testes e após o período inicial do seu uso; verificar quais os ajustes foram necessários, quais foram os mais utilizados, as suas indicações, a frequência com que estes recursos foram utilizados, e avaliar os resultados das mudanças realizadas. Métodos: A adaptação da lente de contato escleral foi analisada prospectivamente, de forma sequencial, não aleatória e não comparativa. Todos os pacientes foram submetidos a um exame oftalmológico completo e tinham indicação para o uso de lentes esclerais. Foi utilizada a lente Zenlens (Alden Optical). Resultados: Foi analisada a adaptação de lentes de contato esclerais em 80 olhos de 45 pacientes. Quanto ao diagnóstico, 72% tinham ceratocone, 12% tinham sido submetidos a ceratotomia radial, 5% tinham ectasia pós-cirurgia refrativa, 5% tinham olho seco, e 3%, alta miopia. Em 66 dos 80 olhos estudados (82,5%), os parâmetros foram modificados quando as lentes foram encomendadas. As razões foram: toque apical ou diminuição da altura sagital, aumento da altura sagital, sobre-refração cilíndrica, baixa acuidade visual, flexão da lente, toque periférico, compressão da borda em 360° e compressão da borda horizontal e/ou vertical. Conclusão: O uso de lentes esclerais Zenlens demonstrou ser uma forma de correção muito promissora para os pacientes que requerem o uso de lentes esclerais. Embora o estudo sugira uma curva de aprendizagem, é possível personalizar as lentes de acordo com as necessidades de cada pacientes. Este fato melhora a adaptação e aumenta a chance de sucesso do uso.

Avaliação do conhecimento sobre cirurgia refrativa por meio de questionário eletrônico / Evaluation of knowledge in refractive surgery using an on-line questionnaire

RESUMO Objetivo: Desenvolver e aplicar um questionário eletrônico para avaliação do conhecimento em cirurgia refrativa na população analisada. Métodos: Foi aplicado um questionário eletrônico a uma população composta de 840 participantes voluntários maiores de 18 anos. Resultados: A média da idade dos participantes foi 37,85 anos, sendo 60,1% do feminino. Dentre os participantes, 20,95% reportaram ter sido submetidos a alguma cirurgia ocular prévia, sendo 73,86% com objetivo refrativo. Entre estes, 73,08% mostraram-se satisfeitos/muito satisfeitos com o resultado. O critério mais importante na escolha de um cirurgião refrativo foi a indicação por um conhecido que realizara a cirurgia (43,81%). Destaca-se que os participantes submetidos à cirurgia refrativa discordaram que "a cirurgia é um procedimento simples e isento de riscos" mais do que as demais pessoas (p=0,0045) e também que "o objetivo principal da cirurgia é 'zerar' o grau" (p=0,0252). Conclusão: Nota-se a necessidade de melhorar o conhecimento pré-operatório da população sobre cirurgia refrativa e também de educação continuada para os oftalmologistas. Este estudo fomenta o desenvolvimento de novas ferramentas de educação com informações claras e de fácil acesso, que tenham caráter informativo, e não de convencimento.

ABSTRACT Objective: The purpose of this study was to develop and apply an online questionnaire to assess knowledge in Refractive Surgery in the analyzed population. Methods: An online questionnaire was applied to a population composed of 840 volunteer participants over 18 years of age. Results: The mean age of population was 37.85 years, of whom 60.1% were female. 20.95% of the participants reported having undergone previous eye surgery, 73.86% of which had a refractive objective. Among these, 73.08% were satisfied / very satisfied with the result. The most important criterion when choosing a refractive surgeon was the indication by a friend who underwent the procedure (43.81%). It is noteworthy that the participants who underwent refractive surgery disagreed more than the other people that "the surgery is a simple and risk-free procedure" (p = 0.0045) and that "the main objective of the surgery is to "zero" the diopter" (p = 0.0252). Conclusion: It is essential to improve population's preoperative knowledge about Refractive Surgery, as well as continuing education for ophthalmologists. Therefore, this study encourages the development of new education tools with clear and easily accessible information, which should be informative, and not convincing.

Unexpectedly high corneal flap thickness and ectasia after mechanical LASIK / Espessura inesperadamente alta do flap corneano e ectasia após LASIK mecânico

ABSTRACT 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.

RESUMO A LASIK é um procedimento cirúrgico refrativo, no qual um retalho corneano é criado para expor o leito estromal corneano. A estimativa pré-operatória da espessura do retalho corneano é necessária para calcular o percentual de tecido alterado no LASIK, um importante fator de risco quantitativo para ectasia. O objetivo deste estudo foi avaliar a espessura do retalho e calcular o percentual de tecido alterado para verificar se retalhos inesperadamente mais espessos e percentuais de tecido alterado mais altos poderiam representar fatores de risco de ectasia. Quatro indivíduos (oito olhos) foram submetidos à LASIK mecânica em 2009 e 2010. Dados clínicos e tomográficos pré e pós-operatórios foram revisados. A média de percentual de tecido alterado pré-operatória estimada foi de 39,18±1,31%, limítrofe para risco aumentado de ectasia quando considerado o limite de 40%. No entanto, ao considerar a espessura do retalho medida no pós-operatório, o percentual de tecido alterado médio real foi de 45,17±4,13%, ou seja, significativamente maior do que o previsto no pré-operatório (p=0,002). O percentual de tecido alterado pós-operatóriao inesperadamente mais alto pode ser responsável pela ectasia da córnea após LASIK mecânico.

The Pentacam® AXL Wave provides a reliable wavefront-based objective refraction when compared to manifest subjective refraction: A prospective study

Purpose: Accurate refraction is arguably the most important parameter for a successful laser vision correction surgery and is based on a combination of manifest and cycloplegic refraction. Wavefront?based objective refraction may be useful in the evaluation of patients. So far, the reliability of objective refraction as measured using the Pentacam® AXL Wave has not been published in the literature. Methods: This was a prospective study including a total of 168 eyes belonging to 84 young non?presbyopic patients evaluated for refractive surgery. Pentacam® AXL Wave full sequence was taken for all patients. Then, a clinician who was unaware of the objective refraction results performed a full physical examination, including manifest refraction starting from an autorefractometer value. All refraction values were transferred to astigmatic power vectors as per the Thibos method. Reliability of the different vectors and a unifying blur value were compared using Spearman correlation, Bland–Altman plot, and intraclass correlation coefficient. Results: The mean age was 28.8 ± 5.4 years, with a female preponderance (60.7%). The correlation between both eyes was high. The difference in M vector between subjective and objective refraction was 0.16 D, while the difference was 0.04 and 0.01 D for the J0 and J45 vectors, respectively. Paired samples Student t was non?significant for all comparisons. Spearman rho correlations were high (0.666–0.924, all P < 0.001). Intraclass correlation coefficients were also high (0.890–0.966). Bland–Altman plots did not demonstrate any systematic errors. Conclusion: Wavefront?based refractive refraction obtained using the Pentacam® AXL Wave is highly agreeable and correlated with measurements obtained by manifest subjective refraction.

Future developments and trends in refractive surgery / 中华实验眼科杂志

Refractive surgery is one of the important methods for refractive error correction, which include corneal refractive surgery and intraocular refractive surgery.In recent years, refractive surgery has a rapid development, and there is still development space and potential market demand.The clinical application of various new technologies has brought the refractive surgery to a new stage.The ultimate aim of refractive surgery is to pursue safer minimally invasive approaches and more customized correction for better visual quality.The new approaches including the guidance of corneal topography and wavefront aberration, the Q-value adjustment, Kappa angle adjustment, and customized corneal cross-linking during the surgery have been developed.The integration of various surgical approaches and research is also a new development direction.The combination with intelligent operation to improve the efficiency and accuracy of treatment seems to be one new direction, too.Ophthalmologists should pay attention to the current development and the possible future directions and trends of refractive surgery in China.

Post-laser in situ keratomileusis interface Arthrographis kalrae keratitis / Interface de pós-laser ceratomileuse in situ Arthographis Kalrae ceratite

ABSTRACT We describe a case of keratomycosis caused by Arthographis kalrae after excimer laser keratomileusis. A 38-year-old female developed stromal keratitis eight weeks after refractive surgery. She developed severe corneal stromal infiltration and mild anterior segment inflammation, which could not be treated with topical voriconazole 1%, but topical natamycin 5% ameliorated her condition. A reactivation of keratomycosis symptoms was observed; therefore, longer treatment was administered to the patient. It has been reported that A. kalrae keratomycosis is associated with exposure to soil and contact lens usage. However, the patient, who lived in a rural location, was neither involved in gardening activities nor had a history of wearing contact lenses. This is the first case of post-refractive A. kalrae keratomycosis.

RESUMO Descrevemos um caso de ceratomicose por Arthographis kalrae após ceratomileusis por excimer laser. Uma mulher de 38 anos desenvolveu ceratite estromal oito semanas após a cirurgia refrativa. Ela desenvolveu infiltração estromal grave da córnea e uma leve inflamação do segmento anterior, que não pode ser tratada com voriconazol tópico a 1%, mas a natamicina tópica a 5% melhorou sua condição. Uma reativação dos síntomas de ceratomicose foi observada; portanto, tratamento mais prolongado foi administrado a paciente. Tem sido relatado que a ceratomicose por A. kalrae está associada à exposição ao solo e ao uso de lentes de contato. No entanto, a paciente, que vivía em um local rural, não estava envolvida em atividades de jardinagem e nem tinha histórico de uso de lentes de contato. Este é o primeiro caso de ceratomicose pós-refrativa por A. kalrae.

Centration in refractive surgery / Centralização em cirurgia refrativa

ABSTRACT The point of centration for refractive surgery is a theme of great importance that generates considerable discussion among specialists and surgeons in the field. Notably, any changes in light can alter the size of the pupil, and the visual axis of the fixation line to the fovea is unique in each patient. A variety of options have been described in the literature with respect to centration in refractive surgery, and the results differ among these methods. No consensus has been established regarding the ideal refractive surgery technique for evaluation of centration in each patient that will yield a satisfactory surgical result.

RESUMO O ponto de centralização da cirurgia refrativa é tema de grande importância e gera muita discussão entre especialistas e cirurgiões da área. Afinal, qualquer alteração na luz pode alterar o tamanho da pupila, além disso, o eixo visual da linha de fixação para a fóvea é particular em cada paciente. Existem opções para centralização em cirurgia refrativa com resultados diferentes na literatura. Ainda não há consenso sobre a melhor técnica em cirurgia refrativa que avalie cada caso específico visando um resultado cirúrgico final satisfatório.

Binocular vision problems associated with refractive surgery and the use of risk screening / 中华实验眼科杂志

Although binocular vision problems do not appear to be one of the common complications of refractive surgery,the available evidence suggests that these problems can occur after refractive surgery,and preoperative binocular vision status may predict the risk of postoperative binocular vision anomalies.Furthermore,because ophthalmologists usually do not clearly recognize binocular vision,or they do not pay enough attention to it,the existing literature may underestimate the actual prevalence of binocular vision problems after refractive surgery.This paper discusses the existing literature on refractive surgery-related binocular vision anomalies and recommends a screening protocol and risk stratification.It also discusses the expected results of binocular vision testing,the diagnostic criteria for common binocular vision problems,and strategies for treating these anomalies before and after refractive surgery.

Clinical Outcomes of Small Incision Lenticule Extraction in Myopia: Study of Vector Parameters and Corneal Aberrations

Binocular vision problems associated with refractive surgery and the use of risk screening / 中华实验眼科杂志

Although binocular vision problems do not appear to be one of the common complications of refractive surgery, the available evidence suggests that these problems can occur after refractive surgery, and preoperative binocular vision status may predict the risk of postoperative binocular vision anomalies.Furthermore, because ophthalmologists usually do not clearly recognize binocular vision, or they do not pay enough attention to it, the existing literature may underestimate the actual prevalence of binocular vision problems after refractive surgery.This paper discusses the existing literature on refractive surgery-related binocular vision anomalies and recommends a screening protocol and risk stratification.It also discusses the expected results of binocular vision testing, the diagnostic criteria for common binocular vision problems, and strategies for treating these anomalies before and after refractive surgery.

Effects of Cyclotorsion Orientation and Magnitude in Eyes with Compound Myopic Astigmatism on the Compensation Capacity of WaveLight EX500 Photorefractive Keratectomy

PURPOSE: To investigate the clinical effects of different orientation and magnitude of cyclotorsion on the compensation capacity of the WaveLight EX500 photorefractive keratectomy (PRK) platform. METHODS: This retrospective study comprised 400 eyes of 200 patients who underwent bilateral simultaneous PRK due to compound myopic astigmatism. The subjects were separated according to the orientation of cyclotorsion into incyclotorsion and excyclotorsion groups, and by the magnitude of cyclotorsion into group 1 (0.50 to 2.50 degrees), group 2 (3.00 to 5.00 degrees), group 3 (5.50 to 7.50 degrees), and group 4 (8.00 to 9.50 degrees). RESULTS: The mean magnitude of cyclotorsion was 3.50 ± 2.4 degrees (0.50 to 9.50 degrees) in the incyclotorsion group and 3.32 ± 2.3 degrees (0.50 to 9.50 degrees) in the excyclotorsion group (p = 0.617). The postoperative refractive outcomes of the incyclotorsion and excyclotorsion groups were similar (p > 0.05 for all). The postoperative mean cylindrical refractive error was −0.32 ± 0.3 diopters (D, −1.25 to 0.00 D) in group 1, −0.47 ± 0.2 D (−2.00 to 0.00 D) in group 2, −0.62 ± 0.2 D (−1.00 to −0.25 D) in group 3, and −0.91 ± 0.2 D (−1.50 to −0.50 D) in group 4 (p < 0.001). Preoperative cylindrical refractive error was positively correlated with magnitude of cyclotorsion (r = 0.125 and p = 0.013), which was also positively correlated with postoperative cylindrical refractive error (r = 0.600 and p < 0.001). CONCLUSIONS: Incyclotorsion and excyclotorsion can be equally compensable in the WaveLight EX500 PRK platform for compound myopic astigmatism. A value of ≤2.50 degrees cyclotorsion magnitude was observed to be more compensable than higher degrees of cyclotorsion magnitude. Preoperative high astigmatism was associated with high cyclotorsion magnitude, which was also associated with a high degree of postoperative astigmatism.

Comparison of Intraocular Lens Power Calculation Methods Following Myopic Laser Refractive Surgery: New Options Using a Rotating Scheimpflug Camera

PURPOSE: To evaluate and compare published methods of calculating intraocular lens (IOL) power following myopic laser refractive surgery. METHODS: We performed a retrospective review of the medical records of 69 patients (69 eyes) who had undergone myopic laser refractive surgery previously and subsequently underwent cataract surgery at Samsung Medical Center in Seoul, South Korea from January 2010 to June 2016. None of the patients had pre-refractive surgery biometric data available. The Haigis-L, Shammas, Barrett True-K (no history), Wang-Koch-Maloney, Scheimpflug total corneal refractive power (TCRP) 3 and 4 mm (SRK-T and Haigis), Scheimpflug true net power, and Scheimpflug true refractive power (TRP) 3 mm, 4 mm, and 5 mm (SRK-T and Haigis) methods were employed. IOL power required for target refraction was back-calculated using stable post-cataract surgery manifest refraction, and implanted IOL power and formula accuracy were subsequently compared among calculation methods. RESULTS: Haigis-L, Shammas, Barrett True-K (no history), Wang-Koch-Maloney, Scheimpflug TCRP 4 mm (Haigis), Scheimpflug true net power 4 mm (Haigis), and Scheimpflug TRP 4 mm (Haigis) formulae showed high predictability, with mean arithmetic prediction errors and standard deviations of −0.25 ± 0.59, −0.05 ± 1.19, 0.00 ± 0.88, −0.26 ± 1.17, 0.00 ± 1.09, −0.71 ± 1.20, and 0.03 ± 1.25 diopters, respectively. CONCLUSIONS: Visual outcomes within 1.0 diopter of target refraction were achieved in 85% of eyes using the calculation methods listed above. Haigis-L, Barrett True-K (no history), and Scheimpflug TCRP 4 mm (Haigis) and TRP 4 mm (Haigis) methods showed comparably low prediction errors, despite the absence of historical patient information.

Investigation of the Changes in Refractive Surgery Trends in Korea

PURPOSE: To evaluate changes in clinical practice in the field of refractive surgery in Korea over the past 10 years. METHODS: A survey consisting of 59 multiple-choice questions regarding the preferred types of refractive surgery, excimer laser machine, and presbyopia surgery was mailed to 742 members of the Korean Society of Cataract and Refractive Surgery in January 2016, and 50 members responded to the survey. These data were compared with the 2005 or 2007 survey results.

Corneal Power Determination with Corneal Tomography after Refractive Surgery with Excimer Laser / Determinación del poder corneal con un tomógrafo corneal luego de cirugía refractiva con láser excimer / Determinação da potência corneana com uma topografia de córnea após cirurgia refrativa com excimer láser

Introduction. Corneal power determination after refractive surgery with excimer laser is complex. Different alternatives with the use of corneal tomography 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 post-operative corneal tomography taken at least ten weeks after surgery. Results. In myopic eyes, significant differences were found in the value determined by the keratometry derived from the clinical history when compared with the average post-operative manual keratometry, the simulated 32keratometry and the Mean Pupil Power of the Sirius®tomograph. On another note, when averaging the mean post-operative manual keratometry with the post-operative Mean Pupil Power (value called Kpopaverage 1) and comparing it with the keratometry derived from the clinical history method, no statistically significant differences were observed in myopic patients. Likewise, when averaging the simulated post-operative keratometry of the Sirius® equipment with the post-operative 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 myopic patients. On the other hand, in hyperopic eyes and those with mixed astigmatism, mean errors from post-operative Mean Pupil Power, in comparison to the keratometry derived by clinical history method, were not significantly different from the errors when comparing the "Kpop average 1" and the "Kpop average 2"with keratometry derived by the clinical history method. Conclusions. In myopic eyes the post-operative corneal power determinations with the "Kpop average 1" and "Kpop average 2" are closer to the keratometry derived by clinical history method than to measurements from the average post-operative manual keratometry, the post-operative simulated keratometry or the Mean Pupil Power of the Sirius® equipment.

Introducción. La determinación del poder corneal, después de la cirugía refractiva con láser excimer, es difícil. Diferentes alternativas con el uso de tomógrafos corneales se han utilizado para esta medición. Objetivo. Evaluar diversos métodos de determinación del poder corneal en pacientes operados de cirugía fotorrefractiva, incluyendo pruebas diagnósticas con medidas cuantitativas. Metodología. Estudio retrospectivo de pacientes operados de cirugía fotorrefractiva que tuvieran resultados refractivos y tomografía corneal post-operatoria al menos diez semanas luego de cirugía. Resultados. En los ojos miopes se encontraron diferencias significativas en el valor determinado por la queratometría derivada de la historia clínica al compararla con la queratometría manual promedio postoperatoria, la queratometría simulada y el Mean Pupil Power del tomógrafo Sirius®. Por otra parte, al promediar la queratometría manual promedio postoperatoria con el Mean Pupil Power postoperatorio (valor denominado Kpop promedio 1) y compararla con la queratometría derivada por el método de la historia clínica, no se observaron en los pacientes miopes diferencias estadísticamente significativas. Asimismo, al promediar la queratometría simulada postoperatoria del equipo Sirius® con el Mean Pupil Power postoperatorio (valor denominado Kpop promedio 2) y compararla con la queratometría derivada por el método de la historia clínica tampoco se observaron en los pacientes miopes diferencias estadísticamente significativas. Por otro lado, en los ojos hipermétropes y con astigmatismo mixto, los promedios de los errores del Mean Pupil Power postoperatorio, con respecto a la queratometría derivada por el método de la historia clínica, no fueron significativamente diferentes de los errores al comparar la Kpop promedio 1 y la Kpop promedio 2 con la queratometría derivada por el método de la historia clínica. Conclusiones. En ojos miopes las determinaciones del poder corneal postoperatorio con las Kpop promedio 1 y Kpop promedio 2 se aproximan más a la queratometría derivada por el método de la historia clínica que a las mediciones de la queratometría manual promedio postoperatoria, la queratometría simulada postoperatoria o el Mean Pupil Power del equipo Sirius®. [Jaramillo LC, Galvis V, Tello A, Camacho PA, Castillo A, Pareja LA. Determinación del poder corneal con un tomógrafo corneal luego de cirugía refractiva con láser excimer. MedUNAB. 2018;21(1):16-30. doi:1029375/01237047.2397].

Introdução. A determinação da potência corneana, após a cirurgia refrativa com excimer láser, é difícil. Foram usadas diferentes alternativas com o uso de tomógrafos de córnea para esta medição. Objetivo. Avaliar vários métodos de determinação da potência corneana em pacientes submetidos à cirurgia fotorrefrativa, incluindo testes diagnósticos com medidas quantitativas. Métodos. Este é um estudo observacional retrospectivo. Foram incluídos pacientes submetidos à cirurgia fotorrefrativa com resultados refrativos e topografía corneana pós-operatória pelo menos um mês após a cirurgia. Resultados. Nos olhos míopes foram encontradas diferenças significativas no valor determinado pela ceratectomia derivada da história clínica, quando comparada com a média da ceratectomia manual pós-operátoria, a ceratectomia simulada e o Mean Pupil Power do tomógrafo Sirius®. Por outro lado, ao calcularmos a média da ceratectomia manual pós-operatória com o Mean Pupil Power pós-operatório (valor denominado Kpop média 1) e compará-la com a ceratectomia pelo método da história clínica, não foram observadas diferenças estatisticamente significantes nos pacientes miopes. Da mesma forma, ao calcular a média da ceratectomia pós-operatória simulada do equipamento Sirius® com o Mean Pupil Power pósoperatório (valor denominado Kpop média 2) e comparála com a ceratectomia derivada do método de história clínica, não foram observadas diferenças estatisticamente significantes nos pacientes miopes. Por outro lado, em olhos hipermetrópicos e com astigmatismo mixto, as médias de erros do Mean Pupil Power pós-operatório, em relação à ceratectomia derivada pelo método da história clínica, não foram significativamente diferentes dos erros na comparação do Kpop média 1 y la Kpop média 2 com a ceratectomia derivada pelo método da história clínica. Conclusões. Nos olhos míopes, as determinações de potência corneana pósoperatória com Kpop média 1 e Kpop média 2 estão mais próximas da ceratectomia derivada pelo método da história clínica do que das medidas de ceratectomia manual média pós-operatória, da ceratectomia simulada pós-operatória ou Mean Pupil Power do equipamento Sirius®. [Jaramillo LC, Galvis V, Tello A, Camacho PA, Castillo A, Pareja LA. Determinação da potência corneana com uma topografia de córnea após cirurgia refrativa com excimer láser. MedUNAB. 2018;21(1):16-30. doi:1029375/01237047.2397].

Lentes intraoculares fácicas de câmara posterior / Phakic posterior chamber intraocular lenses

Resumo O objetivo deste artigo foi reunir estudos que reportam resultados disponíveis na literatura científica, considerando a previsibilidade, segurança, eficácia, e estabilidade das lentes intraoculares fácicas de câmara posterior. E relatar as complicações documentadas para estas lentes. A revisão criteriosa dos estudos publicados na literatura ate o momento revelam resultado satisfatórios quanto à eficácia, elevada previsibilidade, estabilidade e segurança do implante de lente intraocular de câmara posterior, para correção das miopia, hipermetropia e astigmatismo.

Abstract The objective of this article was to gather studies that report results available in the scientific literature, considering the predictability, safety, efficacy, and stability of posterior chamber phakic intraocular lenses. And report the documented complications for these lenses.

Intraocular Lens Power Calculation after Refractive Surgery: A Comparative Analysis of Accuracy and Predictability

PURPOSE: To compare the accuracy of intraocular lens (IOL) power calculation using conventional regression formulae or the American Society of Cataract and Refractive Surgery (ASCRS) IOL power calculator for previous corneal refractive surgery. METHODS: We retrospectively reviewed 96 eyes from 68 patients that had undergone cataract surgery after keratorefractive surgeries. We calculated the formula with two approaches: IOL powers using the ASCRS IOL power calculator and IOL powers using conventional formulae with previous refractive data (Camellin, Jarade, Savini, and clinical history method) or without prior data (0, 2 and, 4 mm total mean power in topography, Wang-Koch-Maloney, Shammas, Seitz, and Maloney). Two conventional IOL formulae (the SRK/T and the Hoffer Q) were calculated with the single K and double K methods. Mean arithmetic refractive error and mean absolute error were calculated at the first postoperative month. RESULTS: In conventional formulae, the Jarade method or the Seitz method, applied in the Hoffer Q formula with the single K or double K method, have the lowest prediction errors. The least prediction error was found in the Shammas-PL method in the ASCRS group. There was no statistically significant difference between the 10 lowest mean absolute error conventional methods, the Shammas-PL method and the Barrett True-K method calculated with using the ASCRS calculator, without using preoperative data. CONCLUSIONS: The Shammas-PL formula and the Barrett True-K formula, calculated with the ASCRS calculator, without using history, were methods comparable to the 10 most accurate conventional formulae. Other methods using the ASCRS calculator show a myopic tendency.

Choice of intraocular lens power calculation formula after refractive corneal surgery / 国际眼科杂志(Guoji Yanke Zazhi)

To the cataract patient after corneal refractive surgery, if the intraocular lens power was determined by conventional formulas, different refractive errors may be produced after intraocular lens implantation.This inaccuracy of the lens power mainly came from 2 aspects-errors of corneal refractive power measurement and errors of formulas.Besides, imprecise of ocular axial length measurement and invalid lens position calculation also contributed to the inaccuracy of lens power.Therefore, in order to reduce refractive errors of cataractous surgery in patient underwent refractive surgery, appropriate method should be used to estimate the refractive power of corneal, and proper formula should be selected to calculate intraocular lens power.

Vitamin A and the eye: an old tale for modern times / A vitamina A e o olho: uma velha história em tempos modernos

ABSTRACT Clinical presentations associated with vitamin A deficiency persist in poor regions globally with the same clinical features as those described centuries ago. However, new forms of vitamin A deficiency affecting the eyes, which have become widespread, as a result of modern societal habits are of increasing concern. Ophthalmic conditions related to vitamin A deficiency require the combined attention of ophthalmologists, pediatricians, internists, dermatologists, and nutritionists due to their potential severity and the diversity of causes. As the eyes and their adnexa are particularly sensitive to vitamin A deficiency and excess, ocular disturbances are often early indicators of vitamin A imbalance. The present review describes the clinical manifestations of hypovitaminosis A with an emphasis on so-called modern dietary disorders and multidisciplinary treatment approaches. The present review also discusses the relationship between retinoic acid therapy and dry eye disease.

RESUMO As apresentações clínicas associadas à deficiência de vitamina A persistem em regiões pobres ao redor do mundo com os mesmos achados clínicos descritos há séculos. No entanto, novas formas de problemas causados pela vitamina A afetam os olhos, estão associados com os hábitos da sociedade moderna e tem causado preocupação. Eles exigem a atenção dos oftalmologistas, pediatras, internistas, dermatologistas e nutricionistas, devido à sua gravidade e diversidade de causas. Uma vez que os olhos e seus anexos são órgãos muito sensíveis à deficiência e excesso de vitamina A, manifestações oculares podem ser indicadores precoces do desequilíbrio de vitamina A. Essa revisão traz as manifestações clínicas de hipovitaminose A enfatizando os chamados distúrbios dietéticos modernos e formas de abordagem multidisciplinar. E também traz evidências sobre a relação entre a terapia com ácido retinóico e doença do olho seco.

Change in corneal biomechanical properties and influence factors in population with myopia / 中华实验眼科杂志

Background Corneal refractive surgery has significant effects on corneal biomechanical properties.However,there are few study on large scale population with corneal biomechanical properties in the myopic population before corneal refractive surgery.Objective This study was to evaluate the change of corneal biomechanical properties and influence factors in myopic eyes using ocular response analyzer (ORA).Methods A prospective cohort study was carried out in Beijing Tongren Eye Center from April 2010 to January 2011.Corneal hysteresis (CH) and corneal resistance factor (CRF) were detected using ORA in 1 792 eyes of 896 myopic subjects who were going to receive corneal refractive surgery under the informed consent.According to different spherical equivalent (SE) the eyes were grouped into-0.25-＜-3.0 D group,-3.0-＜-6.0 D group,-6.0-＜-9.0 D group,-9.0-＜-12.0 D group,-12.0-＜-15.0 D group and ≥-15.0 D group and according to different central corneal thickness (CCT),the eyes were grouped into ＜500 μm group,500-＜550 μm group,550-＜600 μm group and≥600 μm group.The CH value and CRF value in different SE groups or different CCT groups were compared,and the factors influencing CH and CRF were analyzed by Pearson correlation analysis.Results The mean CH and CRF value were (9.84±1.52)mmHg (1 mmHg =0.133 kPa) and (10.46±1.71) mmHg,respectively in the myopic eyes.The CH values were (10.35±1.53),(10.07±1.55),(9.81±1.46),(9.71±1.59),(9.35±1.55) and (9.23±1.28) mmHg in the-0.25-＜-3.0 D group,-3.0-＜-6.0 D group,-6.0-＜-9.0 D group,-9.0-＜-12.0 D group,-12.0-＜-15.0 D group and ≥-15.0 D group,respectively,showing a significant difference among the groups (F=20.69,P＜0.01),and the CH values in the-6.0-＜-9.0 D group,-9.0-＜-12.0 D group,-12.0-＜-15.0 D group and ≥-15.0 D group were significantly lower than those in the-6.0-＜-9.0 D group,-9.0-＜-12.0 D group (all at P＜0.01).There was no significant difference in the CRF values among different SE groups (F =0.65,P =0.49).CH and CRF values were increasing with the raise of CCT,with evidently differences among the CCT＜500 μm group,500 μm ≤ CCT＜550 μm group,550 μm≤ CCT＜600 μm group and CCT≥ 600 μm group (CH:F=110.99,P＜0.01;CRF:F =84.35,P＜0.01),and the CH and CRF values were significantly higher in the 550 μm ≤ CCT＜600 μm group and CCT ≥600 μm group than those in the CCT＜500 μm group (all at P＜0.01).CH showed a positive correlation with SE (r =0.24,P＜0.01),and no significant correlation between CRF and SE (r =0.03,P =0.20).The CH and CRF showed the positive correlations with the CCT (r=0.42,0.57,both at P＜0.01).In addition,CH and CRF values increased as the increases of SE,corneal curvature (CC) and CCT values,with the regression equation of CH =-7.87+0.08SE+0.16CC+0.02CCT (R2=0.26,P＜0.01) and CRF=-11.42+0.14CC+0.03CCT (R2=0.34,P＜0.01),respectively.The CH and CRF did not change with the age and gender in the subjects.Conclusions Corneal biomechanical properties including CH and CRF were positively correlated with CCT,CC and SE.