Visual rehabilitation after LASIK complication: flap amputation, topo-guided surgery, and phacoemulsification

ABSTRACT We present a case of a patient complaining of monocular diplopia due to a decentered ablation after LASIK. The patient underwent a wavefront-guided retreatment, which resulted in an epithelial ingrowth complication. Additionally, the patient developed cataract, with cataract surgery requiring reliable biometric measurements. Therefore, we opted for corneal treatment and corneal surface regularization. Although we attempted to lift the flap and wash the interface initially, the procedure proved unsuccessful, thereby necessitating immediate flap amputation. Once the corneal surface was regularized in the seventh postoperative month, transepithelial photorefractive keratectomy was successfully performed to homogenize the ocular surface, thereby significantly improving the patient's corrected visual acuity and resolving monocular diplopia. The surface and corneal curvature stabilized by the fifth month after the procedure. Phacoemulsification was then performed along with the implantation of a toric monofocal lens, which was selected using an appropriate formula, resulting in an excellent uncorrected visual acuity.

Vertex distance variability of the Vision-S™ 700 refractors in normal population / Variabilidade da distância vértice do refrator Vision-S™ 700 em uma população normal

ABSTRACT Objective: To study vertex-optical distance variation and estimate its impact on manifest refraction. Methods: Prospective study in a private clinic using the Vision-S™ 700 with five forehead positions. Forehead on the third position showed the closest vertex-optical distance of 12mm. Results: Analysis of 52 eyes from 26 patients revealed mean differences in vertex-optical distance of 12.25mm (right eye) and 11.75mm (left eye). A 2mm change in vertex-optical distance resulted in a 0.05D change for a 5D spherical equivalent and 0.20D for a 10D equivalent. Conclusion: Vertex-optical distance varies among patients and is influenced by forehead adjustment. These variations impact refraction accuracy and treatment evaluation. Adjusting the forehead to the third position on the Vision-S™ 700 is recommended.

RESUMO Objetivo: Estudar a variação da distância vértice-óptico, de acordo com o ajuste da testa, e estimar seu impacto na refração manifesta. Métodos: Estudo prospectivo realizado em clínica privada. A refração foi realizada utilizando cinco posições preestabelecidas com o Vision-Sa 700. A testa disposta na terceira posição apresentou distância vértice do refrator mais próxima de 12mm. Resultados: Foram analisados 52 olhos de 26 pacientes. A diferença média da distância vértice do refrator no olho direito foi de 12,25mm (variação de 11,50mm) e, no olho esquerdo, 11,75mm (variação de 12,00mm). O impacto foi de 2mm na distância vértice do refrator, fomentando em uma mudança de 0,05D para um equivalente esférico de 5D e 0,20D para um equivalente de 10D. Conclusão: A distância vértice do refrator varia entre pacientes, estando relacionada ao ajuste da testa. As variações afetam a precisão da refração, impactando no ajuste dos óculos, das lentes de contato e na avaliação pós-operatória de cirurgia refrativa. Sugerimos ajustar a posição da testa para terceira posição no Vision-S™ 700, se a distância vértice do refrator não for medida em todos os pacientes.

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.

Fellow eye comparison between alcohol-assisted and single-step transepithelial photorefractive keratectomy: late mid-term outcomes.

Objective: To compare late mid-term results of two different surgical approaches of surface excimer laser ablation for myopic and astigmatic errors in contralateral eyes of the same patients. Methods: Prospective cohort study. A photorefractive keratectomy technique was performed on the right eye and single-step transepithelial photorefractive keratectomy on the left eye of the same patient, in 2012. Postoperative uncorrected and corrected visual acuities, manifest refraction, contrast sensitivity, objective scatter index, tear film stability assessed by serial measurements of objective scatter index and aberrometry as well as occurrence of haze, were compared between groups of eyes. Results: Thirty-two eyes of 16 patients with a mean time of follow-up of 35.2 +/ - 5.0 months (range 30-46 months) were evaluated. No significant differences were observed in postoperative results (visual acuity, spherical equivalent, defocus equivalent, higher-order aberrations, objective scatter index, tear film stability and contrast sensitivity). Contrast sensitivity tended to be better in transepithelial photorefractive keratectomy technique, under photopic lighting conditions without glare and mesopic conditions both with glare and without glare, however, no statistically significant differences were found. No eye presented corneal haze at the last examination. Conclusion: No statistically significant differences in visual acuity, refractive results, contrast sensitivity, objective scatter index, tear film stability or ocular aberrometry were observed between the two surface ablation techniques.

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.

Initial Results From a New Model of Posterior Chamber Implantable Phakic Contact Lens: IPCL V2.0.

The aim of this study was to evaluate the corneal safety, intraocular pressure (IOP), vault and refractive efficiency of the new implantable phakic contact lens, IPCL V2.0 (Care Group, India). A prospective case series study was performed to evaluate 100 consecutive surgeries with IPCL V2.0 (spherical and toric models). Refractive results, corneal endothelial cell density (CD) and central corneal thickness (CCT) were measured at baseline and 6 months after surgery. Intraocular pressure was measured at baseline, 1 day and 6 months, and vault, 3 and 6 months after surgery. Surgical complications and cataract development were also evaluated. The mean corneal endothelial CD decreased by 2.9% with a statistically significance difference (p: 0.03). The mean CCT decreased by 0.87% at 6 months postoperative, without a statistical significance difference (p: 0.35). The mean ± standard deviation (SD) of IOP at baseline was 13.72 ±1.4 mm Hg, at 1 day postoperative was 13.88 ±1.2 mm Hg, and at 6 months was 13.62 ±1.3 mm Hg. These differences were not statistically significant (p: 0.37). The difference in vault between 3 and 6 months after surgery was not statistically significant (p: 0.97). The coefficient of correlation between the attempted versus achieved spherical equivalent (SE) change was R2: 0.958. Postoperative SE was between -0.50 D to +0.50 D in 52% of cases. The remaining of the eyes had SE values ranging from -1.5 D to +1.35 D. No intra or postoperative complications occurred and specifically cataract was not developed. The corneal endothelial CD, CCT, vault and IOP remained stable 6 months after surgery. Refraction was improved and the IPCL V 2.0 was implanted safely.

Mitomycin C 0.02 and 0.002% efficacy in preventing haze after photorefractive keratectomy.

PURPOSE: To compare MMC 0.002% efficacy in preventing haze after PRK in relation to MMC 0.02%. PATIENTS AND METHODS: We conducted a prospective study with patients with myopia or myopic astigmatism undergoing PRK in the same conditions. After PRK, MMC was applied for 30 s in a concentration of 0.02% on the right eye (group 1) and 0.002% on the left eye (group 2). Age, gender, spherical equivalent and haze intensity (1, 3, 6 and 12 months postoperatively) were assessed. Haze was quantified at biomicroscopy (0-4 +). P < 0.05 was considered statistical significant. RESULTS: We evaluated 130 patients, 77 women and 53 men, with a mean age of 30.2 ± 9 years. The spherical equivalent was - 3.66 D in the group 1 and - 3.77 D in the group 2. In the 1st month after PRK, incidence of haze was 13.9% eyes in group 1 and 14.6% in group 2. In the 3rd month, incidence of haze was 50.0% eyes in group 1 and 48.5% in group 2 which presented with 3 +/4 + traces of haze. In the 12th month, incidence of haze was 7.7% eyes in group 1 and 5.4% in group 2. There was no correlation between haze and age (p = 0.279/0.333), gender (p = 0.345/0.367) or spherical equivalent (p = 0.100/0.054) in groups 1 and 2, respectively. There was no difference in haze between groups 1 and 2 (p = 0.56). CONCLUSION: MMC 0.002% was effective in preventing haze after PRK. As MMC long-term safety has not been proved, we suggest its use in a lower concentration, in order to prevent potential complications.

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].

[Regarding surface ablation as an ethically superior option when compared to LASIK: primum non nocere]. / Sobre la ablación de superficie como opción éticamente superior al LASIK: primum non nocere.

Refractive surgery is an extremely safe surgical intervention, with excellent profiles of clinical improvement and satisfaction. The ethical responsibility of the refractive surgeon is to look for diminishing the patients' exposure to unnecessary risks. Therefore, surface ablation would be a preferable option over LASIK as the former has a better safety profile than the latter, without compromising final visual acuity. Ethically, surface ablation should be considered as the first choice in those patients undergoing Excimer laser refractive surgery.

La cirugía refractiva es una intervención quirúrgica sumamente segura, con excelentes perfiles de mejoría clínica y satisfacción. La responsabilidad ética del cirujano refractivo debe ir siempre enfocada a disminuir los riesgos innecesarios en las intervenciones que realiza. En ese orden de ideas, la ablación de superficie resultaría ser una opción preferible, ya que tiene un perfil de seguridad claramente superior que el LASIK, a la vez que no es inferior en el resultado visual a largo plazo. La ablación de superficie debería ser considerada la técnica de primera elección en cirugía refractiva con láser Excimer.

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.

Advances in femtosecond laser technology.

Femtosecond laser technology has become widely adopted by ophthalmic surgeons. The purpose of this study is to discuss applications and advantages of femtosecond lasers over traditional manual techniques, and related unique complications in cataract surgery and corneal refractive surgical procedures, including: LASIK flap creation, intracorneal ring segment implantation, presbyopic treatments, keratoplasty, astigmatic keratotomy, and intrastromal lenticule procedures.

[Risk factors and rejection frequency in patients undergoing penetrating keratoplasty]. / Factores de riesgo y frecuencia de rechazo en pacientes con queratoplastia penetrante.

BACKGROUND: Corneal transplantation is one of the surgical procedures most frequently performed worldwide and with better prognosis. Among its main indications include: keratoconus, bullous keratopathy, previous graft rejection, corneal dystrophy, and infection. The known risk factors for graft rejection are: recipient's age, presence of vessels in the recipient cornea, intraocular pressure, and retransplantation. The objective of this article is to determine the risk factors and frequency of corneal rejection in patients undergoing penetrant keratoplasty. METHODS: The study's design was descriptive, observational, transversal, analytical and retrospective. Patients operated of penetrating keratoplasty in cornea clinic with follow up during at least 6 months were studied. A review of the medical records of patients undergoing penetrating keratoplasty at the Hospital de Especialidades del Centro Médico Nacional Siglo XXI was performed. RESULTS: The 35.3 % of the transplanted patients had corneal transplant rejection. Corneal neovascularization of the recipient cornea previous to transplant was present in 21.3 %. CONCLUSIONS: In our study we found similar results to the reported in the literature, the most important risk factors for rejection was the use of threphine 7.50 mm, older patient with a history with previous corneal neovascularization, keratopathy and herpetic keratitis.

Introducción: el trasplante de córnea representa uno de los procedimientos quirúrgicos que con mayor frecuencia se realizan en todo el mundo y de los que tienen un mejor pronóstico. Dentro de sus principales indicaciones se encuentran: el queratocono, la queratopatía bullosa, el rechazo corneal previo, la distrofia corneal y la infección. Los factores de riesgo conocidos para rechazo del trasplante son: edad del receptor, presencia de vasos en la córnea receptora, presión intraocular y retrasplante. El objetivo de este artículo es determinar los factores de riesgo y la frecuencia de rechazo corneal en pacientes sometidos a queratoplastia penetrante. Métodos: el diseño del estudio fue descriptivo, observacional, transversal, retrospectivo y analítico. Se estudiaron los pacientes operados de queratoplastia penetrante en la consulta externa de córnea, con seguimiento mínimo de 6 meses. Se llevó a cabo una revisión de expedientes clínicos de pacientes operados de queratoplastia penetrante en Hospital de Especialidades del Centro Médico Nacional Siglo XXI del IMSS. Resultados: del total de los pacientes trasplantados 35.3 % presentaron rechazo del trasplante corneal. La neovascularización corneal previa al trasplante de la corona receptora estuvo presente en 21.3 %. Conclusiones: en nuestro estudio encontramos resultados similares a los reportados en la literatura, siendo los factores de riesgo más importantes para presentar rechazo: el uso de trépanos mayores a 7.50 mm, paciente con antecedentes de neovascularización corneal previa, queratopatía y queratitis herpética.

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.

Clinical experience with the first 40 cases with femtosecond laser cataract surgery technology: safety of the learning curve / Experiência clínica com os primeiros 40 casos de cirurgia de catarata com a tecnologia de laser de femtossegundo: segurança da curva de aprendizagem

Objective:To evaluate the introduction of the femtosecond laser (FSL) to perform the key steps of the traditional cataract surgery process and the operational difficulties and safety of this new technology during routine use in an operating room in Brazil.MethodsA retrospective study was conducted using the first cases operated on at a single center using the laser platform LenSx/Alcon with a soft contact lens patient interface.All patients underwent a detailed preoperative assessment.The anterior capsulotomy, nuclear fragmentation, and corneal incisions were created with the FSL; then, the surgery was completed following the standard phacoemulsification procedure. The main outcome measurements were difficulties and complications related to the learning curve and an analysis of postoperative uncorrected distance visual acuity (UDVA).Results:Of 31 patients (40 eyes), 9 patients had FSL cataract surgery in both eyes.The mean age was 64 ± 12 years (ranging from 42 to 82), the mean cataract nuclear sclerosis was grading 2 ± 0.6 (ranging from 1 to 4), and the preoperative mean UDVA in logMAR was 0.4 ± 0.2 (ranging from 0.1 to 1.3). Anterior capsulotomy was complete in all patients, and scissors were not needed to cut off any intact portion. The postoperative corneal incisions were not completely linear and showed some irregularities. Laser phaco-fragmentation was effective, with the division of the nucleus into smaller segments easily performed before phacoemulsification.After 1 month, the postoperative mean UDVA in logMAR was 0.1 ± 0.1 (ranging from 0.0 to 0.4) (P < 0.0001).Conclusion:With increasing surgical cases and experience, the phacoemulsification steps are performed precisely and effectively with FSL pretreatment, resulting in a safe learning curve.

Objetivo:Avaliar a introdução do laser de femtossegundo (FSL) para realizar etapas fundamentais da cirurgia de catarata tradicional e as dificuldades e segurança desta nova tecnologia na rotina de um centro cirúrgico no Brasil.Métodos:Um estudo retrospectivo foi realizado com os primeiros casos operados em um único centro usando a plataforma de laser LenSx/Alcon, sendo utilizado lentes de contato gelatinosa na interface do paciente. Todos os pacientes foram submetidos a uma avaliação pré-operatória detalhada. Capsulotomia anterior, fragmentação nuclear e incisões na córnea foram criados com a FSL, em seguida, a cirurgia foi concluída com procedimento de facoemulsificação padrão. As principais medidas de desfecho foram dificuldades e complicações relacionadas à curva de aprendizado e análise da acuidade visual pós-operatória não corrigida à distância (UDVA).Resultados:Dos 31 pacientes (40 olhos), 9 realizaram cirurgia de catarata em ambos os olhos com FSL. A média de idade foi de 64 ± 12 anos (variando de 42 a 82), a média de classificação da catarata através da esclerose nuclear foi 2 ± 0,6 (variando de 1 a 4) e UDVA pré-operatória em logMAR foi de 0,4 ± 0,2 (variando de 0,1 a 1,3). A capsulotomia anterior foi completa em todos os pacientes e não precisou usar da pinça para cortar qualquer porção intacta. Incisões corneanas pós-operatórias não foram lineares, mostrando ainda algumas irregularidades. A facofragmentação a laser foi eficaz, com a divisão do núcleo em segmentos menores facilmente realizados antes da facoemulsificação. Após 1 mês de pós-operatório, UDVA em logMAR foi de 0,1 ± 0,1 (variando de 0,0 a 0,4) (P < 0,0001).Conclusão:Com o aumento do volume dos casos cirúrgicos e ganho de experiência, passos precisos da facoemulsificação são realizados com o pré-tratamento com o FSL, resultando em uma segura curva de aprendizagem.

Intrastromal corneal ring segment implantation for ectasia after refractive surgery / Implante de segmento de anel intraestromal de córnea para ectasia pós-cirurgia refrativa

ABSTRACTPurpose:To evaluate the clinical outcomes of intrastromal corneal ring segment (ICRS) implantation to correct ectasia in eyes with prior refractive surgery.Methods:Forty-one eyes of 25 patients (13 men, 12 women; mean age, 28.66 years) with ectasia after refractive surgery [photorefractive keratectomy (PRK) or laser in situ keratomileusis (LASIK)] were included in a nonrandomized, retrospective, observational case series. Corneal tunnels were created by mechanical dissection in all eyes. Main outcome measures included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BCVA), refraction, keratometry, and computerized analysis of corneal topography. Patients were divided into two groups by the type of refractive surgery (Group A: PRK, Group B: LASIK).Results:The mean preoperative manifest astigmatism decreased from -1.88 to -0.84 D in Group A (p=0.096) and -3.18 to -1.77 D in Group B (p=0.000). The mean keratometric astigmatism decreased from -2.58 to -1.66 D in Group A (p=0.010) and -4.80 to -2.78 D in Group B (p=0.000). The mean spherical equivalent decreased from -2.97 to -2.05 D in Group A (p=0.065) and -3.31 to -2.42 D in Group B (p=0.014). No significant between-group differences were noted on the comparison of preoperative and postoperative results. No intraoperative or postoperative complications were observed.Conclusion:ICRS implantation is a useful treatment option for ectasia following refractive surgery, and it has significantly reduced the refractive cylinder and increased best spectacle-corrected visual acuity.

RESUMOObjetivo:Avaliar os resultados do implante de anel intraestromal de córnea para correção de ectasia pós-cirurgia refrativa.Métodos:Quarenta e um olhos de 25 pacientes, 13 homens e 12 mulheres, com ectasia pós-cirurgia refrativa (PRK ou LASIK) foram incluídos em um estudo não randomizado, retrospectivo e observacional. A média de idade no momento do implante do anel é de 28,66 anos. Em todos os olhos, o túnel corneano foi criado através da dissecção mecânica da córnea. Os resultados avaliaram acuidade visual sem correção (AVSC) e acuidade visual com correção (AVCC), refração, ceratometria e topografia corneana computadorizada. Os pacientes foram divididos em dois grupos de acordo com a cirurgia refrativa. Grupo A: PRK, Grupo B: LASIK.Resultados:A média do astigmatismo pré-operatório foi reduzida de -1,88 D para -0,84 D no grupo A (P=0,096) e de -3,18 D para -1,77 D no grupo B (P=0,000). A média do astigmatismo ceratométrico foi reduzida de -2,58 D para -1,66 D no grupo A (P=0,010) e de -4,80 para -2,78 D no grupo B (P=0,000). A média do componente esférico foi reduzida de -2,97 D para -2,05 D no grupo A (P=0,065) e de -3,31 D para -2,42 D no grupo B (P=0,014). Nenhuma diferença estatisticamente significativa foi observada entre os grupos, quando se comparou os resultados do pré e pós-operatório. Não ocorreram complicações intra ou pós-operatórias.Conclusão:O implante de anel intraestromal de córnea é uma boa opção para o tratamento de ectasia pós-cirurgia refrativa, tendo resultado na redução significativa do astigmatismo refracional e melhora da acuidade visual com correção.