Radial keratotomy: background and how to manage these patients nowadays.

In this review, we presented the principles of radial keratotomy (RK), its evolution, enhancement, and complications, and strategies to manage the consequences of RK in the present day. It is essential to understand the RK procedure f, the theoretical background that supported this surgery, the current effect on the cornea, and how to approach patients needing vision improvement. These patients are developing cataracts that need to be handled well, from the IOL calculation to the surgical procedure. Guided keratorefractive surgery is the most accurate procedure to improve these patient's vision and life. Nevertheless, some patients may need other approaches, such as sutures, penetrating keratoplasty, corneal rings, and pinhole implants, depending on the degree of irregularity of the cornea, ablation depth for guided surgery or if the sutures are open.

Therapeutic visual rehabilitation in a patient with high hyperopia and flat cornea years after radial keratotomy.

A 51-year-old man was referred for refractive surgery evaluation. Spectacle dependence and poor visual quality in both eyes was his chief complaint. He cannot tolerate contact lenses. Corrected distance visual acuity (CDVA) was 20/40 in both eyes. Manifest refraction was +5.25 -2.25 @ 90 (20/40) in the right eye and +6.25 -2.25 @ 105 (20/40) in the left eye. The patient had a history of radial keratotomy (RK) almost 30 years ago in both eyes and at the slitlamp presented 8 RK incisions, proportionally spaced between one another. All incisions were closed, and there were no relevant signs of scarring. The patient denied any history of ocular trauma, systemic disease, or medications. Corneal topography with different technologies revealed an irregular pattern with marked central flattening in both eyes, with some points below 30 diopters (D) (Supplemental Figures 1 and 2, available at http://links.lww.com/JRS/A862 and http://links.lww.com/JRS/A863, respectively). There were no signs of cataract, and fundus examination was normal. Optical coherence tomography (OCT) of the right eye revealed a more homogeneous thickness pattern, little variation between the thinnest and thickest areas, and adequate transparency (Figure 1JOURNAL/jcrs/04.03/02158034-202306000-00018/figure1/v/2023-05-31T172126Z/r/image-tiff). In the left eye, there is wide variability between the thinnest and thickest stromal points, with annular thinning and central thickening (Figure 2JOURNAL/jcrs/04.03/02158034-202306000-00018/figure2/v/2023-05-31T172126Z/r/image-tiff). Both eyes show marked epithelial irregularity. Considering this patient's current ocular status, how would you reach visual rehabilitation? Because he is contact lens intolerant, would you consider surface ablation, for example, photorefractive keratectomy (PRK) with mitomycin-C (MMC)? If that were the case, would you think of an optimized or a topography-guided (TG) treatment? Would you immediately consider a corneal transplant option? Would you instead consider a more conservative approach? Which one and why?

Late Spontaneous Postradial Keratotomy Corneal Perforation After Scleral Contact Lens Use-Case Report.

PURPOSE: To describe a case of late spontaneous postradial keratotomy corneal perforation after scleral contact lens (SCL) wear for optic correction. SETTING: Tertiary referral center for corneal pathology. DESIGN: Case report. RESULTS: A 64-year-old man presented the consequences of a late radial keratotomy (RK) surgery performed for myopia correction 26 years ago. His ophthalmologic history was a RK in both eyes (BE), previous Lasik surgery in BE and Lasik enhancement in the right eye (RE), and pterygium excision with conjunctival transplantation in RE. To improve visual acuity, SCL were fitted in both eyes. After 8 months of use, on a certain day, when removing the lens from the RE, the patient reported experiencing intense eye pain and reduced visual acuity. On ophthalmologic examination, the RE cornea was perforated in one of the previous RK incisions. An urgent corneal transplant was performed in the RE, followed by cataract surgery in the same eye. CONCLUSION: Corneal instability caused by RK scars and daily manipulation with the SCL use may have led to ocular perforation.

Fórmula Barrett True K en pacientes con catarata operados de cirugía refractiva corneal / The Barrett True-K formula in cataract patients undergoing corneal refractive surgery

Objetivo: Determinar los resultados refractivos en pacientes operados de catarata con cirugía refractiva corneal, según el cálculo del poder dióptrico de la lente intraocular con la fórmula Barrett True K. Métodos: Se realizó un estudio pre-experimental, del tipo antes y después, en el cual fueron incluidos 18 pacientes (31 ojos). En ellos se analizaron variables demográficas y clínicas. La principal variable de salida fue la predictibilidad del componente esférico ± 0,50 D, ± 1,0 D según la longitud axial. Resultados: Fueron estudiados pacientes con un promedio de edad de 59,4 años, predominantemente del sexo femenino (66,7 por ciento). El 77,4 por ciento fue operado con queratotomía radial. Con la cirugía de catarata se produjo una mejora ostensible de la agudeza visual no corregida (mediana preoperatoria: 0,12 y mediana posoperatoria: 0,60). Solo el 9,7 por ciento de los ojos analizados presentó una agudeza visual sin corregir de 20/20 y el 90,3 por ciento de 20/40 o más. La cantidad de ojos con un equivalente esférico de ± 0,50 disminuyó en la medida en que aumentó la longitud axial (corta: 100 por ciento; normal: 57,1 por ciento; larga: 22,7 por ciento), no así la predictibilidad del componente esférico de ± 0,50, que aumentó (corta: 50,0 por ciento; normal: 57,1 por ciento; larga: 63,6 por ciento). Conclusiones: La fórmula Barrett True K resulta útil para el cálculo de la lente intraocular en pacientes operados de catarata y cirugía refractiva corneal previa(AU)

Objective: Determine refractive outcomes in patients undergoing cataract corneal refractive surgery based on intraocular lens dioptric power calculation with the Barrett True-K formula. Methods: A pre-experimental before/after study was conducted of 18 patients (31 eyes). Demographic and clinical variables were analyzed. The main output variable was spherical component predictability ± 0.50 D, ± 1.0 D according to axial length. Results: Mean age was 59.4 years; female sex prevailed (66.7 percent). Of the patients studied, 77.4 percent underwent radial keratotomy. Cataract surgery led to notable uncorrected visual acuity improvement (preoperative mean: 0.12; postoperative mean: 0.60). Only 9.7 percent of the eyes examined had an uncorrected visual acuity of 20/20, whereas 90.3 percent had 20/40 or more. The number of eyes with a spherical equivalent of ± 0.50 fell as axial length rose (near: 100 percent; normal: 57.1 percent; far: 22.7 percent), unlike ± 0.50 spherical component predictability, which rose from near: 50.0 percent; normal: 57.1 percent; far: 63.6 percent. Conclusions: The Barrett True-K formula is useful for intraocular lens calculation in patients undergoing previous cataract and corneal refractive surgery(AU)

Laser topoguiado como redutor de aberrações ópticas pós ceratotomia radial e LIO multifocal / Topoguided laser as a reducer of optical aberrations after radial keratotomy and multifocal LIO

Resumo A cirurgia de catarata com implante de lente intra-ocular é uma das cirurgias mais realizadas no mundo e, atualmente, os pacientes que se submetem a essa cirurgia podem utilizar o implante com lente intraocular (LIO) multifocal como alternativa ao uso de óculos. Um grande desafio para o cirurgião são os pacientes já submetidos previamente a ceratotomia radial (RK), pois além de terem um cálculo biométrico mais desafiador, apresentam importantes aberrações ópticas corneanas, sendo uma contra-indicação para o uso de lentes multifocais para a maioria dos oftalmologistas. Neste artigo, relatamos o caso de uma paciente que foi submetida, na juventude, a uma RK e passou a referir importante incômodo visual após a correção de catarata com facectomia e implante de LIO multifocal. Esta paciente foi submetida a uma ceratectomia fotorrefrativa (PRK) para diminuir as irregularidades da córnea com boa evolução clínica e resultado visual satisfatório. Esse caso chama a atenção para a alternativa do excimer laser topoguiado em casos semelhantes e alerta para o risco do uso desse tipo de lente em córneas irregulares.

Abstract Cataract surgery with intraocular lens implantation is one of the most commonly performed surgeries in the world and, currently, patients who undergo this surgery can use the multifocal intraocular lens (IOL) implant as an alternative to wearing glasses. A great challenge for the surgeon are patients who have previously undergone radial keratotomy (RK), because in addition to having a more challenging biometric calculation, they also have important corneal optical aberrations, being a contraindication for the use of multifocal lenses for most patients. ophthalmologists. In this article, we report the case of a patient who underwent a RK in her youth and started to report an important visual discomfort after cataract correction with facectomy and multifocal IOL implantation. This patient underwent a photorefractive keratectomy (PRK) to reduce corneal irregularities with good clinical evolution and satisfactory visual result. This case draws attention to the alternative of topography-guided laser excimer in similar cases and warns of the risk of using this type of lens in irregular corneas.

Opción terapéutica para la apertura de incisiones corneales posqueratotomías / Therapeutic option for opening of post-keratotomy corneal incisions

La cirugía refractiva incisional ha mostrado a lo largo de los años resultados impredecibles y fluctuantes. Se ha apreciado hipercorrección y astigmatismo no convencional en un número elevado de pacientes. Se presentan dos casos de ectasia corneal posquirúrgica, quienes refirieron empeoramiento progresivo de la visión. Al examen biomicroscópico se apreció apertura a nivel de las incisiones corneales por queratotomía radial y arcuata. Se muestran los resultados refractivos obtenidos en la corrección de dicha complicación mediante la utilización de suturas corneales. Se concluye que esta técnica induce resultados satisfactorios que deberíamos evaluar con certeza en el seguimiento posoperatorio de los casos(AU)

ABSTRACT Incisional refractive surgery has shown fluctuating and unpredictable results throughout the years. Hypercorrection and unconventional astigmatism have been observed in a high number of patients. Here are two patients with postsurgical corneal ectasia, who reported progressive worsening of vision. When making the biomicroscopic examination, it was observed that there was an opening at the level of corneal incisions through radial and arcuate ketatotomy. This study showed the refractive results achieved in the correction of this complication by using corneal sutures. It was concluded that this technique leads to satisfactory results that we should evaluate with certainty in the postoperative follow-up of patients(AU)

Efectividad del cálculo del lente intraocular por Pentacam y por el método de Maloney en pacientes con cirugía refractiva corneal previa / Effectiveness of the calculation of the intraocular lens by Pentacam and by Maloney's method in patients with previous refractive corneal surgery

Objetivo: comparar los resultados visuales de los pacientes con cirugía refractiva corneal, operados de catarata e implante de lente intraocular, calculado por el método de Maloney y por Pentacam. Métodos: se realizó un estudio descriptivo, prospectivo y longitudinal en 41 ojos de 31 pacientes con catarata y antecedentes de cirugía refractiva corneal, divididos aleatoriamente en dos grupos (1 y 2) con 23 y 18 ojos respectivamente, para calcular el poder corneal por el método de Maloney y por Pentacam, respectivamente, necesario para el cálculo de la lente intraocular a implantar. Resultados: la mayoría de los pacientes tenía antecedentes de queratotomía radial (90,24 pr ciento). El poder dióptrico medio de la lente mediante el método de Maloney fue de 18,8 ± 4,20, mientras que con la lectura queratométrica, medida a 4,0 mm del Pentacam, fue de 18 ± 4,20, con una diferencia media de 0,80 dioptrías ( p= 0,000) asociada a la prueba de los rangos con signo de Wilcoxon. El componente esférico posoperatorio promedio fue de -0,49 ± 0,65 dioptrías en el grupo 1 y de -0,57 ± 0,685 en el grupo 2, con una diferencia entre la esfera observada y la esperada de 0,16 y 0,15 dioptrías respectivamente (p= 0,906), asociada a la prueba U de Mann-Whitney. quedaron emétropes un 43,48 por ciento del grupo 1 y un 50 por ciento del grupo 2. Conclusiones: ambos métodos brindan resultados visuales favorables, pero el cálculo de la lente intraocular a partir de las lecturas queratométricas aportadas por el Pentacam ofrece mejores resultados visuales para los pacientes con antecedentes de cirugía refractiva corneal(AU)

Objective: to compare the visual results of patients operated from cataract and with intraocular lens implantation through corneal refractive surgery and estimated by Maloney's method and Pentacam camera. Methods: prospective, longitudinal and descriptive study conducted in 41 eyes from 31 patients with cataract and history of refractive corneal surgery. They were randomly assigned to two groups (1 and 2) with 23 and 18 eyes, respectively in order to estimate the corneal power of the intraocular lens to be implanted through Maloney's method and Pentacam camera. Results: most of patients had history of radial keratotomy (90.24 percent). The average dioptric power of the lens according to Maloney's method was 18.8 ± 4.20 whereas the kerametric reading, measured at 4.0 mm from Pentacam was 18 ± 4.20, with a mean difference of 0.80 dioptries ((p= 0,000) associated to Wilcoxon's sign range test. The average postoperative spheral component was -0.49 ± 0.65 D in group 1 and -0.57 ± 0.685 in group 2, with a difference between the observed and the expected sphere of 0.16 and 0.15 dioptries, respectively (p= 0.906), associated to Mann-Whitney's U test. In group 1, 43.48 percent and in group 2, 50 percent remained emetropes. Conclusions: Both methods provide favorable visual results, but the calculation of the intraocular lens power through the keratometric readings by Pentacam offers better visual results for patients with a history of refractive corneal surgery(AU)

Correlación de los valores queratométricos del Pentacam y el método de Maloney / Correlation of the keratometric values of Pentacam and Maloney's method

Objetivo: correlacionar los valores queratométricos obtenidos por el programa Holladay Report del Pentacam en ojos operados de queratotomía radial con diagnóstico de catarata, y los obtenidos a través del método de Maloney. Métodos: se realizó un estudio observacional prospectivo y descriptivo a 18 ojos miopes de 14 pacientes portadores de opacidades cristalinianas previamente sometidos a queratotomía radial que acudieron al Servicio de Catarata del Instituto Cubano de Oftalmología Ramón Pando Ferrer en el período comprendido de febrero a noviembre del año 2013. Se utilizó el Pentacam para obtener de forma directa el poder refractivo corneal utilizando programas diseñados con este fin, y posteriormente compararlo con el obtenido por el método de Maloney. Resultados: se obtuvo una correlación positiva al comparar las lecturas queratométricas equivalentes a 1 mm (r= 0,962); 2 mm (r= 0,845); 3 mm (r= 0,985); 4 mm (r= 0,988); 4,5 mm (r= 0,988) y central (r= 0,976) obtenidas en el programa Holladay Report del Pentacam, y los valores queratométricos aportados por el método de Maloney, lo cual fue estadísticamente significativo (p= 0,001). Conclusiones: el programa Holladay Report del Pentacam aporta poderes corneales que no difieren estadísticamente de los obtenidos por el método de Maloney en pacientes con cirugía refractiva corneal previa y catarata con criterio quirúrgico(AU)

Objective: to correlate the keratometric values from the Pentacam´s Holladay Report software in operated eyes which underwent radial keratotomy with cataract diagnosis and those of Maloney´s method. Method: prospective, descriptive and observational study conducted in 18 myopic eyes from 14 patients who had crystalline opacities and had undergone radial keratotomy. They had gone to the cataract service of Ramon Pando Ferrer Cuban Institute of Ophthalmology from February to November 2013. Pentacam was used to directly estimate the corneal refractive power by using tailor-made software for this purpose, and then compare it with the values obtained by Maloney´s method. Results: there was positive correlation when comparing the keratometric readings of 1 mm (r= 0.962); 2 mm (r= 0.845); 3 mm (r= 0.985); 4 mm (r=0.988); 4.5 mm (r= 0.988) and central (r= 0.976) in the Pentacam´s Holladay Report software and the keratometric values of the Maloney's method, which was statistically significant (p= 0,001). Conclusions: pentacam´s Holladay Report software reached corneal power values that do not differ statistically from those of Maloney´s method in patients who had previously undergone corneal refractive surgery and cataract with surgical criteria(AU)

Simulación de queratotomía arqueada por medio de un modelo de elementos finitos: aplicación de una plataforma de interacción entre Matlab y COMSOL Multiphysics / Simulation of arcuate keratotomy using the finite elements method: an application of an interaction platform of Matlab and COMSOL Multiphysics

La queratotomía radial es uno de los métodos quirúrgicos empleados para corregir los defectos ópticos de las personas; ésta ha sido ampliamente estudiada, e incluso se han propuesto nomogramas que permiten predecir los resultados de algunas geometrías; a pesar de esto, las experiencias postoperatorias han demostrado que la tasa de éxito de las cirugías es baja, ya que se presenta hipocorrección o hipercorrección de los pacientes, obligándolos a usar ayudas externas o llevándolos a someterse nuevamente a una cirugía. Teniendo en cuenta esto, se desarrolló una plataforma para simular estas cirugías por medio del método de elementos finitos, empleando los programas Matlab y COMSOL Multiphysics. Por medio de la rutina creada es posible obtener un modelo de la córnea preoperatoria que se asemeje tanto en geometría, como en condiciones de esfuerzo, a la córnea real; adicionalmente, es posible adaptar la geometría de la queratotomía radial que desee simularse. Se realizaron simulaciones para una cirugía compuesta de dos arcos y otra de tres arcos; los resultados obtenidos demuestran la capacidad de la simulación numérica para avanzar en el desarrollo de la cirugía refractiva, al ser posible estudiar parámetros, que de forma experimental, son difíciles de tener en cuenta, como la geometría inicial de la córnea y la edad del paciente, lo cual influye en el módulo de elasticidad del material; por otra parte, se encontró que esta aplicación es una potencial herramienta para los oftalmólogos, pues tiene la capacidad de predecir los resultados postoperatorios.

Radial keratotomy is used as a methodology to correct refractive errors. This surgery has been widely studied and also nomograms have been proposed in order to predict postoperative results of some types of keratotomies. Despite these eff orts, surgical evidence has shown a low success rate because of undercorrection or overcorrection, forcing patients to use spectacles or contact lenses, after surgery, or even leads them to a new procedure. A simulation platform was developed in an attempt to study these surgeries, employing the finite element method, using Matlab and COMSOL Multiphysics simultaneously. The routine is capable of simulate the preoperative cornea in terms of geometry and stress configuration. Also, it could be adapted to simulate any kind of radial keratotomy LASIK and PRK surgeries. Simulations for a double arc keratotomy and a triple arc keratotomy were developed. Results provide evidence of the capability of the platform to improve knowledge of refractive surgery taking into account the possibility to analyze the effect produced by corneal geometry and patient age, which aff ects the elastic modulus of the material, parameters difficult to analyze in an in-vivo experiment. Besides, it demonstrates the potential of the program as a tool for the surgeon to plan refractive surgery.

LIO pseudofácica suplementar sulcoflex® toric sobre LIO acrysof® toric / Supplementary pseudopakic iol sulcoflex® toric over toric acrysof®IOL

Para correção de alta hipermetropia e astigmatismo irregular secundário a múltiplas cirurgias refrativas em uma mulher de 45 anos, foi utilizada a sutura das incisões radiais, com implante de lente intraocular (LIO) Acrysof® Toric. Para correção do residual de erro refracional, foi implantada LIO pseudofácica tórica suplementar sobre LIO Primária. A acuidade visual (AV) inicial era de LogMAR 0,9 e a final de LogMAR 0,3. O implante da LIO suplementar tórica sobre LIO tórica primária mostrou-se uma boa opção, proporcionando melhora da acuidade visual.

To correct a high hyperopia and irregular astigmatism secondary to multiples refractive surgeries in a 45 years old female, radial incisions suture and intraocular (IOL) Acrysof Toric lens was performed. To correct the residual refractional error a pseudophakic toric supplementary IOL was implanted over the primary one.The initial visual acuity (VA) was LogMAR 0,9 and the final VA was LogMAR 0,3. The implant of IOL supplementary over a primary toric IOL appears to be a good option, increasing the visual acuity.

Keratoconus and corneal stability after radial keratectomy in the fellow eye: case report.

Keratoconus has usually been described as bilateral but asymmetric disease. Corneal ectasia is one of the long-term complications of modern refractive surgery, especially those submitted to laser in situ keratomileusis (LASIK). We describe a patient with keratoconus in the right eye that was submitted to radial keratectomy (RK) in the left eye 19 years ago with no progression of the ectatic cornea and no complications related to the refractive surgery. Because unilateral keratoconus is rare, we believe that RK was performed on an already ectatic cornea (not clinically detected) or with fruste keratoconus. However, neither corneal ectasia progressed, nor ectasia was induced by RK in the fellow eye.

Keratoconus and corneal stability after radial keratectomy in the fellow eye: case report / Ceratocone e estabilidade corneana após ceratectomia radial no outro olho: relato de caso

Keratoconus has usually been described as bilateral but asymmetric disease. Corneal ectasia is one of the long-term complications of modern refractive surgery, especially those submitted to laser in situ keratomileusis (LASIK). We describe a patient with keratoconus in the right eye that was submitted to radial keratectomy (RK) in the left eye 19 years ago with no progression of the ectatic cornea and no complications related to the refractive surgery. Because unilateral keratoconus is rare, we believe that RK was performed on an already ectatic cornea (not clinically detected) or with fruste keratoconus. However, neither corneal ectasia progressed, nor ectasia was induced by RK in the fellow eye.

O ceratocone é descrito como uma doença bilateral porém assimétrica e vários dados na literatura comprovam que a ectasia corneana é uma das complicações de longo prazo da cirurgia refrativa moderna, especialmente do laser in situ keratomileusis (LASIK). Nós descrevemos um caso de uma paciente com ceratocone no olho direito e que foi submetida à ceratotomia radial no olho esquerdo há 19 anos, desde então sem sinais de progressão da ectasia corneana nem de complicações relativas à cirurgia refrativa. Como o ceratocone unilateral é raro, acreditamos que a cirurgia refrativa tenha sido realizada num olho com ectasia corneana não detectada clinicamente ou com ceratocone frustro. Entretanto, a ectasia do olho direito não progrediu e também não houve sinais de ectasia no olho submetido à cirurgia refrativa nesse período de 19 anos de acompanhamento.

Refractive results of cataract surgery using optical biometry and Haigis formula in eyes with refractive keratotomy

OBJECTIVE: To analyze refractive results in postoperative cataract surgery in eyes previously submitted to keratotomy using Haigis formula and data provided by IOL Master®optical biometer. METHODS: The measurements for IOL calculation were obtained through optical biometry by partial coherence interferometry (IOL Master®- Zeiss, 5.4 and 5.5 version) that provides us with the axial length, the central keratometry of 2.5mm, white-to-white diameter and anterior chamber anatomical depth. The formula chosen was Haigis. The surgical technique applied was with the scleral incision at 1.5 mm from the limbus, with scleral-corneal tunnel of 2.2 mm wide, phacoemulsification using INFINITI Ozil®- Alcon and implantation of hydrophobic acrylic aspheric intraocular lens - SN60WF®- Alcon. RESULTS: We studied 20 eyes submitted to keratotomy in the past and currently with cataract with indication for cataract surgerywith intraocular lens implantation using phacoemulsification. Postoperative spherical equivalent was plano in 40% of the eyes and lower than -1.00 in 85% of the eyes. CONCLUSION: The optical biometry by partial coherence interferometry associated with Haigis formula is a valid alternative in IOL calculation for eyes submitted to keratotomy. The refractive results are highly predictable and reproducible.

OBJETIVO: Analisar os resultados refracionais no pós-operatório de cirurgia de catarata em olhos previamente submetidos à ceratotomia, utilizando a fórmula Haigis e os dados fornecidos pelo biômetro óptico IOL Master®. MÉTODOS: As medidas para o cálculo da LIO foram obtidas por meio da biometria óptica por interferometria de coerência parcial (IOL Master® - Zeiss, versão 5.4 e 5.5) que nos fornece o comprimento axial, a ceratometria central de 2.5mm, o diâmetro branco-a-branco e a profundidade anatômica da câmara anterior. A fórmula escolhida foi a Haigis. A técnica cirúrgica aplicada foi com incisão escleral a 1.5mm do limbo, com túnel esclero-corneal de 2.2mm de largura, facoemulsificação com equipamento INFINITI Ozil® - Alcon e implante de lente intraocular acrílica hidrofóbica asférica - SN60WF® - Alcon. RESULTADOS: Foram estudados 20 olhos submetidos à ceratotomia no passado e atualmente portadores de catarata com indicação de facectomia com implante de lente intraocular por meio da facoemulsificação. O equivalente esférico pós-operatório foi plano em 40% dos olhos e menor que -1.00 em 85% dos olhos. CONCLUSÃO: A biometria óptica por interferometria de coerência parcial associada à fórmula Haigis se apresenta como uma alternativa válida no cálculo da LIO em olhos submetidos à ceratotomia. Os resultados refrativos são altamente previsíveis e reproduzíveis.

Corneal ectasia secondary to LASIK after arcuate keratotomy.

PURPOSE: To present a case of corneal ectasia after LASIK in a patient with previous arcuate keratotomy. METHODS: Case report. RESULTS: The patient underwent arcuate keratotomy in both eyes in 1997 for with-the-rule regular hyperopic astigmatism and uneventful bilateral LASIK for residual astigmatism 5 years later. Visual acuity and refraction remained stable for 5 years, when the patient noticed worsening visual acuity. Corneal topography showed progressive inferior steepening, confirming the diagnosis of ectasia. Corneal high-resolution optical coherence tomography revealed a normal LASIK flap. The patient had no risk factors for corneal ectasia other than previous incisional surgery. CONCLUSIONS: This case suggests that isolated arcuate keratotomy can be a significant risk factor for the development of corneal ectasia after LASIK.

Hipermetropia após ceratotomia radial: flutuação da refração e da acuidade visual entre manhã e tarde e correlações com a pressão ocular e o estado biomecânico da córnea / Hyperopia after radial keratotomy: fluctuation of refraction and visual acuity from morning to evening and correlations with intraocular pressure and corneal biomechanics

OBJETIVO: Verificar as variações entre manhã e tarde da refração, da acuidade visual, das medidas da pressão ocular e dos parâmetros biomecânicos da córnea em pacientes operados de ceratotomia radial e interesse em retratamento refrativo; correlacionar os parâmetros biomecânicos da córnea com a refração, com a acuidade visual e com as suas variações. MÉTODOS: Foram examinados trinta e oito olhos de 19 pacientes pela manhã (9 am) e à tarde (6 pm), obtendo-se refração esfero-cilíndrica dinâmica, acuidade visual (logMAR) sem correção (AVsc) e corrigida (AVcc) e parâmetros do ORA (Ocular Response Analyzer): histerese corneana (corneal hysteresis - CH), fator de resistência da córnea (corneal resistance factor - CRF), pressão intraocular (intraocular pressure &- IOP) calibrada para o padrão Goldmann (IOPg) e pressão compensada da córnea (IOPcc). Considerando a não distribuição normal das variáveis (teste de Kolmogorov-Smirnov), o teste de Wilcoxon signed rank foi utilizado para verificar significância nas diferenças entre as medidas da manhã e as da tarde de cada variável. O teste de Spearman foi utilizado para verificar correlações das medidas do ORA com o estado refracional e com a acuidade visual pela manhã e à tarde, assim como para verificar as correlações entre as medidas do ORA pela manhã e à tarde e as variações da refração e da acuidade visual. RESULTADOS: Grau esférico (E), equivalente esférico (EE), equivalente desfoco (ED), AVsc, IOPcc e IOPg variaram significativamente (Wilcoxon, p<0,05) entre manhã e tarde, havendo maior hipermetropia, pior acuidade visual não corrigida, maior pressão ocular e menor CH pela manhã. Nas medidas pela manhã, observaram-se correlações positivas (Spearman, p<0,05) do EE e do ED com IOPcc (rs=0,39 e 0,34 respectivamente), mas não com IOPg. Nas medidas da tarde, não houve correlações significantes entre os parâmetros refracionais e os pressóricos. Observaram-se correlações negativas (Spearman, p<0,05) entre AVsc (logMAR) e CH pela manhã e à tarde (rs= -0,48 e rs= -0,51), entre E e CH pela manhã e à tarde (rs= -0,66 e -0,76), entre E e CRF pela manhã e à tarde (rs= -0,40 e -0,47), entre EE e CH pela manhã e à tarde (rs= -0,70 e -0,68), entre EE e CRF pela manhã e à tarde (rs= -0,41 e -0,46), entre ED e CH pela manhã e a tarde (rs= -0,64 e -0,54) e entre ED e CRF pela manhã e a tarde (rs= -0,35 e -0,34). Observou-se correlação significante e negativa do CRF pela manhã com a variação do ED (p = 0,05; rs = -0,30) e com a variação da AVsc (p = 0,04; rs = -0,33). CONCLUSÃO: Maior hipermetropia pela manhã foi associada a maior pressão compensada (IOPcc), mas não com IOPg em pacientes operados de ceratotomia radial, o que deve ser considerado no planejamento do retratamento refrativo. Parâmetros biomecânicos (CRF e CH) mais baixos foram associados com maior hipermetropia e pior acuidade visual. Uma tendência de haver maior flutuação relacionada com córneas mais fracas foi encontrada. Novos estudos envolvendo parâmetros biomecânicos derivados do sinal do ORA, além dos parâmetros CH e CRF (derivados das pressões de aplanamento do ORA), juntamente com dados tomográficos da córnea e de aberrometria total são necessários.

PURPOSE: To verify the morning to evening variations of refraction, visual acuity, intraocular pressure and biomechanical parameters on patients operated by radial keratotomy who presented for refractive re-treatments; and to correlate the biomechanical parameters with refraction, visual acuity and their variations among morning and evening. METHODS: 19 patients were examined, respectively thirty-eight eyes in the morning (9 am) and evening (6 pm), recording sphere-cylindrical dynamic refraction, visual acuity (logMAR) without correction (AVsc) and corrected (AVcc) and ORA (Ocular Response Analyzer) parameters: corneal hysteresis (CH), corneal resistance factor (CRF), intraocular pressure calibrated for Goldmann (IOPg) e corneal compensated (IOPcc). Variables had no normal distribution (Kolmogorov-Smirnov test), so that the Wilcoxon signed rank was used for testing the significance on the differences for each variable between morning and afternoon. The Spearman test was used for assessing the correlations between the ORA parameters and refraction, visual acuity in the morning and afternoon, as well as to verify the correlations between the ORA parameters and the variations on refraction and visual acuity. RESULTS: Sphere (E), spherical equivalent (EE), defocus equivalent (ED), AVsc, IOPcc e IOPg varied significantly (Wilcoxon, p<0.05) between morning and evening. There was more hyperopia, worse visual acuity, higher pressure and lower CH in the morning measurements. In the morning measurements, there was a positive correlation (Spearman, p<0.05) between EE and ED and IOPcc (rs=0.39 and 0.34 respectively), but not with IOPg. In the evening measurement, there were no correlations between the refractive and pressure measurements. Negative correlations were observed (Spearman, p<0.05) between AVsc (logMAR) and CH in the morning and in the evening (rs= -0.48 e rs= -0,51), between E and CH in the morning and in the evening (rs= -0.66 and -0.76), between E and CRF in the morning and in the evening (rs= -0.40 and -0.47), between EE and CH in the morning and in the evening (rs= -0.70 and -0.68), between EE and CRF in the morning and in the evening (rs= -0.41 and -0.46), between ED and CH in the morning and in the evening (rs= 0.64 and -0.54) and between ED and CRF in the morning and in the evening (rs= -0.35 and -0.34). There was a significant negative correlation between the morning measurement of CRF and the variation of defocus equivalent (p = 0.05; rs = -0.30) and the variation of AVsc (p = 0.04; rs = -0.33). CONCLUSION: More hyperopia was recorded in the morning which was associated with higher compensated pressure (IOPcc) but not with IOPg ten years after RK. Lower biomechanical parameters (CRF e CH) were associated with higher hyperopia and worse visual acuity. A trend was observed for having higher fluctuation on weaker corneas. New studies involving the variables derived from the waveform signals, beyond CH and CRF (derived from the applanation pressures) along with data from corneal tomography and wavefront aberrometry are necessary.

Corneal wavefront-guided photorefractive keratectomy with mitomycin-C for hyperopia after radial keratotomy: two-year follow-up.

PURPOSE: To assess corneal wavefront-guided photorefractive keratectomy (PRK) to correct hyperopia after radial keratotomy (RK). SETTING: Sadalla Amin Ghanem Eye Hospital, Joinville, Santa Catarina, Brazil. DESIGN: Case series. METHODS: Excimer laser corneal wavefront-guided PRK with intraoperative mitomycin-C (MMC) 0.02% was performed. Main outcome measures were uncorrected (UDVA) and corrected (CDVA) distance visual acuities, spherical equivalent (SE), corneal aberrations, and haze. RESULTS: The mean time between RK and PRK in the 61 eyes (39 patients) was 18.8 years ± 3.8 (SD). Before PRK, the mean SE was +4.17 ± 1.97 diopters (D); the mean astigmatism, -1.39 ± 1.04 D; and the mean CDVA, 0.161 ± 0.137 logMAR. At 24 months, the mean values were 0.14 ± 0.99 D (P<.001), -1.19 ± 1.02 D (P=.627), and 0.072 ± 0.094 logMAR (P<.001), respectively; the mean UDVA was 0.265 ± 0.196 (P<.001). The UDVA was 20/25 or better in 37.7% of eyes and 20/40 or better in 68.9%. The CDVA improved by 1 or more lines in 62.3% of eyes. Two eyes (3.3%) lost 2 or more lines, 1 due to corneal ectasia. Thirty eyes (49.2%) were within ± 0.50 D of intended SE and 45 (73.8%) were within ± 1.00 D. From 6 to 24 months, the mean SE regression was +0.39 D (P<.05). A significant decrease in coma, trefoil, and spherical aberration occurred. Three eyes developed peripheral haze more than grade 1. CONCLUSION: Corneal wavefront-guided PRK with MMC for hyperopia after RK significantly improved UDVA, CDVA, and higher-order corneal aberrations with a low incidence of visually significant corneal haze.

Orbscan II and double-K method for IOL calculation after refractive surgery.

BACKGROUND: Precise IOL calculation in post-refractive surgery patients is still a challenge for the cataract surgeon. The purpose of this study is to test whether adding Orbscan II values into the double-K method improves IOL calculation in this group of patients. METHODS: A prospective study with 43 eyes previously submitted to refractive surgery that underwent cataract extraction. IOL calculation was performed with double-K method. Post-K value was derived from Orbscan total-mean power map. The average corneal curvature of the general population (43.8D) was used as the pre-K value. Refraction results 30 days after surgery were compared with refraction that would be obtained if we used: (1) post-K values from keratometry, (2) post-K values from topography, and (3) pre-K values from Orbscan total-mean power. Anterior chamber depth measures obtained with the IOL Master and Orbscan II were compared. RESULTS: Mean postoperative spherical equivalent (SE) was -0.25 ± 1.10 D in eyes submitted to radial keratotomy , -1.04 ± 1.42 D in eyes previously submitted to myopic Lasik, and +0.05 ± 1.76 D in those submitted to hyperopic surgeries. Had we inputted post-K values derived from keratometer and from topography, we would have obtained significantly higher postoperative refractive errors in eyes previously submitted to myopic refractive surgery (p < 0.05). Refractions using pre-K derived from the central 8 mm Orbscan instead of 43.8 D were similar in all studied groups (p > 0.05). Anterior chamber depth measured with IOL Master or Orbscan were similar. CONCLUSIONS: Orbscan measurements used as the post-K values into the double-K method provide a precise IOL calculation, especially in post myopic refractive surgery patients.

Gaping of radial and transverse corneal incisions occurring early after CXL.

A 33-year-old woman with corneal ectasia after radial and astigmatic keratotomy had corneal collagen crosslinking with resultant gaping of the inferior incisions (2 radials and 1 transverse) that required suturing. At 6 months, the incisions healed leaving fibrotic scars. Visual acuity, refractions, corneal photographs, and topographic and corneal wavefront measurements are presented. At 2.5 years, the topographic inferior corneal irregularity continued to improve.

[Safety of photorefractive keratectomy with mitomycin-C for the treatment of hyperopia after radial keratotomy]. / Segurança da ceratectomia fotorrefrativa com mitomicina-C para o tratamento de hipermetropia após ceratotomia radial.

PURPOSE: To evaluate the safety of photorefractive keratectomy (PRK) with mitomycin-C (MMC) in eyes with hyperopia after radial keratotomy. METHODS: Sixty eyes of 36 consecutive patients treated with corneal wavefront-guided PRK using an Esiris-Schwind excimer laser were prospectively evaluated. Corneal epithelium was mechanically removed, followed by photoablation and use of 0.02% MMC for 20 or 40 seconds. In 16 eyes (26.7%), MMC was applied for 40 seconds. These eyes underwent ablations deeper than 100 micron or had previous corneal sutures. Patients were followed up for 12 months. RESULTS: The mean spherical equivalent (SE) before PRK was +4.27 D +/- 2.18, and the mean best corrected visual acuity (BCVA) was 0.174 +/- 0.139 (logMAR). The planned laser SE correction was +4.74 D +/- 2.11, resulting in an ablation depth of 78 +/- 28 microm (from 33 to 148). No intraoperative complications were observed. At one year, mean SE was +0.04 D +/- 1.03 (p<0.001) and mean BCVA was 0.079 +/- 0.105 (p<0.001). There was a gain of 2 or more lines of BCVA in 20 eyes (33.3%) and only one eye (1.7%) lost 2 lines. Correlation analysis showed that the improvement in BCVA was inversely related to preoperative BCVA (r=-0.694; p<0.001). Five eyes developed peripheral haze grade 2 or 3 and one eye had central trace haze. No significant correlation was found between central or peripheral haze and the number of radial incisions, depth of the ablation or postoperative BCVA. Mean preoperative endothelial cell count was 2,681 +/- 455 cel/ mm(2) and after one year was 2,481 +/- 378 cel/mm(2) (p=0.124). One eye developed keratectasia due to the progressive widening of an inferior radial incision, which was later sutured. CONCLUSION: PRK with MMC was safe after one year of follow-up for the reduction of hyperopia after radial keratotomy. A major improvement in BCVA was obtained with a small incidence of haze and other complications.