Evaluation of perioperative pachymetry of thin corneas during corneal crosslinking using hypo-osmolar riboflavin and hydroxypropyl methylcellulose

ABSTRACT Purpose: This study aimed to analyze variations in intraoperative corneal thickness during corneal cross-linking in patients with keratoconus and to investigate its possible correlation with presurgical maximal keratometry (Kmax) and pachymetry. Methods: This was a prospective case series. We used a method similar to the Dresden protocol, with the application of hydroxypropyl methylcellulose 0.1% hypo-osmolar riboflavin in corneas between 330 and 400 µm after epithelium removal. Corneal thickness was measured using portable calipers before and immediately after epithelium removal, and 30 and 60 min after the procedure. Results: The 30 patients in this study were followed up for one year. A statistically significant difference was observed in pachymetry values during the intraoperative period (p<0.0001) and an increase of 3.05 µm (95%C1: 0.56-5.54) for each diopter was seen after epithelium removal (p0.019). We found an average Kmax difference of —2.12 D between men and women (p0.013). One year after treatment, there was a statistically significant reduction in pachymetry (p<0.0001) and Kmax (p0.0170) values. Conclusions: A significant increase in pachymetry measurements was seen during the procedure, and most patients showed a regression in Kmax and pachymetry values one year after surgery.

Comparative outcomes of mechanical and transepithelial PRK on the same excimer laser: A contralateral eye study.

PURPOSE: Compare refractive results between mechanical PRK (mPRK) and transepithelial PRK (tPRK) with WaveLight Allegretto EX500 excimer laser system (Alcon Laboratories, Fort Worth, TX, USA). SETTING: Department of Ophthalmology of the Federal University of Sao Paulo, Brazil. DESIGN: Prospective and randomized study. METHODS: In 151 eyes of 73 patients with astigmatism and myopia, both eyes had similar refraction before surgery, with a maximum of 15-µm difference in ablation who underwent mPRK in one eye and tPRK in the contralateral eye. The mean age of the patients in this study was 31.45 ± 6.97 years (range, 22 to 54 years). RESULTS: A comparison was made with all variables between the two groups, and we found that UDVA and SE were worse in the tPRK group at six months than in the mPRK group. In the mPRK group, there was a higher frequency in the +/- 0.50 range and a lower frequency in the +/- 1.50 range. In the tPRK group, however, there was a lower frequency in the +/- 0.50 range and a higher frequency in the +/- 1.50 range. Concerning gain or loss of lines of sight, there was no association between the two groups (chi-square test, p = 0.887). CONCLUSION: Both mPRK and tPRK appear to have similar safety. However, mPRK was associated with significantly better UDVA and SE six months post-operatively.

Aspectos a considerar para el diagnóstico del queratocono infantil / Aspects to consider for the diagnosis of infant keratoconus

Introducción: Globalmente, existe un aumento de la prevalencia del queratocono y su diagnóstico en edades tempranas. Se notifican un gran número de casos subclínicos y otros con una rápida progresión, condicionada por el inicio precoz de la enfermedad y la asociación a factores de riesgo. Objetivo: Describir los aspectos epidemiológicos, clínicos y el resultado de los medios de diagnóstico implicados en la detección precoz del queratocono infantil. Desarrollo: En niños con ametropía hay elementos que alertan la presencia de un queratocono como causa del defecto refractivo. Desde el punto de vista epidemiológico se encuentran: distribución geográfica, rol de la herencia y factores ambientales. Clínicamente se señalan los antecedentes de enfermedades, tales como las alergias, la presencia de miopía o astigmatismo miópico con inestabilidad refractiva y los signos clínicos relacionados con la progresión del cono. En los pacientes de riesgo es preciso realizar exámenes mediante diferentes medios de diagnóstico según su disponibilidad, siendo primordial el análisis refractivo, queratométrico y topográfico. Conclusiones: En la evaluación de los niños con ametropía se deben tener en cuenta elementos epidemiológicos y clínicos que permiten sospechar y diagnosticar precozmente el queratocono. En la interpretación de los resultados de los medios de diagnóstico involucrados en su detección, se deben considerar los hallazgos más frecuentes en la población infantil según el grado de progresión de la ectasia.

Introduction: Globally, there is an increase of the keratoconus prevalence and its diagnosis in early ages. A great number of subclinical cases and others with a quick progression are notified, conditioned by the early onset of the disease and the association with risk factors. Objective: To describe the epidemiological, clinical aspects and the result of diagnostic means involved in the early detection of infant keratoconus. Development: There are elements that alert the presence of a keratoconus as a cause of the refractive defect in children with ametropia. From the epidemiologic point of view they are: geographical distribution, heredity role and environmental factors. History of previous diseases are clinically pointed out, such as allergies, myopia or myopic astigmatism with refractive instability and the clinical signs related to cone progression. In risk patients it is necessary to carry out exams by means of different diagnostic means according to their availability, being essential the refractive, keratometric and topographic analysis. Conclusions: In the evaluation of children with ametropia, epidemiological and clinical elements should be taken into account that allow to suspect and early diagnose the keratoconus. In the interpretation of results of the diagnostic means involved in their detection the most frequent findings in the infant population, should be considered according to the ectasia degree of progression.

Results of intrastromal corneal ring implantation in advanced keratoconus With the aim of postpoing or avoiding corneal transplantation.

PURPOSE: To evaluate the safety and efficacy of the surgery of intracorneal ring segment implantation with 320° of arc (320-ICRS) in patients with advanced keratoconus stage IV and maximum keratometry (Kmax) above 60 D. METHODS: A prospective, interventional case series study evaluating 25 eyes of 19 patients with keratoconus stage IV and Kmax > 60D in which 320-ICRS were implanted using VisuMax® femtosecond. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), keratometric values (mean - mean-K, flat - K1, and steep - K2), maximum keratometry (Kmax), tomographic astigmatism, refractive astigmatism and asphericity (Q) were assessed preoperatively and at 3, 6 and 12 months after the procedure. RESULTS: The UDVA improved from 1.03 ± 0.28 LogMAR (20/200) to 0.54 ± 0.21 LogMAR (20/60), (p < 0.001), the CDVA (with glasses) improved from 0.63 ± 0.29 LogMAR (20/80) to 0.31 ± 0.16 LogMAR (20/40),(p = 0.004), K1 reduced from 54.41 ± 4.46 D to 49.36 ± 4.11 D (p < 0.001), K2 reduced from 61.15 ± 4.37 D to 53.715 ± 4.05 D, (p < 0.001), mean-K reduced from 57.55 ± 4,17 D to 51.44 ± 3,94 D (p < 0.001), Kmax reduced from 69.80 ± 8.20 D to 63.43 ± 6.31 D (p < 0.001) and asphericity (Q) changed from -1.57 ± 0.35 to -0.77 ± 0.56 (p < 0.001). A total of 89.9% patients reached BCVA wearing scleral contact lens  0.2 LogMAR(20/25). CONCLUSION: 320-ICRS to treat advanced keratoconus appears to be an efficacious and safe procedure, being a surgical alternative to delay or even prevent corneal transplantation.

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.

Evaluation of unilateral corneal collagen cross-linking on fellow untreated eyes of patients with keratoconus / A avaliação da reticulação unilateral do colágeno corneano em olhos não tratados de pacientes com ceratocone

ABSTRACT Purpose: This study aimed to examine the effects of unilateral corneal collagen cross-linking treatment on visual acuity and the topographic findings of the fellow untreated eye of patients who had bilateral progressive keratoconus. Methods: Patients with progressive keratoconus who underwent cross-linking treatment were screened retrospectively. A total of 188 untreated eyes of 188 patients whose eyes were treated unilaterally with either standard or accelerated cross-linking and refused cross-linking procedure for the fellow eye were included. Visual acuity and topographic findings of the fellow untreated eyes were obtained preoperatively and postoperatively at the 1st, 3rd, 6th, 12th, 24th, 30th, and 36th months. Results: The change over time of variables examined was similar in the untreated eyes of patients who received standard and accelerated cross-linking methods (p>0.05). At the 12th month, 136 (95.8%) untreated eyes were stable according to progression criteria. Only 4 (8%) eyes were progressive at the 24th month. No progression was observed in any of the 16 patients with a 36-month follow up. Conclusions: The results showed that the fellow untreated eyes of patients with bilateral progressive keratoconus did not have significant progression rates after unilateral cross-linking treatment.

RESUMO Objetivo: Examinar os efeitos do tratamento de reticulação unilateral do colágeno corneano na acuidade visual e os achados topográficos em olhos não tratados de pacientes com ceratocone progressivo bilateral. Métodos: Foram rastreados retrospectivamente pacientes com ceratocone progressivo submetidos a tratamento de reticulação. Foram incluídos no estudo 188 olhos não tratados de 188 pacientes tratado unilateralmente com reticulação padrão ou acelerada e que recusaram o procedimento de reticulação no outro olho. A acuidade visual e os achados topográficos dos olhos não tratados foram obtidos no pré- e pós-operatório no 1º, 3º, 6º, 12º, 24º, 30º e 36º mês. Resultados: As alterações ao longo do tempo foram semelhantes para as variáveis examinadas nos olhos não tratados de pacientes tratados com métodos de reticulação padrão e acelerado (p>0,05). No 12º mês, 136 olhos não tratados (95,8%) estavam estáveis, de acordo com os critérios de progressão. Apenas quatro olhos (8%) mostraram progressão no 24º mês. Nenhuma progressão foi observada nos 16 pacientes que tiveram um acompanhamento de 36 meses. Conclusões: O estudo mostrou que os olhos não tratados de pacientes com ceratocone progressivo bilateral não apresentaram taxas de progressão significativas após o tratamento unilateral com reticulação.

Corneal reshaping: an experiment with a type I collagen-based vitrigel for remodeling porcine corneas / Remodelamento corneano: relato de um experimento com um vitrigel a base de colágeno tipo I para remodelamento de córneas porcinas

ABSTRACT Purpose: This study aimed to report an experiment designed to determine anatomical changes in porcine corneas following placement of a novel polymer implant into the cornea. Methods: An ex vivo porcine eye model was used. A novel type I collagen-based vitrigel implant (6 mm in diameter) was shaped with an excimer laser on the posterior surface to create three planoconcave shapes. Implants were inserted into a manually dissected stromal pocket at a depth of approximately 200 μm. Three treatment groups were defined: group A (n=3), maximal ablation depth 70 μm; Group B (n=3), maximal ablation depth 64 μm; and group C (n=3), maximal ablation depth 104 μm, with a central hole. A control group (D, n=3) was included, in which a stromal pocket was created but biomaterial was not inserted. Eyes were evaluated by optical coherence tomography (OCT) and corneal tomography. Results: Corneal tomography showed a trend for a decreased mean keratometry in all four groups. Optical coherence tomography showed corneas with implants placed within the anterior stroma and visible flattening, whereas the corneas in the control group did not qualitatively change shape. Conclusions: The novel planoconcave biomaterial implant described herein could reshape the cornea in an ex vivo model, resulting in the flattening of the cornea. Further studies are needed using in vivo animal models to confirm such findings.

RESUMO Objetivo: Relatar um experimento projetado para determinar alterações anatômicas em córneas porcinas após a colocação de um novo implante de polímero na córnea. Métodos: Foi utilizado olho de porco ex vivo. Um novo agente modelador biocompatível, de colágeno tipo 1, com 6mm de diâmetro foi moldado com excimer laser em sua face posterior, para criar três formatos planocôncavos. Os implantes foram inseridos dentro de um bolsão, dissecado manualmente, a 200 micrômetros (μm). Foram definidos três grupos de tratamento: grupo A (n=3), teve a profundidade máxima de ablação de 70 μm; o grupo B (n=3), profundidade máxima de ablação de 64 μm; e o grupo C (n=3), profundidade máxima de ablação de 104 μm, com buraco central. O grupo controle, D (n=3), foi incluído, com a criação do bolsão estromal, porém sem inserir o material. A avaliação desses olhos foi realizada por tomografia de coerência óptica (OCT) e por tomografia corneana. Resultados: A tomografia corneana mostrou uma tendência para diminuição da ceratometria média em todos os 4 grupos. A tomografia de coerência óptica mostrou córneas com implantes localizados no estroma anterior e aplanamento visível, enquanto as córneas não mudaram qualitativamente o formato no grupo controle. Conclusões: O novo implante de biomaterial planocôncavo descrito aqui foi capaz de remodelar a córnea em modelo de animal ex vivo, resultando no aplanamento corneano. Novos estudos são necessários usando modelos animais in vivo para confirmar tais achados.

Evaluation of corneal tomography in children and adolescents without ocular or systemic allergy / Avaliação da tomografia de córnea em crianças e adolescentes sem alergia ocular ou sistêmica

ABSTRACT Purpose: To determine normal corneal tomographic parameters in children and adolescents without corneal disease or atopy diagnosis. Methods: This descriptive cross-sectional study evaluated patients aged 8-16 years who underwent a complete slit-lamp biomicroscopic examination and tomographic corneal evaluation by a dual Scheimpflug analyzer, excluding those with ocular disease (including allergic conjunctivitis) or a positive prick test for systemic atopies. Results: A total of 170 patients were evaluated, and 34 patients (68 eyes) were analyzed once the exclusion criteria were applied. The sample's mean age was 10.76 ± 2.31 years; with 19 (55.9%) men and 15 (44.1%) women. The mean keratometry in the flat meridian (Kflat), steep meridian (Ksteep), and maximum (Kmax) were 42.37 ± 1.63D, 43.53 ± 1.65D, and 43.90 ± 1.73D, respectively. The mean values for corneal asphericity (ε2) and thinnest point were 0.28 ± 0.11 and 550.20 ± 37.90 μm, respectively. The inferior-superior asymmetry ratio (I-S) and coma were 0.74 ±0.59D and 0.28 ± 0.12D, respectively. Conclusion: The knowledge of normal corneal tomographic parameters and their variation in children and adolescents without corneal disease or atopy may be useful for diagnosing keratoconus and initiating early disease treatment.

RESUMO Objetivo: Identificar parâmetros tomográficos de normalidade em córneas de crianças e adolescentes sem a presença de atopias sistêmicas e alergias oculares. Métodos: Este estudo descritivo transversal avaliou pacientes com idade entre 8 e 16 anos que foram submetidos a exame biomicroscópico completo por lâmpada de fenda e avaliação tomográfica da córnea por tomógrafo dual Scheimpflug, excluindo pacientes com doença ocular (incluindo conjuntivite alérgica) ou prick test positivo para atopias sistêmicas. Resultados: Cento e setenta pacientes foram avaliados e após cumpridos os critérios de exclusão, 34 (68 olhos) foram analisados. A média etária da amostra foi 10,76 ± 2,31 anos; 19 (55,9%) eram meninos e 15 (44,1%) meninas. A média da ceratometria em dioptrias (D) no meridiano mais plano (Kflat), mais curvo (Ksteep) e máxima (Kmax) foram 42,37 ± 1,63D, 43,53 ± 1,65D e 43,90 ± 1,73D, respectivamente. Os valores médios da asfericidade corneana (ε2) e do ponto mais fino da córnea foram 0,28 ± 0,11 e 550,20 ± 37,90 micras (μm). A assimetria corneana inferior-superior (I-S) e coma foi em média 0,74 ± 0,59D e 0,28 ± 0,12D, respectivamente. Conclusão: O conhecimento dos valores médios e sua variação de parâmetros tomográficos da córnea em crianças e adolescentes sem atopias sistêmicas ou alergias oculares pode ser útil para o diagnóstico precoce do ceratocone e o seu tratamento em estágio inicial.

Post-Bader procedure: a long-term follow-up case study / Procedimento pós-Bader: estudo de caso com acompanhamento de longo prazo

ABSTRACT Keratoconus is a progressive disorder that manifests as a cone-like steepening of the central or paracentral inferior cornea and irregular stromal thinning. There is a gradual decrease in visual acuity due to corneal asymmetry, irregular astigmatism, and increased optical aberrations, consequently impacting the quality of life. Several procedures have been developed in an attempt to slow or reverse the progression. The Bader procedure, which includes a pattern of incisions around the circumference of the cornea and at the base of the protruding cone, is one such surgery. These incisions penetrate 70-90% of the cornea's depth. Its goal is to flatten the topography and reduce corneal asymmetry and irregular astigmatism. Though prior research found these to be highly promising, we report a patient who was given contact lenses to restore and maintain his vision while his corneal ectasia and thinning progressed over the following decade.

RESUMO O ceratocone é uma doença progressiva que se manifesta como uma elevação semelhante a um cone da cór­nea central ou paracentral inferior e é associada a uma re­dução irregular da espessura do estroma. Há uma diminuição gradual da acuidade visual devido à assimetria da córnea, ao astigmatismo irregular e a um aumento das aberrações ópticas, o que prejudica a qualidade de vida. Foram desenvolvidos vários procedimentos para tentar interromper ou mesmo reverter a evolução da doença. Um deles é o chamado procedimento de Bader, que inclui um padrão de incisões em volta da circunferência da córnea e na base do cone protuberante. Essas incisões penetram até 70%-90% da profundidade da córnea e têm o objetivo de achatar a topografia e diminuir a assimetria da córnea e o astigmatismo irregular. Embora essa técnica seja muito promissora, segundo um estudo anterior, aqui se apresenta o caso de um paciente no qual esses objetivos não foram atingidos. Esse paciente recebeu lentes de contato para restaurar e manter sua visão, enquanto sua ectasia corneana e a redução da espessura progrediram ao longo da década seguinte.

Therapeutic effects of orthokeratology lens combined with 0.01% atropine eye drops on juvenile myopia / Efeitos terapêuticos da lente de ortoceratologia combinados com colírio atropina 0,01% em miopia juvenil

ABSTRACT Purpose: To explore the therapeutic effects of orthokeratology lens combined with 0.01% atropine eye drops on juvenile myopia. Methods: A total of 340 patients with juvenile myopia (340 eyes) treated from 2018 to December 2020 were divided into the control group (170 cases with 170 eyes, orthokeratology lens) and observation group (170 cases with 170 eyes, orthokeratology lens combined with 0.01% atropine eye drops). The best-corrected distance visual acuity, best-corrected near visual acuity, diopter, axial length, amplitude of accommodation, bright pupil diameter, dark pupil diameter, tear-film lipid layer thickness, and tear break-up time were measured before treatment and after 1 year of treatment. The incidence of adverse reactions was observed. Results: Compared with the values before treatment, the spherical equivalent degree was significantly improved by 0.22 (0.06, 0.55) D and 0.40 (0.15, 0.72) D in the observation and control groups after the treatment, respectively (p<0.01). After the treatment, the axial length was significantly increased by (0.15 ± 0.12) mm and (0.24 ± 0.11) mm in the observation and control groups, respectively, (p<0.01). After the treatment, the amplitude of accommodation significantly declined in the observation group and was lower than that in the control group, whereas both bright and dark pupil diameters significantly increase and were larger than those in the control group (p<0.01). After the treatment, the tear-film lipid layer thickness and tear break-up time significantly declined in the two groups (p<0.01). Conclusions: Orthokeratology lens combined with 0.01% atropine eye drops can synergistically enhance the control effect on juvenile myopia with high safety.

RESUMO Objetivo: Explorar os efeitos terapêuticos das lentes de ortoceratologia combinados com colírio atropina 0,01% em miopia juvenil. Métodos: Um total de 340 pacientes com miopia juvenil (340 olhos) tratados entre 2018 e Dezembro de 2020 foram divididos em Grupo Controle (170 casos com 170 olhos, lentes de ortoceratologia) e Grupo Observação (170 casos com 170 olhos, lentes de ortoceratologia combinadas com colírio atropina 0,01%). A acuidade visual melhor corrigida para longe, acuidade visual melhor corrigida para perto, dioptria, comprimento axial, amplitude de acomodação, diâmetro da pupila brilhante, diâmetro da pupila escura, espessura da camada lipídica da película lacrimal e tempo de ruptura do rasgo foram medidos antes do tratamento e 1 ano depois. A incidência de reações adversas foi observada. Resultados: Antes do tratamento, o grau esférico equivalente foi significativamente melhorado em 0,22 (0,06, 0,55) D e 0,40 (0,15, 0,72) D respectivamente no Grupo Observação e no Grupo Controle após o tratamento (p<0,01). Após tratamento, o comprimento axial foi significativamente aumentado em (0,15 ± 0,12) mm e (0,24 ± 0,11) mm respectivamente nos Grupos Observação e controle (p<0,01), enquanto, no grupo de observação, a amplitude de acomodação diminuiu significativamente e foi inferior a do Grupo Controle, e o diâmetro da pupila brilhante e o diâmetro da pupila escura aumentaram significativamente e foram maiores do que os do Grupo Controle (p<0,01). A espessura da camada lipídica da película lacrimal e o tempo de ruptura do rasgo diminuíram significativamente nos dois grupos (p<0,01) após o tratamento. Conclusões: As lentes de ortoceratologia combinadas com colírio atropina 0,01% podem melhorar significativamente o efeito controle em miopia juvenil com elevada segurança.

Resultados visuais, topográficos e refrativos do implante de segmentos assimétricos de anel corneano intraestromal em ceratocone / Visual, topographic, and refractive outcomes of the implantation of asymmetric segments of the intrastromal corneal ring in keratoconus

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

ABSTRACT Purpose: To evaluate the visual, topographic, and refractive outcomes of the implantation of asymmetric segments (AS) of the ICRS intracorneal ring in eyes with keratoconus and irregular/asymmetric astigmatism (phenotypes type 2 Duck and 3 Snowman by morphological classification of Fernandez-Vega/Alfonso Keratoconus). Methods: Prospective clinical study including 60 patients (60 eyes) with keratoconus who underwent implantation of the Kearing ICRS selected and implanted according to the Mediphacos nomogram (http://kearing.online) with femtosecond laser. Preoperative and postoperative evaluations included uncorrected visual acuity, best corrected visual acuity, refractive astigmatism, spherical equivalent, and topographic astigmatism, Kmax, and coma measured with the Galilei (Ziemer, Port, Switzerland). All parameters were assessed preoperatively and at 3 and 6 months postoperatively. Results: Overall mean age was 26.34 ± 8.49 years; 28 (56.7%) were female, 34 eyes had keratoconus of type 2 phenotype and another 26 eyes of type 3 phenotype. At 6 months postoperatively, eyes with type 2 phenotype obtained gains in uncorrected visual acuity and best corrected visual acuity of 0.30 LogMAR and 0.15 LogMAR, respectively; and reductions of 2.45D in topographic astigmatism; 2.30D in Kmax; 0.32μm in coma; 1.63D in refractive astigmatism and 1.88D in spherical equivalent. At 6 months, eyes with type 3 phenotype obtained gains in UDVA and CDVA of 0.50 logMAR and 0.10 LogMAR, respectively; and reductions of 3.00D in topographic astigmatism; 5.20D in Kmax; 0.09μm in coma; 2.00D in refractive astigmatism and 4.25D in spherical equivalent. The results of the comparisons at 3 and 6 months postoperatively were not statistically significant for any of the variables evaluated, which denotes the stability of the procedure in this follow-up time. Conclusion: Implantation of the asymmetric Kearing in eyes with keratoconus and asymmetric/irregular astigmatism (type 2 and 3 phenotypes) improved visual, topographic, and refractive parameters with safety and clinical efficacy.

Treatment of irregular astigmatism by topography-guided ablation / Tratamento do astigmatismo irregular por ablação guiada por topografia

ABSTRACT Topography-guided ablation was designed to improve corneal regularity throughout the correction of corneal high order aberrations. The present report described three cases with different indications for topography-guided ablation to correct irregular astigmatism. The patients were monitored in the immediate and late postoperative periods to evaluate long-term corneal stabilization. Surgery indications were based on the patient's complaint of poor quality of vision associated with previous radial keratotomy, corneal transplant, or keratoconus. In all three cases, the patients reported an improvement in the quality of their vision and expressed satisfaction with the procedure; however, the patient who had previously been submitted to crosslinking presented with keratoconus progression in the late postoperative period. Finally, topography-guided customized ablation appears to represent a safe and effective technique for reducing corneal irregularities.

RESUMO A ablação guiada por topografia foi projetada para melhorar a regularidade da córnea durante a correção de aberrações de alta ordem da córnea. O presente relato descreveu três casos com diferentes indicações de ablação guiada por topografia para correção de astigmatismo irregular. Os pacientes foram monitorados no pós-operatório imediato e tardio para avaliar a estabilização corneana em longo prazo. As indicações cirúrgicas basearam-se na queixa do paciente de má qualidade de visão associada a ceratotomia radial prévia, transplante de córnea ou ceratocone. Nos três casos, os pacientes relataram melhora na qualidade da visão e manifestaram satisfação com o procedimento; entretanto, o paciente que já havia sido submetido ao crosslinking apresentou progressão do ceratocone no pós-operatório tardio. Finalmente, a ablação personalizada guiada por topografia parece representar uma técnica segura e eficaz para reduzir irregularidades da córnea em córneas não ectásicas.

Corneal topographic alterations in women with endometriosis: data analysis in an ophthalmologic clinic / Alterações topográficas corneanas em mulheres portadoras de endometriose: análise de dados em uma clínica oftalmológica

ABSTRACT Objective: To verify whether there are pathological dysfunctions in the cornea of patients with endometriosis. Methods: Case-control research with a quantitative approach that compared topographic and tomographic examinations of the cornea of patients with a laparoscopic diagnosis of endometriosis, without the use of hormonal medications, to the control group. Results: We analyzed 78 eyes, 34 from the endometriosis group and 44 from the control group. The loss of orthogonality between the axes of the corneal curvatures was more frequent in the group with endometriosis (p = 0.0744). The difference between the mean keratometric measurements of the two eyes was significantly greater in the control group (p = 0.0204). In the tomographic findings, the group with endometriosis presented higher means of posterior elevation compared to the control group (p = 0.0060). Conclusion: The results do not allow us to conclude that women with endometriosis have a higher risk of developing corneal ectasia, although the posterior elevation map demonstrated a greater posterior curvature of the cornea in this group, with a statistically significant difference. However, an isolated increase in the posterior elevation map does not have good diagnostic accuracy.

RESUMO Objetivo: Verificar se há disfunções patológicas na córnea de pacientes portadoras de endometriose. Métodos: Pesquisa do tipo caso-controle de abordagem quantitativa, que comparou exames topográficos e tomográficos da córnea de pacientes com diagnóstico laparoscópico de endometriose, sem uso de medicações hormonais, ao grupo controle. Resultados: Foram analisados 78 olhos, 34 do grupo com endometriose e 44 do grupo controle. A perda da ortogonalidade entre os eixos das curvaturas corneanas foi mais frequente no grupo com endometriose (p = 0,0744). A diferença entre as médias das medidas ceratométricas dos dois olhos foi significativamente maior no grupo controle (p = 0,0204). Nos achados tomográficos, o grupo com endometriose apresentou maiores médias de elevação posterior em relação ao controle (p = 0,0060). Conclusão: Os resultados não permitem concluir que portadoras de endometriose têm maior risco de desenvolver ectasia corneana, embora o mapa de elevação posterior tenha demonstrado maior curvatura posterior da córnea nesse grupo, com diferença estatisticamente significativa. Contudo, um aumento isolado no mapa de elevação posterior não possui boa acurácia diagnóstica.

Asimetría interocular en el queratocono pediátrico / Interocular Asymmetry in Pediatric Keratoconus

El queratocono es una ectasia corneal bilateral asimétrica, en etapas iniciales no se evidencia la afectación binocular. El conocimiento del grado de asimetría en el queratocono pediátrico permite tomar decisiones oportunas en el manejo de los pacientes. Se realizó este trabajo con el objetivo de describir las características clínicas y el tratamiento de tres casos pediátricos con diferente grado de asimetría interocular del queratocono, atendidos en la consulta provincial de ectasias corneales pediátricas en Ciego de Ávila. Los pacientes mostraron diferencia entre ambos ojos de los signos clínicos, la refracción y las variables topográficas. Al paciente dos se le diagnosticó queratocono en un ojo, sin evidencias clínicas ni topográficas de la enfermedad en el ojo contralateral. Todos los pacientes mostraron astigmatismo miópico compuesto en ambos ojos y se les indicó corrección óptica. Al paciente uno se le corrigió con cristales, al dos con lentes de contacto rígidos de gas permeable y al tercero con piggyback en un ojo y lentes de contacto rígidos de gas permeable en el otro. Presentaron, además, una ambliopía asociada y se les orientó tratamiento oclusivo y tareas de visión cercana en los pacientes dos y tres. Es frecuente encontrar asimetría interocular en pacientes pediátricos con queratocono por la diferencia de progresión entre ambos ojos. El seguimiento periódico permite diagnosticar la enfermedad en el ojo contralateral en pacientes con diagnóstico de queratocono en un ojo, indicar una corrección óptica individualizada, sobre todo en presencia de anisometropía, y monitorizar la evolución de la ambliopía refractiva asociada con frecuencia(AU)

Keratoconus is an asymmetric bilateral corneal ectasia, in early stages binocular involvement is not evident. Knowledge of the degree of asymmetry in pediatric keratoconus allows timely decisions in patient management. This research was carried out with the objective of describing the clinical characteristics and the treatment of three pediatric cases with different degree of interocular asymmetry of keratoconus, treated in the provincial consultation of pediatric corneal ectasia in Ciego de Avila. Patients showed difference between both eyes in clinical signs, refraction and topographic variables. Patient two was diagnosed with keratoconus in one eye, with no clinical or topographic evidence of the disease in the contralateral eye. All patients showed compound myopic astigmatism in both eyes and optical correction was indicated. Patient one was corrected with glasses, patient two with rigid gas permeable contact lenses and patient three with piggyback in one eye and rigid gas permeable contact lenses in the other eye. They also presented an associated amblyopia and were directed occlusive treatment and near vision tasks in patients two and three. It is common to find interocular asymmetry in pediatric patients with keratoconus due to the difference in progression between the two eyes. Periodic follow-up makes it possible to diagnose the disease in the contralateral eye in patients diagnosed with keratoconus in one eye, to indicate individualized optical correction, especially in the presence of anisometropia, and to monitor the evolution of frequently associated refractive amblyopia(AU)

Ten-year follow-up of corneal cross-linking and refractive surface ablation in patients with asymmetric corneal topography.

Purpose: Compare the safety and efficacy of wavefront-guided photorefractive keratotomy (PRK) 6 months after cross-linking (CXL) to wavefront-guided PRK alone for refractive correction in patients with bilateral asymmetric corneal topography. Methods: Prospective randomized clinical trial with 16 patients (32 eyes). CXL with subsequent PRK after 6 months in one eye, and PRK alone was performed in contralateral eyes. The follow-up was 10 years. We analyzed visual outcomes, Scheimpflug topography, and corneal haze evaluation. Results: Eyes in the PRK group showed better results than in the CXL + PRK group. Mean postoperative CDVA was 0.044 logmar (SD, 0.073) in the PRK group and 0.1 logmar (SD, 0.21) in the CXL + PRK group, the mean sphere was + 0.21 (SD, 0.6) D in the PRK group and 0.87 (SD, 2.3) D in the CXL + PRK group, and mean SE was -0.35 (SD, 0.65) D in the PRK group and 0.62 (SD, 2.32) D in the CXL + PRK group. In one patient, a steepening of 2.5 D and a thinning of 17 µm occurred in PRK alone group. Two patients in the CXL + PRK group presented corneal haze. The overall complication rate was 18,75% (haze and ectasia). Conclusion: Non-simultaneous CXL and PRK procedures yielded good refractive results, but worse than those obtained with PRK alone. Although one patient in the PRK group developed corneal ectasia, the CXL + PRK group had a higher loss of vision lines, indicating less safety.

Comparação entre os resultados do implante de um segmento de arco longo versus dois segmentos de arco tradicional no tratamento de pacientes com ceratocone / Comparison between the results of implanting a long-arch segment versus two standard arch segments for treatment of keratoconus patients

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

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

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.

Agreement between corneal diameter measurements obtained with an optical biometer and a Placido-based topographer / Acordo de medições do diâmetro da córnea obtidas por um biômetro óptico e um topógrafo com base em Plácido

ABSTRACT Purpose: The purpose of this study was to compare the white-to-white distance measurements of two devices (IOL Master 500 and Atlas corneal topographer) commonly used in clinical practice to determine if they were interchangeable. Providing information on instrument interchangeability could eliminate several unnecessary tests and consequently reduce the economic burden for the patient and society. Methods: In this prospective, comparative case series, the white-to-white distance was measured by independent examiners using the Atlas topographer (Carl Zeiss Meditec) and the IOL Master 500 (Carl Zeiss Meditec). One eye each of 184 patients was tested. Statistical analyses were performed using a paired t-test, Pearson correlation analysis, and Bland-Altman analysis to compare the measurement methods. Results: The mean white-to-white distance measurements with the Atlas topographer and the IOL Master 500 were 12.20 ± 0.44 mm and 12.12 ± 0.41 mm, respectively (p<0.001). The mean white-to-white difference between the two devices was 0.07 mm (95% confidence interval of mean difference: 0.04-0.11 mm). The Pearson correlation coefficient between the two devices was 0.85 (p<0.0001). The 95% limits of agreement between the two devices were -0.38 mm to 0.53 mm. Conclusions: The Atlas topographer and IOL Master 500 can be used interchangeably with respect to white-to-white distance measurements, as the range of differences is unlikely to affect clinical practice and decision making.

RESUMO Objetivo: O objetivo deste estudo é comparar as medições de diâmetro corneano de dois dispositivos normalmente utilizados na prática clínica (IOL Master 500 e Atlas topógrafo corneal) para ver se são permutáveis. O fornecimento de informações sobre a permutabilidade de instrumentos poderia eliminar vários testes desnecessários e, consequentemente, reduzir a carga econômica para o paciente e para a sociedade. Métodos: Nesta série de casos prospectivos e comparativos, a distância do diâmetro corneano foi medida por examinadores independentes utilizando o Topógrafo Atlas (Carl Zeiss Meditec) e o IOL Master 500 (Carl Zeiss Meditec), em um olho de 184 pacientes. A análise estatística foi realizada utilizando o teste t pareado, a correlação Pearson e a análise Bland-Altman para comparar os métodos de medição. Resultados: As medições médias da distância do diâmetro corneano com o topógrafo Atlas e o IOL Master 500 foram de 12,20 ± 0,44 mm e 12,12 ± 0,41 mm, respectivamente (p<0,001). A diferença média de WTW entre os dois dispositivos foi de 0,07 mm (intervalo de confiança de 95% da diferença média: 0,04 - 0,11 mm). O coeficiente de correlação Pearson entre os dois dispositivos foi de 0,85, p<0,0001. Os limites de concordância de 95% entre os dois dispositivos foram de -0,38 mm a 0,53 mm. Conclusões: O Atlas topographer e o IOL Master 500 podem ser utilizados permutavelmente em relação à medição do diâmetro corneano, uma vez que a gama de diferenças encontradas é pouco susceptível de afetar a prática clínica e a tomada de decisões.

Development of an application for providing corneal topography reports based on artificial intelligence / Criação de aplicativo para confecção de laudos de topografia corneana baseado na inteligência artificial

ABSTRACT Purpose: To develop an application (TopEye) in the iOS platform for mobile devices to allow the capture and interpretation of color maps generated by corneal topographers using artificial intelligence. Methods: In the execution, follow-up, and assessment of the project, we used the Scrum methodology and interactive and incremental development process for the project management and agile software development. The ge nerated diagnostic pattern bank consists of 1,172 examples of corneal topography, divided into 275 spherical, 302 symmetrical, 295 asymmetrical, and 300 irregular patterns (keratoconus). For the development of the artificial intelligence of the application, network training was established with 240 images of each pattern type, with a total of 960 patterns (81.91%). The remaining 212 images (18.09%) were used to test the application and will be used for the results. The process is semi-automatic, so the topographic image is captured with a smartphone, the examiner performs the contour of the corneal relief manually, and then the neural network performs the diagnosis. Results: The application diagnosed 201 cases (94.81%) correctly. In 212 images, the algorithm missed the classification of 11 cases (5.19%). The major error that occurred was in distinguishing between symmetrical and asymmetrical classes. In keratoconus screening, the application reached 95.00% sensitivity and 98.68% specificity. Conclusion: The work resulted in obtaining an efficient application to capture topographic images using a smartphone camera and their interpretations through applied artificial intelligence.

RESUMO Objetivo: Desenvolver um aplicativo (TopEye) na plataforma iOS para dispositivos móveis que possibilite a captação e interpretação do mapa de cores gerados por qualquer topógrafo corneano através da inteligência artificial (IA). Metodos: A execução, acompanhamento e avaliação do projeto foi utilizada a metodologia Scrum, processo de desenvolvimento interativo e incremental para gerenciamento de projetos e desenvolvimento ágil de software. O banco de padrões de diagnóstico gerado consiste em 1172 exemplos, divididos em: 275 padrões esféricos, 302 regulares simétricos, 295 regulares assimétricos e 300 irregulares (ceratocone). Para o desenvolvimento da inteligência artificial do aplicativo, foi estabelecido o treinamento da rede com 240 imagens de cada tipo de padrão, totalizando 960 (81,91%) padrões. O restante das imagens, 212 (18,09%), foram utilizadas para testar o aplicativo e usadas para gerar os resultados. O processo é semiautomático, assim a captação da imagem topográfica é realizada com smartphone, o examinador realiza o contorno do relevo corneano manualmente para em seguida a rede neural realizar o diagnóstico. Resultados: O aplicativo diagnosticou 201 (94,81%) imagens corretamente. De um total de 212 imagens, o algoritmo errou a classificação de apenas 11 (5,19%). A principal ocorrência de erro foi na distinção das classes simétrica e assimétrica. No rastreio do ceratocone o aplicativo alcançou 95,00% de sensibilidade e 98,68% especificidade. Conclusão: O trabalho resultou na obtenção de um aplicativo eficiente na captura da imagem topográfica pela câmera do smartphone e na interpretação da mesma através da inteligência artificial aplicada.

Dual-Scheimpflug-Placido-disc corneal analysis in cats.

OBJECTIVE: To evaluate the corneal topography and tomography of cats using a dual Scheimpflug and Placido disc device. ANIMAL STUDIED: Sixteen mixed-breed cats (32 eyes). PROCEDURE(S): Cats were sedated using meperidine (4.3 mg/kg/IM) and xylazine (0.5 mg/kg/IM), and evaluated using the software Galilei™. Values assessed included anterior and posterior corneal curvature, total corneal power, and corneal thickness. RESULTS: Ten males and six females aged between 18 and 48 months were evaluated. The simulated keratometry (SimK) was 38.37 ± 0.83D, mean posterior keratometry -4.89 ± 0.34D, and mean total corneal power 38.04 ± 0.94D. The mean central corneal thickness (CCT) was 617.34 ± 53.38 µm with a mean thinnest point of 583.74 ± 60.60 µm. CONCLUSION: The Galilei™ examination was feasible in cats, enabling a detailed study of the cornea. To the best of our knowledge, this is the first study evaluating the corneal topography and tomography of cats using a device that integrates data from a dual Scheimpflug and Placido disc system.