Corneal ectasia following photorefractive keratectomy: a confocal microscopic case report and literature review / Ectasia corneana após ceratectomia fotorrefrativa: relato de caso de microscopia confocal e revisão da literatura

ABSTRACT The occurrence of corneal ectasia after photorefractive keratectomy is a rare but serious complication of refractive surgery. Possible risk factors are not well assessed, but a probable reason is the failure to detect keratoconus preoperatively. In this report, we describe a case of corneal ectasia after photorefractive keratectomy in a patient who presented a suspicious tomography pattern preoperatively but had no degenerative alterations associated with pathologic keratoconus, as revealed by in vivo corneal confocal microscopy. We also review eligible case reports of post-photorefractive keratectomy ectasia to find similar characteristics.

RESUMO A ocorrência de ectasia corneana após ceratectomia fotorrefrativa é uma complicação rara, porém grave, em cirurgia refrativa. Os possíveis fatores de risco não são bem avaliados, mas a opinião atual é que a falha na detecção de ceratocone pré-operatório possa ser o principal motivo. Neste relato, descrevemos um caso de ectasia corneana após ceratectomia fotorrefrativa em paciente apresentando padrão tomográfico suspeito no pré-operatório, mas sem alterações degenerativas associadas a ceratocone patológico, conforme revelado por microscopia confocal in vivo da córnea. Além disso, revisamos, na literatura, relatos de casos elegíveis de ectasia pós-ceratectomia fotorrefrativa para encontrar características semelhantes.

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

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

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

Clinical outcomes of epithelial ingrowth following laser in situ keratomileusis with mechanical debridement and compressed heating air flow: a case series / Resultado visual do tratamento do crescimento epitelial após laser in situ ceratomileuse através da remoção mecânica e aplicação de ar comprimido aquecido: série de casos

ABSTRACT Purpose: To describe the clinical outcomes of manual scraping of epithelial ingrowth followed by compressed heating air flow after laser in situ keratomileusis (LASIK). Methods: We underwent a retrospective, noncomparative, and interventional case series. Twenty eyes of 17 patients were included in this study. Each patient with a history of LASIK underwent epithelial removal with mechanical debridement followed by compressed heating air flow. Our primary outcome was the recurrence of epithelial ingrowth after 3 months of follow-up, while our secondary outcomes were uncorrected distance visual acuity, corrected distance visual acuity, and complications after surgery. Results: Ten patients (58.8%) were male, and eight eyes of seven (41.2%) patients underwent primary LASIK surgery, while12 eyes of 10 patients had flap-lift retreatment LASIK; sixteen eyes (80.0%) underwent mechanical microkeratome LASIK and four (20.0%) underwent femtosecond laser-assisted LASIK. Mean age at surgical removal of epithelial ingrowth was 37.0 years ± 9.3 years (range 24 to 55 years). There was recurrence of ingrowth in two eyes (10%) after 3 months of follow-up. The mean corrected distance visual acuity of patients before surgery was 0.07 ± 0.09 logMAR, and after the last follow-up was 0.02 ± 0.04 logMAR (p=0.06). The odds ratio of presenting with epithelial ingrowth after LASIK enhancement compared to primary LASIK was 29.41. Conclusion: Manual scraping followed by compressed heating air flow is a safe and effective treatment of clinically significant epithelial ingrowth after LASIK. At the last follow-up, no eye lost any line in corrected distance visual acuity.

RESUMO Objetivo: Descrever os resultados clínicos do tratamento do crescimento epitelial através da técnica de remoção manual seguido da utilização de um compressor de ar comprimido aquecido após a cirurgia de laser in situ keratomileusis (LASIK). Métodos: Vinte olhos de 17 pacientes foram incluídos no estudo. Cada paciente havia sido submetido a cirurgia de LASIK com presença de crescimento epitelial e foi submetido a tratamento cirúrgico para sua retirada. O objetivo primário foi identificar a presença de crescimento epitelial recorrente ao final de 3 meses de seguimento. Os objetivos secundários foram as medidas de acuidade visual sem correção, acuidade visual com correção, e complicações pós-operatórias. Resultados: Dez pacientes (58,8%) eram homens e 7 mulheres. Oito olhos de sete (41,2%) pacientes apresentavam cirurgia de LASIK primária e 12 olhos de 10 pacientes tinham cirurgia de LASIK com retratamento; dezesseis olhos (80%) utilizaram microcerátomo manual e quatro (20%) laser de femtosegundo. A média de idade no momento da cirurgia de remoção do epitélio era de 37,0 anos ± 9,3 (DP) (variando de 24 a 55 anos). Ocorreu recidiva do crescimento epithelial em dois olhos (10%) após 3 meses de seguimento. A acuidade visual sem correção antes da cirurgia era de 0,07 ± 0,09 logMAR, e após a cirurgia passou para 0,02 ± 0,04 logMAR (p=0,06). A chance (odds ration) de aparecimento do crescimento epithelial após uma reoperação de LASIK é 29,41 vezes maior do que no LASIK primário. Conclusão: A técnica de remoção epitelial manual seguida da utilização de ar comprimido aquecido é segura e efetiva no tratamento do crescimento epitelial após LASIK. Ao final do último acompanhamento, nenhum olho apresentou perda de linhas de visão.

Femtosecond laser-assisted laser in situ keratomileusis for the correction of high myopia in Meesmann corneal dystrophy: a case report / Femto-LASIK para correção de alta miopia na distrofa corneana de Meesmann: relato de caso

ABSTRACT The patient was a 26-year-old woman who had manifest refraction and uncorrected and corrected distance visual acuities of -7.00 × -4.50 at 175°, 20/400, and 20/25, respectively, in the right eye, and -3.25 × -5.25 at 179°, 20/200, and 20/25, respectively, in the left eye. In the right and left eyes, the mean corneal thicknesses were 733 and 749 µm, and the maximum epithelial thicknesses were 70 and 68 µm, respectively. Myriads of intraepithelial cysts were observed in the slit-lamp examination. At 30 months after femtosecond laser-assisted laser in situ keratomileusis (femto-LASIK), the manifest refraction and uncorrected and corrected distance visual acuities were respectively 0.00 × -1.25 at 55°, 20/25, and 20/20 in right eye, and 0.00 × -0.50 at 135°, 20/20, and 20/20 in the left eye. In this case of Meesmann dystrophy, myopia was successfully treated with thick flap femto-LASIK without complications or ectasia.

RESUMO A paciente era uma mulher de 26 anos com refração manifesta, acuidade visual para longe não corrigida e corrigida de -7,00 × -4,50 a175°, 20/400 e 20/25 no olho direito e -3,25 × -5,25 a 179°, 20/200 e 20/25 no olho esquerdo. A espessura média da córnea foi de 733 e 749 µm, e a espessura epitelial máxima foi de 70 e 68 µm, respectivamente no olho direito e no esquerdo. Inúmeros cistos intraepiteliais foram observados no exame com lâmpada de fenda. Trinta meses após o femto-LASIK, a refração manifesta, a acuidade visual para longe não corrigida e corrigida eram respectivamente de 0,00 × -1,25 a 55°, 20/25 e 20/20 no olho direito e 0,00 × -0,50 a 135°, 20/20 e 20/20 no olho esquerdo. Neste caso de distrofia de Meesmann, a miopia foi tratada com sucesso com femto-LASIK de retalho espesso sem complicações ou ectasia.

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

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

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

Ablação personalizada guiada por frente de onda após complicação na dissecção lamelar de FemtoLasik / Personalized wavefront-guided ablation after complication in FemtoLasik lamella dissection

RESUMO O FemtoLasik é uma das técnicas mais empregadas em cirurgia refrativa, por seus bons resultados refracionais, sua previsibilidade, sua reprodutibilidade e sua segurança. Tem alto grau de satisfação, com rápida recuperação visual. Apesar de as taxas de complicações do FemtoLasik serem pequenas, intercorrências podem existir. O objetivo deste trabalho foi relatar um caso de uma complicação na dissecção da lamela por Lasik com laser de femtossegundo com consequente rasgadura da lamela, sendo aplicado Excimer Laser com mitomicina C 0,02%. O retratamento foi realizado com ablação de superfície (ceratectomia fotorrefrativa) guiada por frente de onda, evoluindo com boa qualidade visual final.

ABSTRACT Femtolasik is one of the most used techniques in refractive surgery due to good refractive results, predictability, reproducibility, and safety, achieving excellent results and a high degree of satisfaction. Although the complication rates are small, it is worth noting that there may be intercurrences. The objective of this work is to report a case of complication in the dissection of the lamella of laser in situ keratomileusis (Lasik) with Femtosecond laser, and subsequent lamella tear. Excimer Laser was applied with mitomycin 0.02% and re-approached with wavefront guided surgery, evolving with good final visual quality.

Exérese de pterígio em paciente pós-LASIK com técnica de air bubble / Pterygium surgery with air bubble technique in a post-LASIK patient

RESUMO O pterígio é uma das doenças que mais acomete a superfície ocular, principalmente em regiões próximas ao Equador. Ocorre principalmente em adultos jovens, podendo ocasionar sintomas, danos estéticos e ópticos. Relata-se um caso de exérese de pterígio classificado pela extensão corneana em grau II e, pela vascularização, em grau 2 de Tan, com cirurgia prévia de LASIK, a partir de uma nova técnica, a técnica de Moscovici, a qual fundamenta-se na dissecção com bolha de ar, com a finalidade de separar o epitélio conjuntival do estroma profundo e da Tenon, com maior facilidade e rapidez e para obter enxertos finos.

ABSTRACT Pterygium is one of the diseases that most affect the ocular surface, especially in regions close to the equator. It mainly affects young adults and can cause symptoms, as well as aesthetic and optical impairment. We report a case of pterygium excision classified by grade II corneal extension and Tan grade 2 vascularization with previous laser in situ keratomileusis (LASIK) surgery, using a new technique, the Moscovici technique, which is based on dissection with an air bubble to separate easier and faster the conjunctival epithelium from the deep stroma and the Tenon, obtaining thinner grafts.

Laser topoguiado como tratamento de ectasia pós lasik / Topoguided laser as treatment of ectasia after lasik

RESUMO O laser in situ keratomileusis (LASIK) é o método cirúrgico refrativo mais realizado no mundo com excelentes resultados, porém tal método não é isento de riscos. A ectasia pós LASIK é uma complicação grave e se caracteriza por um aumento progressivo da curvatura e afinamento da córnea, resultando em astigmatismo irregular e diminuição da acuidade visual. Sua incidência na literatura atual é de aproximadamente 0,033%. O principal tratamento dessa complicação é o implante de anel intra-estromal com cross-linking. Neste artigo descrevemos um caso de uma mulher de 45 anos submetida a sucessivas tentativas de tratamento de ectasia pós LASIK, com implante de anel intra-estromal bilateral, sem sucesso em um dos olhos. Foi feito o uso do excimer laser topoguiado através do photorefractive keratectomy (PRK) sem o cross-linking, que optamos por não realizar pela estabilidade há anos, pelo risco alto de haze e pela ablação apenas na lamela (que era espessa).A paciente obteve melhorasignificativa da visão e da qualidade de vida. Mantemos o acompanhamento a cada seis meses desde então com a tomografia da córnea.

ABSTRACT The laser in situ keratomileusis (LASIK) is the most widely used refractory surgical method in the world with excellent results, but this method is not without risks. Post-LASIK ectasia is a serious complication and is characterized by a progressive increase in curvature and thinning of the cornea, resulting in irregular astigmatism and decreasing visual acuity. Its incidence in the current literature is approximately 0.033%. The main treatment for this complication is the implantation of an intra-stromal ring with crosslinking. In this article, we describe a case of a 45-year-old woman who underwent successive attempts to treat post-LASIK ectasia, with bilateral intra-stromal ring implantation, with no success in the eyes. Excimer laser was used, made through photorefractive keratectomy (PRK) without cross-linking and the patient obtained significant improvement in vision and in quality of life.

Corneal suture for acute corneal hydrops secondary to post-LASIK ectasia: a case report / Sutura corneana em hidrópsia aguda secundária à ectasia pós LASIK: relato de caso

ABSTRACT Corneal ectasia is one of the main complications of keratorefractive procedures. In this report, we describe a case of corneal ectasia after laser-assisted in situ keratomileusis), which progressed with acute hydrops and aqueous leakage and required a suture for correction.

RESUMO A ectasia corneana é uma das principais complicações das cirurgias refrativas. Neste caso, descrevemos um caso de ectasia corneana induzida por laser-assisted in situ keratomileusis, que evoluiu com hidrópsia aguda e extravasamento de humor aquoso, necessitando de sutura corneana.

Resultados de la queratomileusis subepitelial asistida con láser combinada con el uso de mitomicina C / Results of the laser-assisted subepithelial keratomileusis combined with the use of mitomycin C

RESUMEN Fundamento: los defectos de refracción pueden ser corregidos mediante cirugía refractiva. Objetivo: describir los resultados de la queratomileusis subepitelial asistida con láser combinada con el uso de mitomicina C. Métodos: se realizó un estudio descriptivo, prospectivo en la consulta de Cirugía Refractiva del Centro Oftalmológico del Hospital Universitario Manuel Ascunce Domenech, en la provincia Camagüey desde marzo de 2016 a marzo de 2017. El universo de estudio estuvo constituido por 91 pacientes (178 ojos) que acudieron a la consulta con diagnóstico de miopía o astigmatismos miópicos simples o compuestos que cumplían con los criterios de inclusión, se les aplicó un formulario para recoger los datos. Los resultados incluyeron las siguientes variables: agudeza visual sin corrección, mejor corregida y equivalente esférico, preoperatorio y postoperatorio al mes, tres, seis y doce meses y complicaciones postoperatorias. Resultados: fue más frecuente el grupo de edades entre 20 y 30 años, el sexo femenino y el astigmatismo miópico compuesto. La agudeza visual sin corrección y mejor corregida se equipararon al año de la cirugía, y el equivalente esférico disminuyó de forma representativa al aproximarse a la emetropía. La opacidad corneal fue la complicación más frecuente seguida de la desepitelización corneal prolongada. Conclusiones: la agudeza visual mejor corregida preoperatoria y sin corrección posoperatoria se equipararon al año de la intervención quirúrgica. El equivalente esférico disminuyó de forma representativa y se acercó a la emetropía a los doce meses de la cirugía. La opacidad corneal fue la complicación más frecuente seguida de la desepitelización corneal prolongada.

ABSTRACT Background: refractive errors can be corrected by refractive surgery. Objective: to describe the results of the laser-assisted subepithelial keratomileusis combined with the use of mitomycin C. Methods: a descriptive, prospective study was carried out in the Refractive Surgery office of the Ophthalmological Center of the University Hospital Manuel Ascunce Domenech, in Camagüey, from March 2016 to March of 2017. The study universe consisted of 91 patients (178 eyes) who attended the refractive surgery consultation with a diagnosis of myopia and / or simple myopic astigmatisms or compounds that met the inclusion criteria; a form was applied to collect the data. The results were related to the following variables: visual acuity without correction, better corrected and spherical equivalent preoperative and postoperative after a month, three, six and twelve months, and complications. Results: it was most frequent the age group between 20 and 30 years old, the female sex and the composite myopic astigmatism. Visual acuity without correction and better corrected were equated to one year after surgery, and the spherical equivalent decreased in a representative way when approaching emmetropia. Corneal Opacity was the most frequent complication followed by prolonged corneal de-epithelization. Conclusions: the best corrected visual acuity preoperatively and without postoperative correction were equated to the year of the surgical intervention. The spherical equivalent decreased representatively and approached the emmetropia to the twelve months after surgery. Corneal Opacity was the most frequent complication followed by prolonged corneal de-epithelization.

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

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

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

Comparision of visual quality after topography-guided and wavefront-optimized FS-LASIK in myopic eyes / 中华实验眼科杂志

Objective@#To compare the visual quality after topography-guided customized femtosecond laser-assisted in situ keratomileusis (FS-LASIK) and wavefront-optimized FS-LASIK treatment in myopic eyes.@*Methods@#A non-randomized controlled clinical study was performed.Seventy-eight eyes of 39 myopic patients undergoing FS-LASIK in Beijing Tongren Hospital from October 2016 to February 2017 were enrolled in this study and divided into two groups according to each patient's opinion, with matched demography between the two groups.Topography-guided customized FS-LASIK was performed on 42 eyes of 21 myopia in the topography-guided group, and wavefront-optimized FS-LASIK was performed on 36 eyes of 18 patients in the wavefront-optimized group.Visual acuity, refractive error, higher order aberrations (HOAs) and contrast sensitivity(CS) were compared between the two groups before and 6 months after surgery.Written informed consent was obtained from each patient before the operation.This study protocol was approved by Ethic Committee of Beijing Tongren Hospital (No.TRECKY2014-026).@*Results@#The postoperative uncorrected visual acuity (UCVA) levels were eaqual to or better than the preoperative best corrected visual acuity (BCVA) in 95.2% patients in the topography-guided group, and in 94.4% patients in the wavefront-optimized group 6 months after surgery, respectively.There were no significant differences in the spherical equivalent, sphere refraction and cylinder refraction between the two groups (all at P>0.05). The amount of induced coma was significantly lower in the topography-guided group than that in the wavefront-optimized group ([0.07±0.22]μm vs.[0.22±0.16]μm) at 6 mm pupil.LogCS improved under the 12.0 c/d in the background of mesopic in the topography-guided group and decreased under the 18.0 c/d both in the background of mesopic and mesopic + glare in the wavefront-optimized group 6 months after surgery, with signifcant differences between them (all at P<0.05). LogCS values under 6.0, 12.0 and 18.0 c/d in the background of mesopic and 18.0 c/d in the background of mesopic+ glare in the topography-guided group were significantly higher than those in the wavefront-optimized group 6 months after surgery, with significant differences between the two groups (all at P<0.05).@*Conclusions@#Topography-guided FS-LASIK has lower higher-order aberrations and better CS than wavefront-optimized FS-LASIK.

[Regeneration of corneal nerve after SMILE, FS-LASIK and T-PRK surgery and study its relationship with subjective visual quality].

Objective: To explore nerve fiber regeneration and subjective visual quality of patients undergoing small incision lenticule extraction (SMILE) surgery, femtosecond laser-assisted in-situ keratomileusis (FS-LASIK) and transepithelial photorefractive keratectomy (T-PRK), and study their correlation. Methods: This is a prospective cohort study including 55 patients (6 male, 49 female, age 25.6±7.3, in total 109 eyes) who chose refractive surgery in Peking Union Medical College Hospital. They are subdivided into 3 groups: 35 patients in SMILE (4 male, 31 female), 9 patients in FS-LASIK (1 male, 8 female) and 11 patients in T-PRK (1 male, 10 female). All surgeries were conducted by the same surgeon. Patients underwent confocal microscopy examinations and filled in subjective visual quality questionnaires before surgery and 7 days, 30 days and 90 days after surgery. ACCMterics V.2 was used for nerve analysis. One-way analysis of variance, Kruskal-Wallis H test and Pearson correlation study was adopted for data analysis on SPSS 22.0. Results: Corneal nerve fiber density is lowest at 7 days after surgery. The nerve fiber length (8.53 (7.32), 9.33 (6.47), 10.98 (4.85) mm/mm(2), χ(2)=9.21, 8.15, 6.54; P<0.05), density (12.50 (12.50), 12.50 (12.50), 18.75 (14.06)/mm(2), χ(2)=6.54, 9.02, 7.01; P<0.05) and total branch density (18.75 (31.25), 24.99 (29.69), 31.25 (32.81)/mm(2), χ(2)=10.23, 7.63, 10.01; P<0.05) of SMILE group are significantly higher than the other 2 groups at 7 days, 30 days and 90 days after surgery. The subjective visual quality scores are (4.13±0.61), (3.54±0.71), (4.03±0.70) and (4.20±0.58) respectively at each visit, with 7 days being the lowest (F=1.51, P=0.23), but there is no statistically significant difference between each group at each visit. At 7 days after surgery, the nerve fiber length (CNFL) and nerve fiber density (CNBD) show strong positive correlation with overall subjective visual quality (r=0.378, 0.504; P<0.05), while there exists no significant correlation between nerve fiber parameters and subjective visual quality 30 days and 90 days after surgery. Conclusions: SMILE shows better results in corneal nerve fiber regeneration. Corneal nerve fiber density of early post-operational period is positively correlated with overall subjective visual quality. (Chin J Ophthalmol, 2018, 54: 737-743).

Thickness and immunohistochemistry of LASIK flaps created by different femtosecond lasers in eye-bank corneas / Espessura e imunohistoquímica de flap de LASIK criado com diferentes laseres de femtosegundo em córneas de banco de olhos

ABSTRACT Purpose: The aim of this study was to compare the corneal cell viability and thickness of LASIK flaps created by 3 femtosecond lasers in eye-bank human corneas. Methods: Forty-five eye-bank human sclerocorneal buttons (15 corneas in each group) were examined after the creation of 120 mm-thick laser-assisted keratomileusis (LASIK) flaps with 150kHz iFS In­traLase™ (IL), Z6 Femto LDV™ (LDV), or 200kHz Wavelight™ FS200 (FS200). The thickness of the flaps was measured using anterior segment optical coherence tomography (AS-OCT; Visante™). Cell viability was blindly evaluated with immunohistochemistry for keratocyte apoptosis using anti-caspase 3 antibodies. Results: The standard deviation from the intended flap thickness was less than 10 mm in all the groups. There was a statistically significant difference in corneas treated with LDV and IL with regard to the flap thickness horizontally at +3.00 mm (p=0.0124), -0.5 mm (p=0.0082), and -1.00 mm (p=0.0425) from the corneal vertex and +0.5 mm from the flap edge (p=0.0240), and those treated with LDV and FS200 with regard to the flap thickness horizontally at -0.5 mm from the corneal vertex (p=0.0082). The mean keratocyte apoptosis numbers were 13.09 ± 1.10, 15.59 ± 3.28, and 17.72 ± 1.49 in corneas treated with IL, FS200, and LDV, respectively (p<0.001). Conclusion: All 3 assessed femtosecond lasers provided predictable LASIK flap thickness. The mean stromal keratocyte apoptosis number was low in all groups.

RESUMO Objetivos: Comparar a viabilidade celular e a espessura do disco de LASIK confeccionado por três laseres de femtosegundo, em córneas humanas de banco de olhos. Métodos: Quarenta e cinco botões córneo-esclerais humanos de banco de olhos (15 córneas em cada grupo) foram examinados, após a criação de disco de LASIK com 120 mm de espessura, utilizando-se o iFS IntraLase® 150kHz (IL), o Femto LDV® Z6 (LDV), ou o Wavelight® FS200 200kHz (FS200). Tomografia de coerência óptica do seguimento anterior (OCT Visante®) foi usada para medir a espessura dos discos. A viabilidade celular foi avaliada por meio de imuno-histoquímica para apoptose dos ceratócitos, com anti-caspase 3. Resultados: O desvio padrão da espessura planejada do disco foi inferior a 10 mm em todos os grupos. Houve diferença estatisticamente significante da espessura do disco horizontalmente a +3,00 mm (p=0,0124), -0,5 mm (p=0,0082) e -1,00 mm (p=0,0425), a partir do vértice corneal, e a +0,5 mm (p=0,0240), a partir da borda do disco, em córneas tratadas por LDV e IL, e horizontalmente a -0,5 mm a partir do vértice corneal, entre LDV e FS200 (p=0,0082). A média de apoptose dos ceratócitos foi (13,09 ± 1,10), (15,59 ± 3,28) e (17,72 ± 1,49), em córneas tratadas pelo IL, FS200 e LDV, respectivamente (p<0,001). Conclusão: Todos os três laseres de femtosegundo estudados produziram disco de LASIK com predictibilidade de espessura. A média de apoptose dos ceratócitos foi baixa em todos os grupos.

Focal phototherapeutic keratectomy for the treatment of apical leucoma syndrome / PTK focal para o tratamento da síndrome do leucoma apical

ABSTRACT The following report describes a case of apical leucoma syndrome after hyperopic photorefractive keratectomy following hyperopic laser in situ keratomileusis and the subsequent treatment of this complication with focal phototherapeutic keratectomy. The patient underwent focal transepithelial phototherapeutic keratectomy of 70 mm ablation and 1.5 mm diameter after pupil and ablation offset correction. After 1 year, significant improvement in vision was observed and only slight residual opacity remained on biomicroscopy and optical coherence tomography. Focal phototherapeutic keratectomy was effective and safe for the treatment of this complication.

RESUMO O relato a seguir descreve um caso da síndrome do Leucoma Apical após cirurgia ceratorrefrativa hipermetrópica depois de Laser hiperópico in situ keratomileusis, e o subsequente tratamento desta complicação com ceratectomia fototerapêutica focal. O paciente foi submetido à ceratectomia fototerapêutica focal transepitelial com ablação de 70 mm e diâmetro de 1,5 mm, após correção de offset pupilar. Depois de um ano, foi observada uma melhora significativa da acuidade visual permanecendo apenas leve opacidade residual na biomicroscopia e tomografia de coerência óptica. A ceratectomia fototerapêutica focal foi efetiva e segura para o tratamento desta complicação.

[Advantages and disadvantages of femtosecond laser assisted LASIK and SMILE].

With the development of excimer laser and femtosecond laser equipment, application of diversified and customized surgical decision in modern corneal refractive surgery has been an inevitable trend. However, how to make a personalized decision with an accurate surgical design to achieve better visual quality becomes the main focus in clinical applications. Small-incision lenticule extraction (SMILE) and femtosecond assisted laser in situ keratomileusis (FS-LASIK) have been commonly acknowledged as the mainstream of corneal refractive surgery for ametropia correction nowadays. Both methods have been verified by clinical practice for many years. This article compares and elaborates the different characteristics with advantages and disadvantages of the two methods so as to provide some reasonable treatment options for refractive surgery. (Chin J Ophthalmol, 2018, 54: 7-10).

[Study on the change of optical zone after femtosecond laser assisted laser in situ keratomileusis].

Objective: To explore the change of optical zone after femtosecond laser assisted laser in sitn keratomileusis(FS-LASIK) so as to provide the reference for measurement and design of clinical optical zone. Methods: This retrospective case series study covers 41 eyes of 24 patients (7 males and 17 females, aged from 18 to 42 years old) with myopia and myopic astigmatism who have received FS-LASIK surgery at Corneal Refractive Department of Qingdao Eye Hospital and completed over 6 months of clinical follow-up. Pentacam system (with the application of 6 corneal topographic map modes including: the pure axial curvature topographic map, the pure tangential curvature topographic map, the axial curvature difference topographic map, the tangential curvature difference topographic map, the postoperative front elevation map and the corneal thickness difference topographic map), combined with transparent concentric software (a system independently developed by Qingdao Eye Hospital) was used to measure the optical zone at 1, 3 and 6 months postoperatively, the optical zone diameters measurement results among different follow-up times in group were analyzed with the repeated measures analysis of variance, and the actual measured values and the theoretical design values of the optical zone were analyzed with independent-samples t-testing. Spearman correlation coefficient (r(s)) have been applied to evaluate the relationship between postoperative optical zone measurement values and the potential influencing factors. Results: The optical zone diameters measured by pure axial curvature topographic map at 1, 3 and 6 months after FS-LASIK showed (6.55±0.50)mm, (6.50±0.53)mm and (6.48±0.53)mm respectively. The differences between values are of no statistical significance (F=1.60, P=0.21), the optical zone diameter measured by pure tangential curvature topographic map at 1, 3 and 6 months after FS-LASIK showed (5.44±0.46)mm, (5.46±0.52)mm and (5.44±0.50)mm respectively, the differences between values are of no statistical significance (F=0.17, P=0.85). The optical zone diameters measured by postoperative front elevation map at 1, 3 and 6 months after FS-LASIK showed (5.06±0.28)mm, (5.12±0.32)mm and (5.17±0.28)mm respectively. The differences between the values of 3 and 6 months postoperatively are of no statistical significance (F=6.14, P=0.15), the optical zone diameters measured by axial curvature difference topographic map at 1, 3 and 6 months after FS-LASIK showed (6.51±0.37)mm, (6.45±0.41)mm and (6.41±0.40)mm respectively, and the differences between the values of 3 and 6 months postoperatively are of no statistical significance (F=7.25, P=0.05). The optical zone diameters measured by tangential curvature difference topographic map at 1, 3 and 6 months after FS-LASIK showed (5.21±0.23)mm, (5.16±0.19)mm and (5.17±0.20) mm respectively, and the differences between the values of 1 and 3 months postoperatively are of statistical significance (F=1.75, P=0.04). The optical zone diameters measured by corneal thickness difference topographic map at 1, 3 and 6 months after FS-LASIK showed (6.53±0.40)mm, (6.39±0.43)mm and (6.41±0.47)mm respectively, and the differences between the values of 1 and 3 months postoperatively are of statistical significance (F=1.67, P=0.032). The actual measured optical zone values from the 6 different modes of Pentacam system are less than the theoretical design values (7.75 mm), and the differences were statistical significance (t=-15.42, -29.39, -59.27, -21.47, -81.69, -18.22, P<0.01). Conclusions: The optical zone measurement values tend to be stable at 3 months after FS-LASIK. The actual measured values from all the 6 different modes of Pentacam system were less than the theoretical design values. The results from pure tangential curvature topographic map, the tangential curvature difference topographic map and the postoperative front elevation map showed greater variation with clear border, which was beneficial for eccentric research. The results from pure axial curvature topographic map, the axial curvature difference topographic map and the corneal thickness difference topographic map were close to the theoretically designed values. Furthermore, the axial curvature difference topographic map showed clearer border and less variation thus maybe more favorable for measuring optical zone in clinical application.(Chin J Ophthalmol, 2018, 54: 39-47).

Use of the Ishikawa diagram in a case-control analysis to assess the causes of a diffuse lamellar keratitis outbreak / Aplicando o diagrama de Ishikawa em uma análise caso-controle para identificar as causas de um surto de ceratite lamelar difusa

ABSTRACT Purpose: To identify the causes of a diffuse lamellar keratitis (DLK) outbreak using a systematic search tool in a case-control analysis. Methods: An Ishikawa diagram was used to guide physicians to determine the potential risk factors involved in this outbreak. Coherence between the occurrences and each possible cause listed in the diagram was verified, and the total number of eyes at risk was used to calculate the proportion of affected eyes. Multivariate analysis was performed using logistic regression to determine the independent effect of the risk factors, after controlling for confounders and test interactions. Results: All DLK cases were reported in 2007 between June 13 and December 21; during this period, 3,698 procedures were performed. Of the 1,682 flap-related procedures, 204 eyes of 141 individuals presented with DLK. No direct relationship was observed between the occurrence of DLK and the presence of any specific factors; however, flap-lifting enhancements, procedures performed during the morning shift, and non-use of therapeutic contact lenses after the surgery were significantly related to higher occurrence percentages of this condition. Conclusions: The Ishikawa diagram, like most quality tools, is a visualization and knowledge organization tool. This systematization allowed the investigators to thoroughly assess all the possible causes of DLK outbreak. A clear view of the entire surgical logistics permitted even more rigid management of the main factors involved in the process and, as a result, highlighted factors that deserved attention. The case-control analysis on every factor raised by the Ishikawa diagram indicated that the commonly suspected factors such as biofilm contamination of the water reservoir in autoclaves, the air-conditioning filter system, glove powder, microkeratome motor oil, and gentian violet markers were not related to the outbreak.

RESUMO Objetivos: Identificar as causas de um surto de ceratite lamelar difusa (DLK) uti­lizando uma ferramenta de busca sistemática em uma análise de caso-controle. Métodos: O diagrama de Ishikawa foi usado para orientar os médicos a identificar os potenciais fatores de risco envolvidos neste surto. Coerência entre as ocorrências e cada causa possível listada no diagrama foi verificada. O número total de olhos em risco foi usada para calcular a percentagem de olhos afetados. A análise multivariada foi realizada por meio de regressão logística para determinar o efeito independente dos fatores de risco, controle de fatores de confusão e interações de teste. Resultados: Todos os casos de ceratite lamelar difusa foram relatados em 2007 entre 13 de junho e 21 de dezembro, durante este tempo foram realizados no total 3.698 procedimentos. De um total de 1.682 procedimentos relacionados a confecção de um flap, 204 olhos de 141 indivíduos apresentaram ceratite lamelar difusa. Não foi observada relação direta entre a ocorrência de ceratite lamelar difusa e a presença de qualquer fator específico; no entanto, procedimentos que incluíam um novo levantamento do flap, procedimentos realizados no turno da manhã, e o não-uso de lentes de contato terapêuticas após a cirurgia foram significativamente relacionados com a ocorrência desta complicação. Conclusão: O diagrama de Ishikawa é uma ferramenta de visualização e organização do conhecimento. Essa sistematização permitiu aos investigadores pesquisar todas as possíveis causas do surto de ceratite lamelar difusa. Uma visão clara de toda a logística cirúrgica permitiu a gestão mais rígida dos principais fatores envolvidos no processo. A análise de caso-controle em relação a cada fatores levantados pelo diagrama indicou que fatores sempre suspeitos, tais como: contaminação do biofilme da água do reservatório das autoclaves, sistema de filtro de ar-condicionado, pó de luva, óleo de motor do microcerátomo e marcador violeta de genciana, não foram relacionados com o surto.

[Comparison of the effects of different side-cut angles on corneal biomechanical properties after femtosecond laser assisted-laser in situ keratomileusis].

Objective: To evaluate the effects of side-cut angles on corneal biomechanical properties after femtosecond laser assisted-laser in situ keratomileusis (FS-LASIK). Methods: In this clinical control study, 97 right eyes of 97 patients with myopia and myopic astigmatism undergoing FS-LASIK surgery were included randomly. Two types of side-cut angles were designed for the flap, 90° in 48 eyes and 130° in 49 eyes. The values of corneal resistance factor (CRF), cornea hysteresis (CH) and 37 biomechanical waveform parameters were measured using the ocular response analyzer preoperatively and at 1 and 3 months postoperatively. The comparison between the two groups at different follow-up time points was made with one-way analysis of variance, and the comparison among different follow-up time points in each group was performed with the repeated measures analysis of variance. Results: The mean CRF, CH, p area, h, dive1, dive2, w11 and w21 in both groups showed significant reduction at 1 month postoperatively (group 90°: CRF 10.49 vs. 6.85, CH 10.02 vs. 7.55, p1 area 3 537.54 vs. 1 918.07, h1 404.74 vs. 283.25, dive1 350.63 vs. 243.33, w11 10.50 vs. 7.58. group 130°: CRF 10.14 vs. 6.38, CH 9.93 vs. 7.13, p1 area 3 498.93 vs. 2 038.74, h1 411.93 vs. 304.49, dive1 352.51 vs. 265.12, w11 10.55 vs. 7.78. P<0.001) . The mean CRF, CH, p area, w, h, dive1 and dive2 in both groups showed significant reduction at 3 months postoperatively (group 90°: CRF 10.49 vs. 6.60, CH 10.02 vs. 7.65, p1 area 3537.54 vs. 2042.91, h1 404.74 vs. 307.77, dive1 350.63 vs. 263.33, w11 10.50 vs. 7.58. group 130°: CRF 10.14 vs. 6.45, CH 9.93 vs. 7.67, p1 area 3 498.93 vs. 2 187.97, h1 411.93 vs. 327.39, dive1 352.51 vs. 284.26, w11 10.55 vs. 7.61. P<0.001). The mean path in both groups showed significant increase at 1 and 3 months postoperatively (group 90°: path1 23.14 vs. 30.50 vs. 30.79. group 130°: path1 24.12 vs. 32.18 vs. 31.49. P<0.001). The mean aplhf, bindex, dive2 and path2 between both groups at 1 month postoperatively showed significant difference (F=8.609, 7.482, 5.238, 4.885, P<0.05). The mean path11 between both groups at 3 months postoperatively showed significant difference (F=6.160, P<0.05). Conclusions: Corneal biomechanical properties significantly decrease after FS-LASIK, and different side-cut angles have some effect on corneal biomechanical properties after FS-LASIK. The corneal deformation is more stable after flap creation with an obtuse side-cut angle making the cornea under stress. Combined with waveform parameters of the ocular response analyzer, more subtle changes of corneal biomechanical properties can be found. (Chin J Ophthalmol, 2017, 53:23-32).

A comparative study of visual quality between implantable collamer lens implantation and femtosecond LASIK for myopia / 中华实验眼科杂志

Background The incidence of myopia is gradually increasing,and how to choose a better corrective method of myopia for the best visual demand is very important.Objective This study was to compare visual quality of implantable collamer lens (ICL) implantation with femtosecond laser in situ keratomileusis (FSLASIK) for moderate and high myopia using double-pass optical quality analysis system (OQAS).Methods A non-randomized controlled clinical trail was performed.Fifty-two eyes with-4.00 to-9.00 D of 26 consecutive patients were included in NO.1 Hospital of Xi'an from January 2015 to January 2016.Twenty-four eyes of 12 patients with the corneal thickness ＜500 μm received ICL implantation as ICL group and 28 eyes of 14 patients which corneal thickness was ≥500 μm underwent FS-LASIK surgery as FS-LASIK group.The demography was matched between the two groups (all at P＞0.05).All the patients were followed-up for 3 months after surgery.The preoperative best corrected distance visual acuity (BCDVA),spherical equivalent (SE),postoperative uncorrected distance visual acuity (UCDVA),BCDVA and SE were examined and compared between two groups.The parameters from OQAS were evaluated and intergrouply compared,including the objective scattering inders (OSI),modulation transfer function (MTF) cut off frequency,Strehl ratio and OQAS values under the contrast of 100％,20％ and 9％ (OV100,OV20,OV9).Results The postoperative BCDVA was not significantly different from preoperative UCDVA in both ICL group and FS-LASIK group (-0.04±t0.10 vs.0.05±0.12;-0.07±0.12 vs.0.00±0.12) (t=3.128,2.358,both at P＞0.05).No statistically significant differnces were found in SE,UCDVA and BCDVA after operation between ICL group and FS-LASIK group (t =1.292,0.900,-0.653,all at P＞0.05).OQAS examination showed that MTF cut off,OSI,Strehl ratio,OV100 were not significantly different after operation between ICL group and FS-LASIK group (t=-2.032,-1.440,-0.224,all at P＞0.05).The postoperative OV20 and OV9 were 0.82±0.14 and 0.80±0.21 in the ICL group,which were significantly higher than those in the FS-LASIK group(0.59±0.15 and 0.47±0.13) (t =4.105,4.702,both at P＜0.05).Conclusions Both ICL implantation and FS-LASIK provide good optical and visual quality for moderate to high myopic eyes,and ICL appears to have a better visual quality in comparison with FS-LASIK under the contrasts of 20％ and 9％.