Resultados refractivos y visuales en cirugía fotoablativa en pacientes miopes / Refractive and visual results in photoablative surgery in myope patients

Objetivo: Evaluar los resultados refractivos y visuales post cirugía refractiva corneal con láser de excímero (LASEK-MMC o PRK-MMC) en pacientes miopes con o sin astigmatismo asociado. Método: Se realizó un estudio preexperimental del tipo antes y después, en el que fueron incluidos 81 pacientes (162 ojos) tratados con LASEK-MMC (65 pacientes) o PRK-MMC (16 pacientes) seguidos por tres meses. Se les realizó un examen oftalmológico completo y se evaluaron las variables: edad, sexo, diagnóstico y tipo de miopía, así como agudeza visual, esfera, cilindro, equivalente esférico precirugía y poscirugía. Además, se analizó la función visual y los resultados de la refracción. Resultados: El valor de la mediana de edad fue de 24,0 años en los pacientes tratados con LASEK-MMC y en el grupo con PRK-MMC fue de 23,0 años. En ambos grupos existió un predominio del sexo femenino. La totalidad de los pacientes tratados presentaba un astigmatismo miópico compuesto con niveles de miopía leve. A los tres meses el 96,9 por ciento de los pacientes tratados con LASEK-MMC y el 93,8 por ciento de los tratados con PRK-MMC tenían una agudeza visual no corregida de 20/20 o más y todos tenían una visión de 20/40 o más. Conclusiones: La cirugía fotoablativa con láser tiene buenos resultados refractivos y visuales ya que la mayoría de los pacientes quedaron emétropes con una marcada mejoría de la agudeza visual sin corrección y de la refracción en el posoperatorio(AU)

Objective: To evaluate refractive and visual outcomes after excimer laser corneal refractive surgery (laser-assisted subepithelial keratectomy [LASEK] or photorefractive keratectomy [PRK], with intraoperative application of mitomycin-C [MMC]) in myopic patients with or without associated astigmatism. Methods: A preexperimental, before-and-after study was carried out with 81 patients (162 eyes) treated with LASEK-MMC (65 patients) or PRK-MMC (16 patients) and followed for three months. A complete ophthalmologic examination was done and the following variables age, sex, diagnosis and type of myopia were assessed, as well as pre-surgery and post-surgery visual acuity, sphere, cylinder and spherical equivalent. In addition, visual function and the refraction results were analyzed. Results: The median age was 24.0 years in the LASEK-MMC group and 23.0 years in the PRK-MMC group. In both groups there was a predominance of the female sex. All treated patients had compound myopic astigmatism with mild myopia. At three months, 96.9 percent of patients treated with LASEK-MMC and 93.8 percent of patients treated with PRK-MMC had uncorrected visual acuity of 20/20 or better, and all had vision of 20/40 or better. Conclusions: Laser photoablative surgery has good refractive and visual outcomes as most patients became emmetropic with marked improvement in uncorrected visual acuity and refraction postoperatively(AU)

LASEK-mitomicina C versus PRK-mitomicina C en pacientes con miopía o astigmatismo miópico compuesto / LASEK-mitomycin C versus PRK-mitomycin C in patients with myopia or compound myopic astigmatism

RESUMEN Objetivo: Evaluar los resultados relacionados con la efectividad y la seguridad en el tratamiento con queratectomía subepitelial asistida por láser con mitomicina C versus queratectomía fotorreactiva con mitomicina C en ojos con miopía o astigmatismo miópico compuesto. Métodos: Se realizó un estudio experimental, longitudinal y prospectivo en el Instituto Cubano de Oftalmología Ramón Pando Ferrer entre abril del año 2016 y abril de 2017. Se empleó un muestreo aleatorio simple por el cual se obtuvo la técnica quirúrgica a realizar. El primer ojo operado fue el derecho y a la semana se realizó la cirugía en el ojo izquierdo, en el cual se aplicó la otra técnica quirúrgica. Esto permitió realizar en cada paciente ambas técnicas quirúrgicas. La muestra quedó constituida por 146 ojos (73 pacientes) que cumplían con los criterios de selección. Resultados: El comportamiento preoperatorio entre los dos grupos fue muy similar. En ninguno de los casos existieron diferencias en las variables que se evaluaron (agudeza visual sin corrección, agudeza visual mejor corregida, esfera, cilindro y equivalente esférico). La diferencia entre los valores preoperatorios y los encontrados a los 6 meses del tratamiento quirúrgico en cada grupo fueron estadísticamente significativos (p= 0,000) para todas las variables analizadas, excepto para la agudeza visual mejor corregida en el grupo de ojos tratados con láser con mitomicina C (p= 0,083). El haze y el defecto de epitelización fueron los dos tipos de complicaciones observadas. Conclusiones: Se demostró que ambas técnicas quirúrgicas son efectivas y seguras(AU)

ABSTRACT Objective: Evaluate the effectiveness and safety of laser-assisted subepithelial keratectomy with mitomycin C vs. photoreactive keratectomy with mitomycin C in eyes with myopia or compound myopic astigmatism. Methods: An experimental prospective longitudinal study was conducted at Ramón Pando Ferrer Cuban Institute of Ophthalmology from April 2016 to April 2017. Simple random sampling was used to decide on the surgical technique to be applied. Surgery was first performed on the right eye using one of the techniques, and then one week later on the left eye with the other technique. That way each patient could undergo both surgical techniques. The sample was composed of 146 eyes (73 patients) meeting the inclusion criteria. Results: Preoperative behavior was very similar in the two groups. In neither case were differences found in the variables analyzed (uncorrected visual acuity, best corrected visual acuity, sphere, cylinder and spherical equivalent). The differences between preoperative values and those found six months after surgery in each group were statistically significant for all the variables analyzed (p= 0.000), except for best corrected visual acuity in the group of eyes treated with laser with mitomycin C (p= 0.083). Haze and epithelization defect were the two types of complications observed. Conclusions: It was demonstrated that both surgical techniques are effective and safe(AU)

Investigation of the Changes in Refractive Surgery Trends in Korea

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

Clinical evaluation of LASEK for residual myopia following phakic posterior chamber implantable contact lens implantation in extreme high myopic eyes / 中华实验眼科杂志

Background Phakic posterior chamber implantable contact lens (PPC-ICL) or phakic posterior chamber Toric implantable contact lens (PPC-TICL) implantation is an effective way for the correction of high myopia or high myopia with astigmia,but it often has residual myopic power.Excimer laser-assisted subepithelial keratectomy (LASEK) can correct the residual myopia following PPC-ICL or PPC-TICL,but its effectiveness and safety deserve attention.Objective This study was to analyze the clinical effectiveness and safety of LASEK for residual myopia after PPC-ICL implantation for extreme high myopia.Methods A prospective cases-observational study was performed,and written informed consent was obtained from each patient before any surgery.Fourteen eyes of 9 patients with residual myopia following PPC-ICL or PPC-TICL for the eyes with spherical equivalent refraction of ≥-20.00 D were collected in the Affiliated Hospital of Guizhou Medical University from July 2010 to March 2015,including PPCICL implantation in 8 eyes and PPC-TICL implantation in 6 eyes.LASEK were performed on the eyes to correct the residual myopic power.Uncorrected visual acuity (UCVA),best corrected visual acuity (BCVA),haze,the distance of intraocular lens to lens,corneal thickness,corneal topography,corneal endothelial cell counting,intraocular pressure (IOP) and fundus were examined and compared before and after surgery.The effectiveness and safety of the surgery were evaluated.Results The operation was smooth and no complication was found after surgery in all of the eyes.The UCVA and BCVA were significantly different in the eyes among before surgery,6 months after PPC-ICL implantation and 12 months after LASEK (F =31.360,1.778;both at P＜0.05),and the UCVA after LASEK was higher than BCVA before LASEK.The refractive powers were (-22.27-±4.29),(-3.75±2.25) and (-0.42±0.63) D before surgery,6 months after PPC-ICL implantation and 12 months after LASEK,showing a significant difference among them (F=46.370,P＜0.05),and the refractive power was considerably lower after LASEK than that before surgery and after PPC-ICL implantation (both at P＜0.05).No significant difference was found in IOP or corneal endothelial cell counting in operated eyes among before surgery,6 months after PPC-ICL implantation and 12 months after LASEK (F=1.663,1.055;both at P＞0.05).The distance of intraocular lens to lens was (0.69±0.26)mm in the eyes after LASEK and (0.71 ±0.29)mm in the eyes after PPC-ICL implantation,with no significant difference between them (t =0.192,P＞0.05).Conclusions PPC-ICL or PPC-TICL implantation for the correction extreme high myopia often remains a certain degree of myopia,and LASEK for the correction of residual refractive power is safe and effective.

Clinical study of two kinds of bandage contact lenses after laser - assisted subepithelial keratectomy / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the clinical safety and effectiveness of the two kind of bandage contact lenses: Senofilcon A (Johnson & Johnson Acuvue Oasys) and Balafilcon A ( Bausch& Lomb pure vision ) after laser - assisted subepithelial keratectomy (LASEK). METHODS: Thirty - eight patients (76 eyes) who had undergone the LASEK were divided into two groups. One group of patients wore Balafilcon A, the other group of patients fitted with Senofilcon A. The lenses were worn continuously for 7d. This was a seven - day experience and the patients scored for the symptom of the eyes (sore eyes, foreign body sensation and tearing) on the third day and the seventh day. Both of the two groups of patients taken off the soft contact lens on the seventh day and let their vision and corneal staining checked. RESULTS: The symptoms of eye sore and tearing of the two groups patients were different. The patients who wore the Senofilcon A were better. The pain of eyes were also different at 3 and 7d after surgeries(Z = - 4. 146, P =0. 000; Z= - 2. 814, P = 0. 005). The difference on tearing between the two groups at 3 and 7d after surgeries were significant ( Z = -2. 309, P = 0. 021; Z= -3. 276, P= 0. 001). There was no difference on sensation of dryness between the two groups at 3 and 7d after surgeries (Z= -0. 447, P=0. 655; Z= -0. 966, P = 0. 334). After the lenses were taken off, the visual acuity of patients wearing Senofilcon A was better ( t = 3. 800, P = 0. 001 ); corneal staining showed limited spots in 1- 2 quadrants with significant difference (Z= -2. 384,P= 0. 017). CONCLUSION: The Senofilcon A ( Johnson &Johnson Acuvue Oasys ) and Balafilcon A ( Bausch& Lomb pure vision) bandage contact lenses are safe and effective after LASEK, and the former is better than the latter in epithelial regeneration.

Factors Affecting Long-term Myopic Regression after Laser In Situ Keratomileusis and Laser-assisted Subepithelial Keratectomy for Moderate Myopia

PURPOSE: High myopia is known to be a risk factor for long-term regression after laser refractive surgery. There have been few studies about the correction of moderate myopias that did not need retreatment after long-term follow-up. We evaluated 10 years of change in visual acuity and refractive power in eyes with moderate myopia after laser refractive surgery. METHODS: We included patients that had undergone laser in situ keratomileusis (LASIK) or laser-assisted subepithelial keratectomy (LASEK) to correct their myopia and that had at least 10 years of follow-up. We evaluated the stability of visual acuity in terms of safety, efficacy, and refractive changes at examinations 6 months and 1, 2, 5, 7, and 10 years after surgery. RESULTS: The study evaluated 62 eyes (36 eyes in LASIK patients and 26 eyes in LASEK patients). In both groups, the efficacy index tended to decrease, and it was consistently higher in the LASEK group compared to the LASIK group over the 10 years of follow-up. The safety index improved over 10 years and was always higher than 0.9 in both groups. The difference between the spherical equivalent at 6 months postoperatively and later periods was statistically significant after 5, 7, and 10 years in both groups (LASIK, p = 0.036, p = 0.003, and p < 0.001, respectively; LASEK, p = 0.006, p = 0.002, and p = 0.001, respectively). Ten years after surgery,26 eyes (66.7%) in the LASIK group and 19 eyes (73.1%) in the LASEK group had myopia greater than 1 diopter. In comparison with the thickness at 6 months postoperatively, central corneal thickness was significantly increased after 5, 7, and 10 years in both LASIK and LASEK groups (LASIK, p < 0.001, p < 0.001, and p < 0.001, respectively; LASEK, p = 0.01, p < 0.001, and p < 0.001, respectively). CONCLUSIONS: Moderately myopic eyes showed progressive myopic shifting and corneal thickening after LASIK and LASEK during 10 years of follow-up. We also found that early refractive regression may indicate the long-term refractive outcome.

Wavefront - guided laser - assisted subepithelial keratectomy in low myopia, myopic astigmatism and high myopia / 国际眼科杂志(Guoji Yanke Zazhi)

To compare the safety, efficacy, predictability, stability and complications of wavefront-guided laser-assisted subepithelial keratectomy ( LASEK ) in low myopia, myopic astigmatism and high myopia correction.METHODS: A retrospective analysis of 416 eyes were assigned to 3 groups:159 eyes with low myopia ( LM) and mean refractive spherical equivalent (MRSE) of-3. 68±1. 33 dioptre ( D ); 161 eyes with myopic astigmatism ( MA ) and MRSE of -5. 99 ± 2. 24D and mean cylinder of 2. 41 ± 1. 07D;and 96 eyes with high myopia (HM) and MRSE of- 7. 41 ± 0. 80D. After an epithelial flap creation, a wavefront-based excimer laser ablation was performed. Safety, efficacy, predictability and stability were evaluated at day 10, 2, 6 and 12mo postoperatively.RESULTS:At 12mo, the MRSE was -0. 36 ± 0. 31D in LM group, 0. 15 ± 0. 41D in MA group and 0. 58 ± 0. 68D in HM group. The uncorrected visual acuity ( UCVA) was 20/20 in 90. 60% of patients in LM group, 78. 90% in MA group and 67% in HM group. Efficacy indices were 0. 98, 1. 04 and 0. 92 in LM, MA and HM groups, respectively. Safety indices were 1. 00, 1. 07 and 1. 05 in LM, MA and HM respectively. Five eyes (3. 1%) in the LM group gained 1 line. Forty-four eyes (27. 3%) in MA gained 1-3 lines and eighteen eyes (19. 2%) of HM group gained 1-2 lines of BSCVA. Only 2 eyes in LM group developed corneal haze. There were not statistically significant differences in efficacy and safety indices amongst three groups.CONCLUSlON:Wavefront-guided LASEK is an effective and safe procedure for the treatment of LM, MA, and HM. although in myopic astigmatism the predictability, efficacy and safety indices had been better.

Expression of occludin in corneal epithelium after flap-free epipolis laser in-situ keratomileusis and laser-assisted subepithelial keratectomy / 中华实验眼科杂志

Background Tight junctions are thought to play a significant role in the maintenance of the corneal epithelial defense for the eye,and the restoration of the tight junctions is critical during epithelial wound healing after refractive surgery.However,there are few reports about this study. Objective The aim of this study was to investigate and compare the expression of occludin in corneal epithelium following flap-free epipolis laser insitu keratomileusis (Epi-LASIK) and laser-assisted subepithelial keratectomy ( LASEK ). Methods Forty-eight clean New Zealand white rabbits were randomized into 2 groups,and 24 rabbits for each group.Flap-free Epi-LASIK and LASEK were performed in the right eyes of the rabbits in two groups,and other 2 age matched normal rabbits were as normal controls.The animals were sacrificed and the corneal samples were obtained at 1,2,3,5 days after surgery.Immunofluorescence staining was used to detect the expression of occludin in the corneal epithelium,and RT-PCR was used to identify the level of occludin mRNA in the central cornea. Results Occludin protein was expressed innormal corneal epithelium and showed the green fluorescence with the regular arrangement.The fluorescence intensity was lower in 1 -2 days in LASEK group with the irregular arrangement;while the fluorescence signal in corneal epithelium was stronger in flap-free Epi-LASIK group.3-5 days after surgery,the fluorescence intensities were bothenhanced in two groups.RT-PCR showed that the relative expression of occludin mRNA in corneal epithelium was 0.11 ±0.02,0.25 ± 0.03,0.43 ± 0.04 in LASEK group 1,2,3 days after surgery,respectively,and was lower than those of flap-free Epi-LASIK group ( 0.20± 0.04,0.44 ± 0.04,0.76 ± 0.04 ),showing significant differences between these two groups ( t =6.476,12.898,17.315,P＜ 0.05 ).No significant difference was seen in the expression of occludin mRNA in 5 days after surgery between two groups( t=-0.733,P＞0.05).The relative values of occludin mRNA expression in corneal epithelium were gradually increased with time prolongation,presenting a significant difference among various time points ( Ftime =768.903,P =0.000). Conclusions The reformation of occludin in flap-free Epi-LASIK group is faster than that in LASEK group.Therefore,flap-free Epi-LASIK is prominant in reducing the stimulated symptoms and complication after the surgery.

Development of EKC after Eximer Laser Photorefractive Surgery and Subsequent Recurrence of EKC-like Keratitis

This research focuses on four cases of patients having undergone eximer laser photorefractive surgery who were diagnosed with adenoviral keratoconjunctivitis during the postoperative period and who later developed epidemic keratoconjunctivitis (EKC)-like keratitis. Two of the patients had undergone laser-assisted subepithelial keratectomy (LASEK), one had undergone laser in situ keratomileusis and one had photorefractive keratectomy. After the surgery adenoviral keratoconjunctivitis and recurrent late-developing EKC-like keratitis were observed in the patients. Recurrent late-developing EKC-like keratitis occurred in one of the patients, who had received LASEK as many as three times. The others had only one or two episodes.The corneal infiltrates of keratitis mainly occurred in the central cornea. Successful resolution of recurrent late-developing EKC-like keratitis was achieved through the use of topical steroids without sequelae and the final best-corrected visual acuity was as good as the base line. These keratitis infiltrates have been presumed to represent an immune response to the suspected adenoviral antigens deposited in corneal stroma during the primary adenoviral infection. Previous reports argued that patients with a history of adenoviral ketatoconjunctivitis were succeptible to adenoviral keratoconjunctivitis becoming reactivated; however, in our research, our patients had their first adenoviral infections after the eximer laser photorefractive surgery and reactivation was confirmed. We recommend that attention be paid to adenoviral infection after laser refractive operations, because these patients seem to have more frequent recurrences.