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)

Diferentes concentraciones de mitomicina C en la prevención del haze en la queratectomía fotorrefractiva / Different concentrations of mitomycin C for haze prevention in photorefractive keratectomy

Objetivo: Evaluar la utilidad de dos concentraciones de mitomicina C para la prevención del haze en la queratectomía fotorrefractiva. Métodos: Se realizó un estudio experimental aleatorizado en 26 ojos de 17 pacientes con defectos miópicos. Los pacientes fueron asignados a dos grupos según las dosis de mitomicina C (0,02 por ciento grupo 1 y 0,002 por ciento grupo 2). La variable de respuesta principal fue la presencia de haze. Se buscó correlación entre la magnitud del haze con grado de ametropía tratada, profundidad de ablación, microscopia endotelial y resultados visuales y refractivos. Resultados: A los 6 meses la mayoría de los pacientes del grupo 1 no presentó haze (ocho ojos / 57 por ciento), y del grupo 2 mantuvieron haze 0,5 (6 ojos / 50 por ciento). En la ametropía severa el haze en el grupo 2 fue mayor que en el grupo 1 durante todo el posoperatorio, y se observó la mayor diferencia al sexto mes con 0,5 ± 0,4 vs. 1,5 ± 0,32. En ablaciones > 75 micras el grupo dos terminó con más haze que el uno, con 0,5 ± 0,44 vs. 1,75 ± 0,76. La agudeza visual sin corrección se vio más afectada en el grupo 2. No hubo daño endotelial en ningún grupo. Conclusión: La presencia de haze predomina en los casos tratados con dosis 0,002 por ciento de mitomicina C, comparada con la dosis 0,02 por ciento, aunque en este caso ambos grupos mantuvieron un resultado visual y refractivo adecuado y baja toxicidad endotelial.

Objective: Evaluate the usefulness of two concentrations of mitomycin C for haze prevention in photorefractive keratectomy. Methods: An experimental randomized study was conducted of 26 eyes of 17 patients with myopic defects. The patients were divided into two groups according to their mitomycin C doses (Group 1: 0.02 percent and Group 2: 0.002 percent). The main response variable was the presence of haze. Verification was performed of the correlation between haze magnitude and the degree of the ametropia treated, ablation depth, endothelial microscopy, and visual and refractive results. Results: At six months most patients in Group 1 did not have any haze (eight eyes / 57 percent), whereas 0.5 (6 eyes / 50 percent) in Group 2 still had haze. In severe ametropia, haze was larger in Group 2 than in Group 1 throughout the postoperative period, the greatest difference being observed in the sixth month with 0.5 ± 0.4 vs 1.5 ± 0.32. In ablations > 75 microns, Group 2 ended with more haze than Group 1, with 0.5 ± 0.44 vs 1.75 ± 0.76. Uncorrected visual acuity was more affected in Group 2. No endothelial damage occurred in either group. Conclusion: The presence of haze prevails in cases treated with 0.002 percent doses of mitomycin C, as compared with 0.02 percent doses, though in this case both groups maintained an appropriate visual and refractive result and low endothelial toxicity(AU)

Immediate and short term visual recovery after SmartSurfACE photorefractive keratectomy.

PURPOSE: To investigate immediate and short-term visual recovery in a large cohort of 2093 myopic eyes (with or without astigmatism) treated with SmartSurfACE procedure, a combination of Transepithelial Photo Refractive Keratectomy (PRK) and Smart Pulse Technology (SPT, SCHWIND eye-tech-solutions GmbH, Kleinostheim, Germany). METHODS: In this retrospective case series, post-operative outcomes were evaluated immediately after the surgery (Day 0), at day 1 and 3 months postoperatively, after myopic SmartSurfACE treatment with mean pre-operative spherical equivalent -4.65±2.53D and range from -16.13D to -0.13D. In all cases, pre and postoperative standard examinations were performed. The analysis evaluated preoperative Corrected and Uncorrected Distance Visual Acuity (CDVA and UDVA, respectively), and postoperative UDVA, monocularly and binocularly, immediately after the surgery, at day 1 and 3 month follow up. RESULTS: Sixty-two percent eyes achieved monocular UDVA 20/40 or better immediately after the surgery, while 82% patients achieved binocular UDVA 20/32 or better immediately after the surgery. At 3-month postoperatively, monocular UDVA 20/25 or better was achieved in 94% eyes. Treated eyes achieved immediately after the surgery or by the next day mean UDVA 20/41±8. UDVA improved significantly from Day 1 to 3-months follow up (p<0.0001 for both OS and OD) to mean UDVA 20/21±5 (equal to preoperative CDVA 20/21±8). CONCLUSION: Immediate and short-term visual recovery after SmartSurfACE PRK in our large cohort was rapid, providing functional binocular UDVA immediately after the surgery.

Comparison of 5468 retreatments after laser in situ keratomileusis by lifting the flap or performing photorefractive keratectomy on the flap. / Comparación de 5.468 retratamientos tras láser in situ queratomileusis levantando el lentículo o mediante queratectomía fotorrefractiva sobre el lentículo.

PURPOSE: To assess visual outcomes of retreatment after laser in situ keratomileusis (LASIK) by lifting the flap or performing photorefractive keratectomy (PRK) on the flap, as well as to establish whether there was an increased risk of epithelial ingrowth (EIG) when LASIK and lifting of the flap are separated by a long time interval and to determine the incidence of corneal haze after PRK. METHODS: Retrospective study of 4077 patients (5468 eyes) who underwent LASIK and subsequent retreatment were reviewed in order to study their visual results and identify cases of EIG and corneal haze. RESULTS: Enhancements included 5196 eyes from 3876 patients that were retreated by lifting the flap, and 272 eyes from 201 patients that were retreated by PRK on the flap. No statistically significant differences were found between the retreatments in terms of predictability, efficacy, and safety. A total of 704 cases of EIG were found after lifting the flap, for which surgical cleansing was necessary in 70. Surgical cleansing decreased the efficacy index when compared with patients with EIG who did not need cleansing (P=.01). Differences in terms of safety and predictability were not statistically significant. The incidence of corneal haze after ablation of the surface of the previous flap was 14.34%, although none of these cases were clinically relevant. CONCLUSIONS: Visual outcomes were similar between patients who were retreated by lifting the flap and those who underwent PRK. The incidence of EIG when the flap was lifted was 13.55%. The incidence of EIG increases with the time elapsed between the primary procedure and retreatment.

Cambios corneales producidos por la cirugía refractiva con excimer láser: revisión de tema / Changes produced by corneal refractive surgery with excimer laser: a review

RESUMEN El auge de la cirugía refractiva con excimer láser en las últimas dos décadas se ha reflejado en que un grupo creciente de pacientes con antecedente de este procedimiento necesitan ahora cirugía de catarata. Debido a las modificaciones generadas en la córnea por la fotoablación con el láser, la determinación del poder corneal necesario para el cálculo del poder del lente intraocular a implantar en la cirugía de catarata, es difícil. Teniendo en cuenta estos aspectos se hace una revisión de las causas de estos errores de medición y los abordajes existentes para minimizar su impacto. MÉD.UIS. 2017;30(1):99-105.

ABSTRACT The rise of excimer laser refractive surgery in the last two decades has been reflected in a growing group of patients with a history of this procedure who now need cataract surgery. Because the generated modifications to the cornea with the laser photoablation, determining the corneal power, necessary for calculating the power of the intraocular lens to be implanted during the cataract surgery, is difficult. We review the causes of these errors of measurement and existing approaches to minimize its impact. MÉD.UIS. 2017;30(1):99-105.

Corneal-Wavefront guided transepithelial photorefractive keratectomy after corneal collagen cross linking in keratoconus.

PURPOSE: To evaluate the efficacy and safety of Corneal-Wavefront guided transepithelial photorefractive keratectomy (TransPRK) after corneal collagen cross linking (CXL) in keratoconic patients. METHODS: In this retrospective, non-comparative, consecutive case series, 39 keratoconic eyes underwent Corneal-Wavefront guided TransPRK for the correction of aberrations at least 4 months after conventional CXL at SEKAL Rovigo Microsurgery Centre, Rovigo, Italy. Two eyes (5%) underwent a secondary laser retreatment for the improvement of post-operative visual acuity and were not included in this retrospective analysis. The mean age of the patients was 35±12 years (19-64 years) at the time of the surgery. Keratron-Scout (Optikon) topographer was used for diagnostic tests and a flying-spot laser (AMARIS; SCHWIND eye-tech-solutions) was used for the refractive surgery. Complete ophthalmic examinations were performed before and after the surgery (4-36 months postoperatively with a mean follow up time of 10±8 months). RESULTS: Preoperatively, eyes showed irregular astigmatism up to 8D. At last postoperative follow-up, 21 eyes (57%) had UDVA better than 20/40, and six eyes (16%) had UDVA of 20/20. Twenty-three eyes (62%) were within 1.50D of attempted correction in spherical equivalent (mean deviation from target was +1.09±2.36D, range -2.50 to +7.38D). No eye lost 2 Snellen lines of CDVA, and 15 eyes (41%) had an increase of more than 2 lines. CONCLUSIONS: Corneal-Wavefront guided transepithelial PRK ablation profiles after conventional CXL yields to good visual, optical, and refractive results. These treatments are safe and efficacious for the correction of refracto-therapeutic problems in keratoconic patients.

Comparative evaluation of Comfilcon A and Senofilcon A bandage contact lenses after transepithelial photorefractive keratectomy.

PURPOSE: To evaluate and compare Comfilcon A and Senofilcon A silicone hydrogel contact lenses used as a therapeutic bandage following transepithelial excimer laser photorefractive keratectomy (PRK). METHODS: Patients undergoing transepithelial PRK for myopia were prospectively recruited. Included patients had a Comfilcon A silicone hydrogel lens inserted in one eye, with a Senofilcon A lens in the contralateral eye. Postoperative assessment of subjective pain, epithelial healing and visual recovery was at day 1, 3 and 7. Contact lens factors including centration, movement and deposits were assessed. RESULTS: 48 eyes of 24 patients were included in the study. Mean age was 31 years (SD 11) and mean refractive error -4.5 D (SD 1.8). Mean pain score at day 1 was significantly higher in the Comfilcon group at 4.6 (SD 2.7) vs. 1.5 (SD2.5) in the Senofilcon group (P<0.005). Mean time to healing was 3.17 days (SD 0.37) in the Comfilcon group, and 3.21 days (SD 0.4) in the Senofilcon group, with no difference in defect size. There was a pronounced central raphe in 1 eye in the Comfilcon group vs. 5 eyes in the Senofilcon group (P=0.19). Significantly more eyes demonstrated no lens movement in the Senofilcon group (18 vs. 4, P=0.0001). CONCLUSION: The variation in material characteristics and lens geometry of different silicone hydrogel lenses affects their clinical characteristics in therapeutic roles. Other factors than oxygen permeability may affect pain and epithelial healing, with superior pain relief from the less permeable Senofilcon lens in this study.

Corneal Regeneration After Photorefractive Keratectomy: A Review.

Photorefractive keratectomy (PRK) remodels corneal stroma to compensate refractive errors. The removal of epithelium and the ablation of stroma provoke the disruption of corneal nerves and a release of several peptides from tears, epithelium, stroma and nerves. A myriad of cytokines, growth factors, and matrix metalloproteases participate in the process of corneal wound healing. Their balance will determine if reepithelization and stromal remodeling are appropriate. The final aim is to achieve corneal transparency for restoring corneal function, and a proper visual quality. Therefore, wound-healing response is critical for a successful refractive surgery. Our goal is to provide an overview into how corneal wounding develops following PRK. We will also review the influence of intraoperative application of mitomycin C, bandage contact lenses, anti-inflammatory and other drugs in preventing corneal haze and post-PRK pain.

Resultados de la aplicación de queratectomía fototerapéutica en adultos mayores con queratopatía bullosa / Results of the application of phototherapeutic keratectomy in the elderly with Bullous Keratopathy

Fundamento: en muchos países se han realizado estudios sobre los beneficios de la queratectomía fototerapéutica en las afecciones corneales; se han encontrado escasas referencias en nuestro país que aborden los resultados de la aplicación del láser de excímeros en los adultos mayores aquejados de queratopatía bullosa.Objetivo: valorar los resultados de la aplicación de la queratectomía fototerapéutica en adultos mayores con queratopatía bullosa.Métodos: estudio de serie de casos realizado durante el año 2009, en el Departamento de Córnea del Hospital General Universitario Dr. Gustavo Aldereguía Lima de Cienfuegos, que incluyó 16 adultos mayores con queratopatía bullosa no tributaria a queratoplastia penetrante. Después de tener en cuenta los principios éticos y una evaluación biomédica, se les realizó la queratectomía fototerapéutica. Se indicó tratamiento y se llevó a cabo el seguimiento con una valoración de síntomas y signos hasta el tercer mes.Resultados: en el posoperatorio la sintomatología disminuyó y el signo más frecuente fue el haze (38 por ciento) seguido de las alteraciones visuales (25 por ciento) y del leve incremento en la agudeza visual mejor corregida.Conclusiones: la aplicación de queratectomía fototerapéutica en pacientes no tributarios a trasplante de córnea contribuye a mejorar el estado ocular, disminuye los síntomas y mejora la agudeza visual(AU)

Background: Many countries have conducted studies on the benefits of phototherapeutic keratectomy in corneal diseases; few references have been found in our country to address the results of the application of the excimer laser in the elderly suffering from bullous keratopathy.Objective: To assess the results of the application of phototherapeutic keratectomy in the eldrly with bullous keratopathy. Methods: A case series study was conducted in 2009, in the Cornea Department of the Dr. Gustavo Aldereguía Lima General University Hospital of Cienfuegos. It included 16 elderly with bullous keratopathy not leading to penetrating keratoplasty. After considering the ethical and biomedical assessment, phototherapeutic keratectomy was performed. Treatment was indicated and follow up was performed with an assessment of symptoms and signs until the third month.Results: In the postoperative stage symptoms decreased and the most frequent sign was the haze followed by slight increase in best corrected visual acuity. Conclusions: The application of phototherapeutic keratectomy in patients that did not apply for cornea transplant helps improving eye condition, reduces symptoms and improves visual acuity(AU)