Centration in refractive surgery / Centralização em cirurgia refrativa

ABSTRACT The point of centration for refractive surgery is a theme of great importance that generates considerable discussion among specialists and surgeons in the field. Notably, any changes in light can alter the size of the pupil, and the visual axis of the fixation line to the fovea is unique in each patient. A variety of options have been described in the literature with respect to centration in refractive surgery, and the results differ among these methods. No consensus has been established regarding the ideal refractive surgery technique for evaluation of centration in each patient that will yield a satisfactory surgical result.

RESUMO O ponto de centralização da cirurgia refrativa é tema de grande importância e gera muita discussão entre especialistas e cirurgiões da área. Afinal, qualquer alteração na luz pode alterar o tamanho da pupila, além disso, o eixo visual da linha de fixação para a fóvea é particular em cada paciente. Existem opções para centralização em cirurgia refrativa com resultados diferentes na literatura. Ainda não há consenso sobre a melhor técnica em cirurgia refrativa que avalie cada caso específico visando um resultado cirúrgico final satisfatório.

Short-term efficacy of high-intensity ultraviolet B versus 308-nm excimer laser for the treatment of vitiligo / 中华皮肤科杂志

Objective To compare the short-term efficacy of high-intensity ultraviolet B (UVB) versus 308-nm excimer laser for the treatment of vitiligo.Methods Eighty patients with vitiligo were equally divided into two groups to be treated with high-intensity UVB twice a week or 308-nm excimer laser once a week for eight weeks.Repigmentation was evaluated at the end of the treatment.Results After eight weeks of treatment,repigmentation of different degrees was observed in 83.6％ and 86.1％,and marked repigmentation in 42.1％ and 50％,of the UVB-and excimer laser-treated lesions,respectively.The response rate was significantly lower in facial lesions receiving high-intensity UVB radiation than in those receiving excimer laser radiation (49.1％ vs.68.4％,x2 =4.32,P ＜ 0.05),but similar at the other body sites between the two treatment (all P ＞ 0.05).The cumulative dosage required for initial repigmentation was similar between high-intensity UVB and 308-nm excimer laser (t =0.89,P ＞ 0.05),while the treatment sessions and cumulative dosage required for marked or better repigmentation were significantly increased in UVB-compared with excimer laser-treated lesions (both P ＜ 0.01).In addition,both high-intensity UVB and 308-nm excimer laser were suitable for childhood and active vitiligo.Conclusions Both high-intensity UVB and 308-nm excimer laser are safe and effective in the treatment of vitiligo with rapid onset of action,and the latter appears to be superior to the former in efficacy.

Resultados refractivos posqueratoplastia lamelar anterior superficial con láser excimer guiado por topografía en queratocono grado III / Refractive results after topography-guided anterior lamellar keratoplasty with excimer laser in keratoconus grade III

Objetivo: determinar los resultados refractivos y funcionales en operados de queratoplastia lamelar anterior superficial asistida con láser excimer topográfico en queratocono grado III. Materiales y métodos: estudio experimental, abierto, no controlado, longitudinal y prospectivo, en 35 ojos de 31 pacientes con edad promedio de 35,3 años, seguimiento entre 12 y 51 meses, operados en la Clínica Internacional de Retinosis Pigmentaria "Camilo Cienfuegos", entre enero de 2006 y diciembre de 2010. Resultados: la agudeza visual sin corrección mejoró de 0,04 a 0,39 y la agudeza visual con corrección de 0,28 a 0,78; el equivalente esférico se redujo de -13,02 a -1,69; la esfera y el cilindro disminuyeron de -10,13D ± 4,73 a -0,44D ± 3,22 y de -5,67D ± 2,32 a -2,52D ± 1,38, respectivamente. La queratometría disminuyó de 56,8D y 51,53D a 45,02 y 42,02 en el postoperatorio. La densidad celular preoperatoria fue de 2313, 81 cel/mm2 ± 322,10; varió a 2170 cel/mm2 ± 294,92 en el posoperatorio. El lecho residual estromal fue de 153,22μ. Discusión: en correlación con la literatura, el queratocono se presenta en la adolescencia y juventud y conduce al trasplante de córnea con más frecuencia en estas etapas de la vida. La queratometría promedio posoperatoria fue inferior a la reportada por otros investigadores que realizaron estudios con semejante técnica quirúrgica. Conclusiones: la queratoplastia lamelar anterior superficial con láser excimer, puede ser considerada como indicación primaria de tratamiento en el queratocono grado III..

Objective: determine refractive and functional results in patients with excimer laser. Materials and Methods: uncontrolled experimental study, longitudinal and prospective, in 35 eyes of 31 patients with an average age of 35.3 years old, followed between 12 and 51 moths; operated at “Camilo Cienfuegos” International Center of Retinitis Pigmentosa, between January 2006 and December 2010. Results: the uncorrected visual acuity improved from 0.04 to 0.39 and the best corrected visual acuity improved from 0.28 to 0.78; the spherical equivalent was reduced from -13,02 to -1,69D. The sphere and cylinder decreased from -10,13D ± 4.73 to -0.44D ± 3.22 and from -5.67D ± 2.32 to -2.52D ± 1.38, respectively. The average of the keratometry decreased from 56,8D and 51,53D to 45.02 and 42.02 in the post-surgery. The cellular density pre-surgery changed from 2313.81cel/mm2 ± 322.10 to 2170 cel/mm2 ± 294.92 in postoperative. The residual stromal bed was 153.22μ. Discussion: in correlation with the literature, the keratoconus appears in the adolescence and youth, leading to the corneal transplantation more often in these life stages. The average postsurgical keratometry was inferior to the reported by others investigators who practiced procedures with similar surgical technique. Conclusions: superficial anterior lamellar keratoplasty, assisted with excimer laser, can be considered as primary indication of treatment in keratoconus grade III..

Combined Ethylenediaminetetraacetic Acid Chelation, Phototherapeutic Keratectomy and Amniotic Membrane Transplantation for Treatment of Band Keratopathy

PURPOSE: The objective of this study is to evaluate the therapeutic efficacy of ethylenediaminetetraacetic acid (EDTA) chelation and excimer laser phototherapeutic keratectomy (PTK) combined with amniotic membrane transplantation (AMT) for the treatment of band keratopathy (BK). METHODS: Eleven eyes in ten patients with BK received combined PTK (ablation zone of central 7.0-7.5 mm, depth of 50 microm), EDTA chelation (0.05 M, 3 minutes), and amniotic membrane transplantation using fibrin glue. Preand postoperative best corrected visual acuities, symptom changes, reepithelialization time, cosmesis, recurrence, and complications were analyzed. RESULTS: Visual acuity improved in three eyes (27.3%) and did not change in eight eyes (72.7%). Symptoms improved in all patients, and the mean reepithelialization time was 10.6+/-5.3 days. The cosmetic results were good in eight eyes (72.7%) and were fair in three eyes (27.3%). During the mean follow-up period of 11.4+/-6.1 months (range, 6 to 23 months), no postoperative complications or recurrences were observed. CONCLUSIONS: The combination of EDTA chelation, PTK, and AMT is safe and effective for the treatment of band keratopathy.