Comparación entre facoemulsificación asistida con femtoláser y facoemulsificación convencional: resultados visuales y complicaciones / Comparison between femtosecond laser-assisted phacoemulsification and conventional emulsification: visual results and complications

La aplicación del femtoláser en la cirugía de catarata podría ser una de las grandes revoluciones contemporáneas ocurridas en el campo del tratamiento de la catarata. Si el uso de esta tecnología provocara una eficacia y seguridad muy superiores sobre la facoemulsificación convencional, justificaría el alto costo que genera para la cirugía de catarata en la actualidad. En revisiones de estudios comparativos no se han encontrado diferencias significativas entre los resultados visuales de ambos procedimientos al final del período de seguimiento posoperatorio. Una mejor circularidad de la capsulorrexis, unido a disminución en la emisión de energía ultrasónica y del tiempo efectivo de faco, son atribuidos como las grandes ventajas del uso del femtoláser en la facoemulsificación. Sin embargo, en cuanto a la pérdida de células endoteliales, el edema corneal posoperatorio y el edema macular posquirúrgico no se han registrado grandes diferencias entre ambas técnicas quirúrgicas, mientras que el costo de la cirugía se incrementa considerablemente con la utilización del femtoláser. Por tanto, se necesitan estudios de gran tamaño de muestra bien diseñados que proporcionen evidencias más fiables respecto al uso del femtoláser en la cirugía de catarata actual(AU)

The application of femtoláser in cataract surgery could be one of the great contemporary revolutions occurred in the field of treatment of cataract. If the use of this technology would cause a very superior efficacy and safety over conventional phacoemulsification, it justifies the high cost it generates for cataract surgery today. In reviews of comparative studies we have not found significant differences between the visual results of both procedures at the end of the period of postoperative follow-up. Better circularity of the capsulorhexis, coupled with decrease in the emission of ultrasonic energy and effective phacoemulsification time, are attributed as the major advantages of using femtoláser in phacoemulsification. However in terms of endothelial cell loss, postoperative corneal edema and macular edema after surgery they have not been recorded big differences between the two surgical techniques, while the cost of surgery is considerably increased with the use of femtoláser. Therefore studies of large sample size, well-designed to provide more reliable evidence regarding the use of femtoláser in current cataract surgery are needed(AU)

Vantagens da frenectomia labial por laser de diodo de alta intensidade / Advantages of lip frenectomy with high-intensity diode laser ­ a case report

Existem condições clínicas em Periodontia na qual o freio labial está posicionado de forma penetrante nas papilas gengivais, ficando muito próximo à margem gengival, podendo predispor ao desenvolvimento de recessões gengivais. Também pode ocorrer dificuldade de higienização, infl amação persistente, restrição no movimento labial, interferência fonética e agravos estéticos, além de dificultar o fechamento de diastemas. Muitas vezes, é indicada a remoção cirúrgica de freios labiais utilizando lâminas de bisturi e, mais recentemente, o laser de alta intensidade. O laser, ao ser absorvido pelos tecidos, gera a vaporização e sublimação, resultando em corte e exérese, além de atuar como auxiliar na cicatrização, provavelmente através da bioestimulação. Seu meio ativo promove a vaporização completa e a coagulação nos tecidos, sem gerar propagação do aquecimento. Há maior controle da hemorragia transoperatória, resultando em um procedimento cirúrgico limpo, frequentemente dispensando suturas, facilitando a visibilidade, execução e remoção do freio labial. O objetivo deste trabalho foi demonstrar as vantagens do laser cirúrgico de alta intensidade (Nd:YAG; 808 nm; 1,2 W; 20 pps; 126 J) a partir de um relato de caso clínico de frenectomia realizada em uma paciente do sexo feminino, com 34 anos de idade, que apresenta freio labial persistente associado a diastema interincisal superior. O procedimento cirúrgico com laser de alta intensidade em tecidos moles apresentou algumas vantagens, como a redução do tempo cirúrgico, de morbidade e sintomatologia pós-operatórias.

There are clinical conditions in periodontics where the labia frenulum is deeply positioned into the gingival papillae getting very close to the gingival margins, predisposing the development of recessions, causing difficulties for cleaning, with persistent infl ammation, lip movement restrictions, phonetic interference, esthetic alteration, besides preventing diastema closure. Oftentimes, removal with a surgical blade or high-intensity lasers is recommended. The laser is absorbed by the tissues generating vaporization and sublimation which results in cutting and excision, and increased improved healing possibly due to its bio-stimulatory effect. Its active medium promotes complete tissue vaporization and coagulation, without heat propagation, control of the intraoperative bleeding and a clean surgery that often does not require sutures. This facilitates visibility, execution and removal of the labial frenulum. The aim of this paper was to demonstrate the surgical benefi ts of the high-intensity laser (Nd:YAG; 808 nm; 1.2 W; 20 pps; 126 J) in a case report of frenectomy for a 34 years-old female patient presenting persistent inter-incisal diastema associated with an atypical labial frenulum. The soft tissue laser therapy has the advantage of reduced clinical time and still not promoting edema, with minimal postoperative pain and side effects.

A influência do laser de baixa intensidade na osseointegração de implantes de titânio ­ revisão sistemática / The influence of low-level laser therapy (LLLT) on the osseointegration of titanium implants ­ a systematic review

Objetivo: fazer uma revisão da literatura sobre o laser de baixa intensidade (LLLT) e seus efeitos na osseointegração dos implantes de titânio. Material e métodos: uma busca eletrônica foi realizada nos bancos de dados PubMed/Medline e Cochrane Library, entre 1995 e 2015, limitando-se aos artigos em inglês e usando as seguintes palavras-chave: "LLLT", "dental implant" e "osseointegration", combinadas por operadores booleanos. Resultados: das 96 referências analisadas inicialmente, apenas 17 artigos foram incluídos (15 estudos em animais, dois estudos em humanos). Quinze artigos mostraram efeitos positivos da LLLT, enquanto dois foram neutros. Houve grande variabilidade no uso da LLLT, sobretudo no que se refere à dose utilizada, ao número de sessões, à energia de irradiação, e ao comprimento de onda. Conclusão: mais pesquisas sobre este tema são necessárias, utilizando doses padronizadas, assim como comprimento de onda e protocolos de aplicação pré-definidos.

Objective: to perform a systematic review on low-level laser therapy (LLLT) and its effects on the osseointegration of titanium implants. Material and methods: an electronic search was on the PubMed/Medline database and Cochrane Library between 1995 e 2015, restricted to the English literature and using the keywords: "LLLT", "dental implant", and "osseointegration" combined by Boolean operators. Results: from the 96 initially retrieved references, only 17 articles were included (15 animal studies, 2 human studies). Fifteen articles showed positive effects, while only two demonstrated neutral effects of LLLT. A great variability was found on LLLT regarding doses, number of sessions, energy, and wavelengths used. Conclusion: further research on this topic need to be made using standard doses, wavelengths, and pre-defi ned application protocols.

Dry eye syndrome after laser in situ keratomileusis [LASIK] for correction of myopia

To evaluate the incidence of dry eye syndrome after laser in situ keratomileusis [LASIK] and to determine the pattern of tears recovery. In a prospective, non comparative case study, 33 eyes [20] patients underwent laser in situ keratomileusis to correct myopia ranging from -0.75 to -14.00D. Each eye was followed for mean period of 12 months [10 - 14 months]. Patients were followed at 2 weeks and 2 days preoperatively and 1 day, 1 and 2 weeks, 1, 3, 6, 9 and 12 months postoperatively, measuring the Snellen visual acuity, corneal sensitivity, corneal fluorescein staining, tear break-up time, basic aqueous tear production by the Anaesthetized Schirmer test, and corneal Surface Regularity Index [SFU]. Patients were divided according to the depth of ablation into group A [ablation depth < 100 microm and group B [ablation depth >100 microm] dry eye syndrome after laser in situ keratomileusis was evident at the ablated zone during the first 3 months after surgery and only at the 6th months it returned to its preoperative values. Recovery was more rapid at the hinge than the other points. The degree of sensation loss appears to correlate with the ablation depth and degree of dry eye symptoms. The results suggest that lamellar cutting of the cornea during LASIK impairs corneal sensitivity and modifies tear production and the depth of the corneal ablation affects the extent of dryness and recovery

Interaction model of laser radiation and structures of the eye-fundus

For some time past lasers have been used in ophthalmology more and more wide, i.e. for microsurgical interventions to structures of eye-fundus. Concurrently with application of lasers there develop theories aimed at explanation of what is the mechanism of action of the laser radi-ation on eye-fundus. Thermal mechanism of visual organ damage by a light beam is the most universal one for visible and infra-red subspectrum [15]. Vos J.J. was the first who tried to create a theory of retinal burns on the basis of experimental data of Ham W.T. It was suggested that the radiation absorbs uniformly in a parallelepiped with thickness 10 ¥um and radiation spot 130 urn with radiation time over 20 ms. Distribution of temperature studied by VOS J.J. with the help of heat-transfer equation showed that thermal effects shall occur at extremely high temperature [over 100° C], though the data did not confirm existence of boiling and steam production in eye tissue under the corresponding conditions[16,8]. One of the first studies concerning temperature measurement in the course of laser coagulation were experiments of Campbell C.J. There was measured the temperature at different distances from the radiation point of retina irradiated by a milli second pulso of a ruby laser. It was defined that in the area of coagulation the temperature increased at 30° C, however at the distance of 1 mm from the coagulation point the temperature increase was not higher than 1° C [5]. A more perfect model of the heating of eye-fundus tissues was developed by Ham W.T. and Clark A.M. It was suggested in the model that pigment epithelium and choroids are uniform absorbers with different absorption factors. Thermal performance has been accepted equal to thermal performance of water. On examination of these models it was defined that in some time after beginning of radiation there establishes a stable temperature, and the speed of its stabilization and its value depend on diameter of a radiation spot[6,7,8]. Subsequently there have been offered some more models of thermal damage of eye tissues taking into account spectral dependence of temperature effects of eye-fundus tissues ra-diation heating, granularity of light-absorbing layers and duration of exposure[4,10,12,14,18]. A number of authors calculate the increase of temperature inside of radiated retinal vessels taking into account their cooling due to blood flow [3]. The most exact temperature prediction 1% inside retina was provided by Wheeler [17]. The model developed by Wheeler suggests exponential absorption within two layers: melanin layer in pigment epithelium with thickness of 4 microm and vascular layer 30 urn thick. Distance between layers' centers is 30 microm, It is assumed that both layers have equal heat and temperature transfer. For forecast of eye-fundus tissues damage by light radiation there have been developed models taking into account character of distribution of light energy in a beam formed by this optical system and absorption characteristics of radiated biological tissue [1,2,3,13].However there is no model of selective action of laser energy on eye-fundus structures. Purpose of our study was development of interaction model of laser radiation and retina tissues. Commencing development of interaction model of laser radiation and eye-fundus structures we suggest that as diameter of laser ray is much lower than eye-fundus flexion it may be deemed flat. One can neglect absorption of laser radiation in cornea!, lens and sclera since it is relatively small comparing to absorption in pig-ment-epithelial layer [PEL] and chorioid. Let us examine effects of biological impact in case of single and series of pulses separately. Laser emits a single pulse with energy EO. At the same time it is not important how this pulse has been obtained: by overlap of continuous radiation or by periodical generation

Laser em dermatologia: princípios físicos, tipos e indicaçöes / Laser in dermatology: phisycal principles, types and indications

O uso de laser em dermatologia tem se expandido muito nos últimos anos. O avanço tecnológico, em mais de 30 anos, permite que a eficácia e as respostas terapêuticas sejam cada vez melhores. Porém, mais complexos tornam-se a compreensäo do seu uso e suas indicaçöes em dermatologia

Aplicación de la nefelometría laser en inmunología y microbiología / Laser nefelometry immunology and microbiology

Objetivo: evaluar la utilidad de la nefelometría láser en los estudios inmunológicos y microbiológicos. Material y métodos: se realizaron cuantificaciones de diversas proteínas plasmáticas: IgG, IgA, IgM, C3 y C4 por nefelometría laser utilizando como controles los estándares proporcionados por una casa comercial. Para su análisis los datos se transformaron a escalas logarítmicas y se calcularon ecuaciones de regresión lineal. Para la evaluación microbiológica se realizaron concentraciones bacterianas decimales hasta 10 a la 6 de E. coli en caldo de Hinto-Muller. Todas las concentraciones se leyeron cada 5 o 10 minuto durante 70 minutos para determinar la cinética de crecimiento. También se midió inhibición de amikacina sobre E. coli. Resultados: las ecuaciones calculadas empíricamente mostraron una buena reproducibilidad y una vigencia aproximada de seis meses para las proteínas plasmáticas. Así mismo la nefelometría mostró que permite realizar un cálculo rápido de la concentración mínima inhibitoria de crecimiento bacteriano

Tratamiento de la patología vascular superficial con el laser SPTL-1A / Treatment of superficial cutaneous vascular lesions with SPTL-1 laser

El laser SPTL-1 es un laser colorante pulsado creado específicamente para el tratamiento por fototermolisis selectiva de lesiones vasculares superficiales, como angiomas planos y telangioectasias faciales. Con este laser es posible el tratamiento en edades tempranas, al eliminar el riesgo de quemaduras y cicatrices hipertróficas, relativamente frecuentes con los láseres de argón y CO2

Irradiaçäo da medula espinhal com laser de arseneto de galio em ratos: aspectos anatomopatologico / Spinal cord irradiation with GaAs laser in rats: anatomopathologic study

Foram estudados os efeitos do laser sobre a medula espinhal de ratos.Os animais do G-1(10)constitiiram o grupo-controle;os do G-ll(10)receberam 9,15 j/cm por 30 seg em seis pontos durante dez dias,sendo sacrificados logo apos a ultima sessao;os do G-lll(10),9,15 j/cm por 30 seg em seis pontos durante dez dias e sacrificados apos 20 dias;os do G-lV(10),18,30 j/cm por 60 seg em seis pontos durante dez dias e sacrificados logo apos a ultima sessao;os do G-V(10)18,30 J//cm por 60 seg em seis pontos durante dez dias e sacrificados apos 20 dias.Nao houve alteracoes anatomopatologicas a microscopia optica.

El laser de CO2 en dermatología / CO2 laser in dermatology

Presentamos 74 pacientes con diferentes patologías que fueron tratadas con laser de CO2. Describimos la técnica usada en cada patología. los resultados y evolución

Experience in using ND: yagt laser for mandibular labial frenectomy

The surgical ND: YAG Sunrise 800 laser has the ability to vaporize soft tissue of frenum with high attachment with little bleeding, pain, swelling. The laser surgeries were evaluated in three reported cases of Saudi subjects with different ages. Surgeries were performed with no bleeding or infection. Vestibular width was also increased after 3 weeks of healing period. ND: YAG laser appears to have a promising future in periodontics. Precise long controlled studies were indicated

effect of minimal dose of Nd: YAG laser on retained plaque and calculus

A scanning electron microscopic [SEM] study was conducted to evaluate the effects of pulsed Nd: YAG laser on retained plaque and calculus on diseased and scaled root surfaces. The experimental materials were 18 human teeth affected by severe periodontal disease, which were extracted because of a hopeless prognosis. Nine of these teeth were scaled with sharp scalers without attempting for removing necrotic cementum. The specimens were cut from the root proximal surfaces starting from CEJ and extending approximately 5 mm apically. All specimens were classified into 4 groups. The results showed that, untreated control specimens revealed a complex subgingival microflora of cocci, rods short, long filamentous and spirochetes. All treated specimens, regardless of treatment sequence, exhibited some degree of laser-induced root surface alteration. Notably, laser-treated calculus deposits were free of their characteristic surface layer of microbial plaque. However, SEM examination revealed residual deposits of plaque and calculus and presence of the smear layer in all treated groups except the group treated with scaling and laser radiation at 150 mj. The present results indicated that Nd: YAG radiation was effective in evaporation of the residual calculus and plaque of scaled root surface and removes the smear layer, uncovers dentinal tubules on the root surface with slight widening of its orifices

Transcanalicular holmium laser dacryocystorhinostomy

Laser dacryocystorhinostomy is gaining popularity among the ophthalmic surgeons. We employed THC: YAG [thulium-and holmium-doped and chromium-senitized YAG] laser operating in the near infrared [2.1 micro m] for this procedure, and have outlined our technique and its adventages. The laser is equipped with a helium-neon aiming beam. A quartz fiberoptic probe is passed through the dilated canaliculus and rested against the bony wall of the lacrimal fossa. Aiming beam is turned on to transilluminate the sac, and THC: YAG laser applications made to create a 3 to 4 mm wide bony opening. A silicone tube is threaded through the canalicular system, and kept in place for about six months. The success rate, though not higher than, compares favorably with the conventional surgical techniques. Out of a total of 12 patients we performed this procedure on, ten [83%] had satisfactory outcome at one-year follow-up. [Pakistan Journal of Ophthalmology, 10:45-46, April and July, 1994]