Lasers in Medicine
Year:2005 | Volume:3 | Issue:4 (22)|Papers Count:14

Background and Objectives: Many advantages have been discussed for transnasal DCR ,the most important of them are lack of skin incision and scar, outpatient basis, decreased overall health care expense, quicker patient rehabilitation and patients' preference; In the procedures that making use of laser, bleeding is less. The aim of present study was to evaluate transnasal DCR with laser and microscope. Materials and Methods: Formerly endoscope has been used for this procedure, but in our study 68 patients underwent 75 operations transnasally, by microscopic magnification. The site of lacrimal sac at lateral wall of nose was localized by the mean of transillumination through 22 gauge light probe. Nd:YAG and KTP 532 lasers were used for ablating the soft tissue and bone. After making fistula between lacrimal sac and nasal mucosa, silicone tubes were inserted in all patients. Results: In our experience, early removal of silicone tubes was associated with lower success rate. The success rate at 6 months postoperation was 89.3% and after 12months 74.6%. No significant intra and postoperative major complications, associated with this technique were recorded.Conclusions: An aesthetically reasonable result is achieved essentially in "UV sensitive" areas, thus appearing to be the appropriate places of choice for this treatment.

Background and Objectives: Tumors can be treated by using photodynamic therapy (PDT) technique. In this study, two types of biocompatible diffusers namely emulsions as liquid and SiO2 powder as solid were used to study the quality of laser light spatial distribution in gas, liquid and solid media.Material and Methods: The applicator was used with different number of biocompatible emulsion such as: ginger, coconut, wall nut, hazel nut, olive, bitter and sweat almond, neutralipid and phospholipid as optical diffusers. The second type of diffusers (solid) was made of SiO2 powder in different geometrical shapes. The uniformity of angular distribution of laser power and intensity emitted from the emulsion containing silicon rubber balloon and solid diffusers were measured at different diameters. Also, lamb meat and chicken breast were used as dark and light samples.Results: Among the pure oils and emulsions used in these experiments, the pure phospholipid and hazel nut were found as the best and worst liquid diffusers respectively.Also, the results showed that the spatial distribution uniformity was improved by increasing the balloon diameter. Finally, in the case of solid diffusers "castted" technique indicated a better mechanical strength as well as diffusing behavior with respect to "pulled” technique.Conclusions: Phospholipids emulsion showed an excellent scattering properties and uniformity of spatial distribution was improved at higher balloon diameters. The geometrical shape as well as mechanical and thermal properties of solid diffuser such as SiO2 fiber is an important deciding parameter in a successful PDT operation.

Background and Objectives: Thicknesses of Ariadent and Harvard Zinc Phosphate (ZP) cements have been measured and compared by an optical set up using optical interference pattern method and a He-Ne laser of 632.8 nm wavelength.Materials and Methods: Ten experimental samples of Ariadent and Harvard Zinc Phosphate (ZP) cements were palced between two glass lamella, harded by 150 N forces, and irradiated by He-Ne laser.Results: It is found that the thickness of Ariadent cement is 35.5 microns when a force of 150 N was exerted on it during the preparation stage. This thickness is about 8.5 microns greater than that of Ariadent with the same material and exerting force.Conclusions: Our study showed that thickness of Harvard cement was greater than thickness of Ariadent cement.

Background and Objectives: This investigation describes the effect of low level laser therapy (LLLT) on treatment of post-mastectomy lymphedema.Materials & Methods: Eleven women with unilateral arm lymphedema were included in this study. Patients received laser or placebo irradiation (GaAs/Mustng 890 nm, fluence: 1.5 J/cm2) over the arm and axillary area as laser and sham groups, respectively. The absorption of laser beam was simulated in tissue using a numerical method based on Monte Carlo Multi Layer (MCML) standard codes.Results: Four patients in each group (laser or sham) completed the treatments. Changes in limb circumference, pain score, motility and heaviness of the affected limb and desire to continue the treatment in five sessions of follow up were measured and compared to pretreatment status. Pain reduction in laser group was more than sham group except for the weeks 3 and 9.Conclusions: Our study showed that LLLT with the wavelength of 890nm may have effects on reduction of pain and circumference of lymph-edematous limb after mastectomy.

Background and Objectives: In the last decade, several studies were undertaken about LASIK surgery to show its role in treatment of myopia and astigmatism. This study was performed to determine the results and complications of LASIK in treatment of myopic astigmatism in Nemazee Hospital LASIK Center of Shiraz University of Medical Sciences.Materials and Methods: In a prospective study, 60 eyes of 37 myopic astigmatic patients with a mean pre-operative relatively spherical equivalent (SE) of -5.6 ± 2.15 D and mean preoperative astigmatism of -2.27 underwent LASIK and were followed after 24 hours, one week, 1, 3 and 6 months in relation to their visual acuity.Results: The mean and SE of refraction reduced significantly to 91% after one week, to 90% after one month, to 89% after 3 and 85% after 6 months. The mean pre-operative astigmatism reduced to 77% after one week, to 7l% after one month, to 68% after 3 and to 60% after 6 months. The pre-operative best corrected visual acuity (BCVA) 10/10 was observed among 55% of patients which increased to 72% after 6 months. The post-operative uncorrected visual acuity (UCVA) was 43% after one week, 45% after one month, 55% after 3 and 4.8% after 6 months. The post-operative decrease of BCVA was seen in 60% of eyes but was not more than two lines.Conclusions: LASIK could produce acceptable post-operative BCVA and UCVA. It was safe and effective in treatment of myopic astigmatism although the stability of the procedure is still needs to be assessed.

Background and Objectives: Different properties of low-level He-Ne laser have been under investigation, one of which is its effect on blood sugar level. In the present study, the effect of low-power laser on hyperglycemia induced by isoniazid has been investigated in mice.Materials and Methods: One hundred male albino mice were divided into four groups: group 1 received intraperitoneal isoniazid, group 2 was treated with laser after isoniazid administration, group 3 was given saline and then irradiated by laser, group 4 received only saline. Laser irradiation was performed at 5 epigastric areas, 45 seconds each. This procedure was repeated twice daily for 9 days in groups 2 and 3.Results: The data indicated that intraperitoneal (IP) injection of isoniazid (100mg/kg) produces hyperglycemia in comparison to group 4. When isoniazid administration coincides with laser irradiation, the blood sugar level will not change significantly compared to the control group.Conclusions: It could be concluded that He-Ne laser is capable of reversing the isoniazidinduced hyperglycemic effect on mice liver, and might have a protective property in case of drug-induced hyperglycemia.