Laser Treatment Time Research Articles

A comparison of primary laser versus laser after anti–vascular endothelial growth factor for type 1 retinopathy of prematurity

To compare characteristics of laser treatment for high-risk type 1 retinopathy of prematurity (ROP) in eyes treated with primary laser versus laser after an initial treatment with intravitreal anti-vascular endothelial growth factor (anti-VEGF). The medical records of consecutive patients at a single academic institution treated for type 1 ROP before 36 weeks' postmenstrual age with primary laser versus laser after initial treatment with anti-VEGF were reviewed retrospectively. Outcome measures were laser spot number, mean laser power, total laser energy (Joules), and retinal vascularization to the nasal ora at time of laser treatment. Compared with the 46 eyes treated with primary laser, the 46 eyes treated with laser after anti-VEGF required fewer spots (mean, 775 vs 1418 [P < 0.01]), less power (182 vs 223 mW [P < 0.01]), and less total energy (27 vs 61 Joules [P < 0.01]), and showed greater vascularization to the nasal ora at the time of laser treatment (47.8% vs 6.5% [P < 0.01]). In our study cohort, laser after initial anti-VEGF treatment may have allowed for greater retinal vascularization and been less destructive than primary laser for high-risk type 1 ROP.

Time of vitreal surgery for active retinopathy of prematurity

Background. The anatomical and functional results of surgery for retinopathy of prematurity (ROP) are determined not only by the stage of the pathological process, but also depend on the timing of its implementation.The aim: to estimate the effectiveness of vitrectomy for severe active retinopathy of prematurity, depending on the timing of surgical treatment.Methods. Vitreoretinal surgery was performed in 138 children (198 eyes) with severe stages of ROP. All patients were divided into three groups depending on the timing of surgical treatment: group 1 – 42–48 weeks of postconceptual age (PCA), with the progression of ROP after laser coagulation of the retina (LCS), group 2 – 39–41 weeks of PCA, with the progression of ROP after LCS, group 3 – 36–39 weeks of PCA, without previous LCS. A 3-port transscleral 27-G vitrectomy was performed by all patients. At the postoperative period, the results of vitrectomy were estimated by the anatomical attachment of the retina. The follow-up period was 12 months. Results. In group 1, in 31 cases (73.8 %), the surgical intervention was completed with silicone tamponade. By the end of the follow-up period, anatomical retinal attachment was achieved in 17 eyes (40.5 %).In group 2, surgical intervention was completed with silicone tamponade in 29 eyes (42 %). By the end of the follow-up period, anatomical retinal attachment was achieved in 52 eyes (75 %).In group 3, surgical intervention was completed with silicone tamponade in 11 of 87 eyes (12.6 %). Anatomical retinal attachment was achieved in 80 eyes (92 %).Conclusion. Untimely vitrectomy (42–48 weeks of PCA) in cases of ROP progression after LCR led to a worse result. If progress of ROP after laser treatment happens, early vitrectomy (39–41 weeks of PCA) should be performed. Primary vitrectomy should be performed in case of the optimal timing of laser treatment has been missed (after 36 weeks of PCV).

Impact of early postnatal exposure of red blood cell transfusions on the severity of retinopathy of prematurity.

Postnatal exposure to red blood cell transfusion (RBCT) in premature infants is an important risk factor for Retinopathy of Prematurity (ROP) progression. We hypothesized that higher number and earlier timing of RBCT are associated with worse ROP severity and result in laser treatment at an earlier postmenstrual age (PMA) in very low birth weight (≤1500 g, VLBW) infants. A retrospective medical record review of 631 VLBW infants over a 5-year period was performed. Demographic features and potential clinical risk factors including number of RBCT, ROP severity, and progression to laser treatment were collected to evaluate predictors of severe ROP. ANCOVA, pairwise post-hoc analyses, and multivariate regression were used to determine associations between frequency and timing of RBCT and ROP severity. Of the 456 eligible infants, 61 developed severe ROP (13%). There was significant correlation between number of RBCTs and ROP severity, adjusted for gestational age and birthweight (Adjusted R2 = 0.53; p < 0.001). Compared to infants with No/Mild and Type 2 ROP, infants with Type 1 ROP received more RBCTs, with higher number of RBCTs per week during the first month of life (mean RBCT in ROP No/Mild 5.7±0.4 vs Type 2 16.3±1.8 vs Type 1 22.4±1.5, p = 0.042). Laser-treated infants received a higher number of RBCTs than non-treated infants (mean RBCT 22.3 vs. 6.5, p < 0.001) but no correlation was observed between number of RBCTs and PMA at time of laser treatment. Higher number of RBCTs in early postnatal life of VLBW infants was associated with more severe ROP.

Nanomechanical Gas Sensing with Laser Treated 2D Nanomaterials

Abstract2D nanomaterials such as graphene oxide (GO), molybdenum disulfide (MoS2), and tungsten disulfide (WS2) are viable candidates for use in chemical gas sensors due to their large specific surface area available for analyte adsorption. In this work, these 2D materials are treated with a femtosecond laser process to intentionally introduce defects, dopants, and functional groups to the material for improved gas adsorption properties. The materials are coated onto a nanomechanical membrane‐type surface stress sensor (MSS) to evaluate their sensing capability toward a select group of volatile organic compounds. By utilizing the MSS platform, the approach avoids the need for 2D materials with conductive properties typically required in chemoresistive sensors. The results show that a longer laser treatment time for graphene oxide increases the sensor response, which is attributed to an increase in defects and oxygen functional groups. Doping of graphene oxide with boron nitride improves sensor response, likely due to the introduction of pyrrolic nitrogen groups with high chemical activity. Additionally, the graphene oxides demonstrate partial selectivity toward the detection of toluene, attributable to π–π interactions. MoS2 and WS2 nanoflakes also show enhanced sensor response attributed to the formation of apical/bridging sulfur bonds with high catalytic activity.

OXIDATION OF NON-METAL INCLUSIONS AND STEEL MATRIX WITH LASER ACTION

Purpose. It is necessary to study the processes of oxidation of steels during their interaction with the atmosphere at the time of laser treatment. The aim of the work was to study the processes of steel oxidation under laser action. Methods. The materials for investigation were commercial steels containing different non-metallic inclusions. The specimens of different steels with preliminary polished surface were exposed to laser beaming on the installations GOS-30M and GUANTUM-16. Methods of investigation – petrography and optical microscopy (Neophot-21) – were used. Results. It was found that at the time of laser exposure due to the interaction of the steel surface with the air atmosphere, steel oxidizes. At the same time, the role of nonmetallic inclusions in which phase transformations occur is of great importance. The oxidation products have different morphology and chemical composition, depending on the chemical composition of steel, as well as on the wettability in the steel-liquid oxide system. The structural features of oxide films are shown. The interaction of steel with the air atmosphere during laser processing is analyzed. Scientific novelty. The features of the oxidation of the surface of steels in the process of interaction with the air atmosphere under conditions of laser exposure are established. The features of phase transformations in nonmetallic inclusions and local zones of a steel matrix near inclusions are shown. The effect of inclusions on oxidative processes is shown. The features of the morphology and chemical composition of oxide films in different steels are shown. Practical significance. The use of the results obtained will allow us to develop laser processing technologies for steels with regulated surface quality parameters, which will prevent the formation of various kinds of defects. A method for removing oxide films from the surface of products is proposed.

Laser surface treatment of pure titanium: Microstructural analysis, wear properties, and corrosion behavior of titanium carbide coatings in Hank's physiological solution

Titanium exhibits poor mechanical features such as low hardness and wear resistance. In this research, we considerably enhance the hardness and wear resistance of Ti by a simple laser surface treatment method. Titanium carbide (TiC) structure was successfully generated on Ti samples by means of laser. Vickers hardness indenter, wear test, impedance spectroscopy, and polarization analyses were carried out to scrutinize the mechanical and corrosion properties of samples. Adhesion between Ti and the formed TiC structure is favorite aspect of this method. The results confirmed that the TiC layer improved the mechanical hardness of the Ti. Additionally, the friction coefficient values of laser-treated Ti samples dramatically decreased. The surface roughness of laser-treated Ti declined to its minimum value with increase in laser-treatment time. Although, laser-surface treatment of Ti did not make an evident change in the corrosion resistance of Ti in Hank's physiological solution compared to reference Ti, the escalation of Ti hardness with laser-treatment time is a favorable aspect of this method.

Clinical and Surgical Outcomes of Femtosecond Laser-Assisted Cataract Surgery (FLACS) on Hard Cataracts in the Egyptian Population.

ObjectiveTo evaluate the clinical and surgical outcomes of femtosecond laser-assisted cataract surgery (FLACS) in hard cataract of Egyptian population.SettingICare Center, Alexandria, Egypt.DesignRetrospective observational.MethodsThe study included 50 FLACS cases of 40 patients who had cataract; NO4 NC4 or more according to Lens Opacities Classification System III (LOCS III), performed between October 2018 and May 2019. The cases underwent anterior capsulotomy, lens fragmentation, and corneal incisions with the femtosecond laser. Arcuate keratotomy was performed in selected cases. Phacoemulsification and implantation of an intraocular lens are then performed.ResultsPatients mean age was 63.06 ± 7.75 yr, mean femtosecond laser energy was 12.92 ± 0.72 mJ, mean docking time was 3.00 ± 0.83 min and overall mean laser treatment time was 92.00 ± 25.01 sec. Mean laser treatment time was lower in cases that did not get astigmatic keratectomy (87.7 ± 18.97 vs 89.47 ± 13.43 sec; p < 0.73). Attempted refraction was −0.09 ± 0.52 D and achieved 12 months postoperative manifest sphere equivalent refraction (SER) was −0.19 ± 1.11 D (r = 0.8 and P˂0.001). Mean error (ME) was −0.2 ± 1.11 (range: −2.5–1.5) while mean absolute error (MAE) was 0.97 ± 0.57 (range: 0–2.5). Eighty percent and 92% of cases had 1 month postoperative SER within 1.0 D and 1.5 D, respectively. One eye (2%) had incomplete capsulotomy, 7 eyes (14%) had incomplete corneal incision and lens fragmentation was complete in all cases except 1 eye (2%). Thirty-four eyes (68%) showed postdocking conjunctival ecchymosis and 35 eyes (70%) had intraoperative miosis.ConclusionFLACS has low complication rate with effective results. High cost of technology is still the main barrier against its popularity.

Carbon dioxide laser treatment in burn-related scarring: A prospective randomised controlled trial

To investigate the effect of ablative fractional CO2 laser (AFCO2L)on burns scar appearance and dermal architecture at 6 weeks and up to 3-years post-treatment. Twenty adult patients with a burn-related scar were recruited. Inclusion criteria were a minimum scar area of 10 × 10 cm and Vancouver scar scale (VSS) score of >5 and ≥6 months since the time of injury. The region of scar was randomised to treatment/control zones. Treatment zones received 3 standardised laser treatments at 4- to 6-week intervals. All areas of scar received standard scar care. Outcome measures were recorded at baseline, 6-weeks post final treatment and up to 3 years post-treatment. Measures included blinded assessor VSS, Patient Scar Assessment Scale and histological tissue analysis. Nineteen and nine patients completed the short- and long-term studies, respectively. Clinical results revealed improvement in all scar areas over time. There was a statistically significant improvement in pain and itch in the treatment zone compared to the control zone at 6 weeks. Histological data revealed a significant increase in medium-sized collagen fibres at 6 weeks relative to the control site. Sub-group analysis according to scar age revealed greater histological improvement following laser treatment in immature scars relative to more mature scar. Results demonstrate that 3 treatments of AFCO2L significantly improve scar pain, itch and dermal architecture at 6 weeks post-treatment. Histological results suggest greater potential in treating immature scar. Further investigation into the timing of laser treatment could help assist treatment protocols.

A black phosphorus/manganese dioxide nanoplatform: Oxygen self-supply monitoring, photodynamic therapy enhancement and feedback

Selecting the timing of laser treatment is an important task for improving O2-dependent photodynamic therapy (PDT) efficiency. Here, a black phosphorus-based strategy was developed for dual-mode monitoring oxygen self-supply, enhancing photodynamic therapy, and feeding back therapeutic effect. The hybridized nanoplatform (R-MnO2-FBP) was prepared by assembly of Rhodamine B (RhB)-encapsulated manganese dioxide (R-MnO2) as O2 supplier and indicator, and fluorescein isothiocyanate (FITC)-labelled peptide-functionalized black phosphorus as the theranostic agent. The time-dependent assays suggested that the O2 release was proportional to the liberation of Mn2+ and RhB in the R-MnO2-FBP system. After specific delivery into cancer cells, R-MnO2-FBP was dissociated in the acidic and H2O2-rich environment and generated oxygen to overcome hypoxia-associated PDT resistance. In the meantime, it released both Mn2+and RhB dye, leading to dual-mode (magnetic resonance imaging/fluorescence imaging) monitoring of the oxygen self-supply process. More significantly, the imaging-guided PDT in hypoxic cells displayed 51.6% of cell apoptosis at optimizing timing of laser application, which could also be confirmed by the FITC fluorescence recovery induced by the activated caspase-3 in apoptotic cells. In vivo photonic therapy by R-MnO2-FBP further demonstrated the ability of R-MnO2-FBP to choose the timing of laser application, providing an efficient approach for the enhancement of PDT process.

Laserowa dakriocystorinostomia – zastosowanie laserów w leczeniu niedrożności dróg łzowych

Obstruction of the nasolacrimal duct, impeding the proper outflow of tears from the conjunctival sac to the nasal cavity, is a common disorder that is clinically manifested as tearing. Dacryocystorhinostomy is the creation of a direct fistula between the tear sack and the nasal cavity. The surgical approach may be external or endoscopic with or without a laser. Laser dacryocystorhinostomy is now a recognized procedure for the treatment of lacrimation resulting from nasal-lacrimal duct obstruction. The method has many advantages over conventional treatment. These advantages include: the absence of external scars, the possibility of simultaneous treatment of nasal cavity pathology, sparing of the medial lining of the eyelids, intact tear pump mechanism. The laser treatment time is also shorter with a comparable success rate to classic surgery. The introduction of a laser for tear-ditch surgery made it possible to treat tear-lacrimal obstruction in a simpler and less invasive way.

Surface Properties of Laser-Treated Molybdenum Disulfide Nanosheets for Optoelectronic Applications

Transition metal dichalcogenide two-dimensional materials have attracted significant attention due to their unique optical, mechanical, and electronic properties. For example, molybdenum disulfide (MoS2) exhibits a tunable band gap that strongly depends on the numbers of layers, which makes it an attractive material for optoelectronic applications. In addition, recent reports have shown that laser thinning can be used to engineer an MoS2 monolayer with specific shapes and dimensions. Here, we study laser-thinned MoS2 in both ambient and vacuum conditions via confocal μ-Raman spectroscopy, imaging X-ray photoelectron spectroscopy (i-XPS), and atomic force microscopy (AFM). For low laser powers in ambient environments, there is insufficient energy to oxidize MoS2, which leads to etching and redeposition of amorphous MoS2 on the nanosheet as confirmed by AFM. At high powers in ambient, the laser energy and oxygen environment enable both MoS2 nanoparticle formation and nanosheet oxidation as revealed in AFM and i-XPS. At comparable laser power densities in vacuum, MoS2 oxidation is suppressed and the particle density is reduced as compared to ambient. The extent of nanoparticle formation and nanosheet oxidation in each of these regimes is found to be dependent on the number of layers and laser treatment time. Our results can shed some light on the underlying mechanism of which atomically thin MoS2 nanosheets exhibit under high incident laser power for future optoelectronic applications.

Exocytosis of gold nanoparticle and photosensitizer from cancer cells and their effects on photodynamic and photothermal processes

We first illustrate the faster decrease of the photothermal (PT) effect with the delay time of laser treatment, in which the illumination of a 1064 nm laser effectively excites the localized surface plasmon (LSP) resonance of cell-up-taken gold nanoring (NRI) linked with a photosensitizer (PS), when compared with the photodynamic (PD) effect produced by the illumination of a 660 nm laser for effective PS excitation. The measurement results of the metal contents of Au NRI and PS based on inductively coupled plasma mass spectroscopy and the PS fluorescence intensity based on flow cytometry show that the linkage of NRI and PS is rapidly broken for releasing PS through the effect of glutathione in lysosome after cell uptake. Meanwhile, NRI escapes from a cell with a high rate such that the PT effect decays fast while the released PS can stay inside a cell longer for producing a prolonged PD effect. The effective delivery of PS through the linkage with Au NRI for cell uptake and the advantageous effect of LSP resonance at a PS absorption wavelength on the PD process are also demonstrated.

Femtosecond laser-assisted cataract surgery in a public teaching hospital setting

BackgroundTo evaluate the efficiency and practicality of femtosecond laser assisted cataract surgery (FLACS) in a public teaching hospital setting using a mobile FLACS system compared to conventional phacoemulsification cataract surgery (CPCS).MethodsNinety eyes from 90 patients underwent either FLACS or CPCS (45 in each group). Cataracts were graded using the Lens Opacities Classification System III system. Outcome measures included total surgery duration, femtosecond laser treatment time, vacuum time (VT), total phacoemulsification time (TPT) and total phacoemulsification power (TPP).ResultsNo differences were observed in the preoperative mean cataract grades and co-morbidities. FLACS took longer than CPCS with a mean difference of 5.2 ± 4.5 min (range: 0–18.8 min). The average femtosecond laser treatment time was 4.3 ± 3.4 min (range: 1–15.5 min). The VT was 2.51 ± 0.45 min (range: 1.59–4.10 min). Although not significant, TPT in FLACS showed a trend towards improvement (mean 1.0 ± 0.6 s; range: 0.1–2.4 s) compared to CPCS (mean 1.2 ± 0.6 min; range: 0.5–2.5 min). Whereas, TPP was significantly less in FLACS (mean 17.9 ± 5.0%; range: 5–27%) compared to CPCS (mean 20.3 ± 4.1%; range: 12.0–28.7%)(p = 0.031).ConclusionsThe mobile FLACS system housed in the same operating room increased the surgical duration by 5.2 min. The average VT was 2.51 min, which was lower in comparison to published experience using non-mobile FLACS systems.

In Vitro Comparison of Stone Fragmentation When Using Various Settings with Modern Variable Pulse Holmium Lasers.

There are limited data regarding optimal laser and energy settings during stone fragmentation. We assessed effects on fragmentation using a variety of energy and frequency settings with two laser systems. Artificial stones were created using BegoStone. A clear polyvinylchloride (PVC) tube with an inner diameter of 13 mm was closed at one end with a removable plug to create the in vitro ureteral and caliceal environments. The Lumenis Pulse 120H and the Cook Rhapsody H-30 holmium lasers were studied in the caliceal and ureteral models. A single urologist fragmented each stone to <2 mm. The caliceal studies assessed the time to fragmentation (n = 56). The ureteral studies measured the retropulsion distance of each stone phantom after 5 minutes of laser treatment time using different pulse width settings (n = 15). Complete treatment of the stone with the 120H required 10.9 minutes at ≥1 J vs 26.9 minutes at <1 J (p < 0.001). The H-30 showed similar results with treatment times of 11.2 minutes at ≥1 J vs 22.8 minutes at <1 J (p < 0.001). There was no significant difference in treatment time when comparing the two lasers using settings of 0.8 J × 8 Hz and 1.5 J × 10 Hz (25.5 minutes vs 24.8 minutes, p = 0.861; and 13.2 minutes vs 9.5 minutes, p = 0.061; respectively). Retropulsion distances using the 120H were 13.9 cm using long pulse, 25.2 cm using medium pulse, and 56.6 cm using short pulse. Retropulsion distances using the H-30 laser were 7 cm using long pulse and 14.5 cm using short pulse, which differed from the 120H (p < 0.001). Laser fragmentation was faster with both lasers when energy settings of ≥1 J were used. Treatment times using the 120H and the H-30 lasers were equivalent. Retropulsion distances were less with both lasers when longer pulse widths were used. The H-30 resulted in less stone retropulsion compared with the 120H.

Lead extraction with high frequency laser sheaths: a single-centre experience

Extraction of chronically implanted cardiac implantable electrophysiological devices leads can be difficult. Excimer laser-assisted extraction with 40 Hz sheaths has shown good results in challenging cases. In 2012, a new 80 Hz high-frequency laser sheath became available that delivers twice as many pulses per second. Here, we report our clinical experience with the new GlideLight 80 Hz laser sheath. Between January 2012 and August 2016, 292 leads were treated in 151 patients using 80 Hz GlideLight laser sheath. Lead extraction indications included systemic infection or lead endocarditis n = 35 (23.2%), local infection n = 73 (48.3%), lead dysfunction n = 32 (21.2%), system upgrade n = 5 (3.3%), tricuspid regurgitation n = 3 (2.0%) and other indications n = 3 (2.0). All patient-related and procedural data were collected into a database and analysed. Mean patient's age was 66.2 ± 14.4 years, 73.5% were male. Ninety-one (31.2%) atrial, 159 (54.4%) ventricular and 42 (14.4%) coronary sinus leads had to be extracted. The mean time from initial lead implantation was 98.0 ± 65.2 months. Mean laser treatment time was 67.5 ± 71.3 s, mean laser pulses delivered were 5130 ± 6592. Clinical success was achieved in 99.3% of the cases, while complete procedural success was observed in 96.7%. A failure of extraction was seen in 2 (1.3%) patients. An overall complication rate of 2.0%, including two major (1.3%) and one minor (0.7%) complications, was observed. No periprocedural mortality was seen. The new GlideLight high-frequency laser sheath allows for a high safety and efficacy in extraction of chronically implanted pacemaker- and implantable cardioverter-defibrillator leads.

Laser lead extraction allows for safe and effective removal of single- and dual-coil implantable cardioverter defibrillator leads: A single-centre experience over 12 years.

Lead extraction in patients with multiple or old leads of an implantable cardioverter defibrillator (ICD) is challenging. As adhesions are common at the side of the shock coils, we investigated success and procedural complication rates of laser lead extraction procedures in single- and dual-coil leads. Between January 2001 and June 2013, 41 single- and 145 dual-coil ICD leads were extracted from 171 patients using laser sheaths. Procedural data, success rates and complications were collected into a database and retrospectively analysed. The mean patient age was 58.2 ± 16.1 years. The mean time from initial lead implantation to extraction was 50.3 ± 18.4 and 45.8 ± 14.5 months in the single- and dual-coil group, respectively (P = 0.1). In the single-coil group, complete procedural success was achieved in 36 of 37 (97.3%) cases, and clinical success in all cases (100.0%). In the dual-coil group, complete procedural success was seen in 131 out of 134 (97.8%) patients, and clinical success in 132 of 134 cases (98.5%). The transvenous extraction failed in 2 cases (1.5%). The overall complication rate was 2.7% in the single-coil group and 3.7% in the dual-coil group, respectively (P = 1.0). No deaths occurred during the 30-day follow-up. The mean laser treatment time was 1.8 ± 1.5 min for the single-coil group and 2.5 ± 1.2 min for dual-coil group (P = 0.002). Laser lead extraction allows for safe and effective removal of ICD leads. Compared with single-coil leads, the extraction of dual-coil leads is associated with longer laser treatment times but without statistically significant differences in complications and procedural success rates.

Low-level red laser improves healing of second-degree burn when applied during proliferative phase.

The aim of this study was to investigate the effects of low-level red laser on tissue repair in rats submitted to second-degree burn, evaluating if the timing of laser treatment influences the healing process. The animals had their backs shaved and divided as follows: control group (n = 12)-rats burned and not irradiated, early laser group (n = 12)-rats burned and irradiated from day 1 after injury for five consecutive days, and late laser group (n = 14)-rats burned and irradiated from day 4 after injury for five consecutive days. Laser irradiation was according to a clinical protocol (20J/cm(2), 100mW, continuous wave emission mode, 660nm) as recommended by the laser device manufacturer. Half of the animals were sacrificed 10days after burn, and the other animals were sacrificed 21days after burn. The late laser group accelerated wound contraction 10 and 21days after burn. The late laser group accelerated reepithelialization 18days after burn. The late laser group increases the granulation tissue 10 and 21days after burn. Both irradiated groups increased type III collagen expression and TGF-β 21days after burn. Both irradiated groups increased macrophage and myofibroblast numbers 10days after burn and decreased 21days after. Low-level red laser exposure contributes to the process of tissue repair of second-degree burns, but the intervention during proliferative phase is crucial in the final outcome of the repair process.

Morphological alterations of periodontal pocket epithelium following Nd:YAG laser irradiation.

The purpose of this in vivo study was to examine morphologic alterations in the periodontal pocket epithelium with presence or absence of clinical inflammation following the use of the Neodymium: Yttrium-Aluminum-Garnet (Nd:YAG) laser irradiation. Subgingival Nd:YAG laser irradiation has been proposed as an alternative technique for treatment of chronic periodontitis. Several published studies have reported the clinical outcomes of such treatment. Twenty patients, diagnosed with moderate chronic periodontitis, were selected for the study. A total of 32 sites was identified and divided into a control (n=18) and laser-treated test groups (n=14). Probing depth (PD) and bleeding on probing (BOP) were recorded for all sites. Test sites were irradiated with an Nd:YAG laser using parameters of 2 W, 200 mJ pulse energy, and 10 pps delivered through a 320 μm diameter tip. Total laser treatment time ranged from 1 to 2 min. Following treatment, all specimens were harvested via biopsy and processed for scanning electron microscopy (SEM) and histologic examination. Control group specimens, depending upon initial PD, exhibited either a relatively smooth and intact epithelium with little desquamation (PD≤3 mm), or increasing degrees of epithelial desquamation and leukocytic infiltration at a PD of ≥4 mm. In the laser-treated test group, the specimens with PD≤3 mm that were BOP negative (-) exhibited a thin layer of epithelium that was disrupted. In the specimens with initial PD of ≥4 mm, complete removal of the epithelium whose extent and degree were increasing, was observed in the inflamed portion, while epithelium remained in the uninflamed portion. The SEM and histologic findings demonstrated the feasibility of ablating pocket epithelium with an Nd:YAG laser irradiation using parameters of 2 W of power (200 mJ, 10 pps). Furthermore, the presence or absence of clinical inflammation appeared to have an impact on the degree of laser-mediated epithelial ablation.

One-year clinical outcome after laser treatment for retinopathy of prematurity at a tertiary center in Turkey.

The purpose of the study is to evaluate the clinical outcome of laser photocoagulation (LPC) in the treatment of retinopathy of prematurity (ROP) at a referral hospital in Turkey. In this retrospective study, a chart review of infants who underwent LPC for ROP between June 2011 and June 2013 was done. Clinical and demographic characteristics, laser parameters, anatomic, and refractive outcomes were evaluated. Totally 113 infants (202 eyes) were enrolled in the study. Of the 202 eyes, 29 eyes had threshold ROP, 141 eyes had prethreshold ROP, and 32 eyes had aggressive posterior ROP (APROP) at initial interventions. The mean gestational age (GA) was 28.13 ± 1.99 weeks (range between 24 and 33 weeks), the mean birth weight (BW) was 1,147.77 ± 341.77 g (range between 530 and 2,000 g) and the mean postmenstrual age (PMA) at first laser treatment time was 35.79 ± 1.74 weeks (range between 33 and 39 weeks). The mean number of laser spots (NLS) applied for each eye was 1,358.05 ± 369.91. Eyes with APROP had higher number of NLS than eyes with threshold ROP and prethreshold ROP (P < 0.01). Anatomic outcome was favorable for 171 eyes (84.7 %) at the end of the 1-year follow-up. Refractive data were available for 56 infants (100 eyes). The mean refractive error was 0.00 ± 2.48D SE. The incidence of high myopia (>5D) and strabismus was 2 and 14.3 %, respectively. Laser photocoagulation is an effective therapy for ROP. Early and appropriate laser treatment improves the clinical outcome of the disease.

Effect of Femtosecond Laser Fragmentation on Effective Phacoemulsification Time in Cataract Surgery

To compare the effect of femtosecond laser-assisted cataract surgery on effective phacoemulsification time (EPT) with standard cataract surgery. This prospective clinical trial evaluated the feasibility of using a femtosecond laser system (Catalys Precision Laser System, OptiMedica) to perform capsulotomy and lens fragmentation in the treatment of patients with senile cataract. Patients were evaluated preoperatively with the Lens Opacities Classification System III (LOCS III). Fifty-two patients underwent standard cataract surgery and 57 patients underwent femtosecond laser-assisted cataract surgery in December 2011. Both groups underwent phacoemulsification using pulsed ultrasound energy and EPT was evaluated. Preoperative LOCS III grades were 3.4±0.9 in the femtosecond laser-assisted cataract surgery group and 3.1±0.9 in the standard group. In the femtosecond laser-assisted cataract surgery group, mean laser treatment time was 54.9 seconds and EPT was 0.16±0.21 seconds compared to 4.07±3.14 seconds in the standard group. The use of the femtosecond laser-assisted system in cataract surgery led to a lower EPT compared to the standard procedure.