Nd-YAG Research Articles

Nonlinear Refraction, Excited State Absorption, and Multiphoton Absorption of 1,3-Thiazolium-5-thiolate Mesoionic Compound.

We synthesized the mesoionic compound 2-(4-chlorophenyl)-3-methyl-4-(4-methylphenyl)-1,3-thiazole-5-thiolate and measured its refractive and absorptive nonlinear optical response in different temporal and spectral regimes. The experiments were performed by using the Z-scan technique with two pulsed light sources: the second harmonic (at 532 nm) of a mode-locked and Q-switched Nd-YAG laser (100 ps, 10 Hz) and a Ti: Sapphire laser system (100 fs, 1 kHz) operating at 800 nm. The observation and characterization of nonlinear refraction, two- and three-photon absorption, and excited state absorption of the mesoionic compound dissolved in dimethyl sulfoxide, in different concentrations, are presented and discussed with basis on the population redistribution in a three-energy-level model that allows the determination of the parameters which characterize the nonlinear response.

Effect of an low-energy Nd: YAG laser on periodontal ligament stem cell homing through the SDF-1/CXCR4 signaling pathway

BackgroundThe key to the success of endogenous regeneration is to improve the homing rate of stem cells, and low-energy laser is an effective auxiliary means to promote cell migration and proliferation. The purpose of this study was to observe whether low-energy neodymium (Nd: YAG) laser with appropriate parameters can affect the proliferation and migration of periodontal ligament stem cells (PDLSCs) through SDF-1/CXCR4 pathway.Methodsh PDLSCs were cultured and identified. CCK8 assay was used to detect the proliferation of h PDLSCs after different power (0, 0.25, 0.5, 1, and 1.5 W) Nd: YAG laser (MSP, 10 Hz, 30 s, 300 μ m) irradiation at 2th, 3rd,5th, and 7th days, and the optimal laser irradiation parameters were selected for subsequent experiments. Then, the cells were categorized into five groups: control group (C), SDF-1 group (S), AMD3100 group (A), Nd: YAG laser irradiation group (N), and Nd: YAG laser irradiation + AMD3100 group (N + A). the migration of h PDLSCs was observed using Transwell, and the SDF-1 expression was evaluated using ELISA andRT-PCR. The SPSS Statistics 21.0 software was used for statistical analysis.ResultsThe fibroblasts cultured were identified as h PDLSCs. Compared with the C, when the power was 1 W, the proliferation rate of h PDLSCs was accelerated (P < 0.05). When the power was 1.5 W, the proliferation rate decreased (P < 0.05). When the power was 0.25 and 0.5 W, no statistically significant difference in the proliferation rate was observed (P > 0.05). The number of cell perforations values as follows: C (956.5 ± 51.74), A (981.5 ± 21.15), S (1253 ± 87.21), N (1336 ± 48.54), and N + A (1044 ± 22.13), that increased significantly in group N (P < 0.05), but decreased in group N + A (P < 0.05). The level of SDF-1 and the expression level of SDF-1 mRNA in groups N and N + A was higher than that in group C (P < 0.05) but lower than that in group A (P < 0.05).ConclusionsNd: YAG laser irradiation with appropriate parameters provides a new method for endogenous regeneration of periodontal tissue. SDF-1/CXCR4 signaling pathway may be the mechanism of LLLT promoting periodontal regeneration.

Power stability of different lasers and its effect on the outcome of phase-stepping shearography experiments

We examined the effect and influence of power stability of different commonly used lasers on the outcome of phase-stepping shearographic experiments. We performed power stability measurements with three different lasers (helium–neon laser, red diode laser and green frequency-doubled neodymium laser). We subsequently performed phase-stepping shearography experiments using these lasers as light sources. We found a correlation with the quality of the shearograms and the power stability of the lasers. This enables us to compare the suitability of various lasers for phase-stepping shearography experiments and to choose the best laser for this application.

Study on surface modification and optical properties of Nd-doped phosphate glass

Using laser neodymium glass (N31) as the substrate, through ion exchange and hydrogen reduction process, a high-efficiency light absorption layer was formed from the substrate around the glass. It has been discovered that increasing the ion exchange temperature and time enhanced the exchange depth of laser glass, but excessive temperature and prolonged time will lead to corrosion of laser glass. The experiment shows that the best exchange temperature is 460°C and the best exchange time is 720min. When the hydrogen pressure was 0.8MP, the reduction temperature was 480°C and the reduction time was 12000 min, the absorption rate of the sample at 1053nm was 95.8%.

Prospects for diagnostics and treatment of neurofibromatosis type 1 in Russia

Purpose of the study. Analysis of available data on modern methods of diagnosis and treatment of neurofibromatosis type 1 (NF1) and their application in the Russian Federation. Material and Methods. The search for relevant sources was carried out in the Scopus, Web of Science, PubMed, Elibrary systems, including publications from February 1992 to December 2022. Of the 1873 scientific articles found, 48 were used to write a systematic review. Results. Neurofibromatosis type 1 (NF1) is caused by germline heterozygous mutations in the NF1 gene, which encodes the neurofibromin protein, which suppresses mitogen-activated signaling pathways necessary for cell proliferation. Clinical manifestations of NF1 are similar to Peutz–Jeghers, Laugier–Hunziker, Rusalkab–Muret–Smith, Bannayan–Zonnana, LEOPARD syndromes, neurofibromatosis type 2 and lipomatosis; therefore, to confirm the diagnosis, the most important criterion is the detection of a gene mutation by sequencing, since there are no mutagenesis hotspots in the NF1 gene. To detect 17q11.2 locus microdeletions, MLPA method is used. In Russia, such methods of molecular genetic identification of NF1 were carried out in Moscow and in the Republic of Bashkortostan. Surgical interventions using a neodymium laser and therapy with mitogen-activated protein kinase inhibitors are the most effective for the treatment of tumor syndrome. Scientific results of the use of a surgical laser in the treatment of plexiform neurofibromas and extramedullary tumors of the spinal cord have been published in Russia. Treatment of NF1 with selumetinib in Russia was announced by the interregional public organization for assistance to patients with neurofibromatosis “22/17”, which provides the drug to children with inoperable neurofibromas free of charge. Conclusion. In modern medicine, it is necessary to widely use methods for identifying mutations in the NF1 gene by creating universal panels of targeted sequencing. This will allow not only the differential diagnosis of NF1, but also the identification of the cause of chemoresistance of sporadic malignant neoplasms for the introduction of mitogen-activated protein kinase inhibitors in their treatment. Combination of this method with surgical excision of neurofibromas using a neodymium laser is optimal.

The use of combined laser therapy in treatment of skin papillomatosis

Objective — to compare the effectiveness of combined ablative and non-ablative methods of laser treatment and cryodestruction in patients with widespread papillomatosis. Materials and methods. For treatment we used the Fotona SP Spectro new laser system which has two handpieces — for ablative (wavelength 2940 nm, erbium laser) and non­ablative (neodymium Nd:YAG laser, wavelength 1064 nm) treatment methods, Fotona S11 scanner (neodymium laser, wavelength 1064 nm) and Cry­ac cryospray.Under observation were 45 patients with widespread recurrent papillomatosis, with confirmed papillomavirus infection (ICD10 code D23.5; ICD11 XH17Q9). The lesion area was the front surface of the chest, under the mammary glands, the area of the treatment area — 10 × 10 cm.According to the inclusion and exclusion criteria from the retrospective analysis of the disease histories, three groups of patients were formed: group 1 — treatment according to the accepted method of laser therapy with an erbium (ER:YAG) laser, group 2— combined ablative and non­ablative laser therapy (with erbium and neodymium lasers) and group 3 — cryodestruction of papillomas. Results and discussion. The best result and the speed of the obtained positive results of the treatment and a significantly less frequent occurrence of new elements during the observation within a year after the start of therapy were shown by group 2 — where combined laser therapy was applied. Significant advantages of laser therapy over cryodestruction were determined according to the results of this study and according to the current literature. Conclusions. The combined method of laser therapy, especially the mechanisms of the pathogenesis of the obtained therapeutic effect, require careful study. According to the obtained results, this approach is the most effective in terms of both aesthetic and therapeutic (positive effect on pathogenetic links) achievements.

A Study of Visual Improvement and Variation in IOP Following Nd-YAG Laser Capsulotomy

AIM: To study the visual improvement and to correlate the effect of energy used and number of shots with post procedural IOP spike following Nd-YAG laser capsulotomy cases. MATERIALS AND METHODS: A total of 36 patients presented with pseudophakia with PCO attending ophthalmology outpaient department at Rajah Muthiah medical college hospital during the period of October 2020 - December 2022 were included in the study. Patients with glaucoma, Uveitis, high myopia, posterior segment disorders will be excluded from the study. The patient will be subjected to visual acuity testing, detailed slit lamp examination, IOP measurement using Non-contact tonometer pre and post laser procedure and detailed fundus examination done and results were interpreted. OBSERVATION: Among the total 36 participants, 31.4% belong to age group 56 to 65 years followed by 28.6% in the age group 66 to 75 years. 51.4% were males and 48.6% were females. Of the total participants 28.6% had visual acuity of 6/24 in the affected eye and 22.9% had visual acuity of 6/36 in the affected eye.one subject presented with visual acuity of hand movements (HM) only in the involved eye.The mean pre-operative intraocular pressure among the participants was 1.85±0.73. 45.7% had preoperative IOP of 13 to 16 mmHg and 34.3% had preoperative IOP of 8 to 12. The mean number of YAG shots among the participants was 1.96±0.81. 36.3% were provided with 5 to 8 YAG shots and 33.3% with 2 to 4.The mean IOP among the participants in the preop was 14.03±2.92. The mean IOP immediately after the intervention was 15.29±2.83.The mean IOP 20 mins after the intervention was 17.43±2.96.Our study shows that the change in mean IOP after ND YAG LASER administration was significant with P value of less than 0.05 and also our study shows improvement in post laser BCVA with significant P values CONCLUSION: The study concluded that all patients had good visual recovery. The post laser IOP raise is minimal and transient. It varies with amount of laser energy used. Hence recommended to use minimum possible laser energy and must be followed up for raised intraocular pressure changes. Keywords: Intraocular pressure, Neodymium: Yttrium Aluminium GARNET Capsulotomy.

THE EFFICACY OF FRACTIONAL PICOSECOND 1064NM ND-YAG LASER IN THE TREATMENT OF ATROPHIC ACNE SCARS

Objectives: To evaluate the efficacy of fractional picosecond 1064nm Nd-YAG laser in the treatment of acne scar. Methods: This is a uncontrolled prospective study. 32 patients with atrophic acne scars were enrolled into study to receive 3 sessions of fractional picosecond 1064nm Nd-YAG laser treatment at 4-week intervals. The laser settings were 0.8J/cm2 in fluence, 8-mm spot size, 5% coverage and 5Hz in repetition rate. The primary outcome was the change in Goodman and Baron’s quantitative and qualitative grading scale between baseline and 3 months after the last treatment. Results: Goodman and Baron scale significantly decreased after the treatments with 12,1 (± 5.51) points in mean reduction (p &lt; 0.001). There was a significant improvement in scar color, in which the red scar color reduced from 24.5% to 3.8% (p &lt; 0.001). There were 73.1% of patients improved a scar degree. The number of scars (including icepick, rolling, and boxcar scars) also significantly decreased from after treatment (p &lt; 0.001). No patient developed postinflamatory hyperpigmentation. Conclusion: Fractional picosecond 1064nm Nd-YAG laser is an effective option for treatmenting atrophic acne scars.

Effect of target thickness and laser irradiance on the back-reflection-enhanced laser-induced breakdown spectroscopy signal in glass

In the work that is being presented here, the effect of sample thickness and laser irradiance on the reduction of the signal-to-background ratio SBG and the plasma parameters, specifically electron temperature and electron density, is being investigated using back-reflection-enhanced laser-induced breakdown spectroscopy (BRELIBS). Copper and silver discs that had been highly polished were attached to the back surface of the glass target, and the Nd-YAG laser beam that was focused on the front surface of the target was tuned to its fundamental wavelength. The thicknesses of the transparent glass samples that were analysed were 1 mm, 3 mm, and 6 mm. One is able to achieve a range of different laser irradiance levels by adjusting the working distance that exists between the target sample and the focusing lens. The end result of this is that the signal-to-background ratio in the BRELIBS spectra of thicker glass samples is significantly lower as compared to the ratio in the spectra of thinner glass samples. In addition, a significant influence of modifying the laser irradiance (by increasing the working distance on the SBG ratio) is seen at various glass thicknesses for both BRELIBS and LIBS, with BRELIBS having a better SBG. Nevertheless, the laser-induced plasma parameter known as the electron temperature has not been significantly impacted by the decrease in the glass thickness.

Innovation in rigid bronchoscopy-past, present, and future.

German laryngologist Gustav Killian performed the first "Direkte Bronchoskopie" using a rigid bronchoscope to extract a foreign airway body from the right main bronchus over a hundred years ago, transforming the practice of respiratory medicine. The procedure instantaneously became popular throughout the world. Chevalier Jackson Sr from the United States further advanced the instrument, technique, safety, and application. In the 1960s, Professors Harold H. Hopkins and N.S. Kapany introduced optical rods as well as fiberoptics that led Karl Storz to develop the cold light system improving endoluminal illumination, achievements that ushered in the modern era of flexible endoscopy. Several diagnostic and therapeutic procedures became possible such as transbronchial needle biopsy, transbronchial lung biopsy, airway electrosurgery, or cryotherapy. Dr. Jean-François Dumon from France advanced the use of Nd-YAG laser in the endobronchial tree and created the dedicated Dumon silicone stent introducing the whole new field of interventional pulmonology (IP). This major milestone revitalized interest in rigid bronchoscopy (RB). Now, advancements are being made in stenting, instrumentation, and education. RB robotic technology advancements are currently anticipated and can potentially revolutionize the practice of pulmonary medicine. In this review, we describe some of the most substantial advances related to RB from its beginning to the modern era.

Combined use of laser therapy and pneumotherapy of 5-fluorouracil and corticosteroid in patients with hypertrophic scars

Therapy of patients with hypertrophic scars is a rather difficult task, and the amount of treatment methods directly depends on the duration of the existence of the scar, its size and localization. There were 34 patients under observation (mean age 37.4 ± 4.2 years) with hypertrophic scars (the average duration of the scar was 6.7 ± 2.3 months), who were prescribed two procedures of pneumokinetic therapy with glucocorticosteroid and 5-fluorouracil with at intervals of 2 months, a month later, laser therapy was performed using a neodymium laser. in patients with hypertrophic scars after the use of a combined physiotherapy technique, there were significant changes in the parameters of ultrasound scanning: An increase in the thickness of the epidermis by 1.5 times (with the restoration of the architectonics of the epidermal layer), a decrease in the thickness of the dermis by 2.1 times. The acoustic density of the dermis increased by 2.5 times.

Optimization of Variable Parameters in Diode Pumped SHG Nd-YAG Lasers

Second Harmonic Generation (SHG) produces many parameters which are the consequences of interaction of fundamental incident power &nbsp;and those created inside the second harmonic cavity, external employing monolithic crystals. In this study, a low power of &nbsp;continuous wave (CW) Nd-YAG laser with principal output of &nbsp;and maximum power of &nbsp;theoretically was used. The crystal is [MgO: LiNbO3] which is lithium niobate, magnesium oxide doped with specific optical properties explained, the parameters in questions are both reflection &nbsp;and circulating &nbsp;powers in the second harmonic cavity. Both are functions of fundamental incident power . The results are compared with their experimental correspondents and interpretation for the causes is discussed.

Synthesis, band gap structure and third order non-linear optical properties of zinc tungsten oxide nanocomposite using a single CW laser beam.

In this study, a composite of zinc tungsten oxide nanoparticles (W-ZnO NPs) has been synthesized via mixing Na2WO4 and zinc acetate in water, followed by dropwise addition of NaOH. The synthesized W-ZnO NPs were characterized using measurement methods such as XRD, dynamic light scattering (DLS), Scanning electron microscopy (SEM) and UV-Vis. Also, the results were compared with the pure synthesized ZnO and WO3 NPs. Non-linear optical properties of the synthesized composite were measured using the Z-scan technique with a continuous wave Nd-Yag laser. The negative non-linear absorption coefficient of the components was obtained which indicates that the saturation absorption occurred in this composite. In comparison with pure ZnO NPs, non-linear absorption decreases which can be attributed to the negligible optical response of WO3 structures. Also, the negative value of the close aperture Z-scan curve shows that the thermal lensing effect is the main reason for the third-order non-linear refraction.

Comparison of a single treatment with a Q-switched ruby laser and a Q-switched Nd:YAG neodymium laser for blue and black tattoo removal

BACKGROUND: Black and blue tattoo pigment are the most commonly used colors and can be injected at different depths. The effectiveness of tattoo removal is related to the selected wavelength, type of laser, energy parameters, number of procedures performed. Q-switched (QS) ruby and neodymium (Nd:YAG) lasers are most effective in removing blue and black tattoos due to their high peak power and ability to break the pigment into small particles that are absorbed by the macrophage system. In the literature available to us, it was not possible to find data on comparative efficacy and adverse events in their application.&#x0D; AIM: comparison of single treatment of blue and black tattoos with QS ruby laser (wavelength 694 nm) and neodymium Nd:YAG laser (wavelength 1064 nm).&#x0D; MATERIALS AND METHODS: 35 patients with blue and black tattoos were included in our study. The tattoos were divided into two parts or two adjacent tattoos were used on the same part of the body with the same density and color of the tattoo pigment; one side was treated with a ruby laser and the other with a neodymium laser. The comparison took into account the instantaneous reaction, the result of processing and side effects. Statistical significance was set at a power level 0.05.&#x0D; RESULTS: Edema and erythema were more common immediately after ruby laser treatment (power 0.05). The neodymium QS laser lightened tattoos better than the ruby QS laser after a single treatment (0.05 power). There was no difference in side effects between the two types of lasers.&#x0D; CONCLUSIONS: Neodymium Nd:YAG QS laser shows more efficiency and fewer procedures when removing blue and black tattoos. The instantaneous reaction after treatment with this type of laser is less pronounced than after the ruby laser.

Intraocular Pressure Changes after Neodymium Doped: Yttrium-Aluminum-Garnet (Nd: Yag) Laser Capsulotomy

Purpose: To assess the difference in intraocular pressure before and after Nd-YAG laser posterior capsulotomy. Study Design: Quasi-experimental study. Place and Duration of Study: Layton Rahmatulla Benevolent Trust Eye Hospital, Karachi, from July 2021 to October 2021. Methods: Patients of both gender with posterior capsular opacification (PCO) after cataract surgery, were included. Age ranged between 40 and 60 years. Patients with less than 6 months of surgery were excluded. Patients with posterior segment pathology like glaucoma, uveitis, high myopia, diabetic retinopathy, macular pathology, and hereditary fundus dystrophies were excluded from the study. After detailed history, complete ocular examination was performed. After pupil dilatation, YAG laser capsulotomy was done.IOP was measured with Goldmann Applanation Tonometer after instilling a topical anesthetic agent. Post-YAG, IOP was again measured at 1 hour and on day 1. Data was analyzed using SPSS version 25. Paired T-tests were used to assess the significance of any change in IOP. Results: Ninety eyes of 90 patients were inducted into the study in which 51 (57%) were male and 39 (43%) were female. The age varied from 40 to 60 years (mean 52.3 ± 10.25 years). There was no statistically significant difference between pre-YAG and post-YAG IOP. Similarly, no difference in IOP was found depending upon the age of the patients. No significant change was observed after 1 hour and 1 day in both groups with P &gt; 0.05. Conclusion: This showed no significant change in intraocular pressure at one hour and one day, after Nd-YAG laser posterior capsulotomy.

Composite-veneering of polyether-ether-ketone (PEEK): evaluating the effects of different surface modification methods on surface roughness, wettability, and bond strength.

This study aimed to evaluate the effects of different surface modification methods on the surface roughness, contact angle, and bond strength of composite-veneer materials of polyether-ether-ketone (PEEK). Fifty-five specimens (n = 11) with a size of 7 × 7 × 2mm were cut out from PEEK discs. The specimens were divided into five groups with different surface treatments: no treatment (NO) (control group), sulfuric acid (SA), plasma (P), femtosecond laser (FS), and Nd-YAG laser (NY). After the surface treatments, the specimens were checked for roughness, contact angle, and bond strength of the composite-veneer material. Data were analyzed with the Welch test for roughness, contact angle, and bond strength parameters. Individual Pearson correlation tests were executed for all surface treatment groups to determine any significant correlations among roughness, contact angle, and bond strength parameters (P < .001). Roughness, contact angle, and bond strength values were affected by surface modification methods (P < .001). In comparison to the control group, NY and FS treatments increased the surface roughness and bond strength; they also provided bond strength values comparable to the SA group. When the relationship between the variables was examined, no correlation was seen between roughness, contact angle, and bond strength values for the NY, SA, and control groups (P > .05); however, significant correlations were determined between the contact angle and surface roughness values for the P and FS groups (P < .05). Femtosecond and Nd-YAG laser treatments are viable surface modification alternatives to the sulfuric acid treatment for the PEEK material.

To Evaluate the Efficiency with which Patients who have had ND-YAG Laser Capsulotomy may Reduce their Intraocular Pressure with a Predetermined Dosage of Brimonidine/Tart-Rate [0.2%] and Timalol/Maleate [0.5%

Background: The most prevalent type of glaucoma, known as primary open-angle glaucoma (POAG), is a major contributor to preventable blindness worldwide. Treating hypertensive ocular diseases, such as elevated intraocular pressure (IOP), may decrease the development and progression of (POAG). Objective: this study was to evaluate the efficiency with which patients who have had Nd-Yag laser capsulotomy may reduce their intraocular pressure with a predetermined dosage of brimonidine tartrate 0.2% and timalol maleate 0.5% Method: From January 2022 to January 2023, a prospective, randomized trial was conducted in the Department of Ophthalmology at KMC and KTH Peshawar. Sample size 100 patients who had undergone (Nd-Yag-laser capsulotomy) were enrolled in the study. After random selection, 50 patients were divided into two groups. Group 1 received (timolol maleate) [0.5%] BID daily and Group 2 received [0.5%] (timolol maleate) in a constant proportion in addition to (0.2%) brimonidine tartrate BID daily. Intraocular pressure (IOP) was assessed at the beginning, after one week, three weeks, and four weeks. The mean IOP at 4 weeks served as the major outcome indicator. Mean IOP at 1 week, 3 week, and 4 week intervals were included as secondary end measures. Descriptive statistics, the Student's t-test, and one-way ANOVA were used to analyse the data. Results: Mean IOP at baseline not significant with in two groups [P=0.36]. At one week, the mean IOP in the timolol group was 15.3 3.3 mmHg, compared to 13.1 2.9 mmHg in the timolol/brimonidine (P=0.001). At 3 weeks, (mean IOP) in the (timolol-group) was 14.4 3.1 mmHg, compared to 12.5 2.8 mmHg in the timolol/brimonidine group (p 0.001). At 4 weeks, the mean IOP in the timolol group was 13.8 3.1 mmHg, compared to 11.7 2.7 mmHg in the timolol/brimonidine group (p 0.001). Conclusion: this study show that persons who have had Nd-Yag laser capsulotomy benefit from a blending together timolol maleate [0.5%] and brimonidine tartrate [0.2%] to significantly reduce intraocular pressure (IOP). Keywords: Intraocular Pressure,ttimolol- maleate, brimoni-dine- tartrate, Nd-Yag Laser-Capsulotomy

PbWO4 Acoustic Properties Measurement by Laser Ultrasonics with the Aim of Optical Damage Recovery

The paper, at first, discusses theoretical aspects of acoustic wave propagation in lead tungstate (PWO). After that, it introduces the application of laser ultrasonics to PWO crystals with the aim of measuring the acoustic properties and the absorbed energy. A specific set-up has been developed to deposit energy in the crystals by means of shock waves generated by a pulsed Nd-YAG laser. We measured the acoustic properties of the PWO crystals along the crystallographic c^ axis and measured the acoustic energy absorption. Calculations confirmed that the majority of the energy has been absorbed in the samples. Since in scintillating crystals the radiation damage leads to a decrease in the optical transmission, the paper formulates the hypothesis that the laser energy absorbed can sustain recovery of the optical transmittance properties. Preliminary tests of light transmittance measurements showed a systematic improvement of optical transmittance after laser treatment in a series of PWO samples. These results are consistent and in agreement with the hypothesis, and they support the feasibility of a laser-based method to recover radiation-damaged crystals.

Prophylactic role of Timolol to prevent rise of intraocular pressure after Nd-YAG laser posterior capsulotomy

This study was conducted to know the effectiveness of topical 0.5% timolol maleate for the intraocular pressure rise after Nd-YAG laser posterior capsulotomy. Ninety-six eyes of 92 patients undergoing Nd-YAG laser posterior capsulotomy were randomly selected for pretreatment with topical 0.5% timolol maleate, 48 patients (Group A) or control 48 patients (Group B). The mean IOP of the group A was 14.8±3.0 mmHg before capsulotomy and 15.7±3.4 mmHg after capsulotomy (P &gt;0.05), whereas 15.1±3.3 mmHg and 17.2±4.3 mmHg (P &lt;0.05) of the group B. There was no statistically significant difference between the two groups with regard to mean IOP before capsulotomy (P &gt;0.05), but statistically significant difference between two groups after capsulotomy (P &lt;0.05). Pretreatment with topical 0.5% timolol maleate is effective in preventing IOP elevation after Nd-YAG laser posterior capsulotomy.

The evaluation of the effect of Nd-YAG capsulotomy on posterior ocular vascular structures by Optical coherence tomography angiography

BackgroundWe aimed to examine the changes in retinal, choroidal and optic nerve head vascular structures after Nd-YAG laser application due to posterior capsule opacification after cataract surgery by Optical coherence tomography angiography (OCTA). MethodsFifteen eyes of 15 patients who have posterior capsule opasification and underwent Nd-YAG laser capsulotomy were included in the study. OCTA imagings of patients were made before and one hour, one week and one month later after the laser procedure. ResultsNo significant change was determined before and after capsulotomy in macular thickness measurements, flow areas and vessel densities (all p > 0.05). Optic nerve head vessel densities and flow areas didn't differ preoperatively and postoperatively (p > 0.05). ConclusionsNd-YAG laser capsulotomy for posterior capsule opacification has no detectable effect on macular and optic nerve flows and vessel densities.