Objective intraoperative assessment of vitreous f loaters localization in YAG-laser vitreolysis

Purpose. To develop an optical method for assessing the localization of vitreous floaters in the vitreous cavity and to evaluate its efficacy compared to ultrasound assessment. Material and methods. The study included 35 patients (35 eyes) with Weiss ring. All the patients underwent echobiometry, as well as measurement of the distance from the vitreous floaters (VF) to the lens posterior capsule or towards retina by ultrasound and developed optical methods. Results. The mathematical modeling and the diopter difference between the slit-lamp oculars were used to develop a formula for the safe position of the VF in the vitreous cavity calculation. A comparative analysis of ultrasound and optical methods measurement results have showed their comparability. The values of the "limits of agreement" with 95% confidence intervals were: -0.02 [-0.07; 0.01] - the lower "consistency limit" and 0.25 [0.20; 0.29] - the upper "consistency limit". The average difference between methods with a 95% confidence interval was 0.11 [0.08; 0.13]. Conclusions. The developed optical method for assessing the safe localization of VF in the vitreous cavity showed comparable results with the ultrasound measurements. Futhermore, optical method allows to intraoperatively control the safe distance from the VF to the intraocular structures, thereby reducing the risk of YAG-vitreolysis complications. Key word: YAG laser vitreolysis, vitreous floaters, safe distance of vitreous floaters.

Download Full-text

Research of the Photo-Optical Method Application for Measuring Selected Data on the Movement of a Parachute for Type M-282

Applied Sciences ◽

10.3390/app11125637 ◽

2021 ◽

Vol 11 (12) ◽

pp. 5637

Author(s):

Peter Kaľavský ◽

Róbert Rozenberg ◽

Peter Korba ◽

Martin Kelemen ◽

Matej Antoško ◽

...

Keyword(s):

Optical Method ◽

Training Programs ◽

Performance Standard ◽

Motion Data ◽

Innovative Methods ◽

Measurement Results ◽

Different Types ◽

Vertical Speed ◽

Individualized Training ◽

Minimum Performance

Testing in the field of parachute technology provides space for the application of new and innovative methods of measuring operating and functional parameters. The main aim of the paper is to present the results of research for the verification of the photo-optical method of measuring the vertical speed of the M-282 parachutes, and for its use in testing, collecting, and investigating motion data in parachuting. As part of this measuring technology, twelve jumps were performed. It was verified that the experiment was completed for the M-282 parachute according to the regulation of SAE AS 8015B “Minimum Performance Standard Parachute Assemblies and Components”. An analysis of the influencing factors and quantification of their influence on the uncertainty of the measurement results was also performed. The results of the measurement achieved by using the photo-optical method were compared with the measurement with the electronic variometer FLYTEC 4030. The vertical speed of the M-282 parachute (4.655 m·s−1) defined by the photo-optical method is significantly similar to the vertical speed of the M-282 parachute (4.662 m·s−1) defined by FLYTEC 4030. We can state that the process of identifying the vertical speed of the parachute by the photo-optical method was correct. This is a suitable method of evaluating motion data in the operation of M-282 type parachutes. In the following research for generalization of the methodology, we assume the performance of more than 60 experimental jumps using different types of parachutes, digital sensors (cameras), and a photo-optical method to examine motion data and formulate recommendations for testing, investigative applications, individualized training programs, and aspects of parachuting injury prevention.

Download Full-text

Safety and Efficacy of YAG Laser Vitreolysis for the Treatment of Vitreous Floaters: An Overview

Advances in Therapy ◽

10.1007/s12325-020-01261-w ◽

2020 ◽

Vol 37 (4) ◽

pp. 1319-1327 ◽

Cited By ~ 1

Author(s):

Andreas Katsanos ◽

Nikoleta Tsaldari ◽

Konstantina Gorgoli ◽

Fotios Lalos ◽

Maria Stefaniotou ◽

...

Keyword(s):

Safety And Efficacy ◽

Yag Laser ◽

Vitreous Floaters

Download Full-text

Efficacy and safety of yttrium-aluminium garnet (YAG) laser vitreolysis for vitreous floaters

Journal of International Medical Research ◽

10.1177/0300060518794245 ◽

2018 ◽

Vol 46 (11) ◽

pp. 4465-4471 ◽

Cited By ~ 1

Author(s):

Jihan Luo ◽

Xiaoju An ◽

Yi Kuang

Keyword(s):

Anterior Segment ◽

Retinal Nerve Fibre Layer ◽

Chinese Patients ◽

Yttrium Aluminium Garnet ◽

Efficacy And Safety ◽

Yag Laser ◽

Yttrium Aluminium ◽

Post Procedure ◽

Vitreous Floaters ◽

Randomised Controlled

Objective To examine the efficacy and safety of yttrium-aluminium garnet (YAG) laser vitreolysis for the treatment of vitreous floaters. Methods Consecutive adult patients with symptomatic vitreous floaters who attended Chongqing General Hospital from April to December 2016 were included in this prospective study. Patients had >3 mm between the vitreous opacity and retina/lens and acceptable quality peri-papillary Optical Coherence Tomography (OCT) images (i.e., signal strength ≥5). Those with history of glaucoma, severe cataracts, vitreous haemorrhages, retinal holes and/or macular disease were excluded from the study. Best corrected visual acuity (BCVA) and non-contact intraocular pressure (IOP) were measured before and for up to 6 months post-YAG laser vitreolysis. Anterior segment photography and peripapillary retinal nerve fibre layer (RNFL) measured by OCT were taken before and 6 months post-procedure. Questionnaires on patient satisfaction were completed 6 months post-procedure. Results No statistically significant differences in BCVA and IOP were observed before or after treatment. Anterior segment photography showed that vitreous opacities partially or completely disappeared after YAG laser treatment. The thickness of RNFL in four directions (upper, below, nasal and temporal) was not statistically significant different before or 6 months after the procedure. 75% patients reported significant improvement and 25% reported moderate improvement. Conclusion The results of this study conducted in a cohort of 30 Chinese patients showed that YAG laser vitreolysis was a well-tolerated and effective treatment for vitreous floaters. Randomised, controlled trials involving large numbers of participants monitored over an extended follow up period are required to confirm these results.

Download Full-text

Efficacy and safety of Nd:YAG laser vitreolysis for symptomatic vitreous floaters: A randomized controlled trial

European Journal of Ophthalmology ◽

10.1177/1120672120968762 ◽

2020 ◽

pp. 112067212096876

Author(s):

Gustavo D Ludwig ◽

Henrique Gemelli ◽

Guilherme M Nunes ◽

Pedro D Serracarbassa ◽

Márgara Zanotele

Keyword(s):

Adverse Events ◽

Contrast Sensitivity ◽

Nd:Yag Laser ◽

Visual Disturbance ◽

Control Group ◽

Efficacy And Safety ◽

Yag Laser ◽

Vitreous Floaters ◽

Significant Difference ◽

Laser Group

Background: Vitreous floaters are a common and inconvenient phenomena. This study aims to examine the efficacy and safety in treating vitreous floaters using Nd:YAG laser vitreolysis. Methods: In this prospective double-blinded randomized clinical trial 24 eyes of twenty-four patients were randomized into intervention with YAG laser vitreolysis and control groups. Primary outcomes were visual disturbance on a 10-point scale, qualitative changes in a 4-level scale, contrast sensitivity measured with the Pelli-Robson table and the National Eye Institute Visual Functioning Questionnaire 25 (NEI VFQ-25). Secondary results included objective change in vitreous opacities, best-corrected visual acuity (BCVA), variation in intraocular pressure (IOP) and other adverse events. Results: Twenty-one patients (21 eyes; 5 male, 16 female) were enrolled in this study (mean age 62 ± 7.9 years), three were lost during follow-up. In the YAG laser group, the 10-point visual disturbance score improved a mean of 4.7 points ( p < 0.001) compared to the control group that improved 2.1 ( p = 0.09). The YAG laser group reported greater subjectively symptomatic improvement (77%) than controls (25%). NEI VFQ-25 revealed improved general vision (75.8 versus 59.2; p = 0.037) and in mental health at 6 months (84.3 versus 70.3; p = 0.048). There was no significant difference in contrast sensitivity ( p = 0.848) and in IOP ( p = 0.505). No differences in adverse events between groups were identified. Conclusion: Vitreolysis with Nd:YAG laser improves visual results in patients with symptomatic vitreous floaters, without adverse events considered clinically relevant. Other trials with a larger number of participants are required to corroborate these results.

Download Full-text

Dexamethasone Implant-associated Vitreous Floaters and Symptom Improvement by YAG Laser Vitreolysis

Journal of Retina ◽

10.21561/jor.2018.3.2.82 ◽

2018 ◽

Vol 3 (2) ◽

pp. 82-87

Author(s):

Seong Joon Ahn ◽

Ji Hong Kim ◽

Sang Hyup Lee ◽

Byung Ro Lee

Keyword(s):

Symptom Improvement ◽

Dexamethasone Implant ◽

Yag Laser ◽

Vitreous Floaters

Download Full-text

Polymerization Shrinkage and Degree of Conversion of New Zirconia-Reinforced Rice Husk Nanohybrid Composite

European Journal of Dentistry ◽

10.1055/s-0040-1713951 ◽

2020 ◽

Vol 14 (03) ◽

pp. 448-455 ◽

Cited By ~ 1

Author(s):

Galvin Sim Siang Lin ◽

Nik Rozainah Nik Abdul Ghani ◽

Noor Huda Ismail ◽

Kiran Prabhakar Singbal ◽

Noraida Mamat Mohd Yusuff

Keyword(s):

Rice Husk ◽

Optical Method ◽

Composite Resins ◽

Degree Of Conversion ◽

Optical Methods ◽

Polymerization Shrinkage ◽

Nanohybrid Composite ◽

Group 3 ◽

Group 2 ◽

Group 1

Abstract Objectives This study aimed to compare the polymerization shrinkage and degree of conversion of new zirconia-reinforced rice husk nanohybrid composite with commercialized microhybrid and nanofilled composites. Materials and Methods Overall, 180 samples were used for polymerization shrinkage (buoyancy and optical methods) and degree of conversion tests in which they were divided into Group 1, nanofilled composite (Filtek-Z350- XT; 3M ESPE, St Paul, MN 55144-1000, USA), Group 2, microhybrid composite (Zmack-Comp), and Group 3, nanohybrid composite (Zr-Hybrid). Polymerization shrinkage test was performed using buoyancy and optical methods. For buoyancy method, samples were weighed in air and water to calculate the shrinkage value, whereas, for optical method, images of nonpolymerized samples were captured under a digital microscope and recaptured again after light-cured to calculate the percentage of shrinkage. Degree of conversion was tested using Fourier-transform infrared spectroscopy spectrometer. Statistical Analysis Data were analyzed using one-way analysis of variance complemented by post hoc Dunnett’s T3 test for polymerization shrinkage and Tukey’s honestly significant difference test for degree of conversion. Level of significance was set at p < 0.05. Results Group 3 demonstrated similar polymerization shrinkage with Group 1, but lower shrinkage (p < 0.05) than Group 2 based on buoyancy method. However, optical method (p < 0.05) showed that Group 3 had the lowest shrinkage, followed by Group 1 and lastly Group 2. Besides, Group 3 showed a significantly higher degree of conversion (p < 0.05) than Group 1 and comparable conversion value with Group 2. Conclusions Zirconia-reinforced rice husk nanohybrid composite showed excellent shrinkage and conversion values, hence can be considered as an alternative to commercially available composite resins.

Download Full-text

Novel OCT Application and Optimized YAG Laser Enable Visualization and Treatment of Mid- to Posterior Vitreous Floaters

Ophthalmic Surgery Lasers and Imaging Retina ◽

10.3928/23258160-20181002-10 ◽

2018 ◽

Vol 49 (10) ◽

pp. 806-811 ◽

Cited By ~ 3

Author(s):

Inder Paul Singh

Keyword(s):

Yag Laser ◽

Vitreous Floaters

Download Full-text

An Optical Method for Immediate Evaluation of Microfoam Stability in Foam Sclerotherapy

Skin Pharmacology and Physiology ◽

10.1159/000514322 ◽

2021 ◽

Vol 34 (3) ◽

pp. 128-134

Author(s):

Taoping Bai ◽

Wentao Jiang ◽

Lin Liang ◽

Yalan Li ◽

Yubo Fan

Keyword(s):

Half Life ◽

Optical Method ◽

Clinical Performance ◽

Foam Stability ◽

Life Time ◽

Optical Methods ◽

Foam Sclerotherapy ◽

Drainage Rate ◽

Short Period ◽

The Stability

Objectives: The objective of our study was to develop an optical method that instantly evaluates the stability of sclerosing foam, which would enable early predictions of the clinical performance of the foam and reduce the occurrence of clinical side effects. Methods: Based on the principle of light scattering, we developed a method to optically test foam stability and verified it experimentally using sodium morrhuate (2 mL; 0.05 g/mL) and carbon dioxide. A self-made foam preparation instrument was used to achieve a preparation speed of 275 mm/s. The liquid-gas ratios were considered as 1:3, 1:4, and 1:5. Curves of illuminance with respect to the drainage rate and decay time were obtained. By fitting the curve, the relationship between foam half-life time (FHT) and foam decay was obtained. Thus, foam stability was evaluated using the initial illuminance value; the foam transfer time was approximately 3 s. Results: The experimental FHT varies between 205 and 232 s. Illuminance is exponentially related to drainage rate and linearly related with time. FHT can be expressed by the initial illuminance and illuminance curve fitting coefficients. The half-life of the foam decreases as the initial illuminance value increases, for the same sclerosing drug. The suitability of foam stability is determined by the position of the initial value in the chart. Conclusion: Optical methods are feasible for evaluating foam stability over a short period of time. Clinically predicting the stability of freshly prepared foam can reduce number of incidences of further complications. This will promote the development of foam sclerotherapy and provide a basic understanding of the internal mechanical properties of foam.

Download Full-text