scholarly journals Features of inflammatory and regenerative reaction to excimer laser refractive keratectomy with photoprotection

2017 ◽  
Vol 98 (1) ◽  
pp. 53-57
Author(s):  
I M Kornilovskiy ◽  
E M Kasimov ◽  
A I Sultanova
Keyword(s):  
Excimer Laser ◽  
Corneal Stroma ◽  
Corneal Tissue ◽  
Aseptic Inflammation ◽  
Excimer Laser Ablation ◽  
Regenerative Response ◽  
Negative Effect ◽  
Inflammatory Drugs ◽  
Myopic Astigmatism ◽  
Observation Period

Aim. To study the features of inflammatory and regenerative reaction to excimer laser refractive keratectomy with photoprotection.Methods. Clinical cases of 560 excimer laser refractive keratectomies with photoprotection in 280 patients with myopia and myopic astigmatism of different severity. The observation period varied from 1 month to 2.5 years.Results. The study showed that intensity of aseptic inflammation and the type of regenerative response are influenced by the amount of evaporated corneal tissue, which correlates with the severity of myopia. Moreover, in case of equal severity of myopia and amount of evaporated tissue inflammatory and regenerative response was less prominent if excimer laser ablation was performed under the superficial corneal flap. In this case epithelial stromal corneal flap allowed reducing the negative effect of ultraviolet exposure and interaction between proinflammatory epithelial and stromal cytokines. At photorefractive ablation of corneal stroma saturated with 0.25% isotonic riboflavin solution aseptic inflammatory and regenerative response, intensity and duration of corneal syndrome decreased. Due to such technique of photorefractive keratectomy stromal layers saturated with riboflavin absorbed the secondary ultraviolet induced by ablation. Clinical observation demonstrated the need for additional photoprotection by glasses from external unltraviolet in all types of photorefractive surgeries on cornea up to full recovery of visual and optometric parameters. Use of photoprotection during excimer laser refractive ablation allowed achieving early stabilization of vision and refraction, decreasing the duration of postoperative steroidal and nonsteroidal anti-inflammatory drugs intake by one third in average.Conclusion. Local photoprotection with riboflavin during excimer laser refractive keratectomy and photoprotection by glasses from external ultraviolet reduce the risk of oxidative stress in the cornea, postoperative aseptic inflammatory and regenerative reactions, promote stabilization of visual, optic refractive parameters and improve their predictability.

scholarly journals New Possibilities of Refractive Modeling of the Cornea by the Radiation of an Argon-fluorine Excimer Laser

2021 ◽  
pp. 7-18
Author(s):  
I. M. Kornilovskiy
Keyword(s):  
Excimer Laser ◽  
Clinical Studies ◽  
Ablation Threshold ◽  
Objective Assessment ◽  
Corneal Stroma ◽  
Strength Properties ◽  
Secondary Radiation ◽  
Total Radiation Dose ◽  
Corneal Nerves ◽  
Negative Effect

Purpose: To consider new possibilities of refractive modeling of the cornea by the radiation of an argon-fluorine excimer laser in ablative and subablative modes after saturation of the stroma with riboflavin. Materials and Methods: Experimental (20 pork, 90 rabbit eyes) and clinical studies on photorefractive and phototherapeutic operations with saturation of the corneal stroma with riboflavin (610 operations) were analyzed. To activate riboflavin, secondary radiation induced by exposure to ablative and subablative energy densities was used. A quick transition to energy densities below the ablation threshold without additional calibrations was carried out using a “Microscan Visum-500” excimer laser (Optosystems, Russia). An objective assessment of the refractive keratomodelling effect and visual results was carried out according to the data of complex optometric studies. Results: Experimental and clinical studies have shown the advantages of refractive keratomodeling by theradiation of an argon-fluorine excimer laser in ablative and subablative modes after saturation of the stroma with riboflavin. Isotonic 0.25% riboflavin solution did not affect the accuracy of refractive ablation and blocked the negative effect of induced secondary radiation on keratocytes and corneal nerves. This reduced the aseptic inflammatory response and the risk of developing an irreversible form of fibroplasia. Ablation with riboflavin initiated a damped crosslinking effect, which increased the photoprotective and strength properties of the thinned cornea. A refractive keratomodelling effect was found when energy densities were applied below the stromal ablation threshold. The magnitude of this refractive effect depended on the total radiation dose and the topography of the affected area. This approach made it possible to implement laser-induced refractive keratomodeling without ablation of the corneal stroma. Conclusion: Refractive modeling of the cornea by the radiation of an argon-fluorine excimer laser in ablative and subablative modes after saturation of the stroma with riboflavin opens up new possibilities in laser correction of ametropia.

New Developments in the Lenticule Extraction Procedure

2014 ◽  
Vol 08 (01) ◽  
pp. 31
Author(s):  
Jesper Hjortdal ◽  
Anders Ivarsen ◽  
◽  
Keyword(s):  
Laser Ablation ◽  
Extraction Procedure ◽  
Corneal Stroma ◽  
Corneal Tissue ◽  
Safe Procedure ◽  
Visual Recovery ◽  
New Developments ◽  
Excimer Laser Ablation ◽  
Technological Developments ◽  
Lenticule Extraction

For the last 20 years controlled excimer laser ablation of corneal tissue, either directly from the corneal stromal surface or from the corneal interior after creation of a superficial corneal flap, has become widely used to correct myopia, hyperopia and astigmatism. Recently, an intrastromal refractive procedure whereby a tissue lenticule is cut free in the corneal stroma by a femtosecond laser and removed through a small peripheral incision has been introduced. The procedure avoids creation of a corneal flap and the potential associated risks while avoiding the slow visual recovery of surface ablation procedures. The all-femtosecond-based flap-free intracorneal refractive procedure has been documented to be a predictable, efficient and safe procedure for correction of myopia and astigmatism. Technological developments related to further improved cutting quality, hyperopic and individualised treatments are desirable.

Correcting myopic astigmatism with an areal 193 nm excimer laser ablation

1995 ◽  
Vol 21 (3) ◽  
pp. 278-281 ◽  
Author(s):  
Werner Förster ◽  
Rasmus Beck ◽  
Andreas Borrmann ◽  
Holger Busse
Keyword(s):  
Laser Ablation ◽  
Excimer Laser ◽  
Excimer Laser Ablation ◽  
193 Nm ◽  
Myopic Astigmatism

New Developments in the Lenticule Extraction Procedure

2014 ◽  
Vol 07 (01) ◽  
pp. 20
Author(s):  
Jesper Hjortdal ◽  
Anders Ivarsen ◽  
◽  
Keyword(s):  
Laser Ablation ◽  
Femtosecond Laser ◽  
Extraction Procedure ◽  
Corneal Stroma ◽  
Corneal Tissue ◽  
Safe Procedure ◽  
Visual Recovery ◽  
New Developments ◽  
Excimer Laser Ablation ◽  
Lenticule Extraction

For the last 20 years controlled excimer laser ablation of corneal tissue, either directly from the corneal stromal surface or from the corneal interior after creation of a superficial corneal flap, has become widely used to correct myopia, hyperopia, and astigmatism. Recently, an intrastromal refractive procedure whereby a tissue lenticule is cut free in the corneal stroma by a femtosecond laser and removed through a small peripheral incision has been introduced. The procedure avoids creation of a corneal flap and the potential associated risks while avoiding the slow visual recovery of surface ablation procedures. The all-femtosecond-based flap-free intracorneal refractive procedure has been documented to be a predictable, efficient, and safe procedure for correction of myopia and astigmatism. Technologic developments related to further improved cutting quality, hyperopic, and individualized treatments are desirable.

Pengaruh Likuiditas, Pertumbuhan Kredit, Efisiensi, dan Kecukupan Modal Terhadap Profitabilitas

2020 ◽  
Vol 1 (1) ◽  
pp. 27-35
Author(s):  
Lia Hendrawati ◽  
Said Djamaludin
Keyword(s):  
Stock Exchange ◽  
Growth Efficiency ◽  
Research Data ◽  
Capital Adequacy ◽  
Annual Data ◽  
Significant Positive Effect ◽  
Credit Growth ◽  
Negative Effect ◽  
Positive Effect ◽  
Observation Period

This study to examine and analyze the effect of liquidity, credit growth, efficiency, and capital adequacy on the Bank’s profitability listed on the IDX partially and simultaneously. The research data are annual data for the 5-year observation period (2009-2013). This research was conducted at 33 banks listed on Indonesia Stock Exchange. Banks Analyzed that met the population criteria were 23 banks. The analytical method used in multiple linier regression. The results showed that liquidity, credit growth, efficiency, and capital adequacy together (simultaneously) significantly influence profitability. Partially,  liquidity has a significant positive effect on profitability, while efficiency has a significant negative effect. Credit growth and capital adequacy have no significant effect on profitability. Liquidity is the variable that has the biggest effect on the Bank’s profitability. 

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