Prediction of flap response Potgieter, Frederik J; Roberts, Cynthia; Cox, Ian G ...
Journal of cataract and refractive surgery
31, Issue:
1
Journal Article
Peer reviewed
To find predictors of the induced biomechanical and optical effects of lamellar flap creation on the cornea.
Optimed Eye and Laser Clinic, Pretoria, South Africa, and the Department of Ophthalmology ...and Biomedical Engineering Center, The Ohio State University, Columbus, Ohio, and Bausch & Lomb Vision Research Laboratory, Rochester, New York, USA.
This prospective study monitored the refractive, wavefront aberration, and corneal topographic changes in 29 eyes of 15 patients for 3 months after the creation of a corneal lamellar flap. The main outcome measures for statistical analysis were refraction, total corneal thickness, residual corneal bed thickness, horizontal white-to-white corneal diameter, horizontal flap diameter, topography data, and wavefront data.
Statistically significant changes were seen in the autorefraction mode. Wavefront data showed significant change in 4 Zernike modes-90/180-degree astigmatism, vertical coma, horizontal coma, and spherical aberration. The topography data indicated the corneal biomechanical response was significantly predicted by stromal bed thickness in the early follow-up period and by total corneal pachymetry and flap diameter in a 2-parameter statistical model in the late follow-up period.
Uncomplicated lamellar flap creation is responsible for systematic changes in corneal topography and induction of higher-order optical aberrations. Predictors of this response include stromal bed thickness, flap diameter, and total corneal pachymetry.
Benchmarking is a tool available to furnace operators to evaluate their tap-hole life-cycle management practices against those of their peers. It allows furnace operators to challenge their own ...practices in order to increase furnace utilization. To facilitate the benchmarking process, it is necessary to define the variables to be considered and how they relate to one another. This article develops, from the literature and industry interviews, a holistic conceptualization of the variables that form part of tap-hole lifecycle management and performance. Specifically, the article focuses on the variables related to coke-bed-based processes (FeCr, SiMn, and HCFeMn) applying SAF technology of circular design.
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