Novel Microsoft Excel spreadsheet calculator for vector analysis of mass astigmatism data and comparison between Alpins and Thibos methods

Autor: Mohamed Elkadim, Ahmed El-Shehawy
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Delta Journal of Ophthalmology, Vol 23, Iss 4, Pp 292-297 (2022)
Druh dokumentu: article
ISSN: 1110-9173
2090-4835
DOI: 10.4103/djo.djo_23_22
Popis: Background Vector analysis is mandatory for reporting astigmatism and for the evaluation of different refractive procedures. Aim The aim of this study was to describe and evaluate a new spreadsheet calculator for vector analysis of mass astigmatism data and to compare between Alpins and Thibos methods. Patients and methods Using Microsoft Office Excel 2016, a new astigmatic calculator was designed, based on Alpins and Thibos methods of vector analysis. Mass astigmatic data input involved power in diopters and axis direction in degrees. The calculator was investigated on 20 eyes for which photorefractive keratectomy was performed. Preoperative and postoperative manifest refractions were measured. Comparisons were done between the results of Alpins and Thibos methods of analysis. Results The mean surgically induced astigmatism (SIA) was 2.547±0.721 D and the change in astigmatism power vector (ΔAPV) calculated with the Thibos method was 1.27±0.36 D. A perfect positive correlation (r=1; P
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