Abstract
Purpose
To find an appropriate correlation between the base curve (BC) of rigid gas permeable
(RGP) contact lenses and manual keratometry findings in Iranian patients with keratoconus
(KCN) in order to simplify the fitting process, reduce the time, and lower the costs.
Method
This retrospective study was done in 121 eyes of 69 patients with KCN fitted with
a specific trial set of RGP contact lenses over a 7-year period. The specifications
of the final lens parameters included power, total diameter (1), and BC, the first
two of which were fixed in all of the lenses in the trial set while BC was changed
in 0.1-mm steps. Javal keratometer was used to measure keratometric values. The final
fit assessment was performed based on the standard criterion of "three-point touch".
Result
Single and multiple linear correlations were done and the result was the following
equation: BC = 2.455 (constant of the final multiple regression model) + 0.280 (steep
keratometry) + 0.368 (flat keratometry) + 0.047 (corneal astigmatism)
Conclusion
The advantages of this study include simplifying the RGP fitting process, reducing
the examination time, lowering the costs, enhancing the confidence of the examiners
and patients, easier lens fitting in remote places where more advanced devices are
not accessible.
Keywords
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Article info
Publication history
Published online: June 01, 2020
Accepted:
May 13,
2020
Received in revised form:
May 13,
2020
Received:
January 11,
2020
Identification
Copyright
© 2020 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.
