Related Experiment Video
Updated: May 15, 2026
11:29
Corneal Confocal Microscopy: A Novel Non-invasive Technique to Quantify Small Fibre Pathology in Peripheral Neuropathies
Published on: January 3, 2011
RGP contact lens fitting in keratoconus using FITSCAN technology.
Preeji S Mandathara1, Mariya Fatima, Sobia Taureen
1L V Prasad Eye Institute, Hyderabad, India. mspreeji@gmail.com
Summary
For keratoconus eyes, FITSCAN technology calculated a steeper base curve (BC) for rigid gas permeable contact lenses compared to the diagnostic fitting method. Adjusting the initial trial lens BC by 0.22mm steeper than FITSCAN may simplify RGP lens fitting.
Area of Science:
- Ophthalmology
- Optometry
- Biomedical Engineering
Background:
- Keratoconus management often requires specialized rigid gas permeable (RGP) contact lenses.
- Accurate base curve (BC) calculation is crucial for successful RGP lens fitting in keratoconus.
- Corneal topography and advanced fitting technologies offer potential improvements in BC determination.
Purpose of the Study:
- To compare the base curve (BC) of RGP lenses calculated by FITSCAN technology versus the conventional diagnostic lens fitting method in keratoconus eyes.
- To evaluate the agreement and identify any systematic bias between these two methods for BC determination.
Main Methods:
- A prospective comparative study involving 85 keratoconus eyes.
- Two masked observers determined RGP lens parameters using both diagnostic fitting and FITSCAN technology.
- Statistical analysis included Wilcoxon signed rank test and Bland-Altman plots to compare BC values.
Main Results:
- FITSCAN calculated BC was, on average, 0.22mm steeper than the diagnostic method (P < 0.0001).
- A systematic bias of 2.7% was observed between the two methods.
- A regression formula was derived: BC = (FITSCAN BC × 0.86563) + 0.78738.
Conclusions:
- The FITSCAN technology provides a steeper BC compared to diagnostic fitting for keratoconus.
- Selecting an initial trial lens BC 0.22mm steeper than FITSCAN's calculation may streamline RGP lens fitting in keratoconus.
- This finding could reduce the complexity and time associated with fitting RGP contact lenses for keratoconus patients.
