This document outlines the process for contact lens fitting, which includes patient screening, preliminary examinations and measurements, trial lens fitting, lens dispensing, and aftercare. The preliminary examinations involve assessing the anterior segment, measuring keratometry, corneal and pupil size, lid characteristics, and tear production. Trial lens fitting involves selecting lenses of varying parameters until an optimal fit is achieved based on criteria like centration and movement. After fitting is complete, patients are instructed on lens care and insertion/removal and scheduled for follow-up visits to monitor fit and address any issues.

1. Contact Lens Fitting
1. Introduction to Contact Lens Fitting

2. CONTACT LENS FITTING –
PROTOCOL
Patient screening
Preliminary examination &
measurements
Trial lens fitting
Lens dispensing
After-care

3. PATIENT SCREENING
Establish why the patient wants CLs
Is the patient suitable for CLs ?
Obtain baseline information
Advise patient of their options

4. PRELIMINARY EXAMINATION
AND MEASUREMENTS
 A slit-lamp examination of the anterior
segment.
 Keratometry.
 Corneal and pupil size measurements.
 Assessment of lid characteristics.
 A tear assessment.
 A spectacle refraction and calculation of
the ocular Rx (corneal-plane refraction).

5. KERATOMETRY
 Corneal curvature is the most important
measurement needed before starting CL
fitting.
 Measures only 3 mm of the corneal curvature
 Corneal topography gives the complete
mapping of the cornea.
 KR measurement is sufficient in most of the
fittings.

6. Corneal irregularity also noted.
The reading also tell us about the
degree of corneal astigmatism.
The BC of the CL is determined by
the corneal curvature
measurements.

7. CORNEAL DIAMETER
 HVID – Horizontal Visible Iris Diameter
 VVID – Vertical Visible Iris Diameter
 With a simple millimeter scale ,measuring
the limbus to limbus size both across the
horizontal and vertical lengths.
 The corneal diameter aids in
determination of the total diameter of the
CL.

8. PUPIL SIZE
 The diameter of the pupil is measured by
a simple millimeter scale both in standard
room illumination and low illumination .
 This aids in determining the optic zone
size of the CL.

9. TRIAL FITTING: ROUTINE
 Diagnostic fitting
A diagnostic or trial fitting uses a series of
lenses, chosen on the basis of the findings of
the preliminary examination.
Lenses are assessed sequentially until a
desirable fit is obtained.
The aim of the trial fit is ensure a good lens-
cornea relationship with the design chosen
and to confirm the final Rx required.
 Final lens order

10. TRIAL FITTING: LENS SELECTION
Back optic zone radius (BOZR).
Total diameter (TD).
Water content (for soft contact lenses).
Lens design (lenticular, multicurve,
surface shape, etc.).
Lens type (spherical, toric, bifocal, etc.).
Lens material.
BVP

11. TRIAL FITTING: PROCEDURE
 Initial lens selection.
 Trial lens fitting and vision assessment.
 Subsequent trial lens selection.
If Trial lens required is not available:
Empirical Prescribing

12. TRIAL FITTING: DESIRED RGP
LENS FIT
 Central alignment. (BOZR of the lens closely
matches the central corneal curvature)
 Moderate edge clearance
 Good centration.
 Corneal Coverage (SCL)
 Adequate movement
 Comfort

13. TRIAL FITTING: FINAL LENS
ORDER
 Lens parameters
 Lens material and type
 Special requirements
 Delivery date required

14. LENS DISPENSING
 •Provide information on the lens care regimen
 • Practise insertion and removal techniques
 • Provide information on adaptation
 • Provide information on signs of complications
 • After-care visit schedule

15. AFTER-CARE
 Investigate complaints
 Perform general ocular examination:
 - Over-refraction
 - Slit-lamp microscopy
 - Other tests particular to the patient
 Assess lens fit
 Review lens care regimen
 Schedule next after-care visit

16. THANK U