This course is arranged to move from clinical recognition to imaging interpretation, practical management, referral decisions, and final assessment.

Introduction

Risk Factors and Optometric Red Flags

Clinical Examination

Pentacam Interpretation for Optometrists

Belin/Ambrósio Display and BAD-D

ABCD Keratoconus Staging

KISA% Index

Differential Diagnosis and Mimickers

Progression Monitoring

Management Pathway

Case-Based Learning

Real Slit-lamp and Pentacam Examples

Optometrist Screening Checklist

Post-test MCQs

MCQs on Keratoconus

Keratoconus is a bilateral but often highly asymmetric ectatic corneal disorder. It is usually first suspected when refraction stops behaving like ordinary astigmatism: cylinder changes, the axis becomes unstable, and the patient reports ghosting or glare despite acceptable Snellen acuity.

Modern assessment combines symptoms, refraction, retinoscopy, slit-lamp findings, and advanced tomography.

1. Introduction

Clinical trap: A patient with 6/6 or 20/20 visual acuity may still have early ectasia. Do not use visual acuity alone to exclude keratoconus.

2. Risk Factors and Optometric Red Flags

Epithelial iron deposition around the cone base.

V-shaped lower lid indentation on downgaze.

Fine vertical stress lines in deep stroma.

3. Clinical Examination

3.2 Slit-lamp and retinoscopy signs

A safer clinical habit is to read the scan in layers. Confirm quality, review anterior sagittal curvature, check elevation maps, review pachymetry, and review BAD display.

4. Pentacam Interpretation for Optometrists

5. Belin/Ambrósio Display and BAD-D

6. ABCD Keratoconus Staging

7. KISA% Index

8. Differential Diagnosis and Mimickers

Increase in posterior elevation or posterior curvature abnormality.

Reduction in best corrected visual acuity.

Referral trigger: Do not wait for severe vision loss before referral. A young patient with suspicious tomography and documented progression should be referred for CXL evaluation early.

9. Progression Monitoring

1. Patient Education: Stop eye rubbing, treat allergy/itching.
2. Visual Rehabilitation: Spectacles -> Custom Soft -> RGP -> Hybrid -> Scleral.
3. Stabilization: Referral for CXL if progressive.

10. Management Pathway

10.2 Contact lens selection

Vogt striae are fine vertical or occasionally horizontal stress lines in the deep/posterior stroma and Descemet membrane. They are usually seen in established keratoconus and may temporarily disappear with external pressure on the globe.

13.1 Real slit-lamp findings: Vogt striae

Vogt striae (Close-up)

This advanced case demonstrates markedly abnormal tomography. Kmax 59.9 D, TCT 413 µm, back elevation +72 µm, BAD-D 11.80.

13.2 Real Pentacam Belin/Ambrósio display: advanced keratoconus

A very steep cone may produce poor contact lens centration, apical bearing, and unstable over-refraction.

13.3 Real Scheimpflug image: advanced keratoconus

Mild keratoconus may show only borderline or mildly abnormal values. BAD-D 2.78, posterior elevation +23 µm.

13.4 Real Pentacam BAD display: mild keratoconus

Asymmetric cone severity between right and left eyes.

13.5 Real Pentacam axial/sagittal curvature maps

Advanced, decentered cones may require specialized lens geometry to match the sagittal height and cone location.

13.6 Real Scheimpflug/contact lens fitting result

Age, symptoms, rubbing, allergy, family history.

Increasing cylinder, oblique axis, reduced BCVA.

Counsel no rubbing, treat allergy, refer when suspicious.

Keratoconus

Course Outline