MODI II Keratoconus Screening Case

Submitted by on Tue, 01/26/2016 - 8:43am

 OU Topography Report:

Tangential maps above show substantial differences between eyes.

The OS map shows a large amount of asymmetry in curvature with inferior steepening.

The OD map shows some astigmatism – mildly asymmetrically.

The parameters shown to the right  present the keratoconus screening parameters for each eye.

  •   The OS parameters identify Outside Normal Limits with the explanation mark
  •   The software identifies the left eye as Keratoconus Compatible
  •   The OD parameters all fall within the Normal range

 

4UP Summary OS: 

 

 

The top left map shows local curvature and top right map shows global curvature.

Inferior steepening consistent with keratoconus is clearly displayed.

The elevation map (bottom left) show inferior vaulting in the corneal elevation,  consistent with the classic presentation of a keratoconus .

 

Keratoconus Summary:

 

Specializes maps for keratoconus screening and diagnosis , displayed in summary.

All summary report maps are shown with a radius of 3mm

The top left map shows the asymmetric astigmatism of the Tangential (local) curvature.

At the top right a Gaussian curvature map is displayed. This  presentation map is useful as it removes normal astigmatism from the map but preserves the ectasia.

The bottom left is a specialised Elevation Map that uses a toric ellipsoid as the reference plane. This better approximates  the corneal shape so the elevated cone is clearly localised and quantified.

Bottom right map displays the area of suspect curvature traced onto the eye image for easier localization.

 

 

Keratoconus Parameters:

The MODI uses a normative database with the following corneal parameters to identify patients with Keratoconus:

•Symmetry Index
•BCV Index
•Best Fit Radius
•Root Mean Square/Area

Visually, they are presented in a bar showing how that parameter compares to normal

•The Green zone is “Normal”
•The Yellow zone is “Suspect”
•The Red zone is “Keratoconus”
 
 

Keratoconus Parameters (con’t):

The MODI software then uses a neural network to process the parameters and make a determination about the patient’s condition

When the topographic context appears compatible with keratoconus or indicates a suspicion of keratoconus, a series of morphological indicators are presented for evaluation:

•KV:  Indicates the height and polar coordinate of the most prominent point of the cone
•Area:  Area covered by the cone
•Volume:  Volume of the cone

In the case presented here, the OD parameters are normal and all the OS parameters  indicate keratoconus . The patient is flagged as Keratoconus Compatible  with additional parameters displayed.