Diabetic retinopathy-screening training program for nurses St John Eye Hospital - UNRWA

1. UNIT6:
IMAGING OF THE EYE
Dr. Riyad Banayot
St. John of Jerusalem Eye Hospital
Diabetic Retinopathy Screening

2. Preparing the retinal camera and
associated environment and equipment for
obtaining images
 Ensure suitable and safe working environment
for the screening episode
 Verify that the equipment is working correctly
(follow camera manual)
 Open the appropriate imaging software package
on the retinal camera’s computer (follow camera
manual)
 Prepare and align the retinal camera for a
specific patient imaging session
 Prepare a patient’s record for the current
imaging visit

3. Assessment of images for clarity,
positioning and gradability
 Photographers should capture 2x nominal
45O fields per eye (1 x fovea centered, 1 x disc
centered)
 A combined assessment of field position and
image quality should be made for each eye
 Images must be graded for diabetic eye
disease only if the grader is confident the
quality is sufficient

4. Definitions of disc, fovea, 1DD
Perfectly aligned macular view of the RE.The fovea at the center of the image marked “+”

5. Combined assessment of field
position and image quality
Macular image Disc image
 Center of fovea ≤1DD from
center of image
 Vessels clearly visible within 1DD
of center of fovea
 Vessels visible across >90% of
image
 Center of disc ≤1DD from center
of image
 Fine vessels clearly visible on
surface of disc
 Vessels visible across >90% of
image

6. Combined assessment of field
position and image quality
Macular image Disc image
 Center of fovea >2DD from edge
of image
 Vessels visible within 1DD of
center of fovea
 Complete optic disc >2DD from
edge of image
 Fine vessels visible on surface of
disc

7. Combined assessment of field
position and image quality
Macular image Disc image
Failure to meet definition of
adequate:
 Center of fovea >2DD from edge of
image
 Vessels visible within 1DD of center of
fovea
 Failure to meet definition of
adequate:
 Complete optic disc >2DD from edge of
image
 Fine vessels visible on surface of disc
UNLESS referable diabetic retinopathy is visible anywhere
in the eye

8. Left retina - normal

9. Left retina - normal

10. Normal findings in retinal images that
maybe misread as abnormal
 Reflective layer of
the retina: Often
found in young
patients, nerve fiber
layer is usually thick
and causes light
reflection.The light
reflected from the
fovea can be seen as
a white circular line.

11. Normal findings in retinal images that
maybe misread as abnormal
 Small blood vessels
around the optic
disc:They maybe
misread as
abnormal blood
vessels

12. Normal findings in retinal images that
maybe misread as abnormal
 Drusen : It is a waste
product
accumulated
beneath the retina.
 It is in pale-yellow,
round shape, with
various sizes, usually
found beneath the
retina in older
patients.
 This maybe misread
as hard exudates

13. Obtain images of the retina
 Obtain color retinal image(s) of sufficient
quality and quantity and in the correct
position(s) for both eyes
 It might be appropriate to take additional
retinal images
 Save the images and complete the session
 Document reasons why it was not possible to
obtain retinal images of sufficient quality for
assessment