www.diabeticretinopathy.org.uk

Examining and grading retinopathy, for professionals

David Kinshuck

 

Diabetic Eye Screening Program

The Diabetic Eye Screening Program propose the following classification. Some centres use a more detailed classification, based on the NSC system proposal. The condition is graded by examination of digital retinal photographs, red free.

 

Abbreviations

NSC

International Term

Symptoms

Features (see)

Action

R0 No DR None Normal retina.   Grade 0 (US) annual rescreen
RI Mild non-proliferative (mild pre-proliferative) None Haemorrhages & microaneurysms, only see photo       Grade 1 (US). Very minor IRMAs

Inform diabetes team

see M1

R2

Moderate non-proliferative, moderate  pre-proliferative

None Previously termed mild pre-proliferative. Extensive Microaneurysm, intraretinal haemorrhage, and hard exudates. See photo   and photo     Grade 2 (US)

refer HES

see R2

R2

Severe non-proliferative

severe pre-proliferative

None Previously termed severe pre-proliferative. Venous abnormalities, large blot haemorrhages, cotton wool spots (small infarcts), venous beading, venous loop, venous reduplication, IRMASee photo and photo .
Grade 3 (US)

urgent refer HES

see R2

R3 Proliferative retinopathy Floaters, sudden visual loss New vessel formation either at the disc (NVD) or elsewhere (NVE).
Photos: flat new vessels,    raised,   florid       Grade 4a (US)

urgent refer HES

see R3

R3 Pre-retinal fibrosis+/- tractional retinal detachment Floaters, central loss of vision Extensive fibrovascular proliferation, retinal detachment, pre-retinal or vitreous haemorrhage, glaucoma.   Grade 4b (US). Traction  photo and photo.   Subhyaloid haemorrhage photo

urgent refer HES

 

R3s treated proliferative retinopathy (s = stable)   no haemorrhages or exudates or new vessels, laser ('P' added) annual rescreen
M 0     no maculopathy annual rescreen
M 1 Diabetic maculopathy Blurred central vision

The macula is defined as a circle centred on the fovea, with a radius of the distance to the disc margin.  If the leakage involves or is near the fovea the condition is termed clinically significant macular oedema (CSME).
Exudative maculopathy presents with leakage , retinal thickening, microaneurysms, hard exudates at the macula. Ischaemic form can have a featureless macular with NVE and poor vision.
Photos: moderatesevere 

Milder forms:
  • exudate < or = 1DD of centre of fovea
  • circinate or group of exudates within macula
  • any microaneurysm or haemorrhage < or = 1DD of centre of fovea only is associated with a best VA of < or = 6/12
    retinal thickening < or = 1DD of centre of fovea (if stereos available)

refer HES

see M1

P Photocoagulation Reduced night vision, glare Small retinal scars through out the peripheral retina. Grade 4b (US)  
OL/
UG
Other lesion / Un-gradable   Un-gradable is usually due to cataract, other lesions usually referred for assessment  

 

Clinical Examination

Examination can also be carried out using an ophthalmoscope. This should include use of the green filter (red free) as It shows haemorrhages and new vessels much more easily, see . The slit lamp is very useful clinically.

 

Links..other grading systems in use

There are many studies in the academic literature, but few are available in full online. See and here.  Other links available online: photos    medline search (abstracts)     EURODIAB

 

Issues for Screening

M1 

IRMAs

Medical Control

If mild retinopathy is found, that is retinopathy without needing referral, there is an opportunity to inform the primary care team and get the diabetes under good control. However, this does not seem to be happening efficiently. We can calulate the risk of retinopathy progression www.risk.is.

Numbers

10% of patients being screened are new patients...new patients are increasing at 5% a year.