www.diabeticretinopathy.org.uk

Case 4: maculopathy

David Kinshuck

 

macular oedema

A photograph of severe diabetic maculopathy. Laser as below is important to help slow down any deterioration. If the patient is well, controlling blood pressure to a level of 140/80 or below if reasonably possible, and controlling the diabetes to reach an HbA1c level of 7% would be ideal.

A hypothetical case report: 60y, diabetic 8 yearsUnfortunately the condition is quite advanced and the sight may get worse. This vision depends on whether the fovea is affected, as shown by the arrow.

Sometimes the fovea may not be oedematous before laser, but becomes oedematous after... but usually the condition would have affected the fovea itself in a short time after this photo was taken.... if it was not affected already.

New vessels are best seen with a green light, such as that in a Welch-Allyn or Heine halogen rechargeable ophthalmoscope.

It is extremely healpful to use a 60d or 66d lens, or an are central contact lens laser lens. An area cnetralis lens with a good slit lamp shows oedema really well.

 

macular oedema is seen with a 60/66 d lens

(the same eye as above)
blue stripes = oedema seen with 60 or 78d lens (or 90d)
white arrow = fovea
green area = exudate

When lasering, many ophthalmologists leave a disc diameter between any laser and the fovea, nearly 1 millimetre. Inevitably some laser may stray nearer the fovea. In the last couple of years laser within this 'protected area' has been thought not to be necessary. If the oedema does not respond (usually it takes 12 weeks to confirm there is no response), a PRP laser, or at least laser of the retina just temporal to the grid may be helpful (in such a severely oedematous eye). Without laser the sight would get worse, and laser offers the best hope. Avastin treatment might be helpful. See

grid laser for severe diabetic maculopathy

 

Laser is needed: this is a grid. A grid of 1-300 x 50 μ, about 80-110mw, 0.05 second, burns is needed if there are no new vessels.
Much less power is used now (subthreshold)
However, such an eye with severe maculopathy may well have new vessels, and if so PRP (peripheral pan-photocoagulation) laser will be needed (1200 x 500μ, 0.02 second).
A very good result in this patient would be 6/12, a bad but all too common result 6/36.