The Eye and Diabetes

• Sugar can be taken up by the lens within the eye. The lens becomes denser, bending the light more and causing fluctuations in a diabetic's spectacle prescription; sometimes this may be the first sign that someone is diabetic.
  
• Fine capillary vessel walls become weakened and can leak a little. The weakening can give rise to little 'bubble-like' swellings on the walls, known as microaneurysms.
• The fine capillary vessels can leak a little. The leaked fluid leaves yellow tell-tale deposits called exudates.

Photo by permission of the Internet Ophthalmology Society A diabetic eye showing exudates which have leaked from the capillaries (The appearance of the normal fundus, the back of the eye, can be found in our Interactive Eye pages.)

• The weakened vessels can also leak a little blood. These tiny haemorrhages do not always remain.
• Weakened capillaries have difficulty distributing the blood to the retina which gives rise to patches where the retina has been starved of nourishment (known as ischaemia).
• At this stage careful monitoring is vital, as the lack of an effective blood supply causes more capillaries to develope, only they do so in a haphazard fashion. Untreated they multiply and can haemorrhage. Scarring from these haemorrhages can tear the retina, with very serious results.

Photo by permission of the Internet Ophthalmology Society This looks deceptively normal. In fact it is the appearance of a diabetic eye with the start of fine new vessels to the right of the optic nerve head.

Safeguard your vision

• keeping sugar levels stable - dramatic fluctuations have been shown to affect this process adversely.
• regular eye examinations - careful monitoring (certainly annually) will pick up any danger signs. Using laser it is relatively easy to treat the early signs, reducing the likelihood of the major sight-threatening condition taking hold.