Diabetic Retinopathy . Waseem Al-Zamil, MD. the two main types of diabetes : Insulin-dependent diabetes (IDD) : - known as type 1 . - develops most frequently between 10 and 20 years of age . Non-insulin-dependent diabetes (NIDD) : - also known as type 2.
Waseem Al-Zamil, MD.
- known as type 1 .
- develops most frequently between 10 and 20 years of age .
- also known as type 2.
- develops most frequently between the ages of 50 and 70 years.
NPDR : 2 -6 %
PDR :20-63 %
20.1 % in younger onset group.
25.4 % in older onset group taking insulin
13.9 % in older onset group not taking insulin
- progression of DR was 83%.
- progression to PDR was 42%.
- macular edema was 26%.
( WESDR Ophthalmology. 2008 Nov;115(11):1859-68 (
- after 10 years is 50%
- after 30 years is 90%
2 . Glycemic control :
- risk of developing retinopathy was reduced by 75% .
- 50% reduction in the rate of progression of retinopathy in existing retinopathy
- early worsening of retinopathy is unlikely to threaten vision .
Diabetes Control and Complications Trial Research Group N Engl J Med 1993; 329:977-986.
3 . Miscellaneous factors :
- pregnancy. (Hormonal changes )
- systemic hypertension.
- renal disease .
- anaemia.( ↓oxygen )
- elevated serum lipid.
- carotid artery occlusive disease.
- Alcohol. ( ? )
- microvascular leakage. (mild- mod NPDR)
- microvascular occlusion .(sever NPDR-PDR)
Fibrous glial cell
( IRMA )
New vessel proliferation
Fibrous glial tissue proliferaion
Tractional RD RD
- due to reduction in the number of pericytes .
- The pericytes are wrapped around the capillaries and are thought to be responsible for the structural integrity of the vessel wall.
- Development of retinal edema requires accumulation of fluid which occurs if :
- Uptake from adjusent capillaries
- Healthy RPE cells
- Incompetent capillaries
- located in the inner nuclear layer .
- the first clinically detectable lesions .
- small round dots .(20-200 μ)
- mostly located near and temporal to the macula.
- When coated with blood they may be indistinguishable from dot haemorrhages.
The clinical appearance depending on location
- 'dot' and 'blot' :
* originating from the venous end of the capillaries. *located in the compact middle layers of the retina .
- Flame-shaped :
* originate from the more superficial precapillary arterioles, follow the course of the retinal nerve fibre layer. (liner disribution)
- located between the inner plexiform and inner nuclear layers of the retina. (OPL)
- They are often distributed in a (circinate pattern) .
- The centres of rings of hard exudates usually contain microaneurysms .
- Made up of accumulated lipoproteins .
Focal ME :which has identifiable leakage source.
Diffuse ME: which has multiple unidentifiable source of leakage.
Cystoid ME: in which fluid accumulate in OPL and INL to form cystoid spaces.
Kim BY, Smith SD, Kaiser PK: Optical coherence tomographic patterns of diabetic macular edema. Am J Ophthalmol 142(3):405-412, 2006
- The most powerful predictors for development of PDR.
- Nerve fiber layer infarction.
- caused by capillary occlusion in the retinal nerve fibre layer.
4 : 2 : 1
- Higher risk of developing glaucoma.
DCCT , Tight control decrease risk of progression of retinopathy , nephropathy and neuropathy.
The treatment of depends on the severity of retinopathy and the presence or absence of CSME, which may be present at any stage .
- The duration of : 0.10 second or less.
- The power : sufficient power to obtain a gentle whitening or darkening of the microaneurysm.
- Wave length : green – yallow Argon
- The exposure time : 0.10 second.
- The burns should be of very light intensity and one burn width apart.
- Wave length : green – yallow Argon .
The following are the clinical features of eyes at high risk PDR:
- The duration : between 0.10 and 0.05 second
- The power level : produces a gentle burn
3. burns spaced about one half burn apart.
4. the power is increased by 50 mW increments until a grey-white burn of gentle intensity is produced .
- is after an interval of 4-8 weeks.
- In eyes with severe NVD, several treatment sessions with 5000 or more burns may be required. - the most important cause of persistent neovascularization is inadequate treatment.
Further argon laser PRP filling in any gaps between previous laser scars.
6. Dense, persistent, premacular, subhyaloid haemorrhage .
7. Red Blood Cell-induced glaucoma.
8. Bilateral vitreous haemorrhage .
9. Dense cataract associated with vitreous haemorrhage .
Argon blue : 488 nm.
Argon green : 514 nm.
Dye yellow : 577 nm.
Krypton red : 647 nm.