This article has been written in the interest of patients with Diabetic Retinopathy who could enjoy better vision if they received the correct guidance and treatment at the correct time. 

Since the Diabetic patient sees a General Physician, Diabetologist, Endocrinologist, Nephrologist, Cardiologist etc. first & more often – much before the Ophthalmologist – it is you who could help them the most. 

The threat 
Diabetic retinopathy poses a serious threat to vision. In the Wisconsin Epidemiologic Study of Diabetic Retinopathy ( WESDR ) – 
* 3.6% of Type 1 diabetics were legally blind ( 86 % due to diabetic retinopathy) 
* 1.6% of Type 2 diabetics were legally blind ( 33% due to diabetic retinopathy). 
* Diabetic retinopathy is estimated to be the most frequent cause of new cases of blindness among adults aged 20 – 74 yrs. 

The statistics in India could be a lot more alarming because: 
1. Indians are more prone to diabetes than almost any other population in the world. 
2. There is no screening programme – the patient reaches the physician much later. 
3. The load of Cataract blindness is so high that the General Ophthalmologist is often too burdened to do justice to the patients with retinopathy. 
4. Detection of early retinopathy requires sophisticated examination of the retina ( esp. macula) by a Retina specialist. 
5. Almost all Retina specialists and centres with facility for LASER photocoagulation are located in cities making them inaccessible to a major part of the population. 

Diabetic retinopathy 
It is a highly specific vascular complication of both Type 1 and Type 2 diabetes. The prevalence of retinopathy is strongly related to the duration of diabetes. After 20 years of diabetes, nearly all patients with type 1 & > 60% of patients with type 2 diabetes have some degree of retinopathy. 
In general, the progression of retinopathy is orderly, advancing step by step 
Background Diabetic Retinopathy- (BDR) due to increased vascular permeability – microaneurysms, edema, hard exudates, dot & blot hemorrhages. 
Pre-Proliferative Diabetic Retinopathy- (prePDR) due to vascular closure – cotton wool spots, IRMA, beading& looping of veins, large retinal hemorrhages. 
Proliferative Diabetic Retinopathy- (PDR) growth of new vessels on the retina and posterior surface of vitreous. 

Vision loss in Diabetic Retinopathy : 
* Loss of central vision – macular edema / capillary non perfusion 
* Bleeding from new blood vessels – Vitreous Haemorrhage 
* Contraction of accompanying fibrous tissue – tractional retinal detachment. 

Examination of the Retina : 
* Indirect biomicroscopy on a slit lamp – A three-dimensional view greatly facilitates the evaluation of macular oedema. 
* Binocular Indirect Ophthalmoscope – A panoramic view facilitates the evaluation of the equator & periphery of the retina. 
* The Direct Ophthalmoscope (used by physicians & general ophthalmologists) is limited in this respect – it offers a two-dimensional & a small field of view. 

The role of LASER Photocoagulation 
The Diabetic Retinopathy Study (DRS)established that panretinal photocoagulation could improve the prognosis of proliferative retinopathy. 
* The Early Treatment of Diabetic Retinopathy Study (ETDRS) and other studies established the benefit of focal laser photocoagulation in eyes with macular oedema. 
* Laser photocoagulation in both these studies was beneficial in preventing further visual loss. 

RECOMMENDED GUIDELINES – in Indian context 

GOOD VISION / GOOD GLYCEMIC CONTROL – DOES NOT MEAN – NO RETINOPATHY 

* Dilated Fundus examination at diagnosis for all diabetic patients by Ophthalmologist 
* Annual check up for patients with no retinopathy or slowly progressive retinopathy 
* More frequent examination in cases of : 
1. Progressive retinopathy 
2. Higher level of the glycosylated hemoglobin (HbA1c) 
3. Gross proteinuria / poor glycemic control 
4. After institution of intensive treatment in patients who have had a long history of poor diabetic control. 
5. Diabetic with Pregnancy (not gestational diabetics) 
* Patients with macular edema, Pre PDR & Proliferative retinopathy require prompt care of an experienced Ophthalmologist / Retina specialist – LASER treatment at this stage is associated with 50% reduction in the risk of severe visual loss.