Visual outcomes of pan-retinal photocoagulation in diabetic retinopathy at one-year follow-up and associated risk factors.
OBJECTIVE
To assess the visual outcomes at one-year follow-up after pan-retinal photocoagulation (PRP) in type 2 diabetes mellitus subjects with proliferative diabetic retinopathy (PDR) and associated risk factors.


METHODS
A retrospective study, using data from medical records of 5000 Type 2 diabetic patients who underwent a retinal examination between 1995 and 1999 at a diabetic centre. Ocular, clinical and biochemical parameters were assessed at baseline and at one-year follow-up after PRP. Diabetic retinopathy (DR) was documented by colour photography and PRP was performed according to the ETDRS criteria.


RESULTS
PRP was done in 413 eyes, of which 261 eyes of 160 subjects were eligible for the study. One hundred and forty eyes (73%) of 191 eyes with good visual acuity (6/9) at baseline maintained the same vision at one-year follow-up. Of the 53 eyes with visual acuity of 6/12-6/36 at baseline, 58.5% (31 eyes) maintained same vision and 18.9% (10 eyes) improved their vision at one-year follow-up. Of the 17 eyes with visual acuity < or =6/60 at baseline, 12 maintained the same vision and the remaining 5 improved their vision. The causes of visual loss included vitreous haemorrhage in 20 subjects (31.7%), progression of cataract in 19 (30%), chronic macular oedema in 15 (23.8%), pre-retinal haemorrhage in the macula in 6 (9.5%) and pre-retinal fibrosis in the macula in 3 (4.7%) subjects. On multiple logistic regression analysis, diastolic blood pressure (P =0.03), duration of diabetes (P =0.006), fasting blood glucose (P =0.02) and nephropathy (P =0.01) were associated with decreased vision after PRP. Glycated haemoglobin (HbA1c) (P < 0.001), serum creatinine (P =0.03), HDL cholesterol (P =0.05), diabetic neuropathy (P < 0.001), hypertension (P =0.01) and diabetic nephropathy (P < 0.001) showed a significant association with PDR.


CONCLUSIONS
Visual acuity at baseline, the duration of diabetes and proteinuria played a significant role in determining the post-PRP visual acuity.
Rema
Mohan
M
Madras Diabetes Research Foundation, Dr. Mohans' M. V. Diabetes Specialities Centre, Gopalapuram, Chennai, India. drrema@vsnl.com
Sujatha
Purushothaman
P
Pradeepa
Rajendra
R
D001786:Blood Glucose / Q000032:analysis; D001794:Blood Pressure; D003924:Diabetes Mellitus, Type 2 / Q000150:complications; D003928:Diabetic Nephropathies / Q000150:complications; D003930:Diabetic Retinopathy / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D017075:Laser Coagulation; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology*
D001786:Blood Glucose