Sunil Maruthivila Sudhakaran1, Naina Jabeen Hyder2, Pappa Padmavathi3
BACKGROUND
Panretinal photocoagulation (PRP) is done for severe nonproliferative diabetic retinopathy (NPDR) or early proliferative diabetic retinopathy (PDR). When it is done for patients without macular oedema PDR may induce a macular oedema which may worsen the visual acuity.
MATERIALS AND METHODS
A prospective cohort study was conducted for one year with minimum follow up period of 6 months .Seventy eyes of 41 patients who were undergoing PRP for severe nonproliferative diabetic retinopathy or early proliferative diabetic retinopathy were studied. These eyes had best corrected visual acuity (BCVA) ≥0.6 and no macular oedema as determined by clinical examination using 78 diopter lens and Optical Coherence Tomography (OCT)) (Zeiss Cirrus HD OCT). The BCVA was determined using decimal charts and converted into logarithm of minimal angle of resolution scale for statistical analysis. Visual acuity and macular thickness at 1, 3, 6 and 12 months post PRP were studied.
RESULTS
The Central Macular Thickness (CMT) measurements (mean±standard deviation)were 160±15 before PRP and 176±16,178±20,189±30,187±25μm at 1,3,6 and 12 months after PRP respectively (P <0.05 for each). The mean±standard deviation of the visual acuity measurements converted into logarithm of the minimal angle of resolution was 0.03±0.12 before PRP and 0.04±0.13, 0.04± 0.12, 0.03±0.08, 0.03±0.08 at 1,3,6 and 12 months after PRP. There was no statistically significant difference in visual acuity in follow up examinations from the pre PRP levels (P>0.05 for each).
CONCLUSION
Routine PRP with 2000 burns given in two divided sessions at two weekly intervals can safely be performed with no effect on visual acuity in patients with severe DR without pre-existing macular oedema.
