Abstract
Purpose: :
This study is done to evaluate the short and long term effects of laser photocoagulation in patients with centre involving diabetic macular oedma(DMO).
Methods: :
We evaluated 30 patients at baseline, 4 to 6 months and 12 months with centre involving DMO that responded to macular laser therapy as proven with improved visual acuity(VA) or decreased central subfield thickness(CST) on spectralis OCT at 12 months. Changes in the following quantitative and qualitative parameters were evaluated at the 2 time points, namely, CST, macular volume, presence or absence of fine exudates, clumped exudates, inner segment/outer segment(IS/OS), external limiting membrane(ELM), outer retina cysts(large, medium, small), inner retina cysts(large, medium,small), nerve fiber layer cysts, change in pattern of DMO( cystoid, diffuse, mixed, subretina detachment(SRD)) were evaluated. Results were tabulated using SPSS ver 17.0, using independent T tests, and crosstabulated using chi-square tests. P<0.05 were considered significant for our study.
Results: :
None of the quantitative or qualitative parameters changes significantly at 4 months except for the disappearance of large inner retinal cysts. However, at 12 months, there was a significant decrease in CST(p<0.001); decrease in both fine and clumped exudates(P=0.002, p=0.001), disappearance in both large inner and outer retina cysts(p=0.007,p=0.018) and significant improvement in patients with preserved ELM(p=0.007). That may explain the delayed improvement in VA with laser. The morphological pattern of diffuse and cystoid oedema at baseline did not influence the final outcome of laser treatment.(p=0.679,p=0.663)
Conclusions: :
The study suggests that laser photocoagulation should still bet he first line treatment for centre involving macular oedema but the beneficial effects on macular morphology is delayed up to 12 months.
Keywords: diabetic retinopathy • imaging/image analysis: clinical