Efficacy of optical coherence tomography and fundus fluorescein angiography in detection of diabetic macular edema

Purpose: Significance of clinical DME in an up becoming capital nation of diabetes mellitus in world has socio-economic effect due to VTDR is identified as the major cause of irreversible blindness in DR subjects in all age groups. Therefore, the need for reliable, safe and immediate detection of DME is a need for prevention of the disease & related socio economic burden. The study was to compare the diagnostic potential of two commonly established diagnostic instruments i.e.-SD-OCT & FFA for the detection of DME. Materials and Methods: A prospective study with purposively sampling technique was carried on 308 eyes of 154 type II DM patients to compare the detection potential between two popular retinal diagnostic techniques, SD-OCT a non-invasive technique versus FFA invasive method for DME. The standard parameters such as focal macular edema, diffuse macular edema and mixed edema with cystoid type were evaluated with FFA. Subsequently DME classification with presence of intraretinal edema, sub retinal fluid and mixed edema were diagnosed with SD-OCT for the same pool of patients. Clinical features in DME using reference ‘EDTRS' scale of measurement. Results: Noninvasively 305 (99.1%) eyes were detected positive for various type of DME by SD-OCT while 282 (91.6%) eyes were detected positive by FFA. The prevalence of different types of DME such as cystoids, diffuse, focal and mixed was 7.8%, 13%, 7.1% and 63.7% respectively as diagnosed with FFA. Whereas, SRF, IR edema and mixed type was 4.9%, 3.6% and 90.6% respectively as diagnosed with SD-OCT. DME was not detected by FFA in 8.4% of eyes in overall study population. Whereas, SD-OCT was unable to detect DME in 0.9% of eyes. In our study overall performance of SD-OCT was better in detection of DME when compared to FFA. Conclusion: The present study showed the diagnostic potential and efficacy of SD-OCT over FFA in reliable and safe detection of DME in Type II Diabetic Mellitus patients was more and was easy and comparable to diagnostic findings of FFA specifically in cases of sub retinal macular as well choroidal edema due DME by SD-OCT.