Purpose: To describe the pathoanatomy of diabetic macular edema in optical coherence tomography and its correlation with fluorescein angiography patterns.
Methods: Sixty eyes of 56 patients were analyzed. Diabetic macular edema was classified into typical focal leakage (from microaneurysm), typical diffuse leakage (the capillary plexus), or combined/questionable leakage using fluorescein angiography and retinal thickness profiles. The leakage and pooling patterns in fluorescein angiography were matched to the corresponding optical coherence tomography images and analyzed.
Results: Focal leakage shows swelling predominantly in the outer plexiform layer (OPL). Deeply located microaneurysms directly leak into the loose fiber portion of OPL (Henle layer) through the “fluid conductivity barrier” (synaptic portion of OPL). Diffuse leakage caused swelling predominantly in the inner nuclear layer and secondarily in the OPL. The deep capillary plexus is located between the two “fluid barriers” (inner plexiform layer and OPL); thus, diffuse leakage is primarily related with swelling in the inner nuclear layer. In the combined/questionable leakage, partial sections consisting of inner nuclear layer swelling and much larger areas of OPL/outer nuclear layer swelling are noticed.
Conclusion: Based on the concept of the fluid conductivity barrier, we revealed a correlation between the intraretinal location of the leakage source and where the fluid accumulated within the retinal layers.
Optical coherence tomography imaging analysis of diabetic macular edema based on the concept of the “fluid conductivity barrier” of the plexiform layers revealed a correlation between the leaking source and where the fluid accumulated within the retinal layers.
*Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea
†Siloam Eye Hospital, Seoul, Korea
Reprint requests: Suk Ho Byeon, MD, Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, 134 Shinchon-Dong, Seodaemun-Gu, Seoul, Korea 120-752; e-mail: firstname.lastname@example.org
Supported by the Conversing Research Center Program; funded by the Ministry of Education, Science, and Technology (2011K000680).
Partly presented at The 27th Annual Meeting of Japan Society for Ocular Circulation, Kobe, Japan, July 2010.
The authors declare no conflict of interest.
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