Imaging of laser-photocoagulated diabetic microaneurysm with spectral domain optical coherence tomography

Abstract

Purpose: To analyze the morphology of microaneurysms before and after direct photocoagulation using spectral domain optical coherence tomography.

Methods: In 13 eyes of diabetic patients who underwent focal photocoagulation for clinically significant macular edema, microaneurysms were evaluated before, immediately after, 1 month after, and 2 months after photocoagulation with spectral domain optical coherence tomography. The microaneurysms were also evaluated by fluorescein angiography and color fundus photography. The patients underwent focal photocoagulation for microaneurysm.

Results: The microaneurysms before photocoagulation in spectral domain optical coherence tomography were observed as circular or elliptical structures with hyperreflective foci within vessel walls. Immediately after photocoagulation, the microaneurysms were changed to indistinct lesions with hyperreflectivity around the microaneurysms. Acoustic shadows developed on the choroidal side of the microaneurysms. If photocoagulation for microaneurysms was appropriately done, retinal changes were limited to within the inner retina around the microaneurysms and no changes were observed in retinal pigment epithelium. Within 2 months after photocoagulation, the microaneurysms changed into fine scars and the retinal structure normalized. Average retinal thickness of the fovea was 432 ± 70 μm before the procedure but reduced to 373 ± 84 μm at 2 months post surgery.

Conclusion: Focal photocoagulation may be a less invasive method for treating microaneurysms, and spectral domain optical coherence tomography is useful for evaluating the efficacy of photocoagulation.