Abstract
Purpose:
The present study was designed to report retinal blood flow levels measured by Laser Speckle Flowgraphy (LSFG) in refractory diabetic macular edema (DME) patients and idiopathic epiretinal membrane (ERM) patients before and after undergoing vitrectomy.
Methods:
From March in 2011 to July in 2013, vitrectomy was performed on 30 eyes of 25 consecutive patients with clinically refractory DME, and 35 eyes of 35 ERM patients as controls. The mean blur rate (MBR) that represents retinal blood flow velocity of the major vessels at the optic disc and the relative flow volume (RFV) which represent retinal blood volume of a specific blood vessel were measured by LSFG. The 1000-μm central retinal thickness (CRT) was measured by optical coherence tomography using Macular Cube 512 x 128 scanning protocol. Visual acuity was measured preoperatively and postoperatively, and the results were converted to the logarithm of the minimum angle of resolution (logMAR).
Results:
CRT decreased and visual acuity improved 3 months after vitrectomy in ERM and DME patients. MBR and RFV in ERM patients did not change after surgery. In contrast, MBR in DME patients significantly increased after surgery (118%, P<0.001). The RFV artery and the RFV vein were also significantly increased (160 ± 127%, P=0.02 and 165 ± 142%, P=0.02 respectively).
Conclusions:
Vitreous surgery may improve retinal blood flow levels in patients with diabetic macular edema. In DME, LSFG can become one of the index of curative effects. LSFG can evaluate blood flow levels noninvasively and quantitatively in the diseases which bases are circulatory disorder, such as diabetic retinopathy.
Keywords: 499 diabetic retinopathy •
688 retina •
436 blood supply