Alterations in Choroidal Vascular Parameters Following Pan-retinal Photocoagulation Using Enhanced-Depth Imaging Optical Coherence Tomography
Hamid Riazi Esfahani1 *, Ahmad Mirshahi1 , Elias Khalili Pour1 , Kaveh Fadakar1 , Reza Mirshahi2 , Nazanin Ebrahimiadib1 , Fariba Ghassemi1 , Hassan Khojasteh1 , Fatemeh Bazvand1 , Hooshang Faghihi1
- Retina Service, Farabi Eye Hospital, Tehran University Of Medical Sciences, Tehran, Iran
- Eye Research Center, The Five Senses Institute, Iran University of Medical Sciences, Tehran, Iran
Abstract: To investigate the alteration of choroid in patients with very severe non-proliferative diabetic retinopathy (NPDR) or early proliferative diabetic retinopathy (PDR) following panretinal photocoagulation (PRP).
Methods: Thirty-nine eyes of 21 patients with very severe NPDR and early PDR were recruited. Enhanced-depth imaging optical coherence tomography at baseline, 1, and 6 months after PRP was employed to measure choroidal parameters including total choroidal area (TCA) and choroidal vascular index (CVI) using a public domain image J software. Binarization and segmentation of OCT images were performed using the protocol described by Sonoda et al .
Results: In eyes with very severe NPDR a non-significant decrease in total choroidal area happened at month 1, followed by a significant increase at month 6 (539 ± 131 µm2 at baseline, 502 ± 134 µm2 at month 1, 598 ± 168 µm2 at month 6 ; P=0.003). An increase in CVI at month 1 was followed by a decrease at month 6 (68.25 ± 3.05 at baseline, 69.74 ± 3.62 at month 1, 67.84 ± 1.77 at month 6; P<0.001). A reverse pattern was observed in eyes with PDR, which was a non-significant increase in total choroidal area at month 1 followed by a decrease at month 6 (497 ± 95 µm2 at baseline, 514 ± 133 µm2 at month 1, 425 ± 95 µm2 at month 6; P=0.011). CVI decreased at month 1 and remained relatively stable at month 6 (69.34 ± 3.11 at baseline, 68.33 ± 3.41 at month 1, 68.50 ± 5.04 at month 6; P=0.023). Alteration of choroidal thickness was not statistically significant in both groups.
Conclusion: Eyes with very severe NPDR and early PDR exhibit a reverse pattern regarding choroidal indices after PRP.
