Abstract
Purpose :
Controversy exists whether choroidal thickeness (CT) changes with diabetic macular edema (DME). LASER focal photocoagulation has been reported to have no effect on CT but there were important drawbacks to consider . We performed a retrospective, observational clinical study to understand how CT changes in the 1st year of follow-up after focal/grid LASER (FGL) treatment for DME.
Methods :
We reviewed eyes submitted to FGL for DME treatment in our department from August 2014 to October 2016. We excluded eyes with proliferative diabetic retinopathy, eyes treated with pan photocoagulation or with intravitreal agents and those without EDI OCT assessment. CT was manually measured using the caliper tool in the Heidelberg Eye Explorer software, from the hyperreflective line of the Bruch membrane to the hyperreflective line of the chorioscleral interface, in the central 3500 μm area, subfoveally and 1750 μm right and left from the center, in the horizontal plane, and 1750 μm up and down from the center in the vertical plane. Follow up by OCT included baseline (BL), 6 months (6M) and 12 months (12M) treatment. As a second outcome we also correlated CT changes with central macular thickness (CMT) and macular volume (MV).
Results :
From August 2014 to October 2016, 161 patients were submitted to FGL for DME in our department but only 34 eyes of 24 patients (17 male and 7 female) were eligible. Mean sub-foveal CT at BL, 6M and 12M was 264±76µm, 288±73µm and 271±85µm, respectively. Mean difference between BL and 6M was -4 (CI95 -22 to -13), p=.605 and between BL and 12M was -10 (CI95 -26 to 7), p=.235. The difference between 6M and 12M was -9 (CI95 -33 to 15), p=.418. Mean differences on the other 8 macular points was not statistically significant between both BL and 6M and BL and 12M for any location. CT and CMT variation at 6M had a negative correlation (p=.0,02). CT and CMT variation at 12M, as well as CT and MV variation at 6M and 12M did not correlate.
Conclusions :
We did not find evidence that FGL alters significantly sub-foveal CT, and we also verified the same finding irrespective to the other 8 macular points we measured. We found a negative correlation between CT and MV variation at 6M. This may only reflect the decrease in macular edema and hence in CMT and MV following focal laser treatment. Our findings agree with previous reports even considering that we widened the area of search in the macula.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.