Abstract
Purpose :
Laser therapy is an established method to stabilize and control proliferative diabetic eye disease. Questions on the long-term effect on the nerve fiber layer and optic disk from these treatments remain to be answered. The purpose of the study was to evaluate changes in the macular retina, nerve fiber layer and optic nerve following pan-retinal photocoagulation (PRP) over time, using structural and functional diagnostic tests.
Methods :
Diabetic retinopathy patients requiring PRP underwent baseline structural Heidelberg Retinal Tomography (HRT) of the nerve and Optical Coherence Tomography (OCT) testing of the nerve and macula. In addition, functional visual field (VF) testing was done to measure peripheral vision. A wide field fluorescein angiogram (IVFA) was performed to monitor diabetic ischemia and its progression. The OCT, HRT, VF and IVFA were performed at baseline prior to laser and 6, 12, and 24 months post laser.
Results :
A total of 42 patients were enrolled in the study. From baseline, average retinal nerve fiber layer (RNFL) thickness did not change significantly (P>0.05) by 24 months post-treatment (6 months +5.4 μm; 12 months +2.5 μm, 24 months +1.9 μm) compared to control diabetics not requiring treatment. A non-significant thickening of the macula was observed at 6 months (+3.6 μm), 12 months (-0.3μm) and 24 months (+5.75 μm) compared to baseline. Visual field mean deviation (MD) decreased non-significantly compared to baseline (24 months -3.53 dB). Average cup to disk ratio (-0.093) and vertical cup to disk ratio (-0.078) did not change significantly by 24 months.
Conclusions :
24 month analysis indicates that laser does not cause structural and functional changes to the retina and optic nerve.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.