Abstract
Purpose :
The gold standard treatment for severe diabetic retinopathy is panretinal photocoagulation (PRP) of the peripheral retina. We performed a prospective, observational clinical study to determine the effect of PRP on the peripapillary retinal nerve fiber layer (RNFL) as measured by Spectral Domain Optical Coherence Tomography (SD-OCT).
Methods :
Patients who had proliferative diabetic retinopathy (PDR), were naïve to PRP treatment, and had clear ocular media were recruited from the retina subspecialty clinic. Patients with prior retina laser treatment, a history of intravitreal injection, prior retinal surgery, or concomitant retinal or optic nerve disease, such as glaucoma, were excluded. Demographics including age, sex, and race were recorded. PRP was administered by a retina faculty physician in one or two sessions within a 1 week period with a standardized setting (1250 mean spots, 200 micron size, 100 ms duration). SD-OCT RNFL scans were performed using a Heidelberg Spectralis (Heidelberg, Germany) prior to PRP as well as 1, 3, 6, and 12 months post procedure. Paired T-tests were used to compare RNFL thickness from baseline to one month.
Results :
31 eyes of 20 patients were enrolled into the study from February 2014 to August 2015. Three patients were lost to follow-up. The majority of patients were female (n=14, 70%) and African American (n=17, 85%) with a mean age of 56.7 +/- 8.2. The average change in RNFL from baseline to 1 month was 3.58 +/- 11.07 microns (3.63%). Baseline overall RNFL thickness was 85.44 microns, which increased to 89.28 microns at one month (p=.001). Inferior RNFL was 107.22 microns at baseline and increased to 113.08 microns at one month (p=.001). Inferotemporal was 118.89 microns at baseline and increased to 126.64 at one month (p=.03). There was no significant effect on RNFL thickness in any other optic nerve head regions.
Conclusions :
In a cohort of patients with PDR, PRP appears to increase the overall RNFL thickness as well as inferior and inferotemporal RNFL thickness after one month. Further follow up is needed to assess the long term effect of PRP on RNFL.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.