Short Wavelength Automated Perimetry and Peripapillary Retinal Nerve Fiber Layer in Early Diabetes
Nikki Doreen S. Angbue Te, MD, Pearl M. Tamesis-Villalon, MD, Romulo N. Aguilar, MD, Joseph Anthony J. Tumbocon, MD, Kristine D. Corpus, MD
To investigate the significance of short wavelength automated perimetry (SWAP) in detecting retinal functional impairment in early diabetic patients without retinopathy and with mild non-proliferative diabetic retinopathy (NPDR).
This is a prospective, cross-sectional study of 37 eyes of early diabetics which were divided into 2 groups: no DR with 18 subjects and mild NPDR with 19. All subjects underwent HBA1C, SWAP, peripapillary RNFL thickness measurement and fundus photo. Visual field indices: MD and PSD as well as average RNFL thickness were compared among the 2 groups. Correlation of MD with RNFL thickness and HBA1C were also analyzed.
There was no statistically significant difference in the MD (-4.46 ± 3.03 vs -2.94 ± 2.21; p=0.09), PSD (3.08 ± 1.28 vs 2.69 ± 0.47; p=0.23) and average peripapillary RNFL thickness (98.47 ± 6.89 vs 98.72 ± 11.01; p=0.93) among early diabetics with mild NPDR and no signs of DR. There is no correlation between MD and RNFL thickness in the no DR group (R2=0.017) and the mild DR group (R2=0.000). There was a weak correlation between MD and HBA1C in the no DR group (R2=0.137), while no correlation was seen in the mild NPDR group (R2=0.000).
SWAP does not appear to be a sensitive measure of worsening retinopathy in older individuals with early diabetes. The usefulness of SWAP and peripapillary RNFL thickness in the early stages of retinopathy are inconclusive.
Keywords: SWAP, perimetry, RNFL, diabetes, retinopathy, sensitivity