Early visual field changes in patients with type 1 diabetes mellitus

To assess the visual field sensitivity changes and investigate the association between visual field sensitivity and retinal nerve fiber layer thickness in patients with type 1 diabetes mellitus.

In this cross-sectional and observational study, 46 patients (22 males, 24 females) with type 1 diabetes mellitus and no diabetic retinopathy formed the diabetes mellitus group and 50 age-matched healthy subjects (32 males, 18 females) formed the control group. Retinal nerve fiber layer thickness, full-threshold standard automated perimetry, and short-wavelength automated perimetry were performed. Main outcomes were retinal nerve fiber layer thickness, mean deviation, pattern standard deviation, and short fluctuation.

Average retinal nerve fiber layer thickness was significantly thinner in the diabetes mellitus group (p < 0.001). The mean values of mean deviation and pattern standard deviation of the full-threshold standard automated perimetry did not differ between the groups (p = 0.179, p = 0.139, respectively). Mean short fluctuation was significantly greater in the diabetes mellitus group (p < 0.001). Both mean deviation and pattern standard deviation of the short-wavelength automated perimetry were significantly greater in the diabetes mellitus group (p < 0.001, p < 0.001, respectively). Pattern standard deviation of short-wavelength automated perimetry equal or higher than 1.57 dB had 91% sensitivity and 90% specificity (area under the curve = 0.969, p < 0.001) and short fluctuations of full-threshold standard automated perimetry equal or higher than 0.80 dB had 80% sensitivity and 76% specificity over detecting early retinal nerve fiber layer loss in patients with type 1 diabetes mellitus (area under the curve = 0.855, p < 0.001).

This study showed that thinner retinal nerve fiber layer in patients with type 1 diabetes mellitus may be associated with abnormal retinal sensitivity to short-wavelength stimulations in short-wavelength automated perimetry; however, retinal sensitivity to white stimulus was similar to that in healthy subjects in full-threshold standard automated perimetry.