Evaluation of visual function and prognosis for patients with proliferative diabetic retinopathy with the low vision evaluator

Proliferative diabetic retinopathy (PDR) is a leading cause of visual loss in adults in industrialized countries. PDR patients with light perception (LP) or hand movement (HM) acuity due to severe vitreous hemorrhage require vitreous surgery. The purpose of this study was to determine whether the visual acuity of PDR patients with LP or HM can be graded into finer steps with the Low Vision Evaluator (LoVE). In addition, we determined whether the LoVE results are correlated with the amplitude of the electroretinogram (ERG), the presence of retinal detachment (RD), or postoperative visual prognosis. The LoVE instrument is a subjective device that measures the thresholds for light stimulus and is equipped with a pair of goggles with white light-emitting diodes as the stimulus. We measured the LoVE thresholds of 19 PDR patients, whose fundi could not be observed due to vitreous hemorrhage and whose visual acuity was LP or HM. The 13 patients with HM vision had LoVE thresholds that ranged from 25.0 and 40.0 dB, and the 6 patients with LP vision had LoVE thresholds that ranged from 20.0 and 40.0 dB. The LoVE thresholds of 9 patients with RD were significantly lower than those of 10 patients without RD (p < 0.001). The LoVE thresholds were correlated with the amplitude of the a- and b-waves of the ERG and the postoperative best-corrected visual acuity (BCVA) (a-wave: r = 0.70, p < 0.001; b-wave: r = 0.71, p < 0.001; postoperative BCVA: r = 0.46, p < 0.05). These results indicate that the LoVE is capable of grading the visual function of PDR patients with conventional LP and HM vision into finer steps. Thus, the LoVE is an invaluable device in predicting the postoperative visual acuity of patients with vitreous hemorrhage.