Predicting diabetic retinopathy stages using a simple nerve conduction measuring device, DPNCheck®: A retrospective observational study

Mayu Sakai^1,2Takehiro Kato^2*Takuma Ishihara³Ken Takao²Tokuyuki Hirose²Sodai Kubota²Saki Kubota- Okamoto²Toshinori Imaizumi²Yoshihiro Takahashi²Masami Mizuno²Takuo Hirota²Yukio Horikawa²Hirokazu Sakaguchi^4,5Shin Tsunekawa⁵Daisuke Yabe^2,5

• ¹Department of Occupational Health, Gifu University Graduate School of Medicine,, Gifu, Japan
• ²Department of Diabetes, Endocrinology and Metabolism and Department of Rheumatology and Clinical Immunology, Gifu University Graduate School of Medicine, Gifu, Japan
• ³Innovative and Clinical Research Promotion Center, Gifu University Hospital, Gifu, Gifu, Japan
• ⁴Department of Ophthalmology, Gifu University Graduate School of Medicine,, gifu, Japan
• ⁵Center for One Medicine Innovative Translational Research, Institute for Advanced Study, Gifu University, Gifu, Gifu, Japan

Aims/Introduction. Diabetic retinopathy (DR) often remains asymptomatic until it reaches advanced stages, when delayed treatment can lead to irreversible visual impairment. To promote timely ophthalmology visits, this study investigated the utility of a simple nerve conduction device, DPNCheck®, as a predictor of DR severity. Previous research has established a relationship between diabetic neuropathy (assessed by conventional nerve conduction studies) and DR progression; however, the specialized equipment and expertise required limit its practicality. In contrast, DPNCheck® is a simpler alternative that quantifies neuropathy severity through the severity of the estimated modified Baba classification (eMBC).Materials and Methods. Using electronic medical records (EHRs), we identified individuals with diabetes who underwent DPNCheck® and subsequent ophthalmologic assessment for DR. Based on age and sural nerve conduction data, an eMBC was calculated. Meanwhile, DR severity was scored using a modified Davis classification, defining four stages (DR severity scores 0–3). Results. Of 181 individuals extracted from our hospital’s EHRs, 146 were eligible for analysis. Ordinal logistic regression showed that eMBC was significantly associated with DR stage, independent of diabetes duration and HbA1c. Receiver operating characteristic (ROC) curve analyses yielded eMBC cut-off values of 1.11, 1.51, and 1.51 to predict DR severity scores of ≥1, ≥2, and ≥3, respectively. Sensitivities ranged from 0.67 to 0.78, and specificities from 0.66 to 0.81. An eMBC of 1.51 or above was strongly associated with preproliferative or proliferative DR, indicating a need for urgent ophthalmology referral.Conclusions. DPNCheck®, a simple nerve conduction measurement device, may help predict DR severity and facilitate timely ophthalmologic care.