Patients with type 2 diabetes may experience peripapillary retinal nerve fiber layer (RNFL) loss even if they don’t have diabetic retinopathy (DR), a study in JAMA Ophthalmology reports.

Korean researchers enrolled 63 healthy individuals and 101 patients with type 2 diabetes, including 49 patients without DR (the non-DR group) and 52 subjects with mild-to-moderate nonproliferative DR (NPDR group). The study ran from 2013 to 2015, and participants were followed for thee years. The researchers measured peripapillary and RNFL thickness levels at one-year intervals.

The study reported the baseline mean peripapillary RNFL thickness was 96.2μm in the control group, 93.5μm in the non-DR group and 90.4μm in the NPDR group. During the three-year follow-up, investigators found the values decreased to 95.0μm in the control group, 90.3μm in the non-DR group and 86.6μm in the NPDR group.

Progressive reduction of peripapillary RNFL thickness was observed in healthy controls and patients with type 2 diabetes with or without DR, the researchers noted. However, type 2 diabetes was associated with a greater loss of peripapillary RNFL regardless of whether DR was present.

These findings suggest clinicians should be on the lookout for peripapillary RNFL loss in patients with type 2 diabetes, even in the absence of DR progression, the investigation concluded.

Lim HB, Shin YI, Lee MW, et al. Longitudinal changes in the peripapillary retinal nerve fiber layer thickness of patients with type 2 diabetes. JAMA Ophthalmol. July 25, 2019. [Epub ahead of print].