Photo Credit: Belus

The following is a summary of “Diabetic corneal neuropathy and its relation to the severity of retinopathy in patients with type 2 diabetes mellitus: an in vivo confocal microscopy study,” published in the February 2024 issue of Ophthalmology by Akkul et al. 

Researchers conducted a retrospective study to explore corneal neuropathy and nerve changes in individuals with type 2 diabetes mellitus (DM) across varying diabetic retinopathy (DR) statuses.

They included 87 eyes from 87 patients diagnosed with (DM and 28 eyes from 28 healthy control subjects. The DM patients were divided into three groups; those without DR (NDR), those with non-proliferative DR (NPDR), and those with proliferative DR (PDR). Within the PDR group, patients were further categorized based on whether they had undergone retinal argon laser photocoagulation treatment (ALP). Various parameters including ocular surface disease index score (OSDI), average tear break-up time (A-BUT), corneal sensitivity, and metrics of corneal nerve morphology such as corneal nerve fiber length (CNFL), corneal nerve fiber density (CNFD), and corneal nerve branch density (CNBD) of the corneal subbasal nerve plexus (SBNP) were assessed using in vivo confocal microscopy (IVCM).

The results showed that in DM patients, compared to the control group, there was an increase in OSDI scores and a decrease in A-BUT. No significant difference was observed between different DM patient groups. Corneal sensitivity was found to decrease in DM patients who developed DR compared to both the controls and the NDR group. Furthermore, CNFD and CNFL decreased in patients with NPDR and PDR compared to controls. CNFD and CNBD decreased in patients with PDR compared to all three groups. Overall, all IVCM parameters decreased with the progression of DR.

Investigators concluded that IVCM reveals early corneal nerve damage in diabetes, worsening with disease duration and severity, suggesting its potential as a tool for early diagnosis and monitoring complications like DR. 

Source: link.springer.com/article/10.1007/s10792-024-03043-7