Retrospective evaluation of choroidal and retinal changes in patients with diabetic peripheral neuropathy but no diabetic retinopathy.

Central macular thickness, retinal nerve fiber layer, and subfoveal choroidal thickness did not differ significantly between patients with diabetic peripheral neuropathy without diabetic retinopathy and healthy controls.

• Mean CMT values were compared between study and control groups with p = 0.139.
• Mean RNFL values were compared between study and control groups with p = 0.372.
• Mean SFCT values were compared between study and control groups with p = 0.594.
• None of these three measurements reached statistical significance (all p > 0.05).

GCIPL thickness was significantly reduced in the inferior and inferonasal sectors in patients with diabetic peripheral neuropathy without diabetic retinopathy compared to healthy controls.

• The inferior GCIPL sector showed a statistically significant difference (p = 0.012).
• The inferonasal GCIPL sector showed a statistically significant difference (p = 0.023).
• No significant differences were found in the mean, minimum, superonasal, superior, superotemporal, or inferotemporal GCIPL sectors (p > 0.05 for all).
• Eight GCIPL sectors were compared in total: mean, minimum, superonasal, superior, superotemporal, inferotemporal, inferior, and inferonasal.

Luminal area and total choroidal area were significantly increased in patients with diabetic peripheral neuropathy without diabetic retinopathy compared to healthy controls.

• Luminal area (LA) showed a statistically significant difference between study and control groups (p = 0.009).
• Total choroidal area (TCA) showed a statistically significant difference between study and control groups (p = 0.008).
• Stromal area (SA) did not differ significantly between the groups (p = 0.121).
• The increase in LA and TCA occurred while choroidal vascular index (CVI) remained constant.

Choroidal vascular index did not differ significantly between patients with diabetic peripheral neuropathy without diabetic retinopathy and healthy controls.

• CVI was 0.68850 in the study group and 0.68575 in the control group.
• No significant difference was found between the groups (p = 0.456).
• CVI remained constant despite significant increases in luminal area and total choroidal area in the study group.