Corneal Sensitivity Impairment in Diabetic Retinopathy Not Reversed By Anti-VEGF

Patients with proliferative diabetic retinopathy experience reduced corneal sensitivity, even after anti-VEGF therapy, setting the stage for complications such as neurotrophic keratopathy.

Patients with proliferative diabetic retinopathy (PDR) are more likely to have impaired corneal sensitivity compared with patients with nonproliferative diabetic retinopathy (NPDR), according to a study published in American Journal of Ophthalmology. Anti-vascular endothelial growth factor (anti-VEGF) therapy does not reverse the impairment, the research shows.

This study is the first to assess the relationship of corneal sensation and DR severity with robust representation of individuals with Hispanic ethnicity, who are frequently underrepresented in clinical trials for DR treatment. The researchers add that corneal sensitivity impairment can factor into the development of complications such as neurotrophic keratopathy (NK) and potential vision loss.

Fifty consecutive adult patients (aged mean 57.9 years; 66% Hispanic; 25 men) from a retinal practice who had diabetes mellitus type 1 or 2 and DR were included in the study. Patients underwent eye exams, which included an assessment of corneal sensitivity with a Cochet-Bonnet esthesiometer. The investigators compared eyes’ corneal sensitivity (65 no history of PDR 35 current or regressed PDR) with the Mann-Whitney U test and tested the effect of prior anti-VEGF therapy on corneal sensitivity.

While therapy with anti-VEGF medications can promote vascular regression of PDR, this improvement in DR is not accompanied by recovery of neural corneal sensitivity.

At baseline, 26 eyes had PDR while 74 had NPDR. Nine of the NPDR eyes had regressed from PDR to NPDR, including 7 that regressed after anti-VEGF therapy. Eyes with history of PDR had shorter median corneal sensitivity compared with eyes of patients without PDR history (0.5 cm vs 4.75 cm).

Eyes that had regressed from having PDR to NPDR and eyes with untreated PDR had lower median corneal sensitivity compared with eyes with no PDR history (0 cm vs 0 cm vs 4.5 cm P =.0076). Compared with eyes with NPDR, eyes were 3.6 times more likely to have complete corneal sensitivity loss and 90% more likely to have corneal sensitivity of no more than 4 cm in at least 2 quadrants if they had PDR.

“In the context of previous studies, which describe a higher risk of worse outcomes for both DR and NK among diabetic patients from underrepresented backgrounds, it stands to reason that clinical practice could benefit from improved collaboration between primary care, cornea specialists, and retina specialists,” the study authors suggest. “While therapy with anti-VEGF medications can promote vascular regression of PDR, this improvement in DR is not accompanied by recovery of neural corneal sensitivity.”

They said doctors might consider assessing corneal sensitivity when evaluating diabetic eye disease as early detection is essential and DK frequently occurs in patients with diabetes.

Limitations of the study include cross-sectional nature of the data and underrepresentation of eyes with regression from PDR to NPDR.

Disclosure: One study author declared affiliations with biotech, pharmaceutical, and/or device companies, and Oyster Point Pharma provided funding for the research. Please see the original reference for a full list of authors’ disclosures. 

This article originally appeared on Ophthalmology Advisor


Singer M, O’Brien P, Mein L. Corneal sensitivity is inversely correlated with severity of diabetic retinopathy in a predominantly underrepresented population. Am J Ophthalmol. Published online August 27, 2023. doi:10.1016/j.ajo.2023.08.010