A local cross-sectional study conducted by the Department of Research, SingHealth Polyclinics, found that one in five T2DM patients developed Impaired Colour Vision (ICV), specifically tritanomaly or blue-yellow colour deficiency.
Risk factors of this lesser known visual complication now brought to light
Visual complications in the form of diabetic retinopathy have long been established in patients with Type 2 Diabetes Mellitus (T2DM). What is lesser known is the higher risk for Impaired Colour Vision (ICV) that these patients are also subjected to.
A local cross-sectional study conducted by the Department of Research, SingHealth Polyclinics, found that one in five T2DM patients developed ICV, specifically tritanomaly or blue-yellow colour deficiency. And given that the prevalence of T2DM in our population is expected to rise to 15 percent in 2050, more individuals are likely to experience the poorer quality of life and reduced social functioning associated with ICV.
“The subtle effect on colour vision may not be noticed by the patients as adaptation sets in,” said Dr Tan Ngiap Chuan, principal investigator of the study.
“But we anticipate that selection of items for daily use, including fruits such as bananas, may be affected. Recognising traffic lights is potentially an issue, but affected patients can take cues from the blinking lights,” he added.
The study, which was published in BMC Endocrine Disorders, also found that the risk of ICV increased for each additional year after the onset of T2DM, with most patients developing it after 6 years.
The authors therefore suggest ICV screening after patients have had T2DM for 6 years or longer, following further feasibility and cost-effectiveness evaluation.
“In the meantime, clinicians can initiate screening using the Farnsworth D-15 instrument. They can also consider partnering with optometrists or exploring digital screening platforms,” suggested Dr Tan.
Ultimately, Dr Tan hopes that the study will help to increase awareness of ICV among clinicians, so that they can advise their patients appropriately.
“What they can do is to constantly remind patients to be prudent and keep their diabetes under good control to avoid any potential adverse visual or other vascular complications.”