Diabetes and DED’s


Diabetes is a chronic condition that affects many different organs and systems in the body, including the cardiovascular system, the kidneys, the nervous system and the eyes. In a healthy body, insulin is a hormone produced by the β -cells in the pancreas gland which regulates blood glucose (sugar) levels. This is achieved by insulin transporting glucose from the blood into the cells of the body where the glucose can be converted to energy. Diabetes occurs when there are elevated levels of glucose in the blood (hyperglycaemia), due to insufficient insulin production by the pancreas, and/or insufficient use of insulin.

Diagnostic criteria have been debated and updated over decades; the current criteria from the World Health Organisation (WHO) states diabetes should be diagnosed if one or more of the following criteria are met:

  • Fasting plasma glucose ≥ 7.0 mmol/L (126 mg/dL).
  • Two-hour plasma glucose ≥ 11.1 mmol/L (200mg/dL) following a 75g oral glucose load.
  • A random glucose >11.1 mmol/L (200mg/dL) or HbA1c ≥ 48 mmol/mol (equivalent to 6.5%).


According to the International Diabetes Federation 2019’s Atlas, nearly half a billion adults worldwide are currently living with diabetes. By 2045, this number will rise to 700 million.

There are three main types of Diabetes, namely Type-1 Diabetes (T1D), Type-2 Diabetes and Gestational Diabetes. Approximately 5-10% of all diagnoses are attributed to Type-1 Diabetes, while ~90% of diagnosed cases are classed as Type-2 diabetes. Additionally, as many as 1 in 7 births are affected by gestational diabetes.

More detailed information relating to the risk factors, symptoms, available therapies and best management practices for Type-1 Diabetes, Type-2 Diabetes and Gestational Diabetes is available via the links provided below.


Type-1 Diabetes

Type-2 Diabetes

Gestational Diabetes


*Other less common forms of diabetes, including monogenic diabetes, and secondary diabetes due to hormone disturbances such as Cushing’s disease.

Diabetes Management

Improper diabetes management and unstable blood-glucose levels over a prolonged period can increase the risk of one or many diabetes-related eye conditions developing.

However, certain interventions can slow the progression of Diabetes-related Eye Diseases and are particularly effective when initiated shortly after initial diagnosis. This includes regular screening and improved diabetes control, with intensive blood-glucose control through diet and medication preventing the onset of Diabetes-related Retinopathy by up to 76% 1.

Diabetes-related Eye Diseases occur directly as a result of chronic high blood glucose levels causing disruptions to normal function of all parts of the eye, and disrupting signalling networks in all parts of the eye. The spectrum of DEDs includes Diabetes-related Retinopathy, Diabetes-related Macular Edema, Diabetes-related Cataract, Diabetes-related Glaucoma, Diabetes-related Uveitis, Diabetes-related Keratopathy, and Diabetes-related Dry Eye Syndrome. These conditions are not mutually exclusive and patients with diabetes may develop one or many of these eye conditions. Each of these DED’s are explored in greater detail with respect to their pattern of onset, prevalence, risk factors, diagnostic techniques and available therapies in their individual sections below (“End of this page”).

For example, the advanced form of Diabetes-related Retinopathy can progress to Diabetes-related Macular Edema and certain types of Diabetes-related Glaucoma; steroid treatment of Diabetes-related Macular Edema and other ocular surface complications associated with diabetes can also induce glaucoma. Cataract surgery at certain stages of disease can exacerbate and progress Diabetes-related Retinopathy and Diabetes-related Macular Edema. Diabetes-related Retinopathy is of particular concern as it the leading cause of irreversible blindness in the working age population 2.


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