Diabetes Mellitus: Retinal Ischaemia and Neovascularization

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Questions and Answers

What is an additional indication for cataract extraction in diabetes?

The prevention of adequate assessment of the fundus (correct)

The presence of retinopathy

Poorly controlled diabetes

The presence of diabetic nephropathy

What is the pathognomonic feature of diabetic kidney disease?

Thickening of basement membranes

Nodular glomerulosclerosis

Kimmelstiel–Wilson nodule (correct)

Mesangial expansion

What percentage of patients with type 1 diabetes develop diabetic nephropathy 20 years after diagnosis?

10%

40%

30% (correct)

20%

What is the current trend in the incidence of diabetic nephropathy?

It is decreasing Signup and view all the answers

What proportion of patients do not develop diabetic nephropathy despite having long-standing, poorly controlled diabetes?

Some patients Signup and view all the answers

What is the main reason for the variability in individual risk of diabetic nephropathy?

Unknown factors Signup and view all the answers

What percentage of susceptible patients with type 1 diabetes mellitus develop sustained proteinuria after about 10 years?

30% Signup and view all the answers

What is the primary factor that accelerates the thickening and opacification of the lens in diabetic patients?

Increased metabolic insult to the lens Signup and view all the answers

What is the approximate time period for the end stage of diabetic nephropathy to be reached in patients with type 1 diabetes mellitus?

16 years Signup and view all the answers

What is the term for the type of cataract that occurs in young patients with poorly controlled diabetes?

Snow-flake cataract Signup and view all the answers

What is the approximate duration of type 1 diabetes mellitus required for the glomerular filtration rate (GFR) to return to a normal value?

10 years Signup and view all the answers

Which of the following is NOT a risk factor for diabetic nephropathy?

Cataract Signup and view all the answers

What is the primary goal of pan-retinal photocoagulation in diabetic retinopathy?

To reduce the risk of recurrent haemorrhage Signup and view all the answers

What is the purpose of vitrectomy in advanced diabetic eye disease?

To clear vitreous haemorrhage and restore vision Signup and view all the answers

What is the main reason for reviewing patients regularly after pan-retinal photocoagulation?

To look for further development of new vessels and/or maculopathy Signup and view all the answers

What percentage of visual loss in people with type 2 diabetes is due to causes other than diabetic retinopathy?

50% Signup and view all the answers

What is the primary cause of visual loss in people with diabetes, excluding diabetic retinopathy?

All of the above Signup and view all the answers

What is the complication that requires early and extensive pan-retinal photocoagulation?

Rubeosis iridis Signup and view all the answers

What percentage of patients with diabetes are affected by diabetic neuropathy?

Between 50 and 90% Signup and view all the answers

What is the primary site of nervous system damage in diabetic neuropathy?

Peripheral nervous system Signup and view all the answers

What is a characteristic pathological feature of diabetic neuropathy?

Axonal degeneration of both myelinated and unmyelinated fibers Signup and view all the answers

What is the underlying mechanism of diabetic neuropathy?

Metabolic disturbance Signup and view all the answers

What is a common clinical presentation of diabetic neuropathy?

Asymptomatic Signup and view all the answers

What is a common clinical sign of diabetic neuropathy?

Diminished perception of vibration Signup and view all the answers

What is the reduction in risk of nephropathy with intensive treatment in type 2 diabetes patients with microalbuminuria?

61% Signup and view all the answers

What is the benefit of renal transplantation in diabetic patients with end-stage renal failure?

It dramatically improves the life of many diabetic patients Signup and view all the answers

What is the benefit of pancreatic transplantation in diabetic patients?

It produces insulin independence and delays or reverses microvascular disease Signup and view all the answers

What is the benefit of halving the amount of albuminuria with an ACE or ARB?

A nearly 50% reduction in long-term risk of progression to end-stage renal disease Signup and view all the answers

What is a limitation of pancreatic transplantation in diabetic patients?

The supply of organs is limited Signup and view all the answers

What is a potential complication of diabetic nephropathy in a transplanted kidney?

It progresses slowly and is usually not a serious problem Signup and view all the answers

Study Notes

Cataract Extraction in Diabetes

Indications for cataract extraction mirror those for non-diabetic patients, focusing on visual impairment level.
In diabetes, an additional reason for extraction is the inability to assess the fundus or provide laser treatment.

Diabetic Nephropathy

Major cause of morbidity and mortality, particularly leading to end-stage renal failure in developed countries.
Approximately 30% of type 1 diabetes patients develop nephropathy 20 years post-diagnosis, with risk decreasing to <1% annually afterward.
Genetic factors play a role; some patients may be genetically shielded from nephropathy despite poor diabetes control.
Decline in diabetic nephropathy incidence correlates with improved glycaemic and blood pressure management.
Risk factors include poor glycaemic control, longer diabetes duration, presence of other microvascular complications, ethnicity, hypertension, and family history.

Renal Changes Over Time

In type 1 diabetes, early renal changes feature hyperfiltration, normalizing around 10 years.
30% of susceptible patients develop sustained proteinuria after about 10 years, with nephrotic range proteinuria by 14 years.
Further renal function decline leads to end-stage renal failure approximately 16 years after diabetes onset.

Cataract Overview

Cataracts, characterized by permanent lens opacity, commonly affect the elderly.
Diabetes accelerates lens thickening and opacification, leading to earlier cataract development.
A unique 'snow-flake' cataract exists in young patients with severe diabetes; typically does not impair vision but complicates fundal examination.

Diabetic Eye Disease Management

Pan-retinal photocoagulation (PRP) targets areas of retinal ischaemia to lower intraocular VEGF, reducing neovascularisation and hemorrhage risks.
Argon laser is the standard method for photocoagulation, performed under topical anesthesia, with regular follow-up required.
Extensive bilateral PRP can lead to visual field loss, impeding driving and night vision.
Vitrectomy is an option in advanced diabetic eye disease from type 1 diabetes complicated by vitreous hemorrhage or retinal detachment.

Non-Retinopathy Causes of Visual Loss in Diabetes

About 50% of visual loss in type 2 diabetes is attributed to causes other than diabetic retinopathy, such as cataract, age-related macular degeneration, and glaucoma.
These conditions often stem from shared cardiovascular risk factors.

Diabetic Neuropathy

Predominantly impacts the peripheral nervous system; may affect 50-90% of diabetes patients.
Painful diabetic neuropathy (PDN) occurs in 15-30% of affected individuals.
Associated with metabolic disturbances, duration of diabetes, and glycaemic control.
Pathological findings include axonal degeneration, Schwann cell basal lamina thickening, and changes in intraneural capillaries.

Clinical Features and Risk Management

Common symptom of symmetrical sensory polyneuropathy may be asymptomatic; vibration perception is typically diminished.
Intensive treatment strategies for type 2 diabetes patients aim to lower risks: glycaemia control, hypertension management, and use of ACE inhibitors, statins, and aspirin significantly reduce complications and mortality rates.
Patients with worsening renal function could benefit from renal replacement therapy or even transplantation options to improve life quality.

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Description

Learn about the effects of diabetes mellitus on the retina, including retinal ischaemia and neovascularization. Understand the role of VEGF and the treatment options, including pan-retinal photocoagulation. Test your knowledge on this important topic in ophthalmology.