Guide: Type 2 diabetes-related retinopathy

The RACGP guidelines (2020) and RANZCO guidelines (2019) recommend that patients with type 2 diabetes should be screened for diabetic retinopathy (DR) at the time of diabetes diagnosis.^1,2 The RACGP guidelines state that retinal photography may be used by GPs as a screening tool for DR but cannot replace a comprehensive eye exam; regardless, people with type 2 diabetes are recommended to be referred to an ophthalmologist or optometrist at the time of diabetes diagnosis.¹ However, there is actually an average 3-year delay for the first eye referral, according to a cross-sectional GP survey in Victoria.³ Furthermore, only about 1 in 2 GPs checked whether their patients followed through with the initial referral.³

This guide summarises key information about DR in patients with type 2 diabetes and the GP’s role in screening, management and referral.

Diabetic retinopathy essentials

DR is a progressive, microvascular disorder affecting up to 1 in 3 people with diabetes.¹
It is the leading cause of vision loss in the working adult population.⁴
Risk factors for DR include:^1,5
- long duration of type 2 diabetes (> 10 years)
- poor glycaemic control
- hypertension
- dyslipidaemia
- microalbuminuria
- anaemia
- pregnancy

Progression of DR

Adapted from RACGP 2020,¹ Simo et al 2012.⁶

While asymptomatic in the early stages, disease progression can result in vision loss.^1,4
Vision-threatening DR includes severe non-proliferative DR, proliferative DR and foveal-threatening diabetic macular oedema.¹

The GP’s role

GPs play an important role in:¹

ensuring timely screening for DR
delaying DR onset or progression through modifying risk factors
making specialist referrals, as appropriate

Screening

Frequency of screening

When to start screening

Refer to an optometrist or ophthalmologist at the time of diabetes diagnosis for the initial screening.¹

Note: Medicare Benefits Schedule (MBS) item numbers 12325 and 12326 are for retinal photography with a non-mydriatic retinal camera by a medical practitioner – refer to the MBS schedule for more information. According to the RACGP guidelines, retinal photography may be used as a screening tool for DR but cannot replace a comprehensive eye exam.¹

Follow-up interval if retinopathy is present

Refer to ophthalmologist as appropriate. Monitoring intervals are dependent on the severity of DR (usually < 1 year), and may be established with the optometrist or ophthalmologist involved in screening.^1,2,5

Follow-up interval if retinopathy is NOT present

Ensure individuals are screened every 2 years unless the person is at higher risk* or is a Aboriginal or Torres Strait Islander or from a non-English-speaking background, in which case rescreen every year.¹

* People at higher risk includes those with:

diabetes for > 15 years
suboptimal glycaemic control
systemic disease (poorly controlled hypertension or lipids; other diabetic complications or foot ulcers)

Adapted from The Royal Australian College of General Practitioners. Management of type 2 diabetes: A handbook for general practice. East Melbourne, Vic: RACGP, 2020.¹

Practical tips for timely screening and referral:

In every screening and follow-up referral, check the patient has taken up the referral – consider setting up an alert in their medical record.
Consider advising patients to register for the free online KeepSight reminder system to help them remember to attend their next diabetes eye examination.¹
Ensure the screening and follow-up results are received from optometrist/opthalmologist.^2,5

Referral to ophthalmologist

If the GP undertakes screening, RANZCO guidelines recommends referral to an ophthalmologist in the following circumstances: if the patient’s visual acuity is less than 6/12 without obvious cause or if image quality is inadequate for grading of DR.²

The table below is the recommended timeframe of ophthalmologist referral based on the grade of DR.²

RANZCO: Referral pathway guidelines for DR

Adapted from RANZCO Patient Screening and Referral Pathway Guidelines for Diabetic Retinopathy (2019).²

Delaying onset and progression of DR by the GP

Management of DR includes:¹

Optimising glycaemic control.
Optimising blood pressure control.
Early initiation of fenofibrate to help slow progression in people with type 2 diabetes diagnosed with DR. The addition of fenofibrate therapy to slow DR progression does not replace usual strategies for achieving glycaemic, blood pressure and lipid control.
Referral for ophthalmological care – treatment may include laser therapy, vitrectomy and/or intraocular anti-vascular endothelial growth factor (VEGF) agents.

The table below shows the treatment options and the clinicians who are expected to administer them. The GP’s role is specifically in risk factor control as well as prescribing fenofibrate therapy.

Treatment options by DR stage

Source: Adapted from RACGP 2020,¹ Simo et al 2012,⁵ Wright et al 2011,⁷ and Hooper et al 2012⁸

Prescribing fenofibrate for DR

In Australia, a particular brand of fenofibrate has been available since 2013 for the reduction in the progression of DR in patients with type 2 diabetes and existing DR.⁹ Currently, there are two brands of fenofibrate indicated for DR.

Prescribing information

Lipidil®	DR indication approved in 2013, click here to view the Product Information.
Fenofibrate Sandoz®	DR indication approved in 2020, click here to view the Product Information.

The use of fenofibrate does not replace the appropriate control of blood pressure, blood glucose and blood lipids in reducing the progression of diabetic retinopathy.¹⁰

The usual and maximum recommended dose for patients without renal impairment is 145 mg per day, i.e. one tablet to be taken once daily with or without food at the same time each day.¹⁰

It is recommended that serum creatinine is measured during the first 3 months after initiation of treatment and thereafter periodically. Monitoring of creatinine should also be considered for patients taking fenofibrate at risk for renal insufficiency such as the elderly and patients with diabetes. Treatment should be interrupted in case of an increase in creatinine levels > 50% of upper limit of normal.¹⁰

Key resources

Abbreviations: DR: diabetic retinopathy; RACGP: Royal Australian College of General Practitioners; RANZCO: Royal Australian and New Zealand College of Ophthalmologists

References

The Royal Australian College of General Practitioners. Management of type 2 diabetes: A handbook for general practice. East Melbourne, Vic: RACGP, 2020.
RANZCO Patient Screening and Referral Pathway for Diabetic Retinopathy (2019). Available from https://ranzco.edu/wp-content/uploads/2020/08/Patient-Screening-and-Referral-Pathway-and-Clinical-Notes-for-Diabetic-Retinopathy-Management-in-Australia-2019.pdf
Papa BM et al. Clin Exp Ophthalmol 2016;44:867–68.
International Council of Ophthalmology. ICO Guidelines for Diabetic Eye Care. Updated 2017. Available at: http://www.icoph.org/downloads/ICOGuidelinesforDiabeticEyeCare.pdf
Optometry Australia. Clinical guideline: Examination and management of patients with diabetes. 2018. Available at: https://www.optometry.org.au/wp-content/uploads/Professional_support/Guidelines/clinical_guideline_diabetes_revised_sept_2018_final_designed.pdf
Simo R et al. Br J Ophthalmol 2012;96:1285-90.
Wright AD et al. Eye 2011;25:843-49.
Hooper P et al. Can J Ophthalmol 2012;47 (2 Suppl):S1–30.
Australian Government Department of Health. Therapeutic Goods Administration. Available from https://www.tga.gov.au/prescription-medicines-new-or-extended-uses-registered-medicines Accessed October 2020.
Lipidil Product Information.