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Multidisciplinary approach to diabetic retinopathy

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Mike Jackson
BOptom (UNSW), GOVOceania.com

Dr Michael Chilov
MB BS FRANZCO, Retina Associates

CASE REPORT 1

Optometrist

The story of this patient was first reported in Australian Optometry in November 2013. A 50-year-old male presented for a check-up at our Sydney optometric practice only because he had to complete a form for the Roads and Traffic Authority (RTA) of NSW. Because of his unstable diabetes, he had been required by the RTA to have his health assessed regularly to keep his licence. He had not had an eye examination for some time and was using ready-made spectacles that he had purchased from a petrol station.

Visual acuity was 6/12 in each eye and refraction did not help. His previous history included laser treatment and Avastin injections. He said he had not visited his ophthalmologist for two years because he could not afford the cost. It was my impression that he had not thought about his eyes since his previous consultation.

A fundus examination revealed that the patient had a long history of diabetic retinopathy. (Figures 1 and 2) There were scars from previous laser treatment, some lipid deposits and a haze around the discs, which were probably from new vessels. The left eye was marked by a large pre-retinal haemorrhage reaching down and around the macula.

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Figure 1. Case 1. Fundus of right eye reveals laser treatment scars, lipid deposits and a haze around the discs

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Figure 2. Case 1. Fundus of left eye shows enormous pre-retinal haemorrhage

Given the magnitude of the situation, the patient and I had a long conversation about his situation and the severity of his condition. During our discussion, he told me he had been seeing an ophthalmologist but stopped going when he could no longer afford to continue the visits. Rather than asking the ophthalmologist what he could do, he simply gave up and stopped attending.

The changes in his retina were affecting his vision but he managed until he met me. When I explained how urgently he needed to see an ophthalmologist, he said he would sell everything he owned so that he could afford to pay for specialist care.

At this point I contacted Dr Michael Chilov, a retina sub-specialist at the Retina Associates ophthalmic centre in Sydney to explain the situation. Dr Chilov asked me to send the patient to the centre the same day.

Ophthalmologist

The patient seen by Mr Jackson was examined by me on the same day. He had high-risk proliferative diabetic retinopathy with a left vitreous/preretinal haemorrhage. He had a 20-year history of diabetes with suboptimal glycaemic control and he had not seen an ophthalmologist for almost two years.

When I examined him, there was bilateral proliferative diabetic retinopathy, with a preretinal haemorrhage in the left eye and extensive neovascularisation at the right disc. The macula OCT also demonstrated macular oedema (Figure 3, right eye and Figure 4, left eye).

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Figure 3. Case 1. Extensive neovacularisation at the right disc (bilateral proliferative diabetic retinopathy)

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Figure 4. Case 1. Preretinal haemorrhage in the left eye

Prompt treatment was required in the left eye to prevent further bleeding. In patients with both proliferative retinopathy and macula oedema, Avastin (bevacizumab) is often used in the first instance. While panretinal photocoagulation remains the mainstay of proliferative diabetic retinopathy, it does take longer to have an effect on neovascularisation and can worsen diabetic macular oedema. Avastin has the ability to rapidly induce new vessel regression, prevent further bleeding and treat the coexisting macular oedema, and is followed by PRP laser surgery when the macular oedema is improved.

The other aspect to this patient’s treatment was his diabetic control. His glycated haemoglobin (HbA1C) was 12.3 per cent (the general target is less than seven per cent) suggesting poor glycaemic control. In an effort to address this, I arranged a referral via his GP to an endocrinologist.

Once the diabetic macular oedema had come under control, I commenced PRP. Unfortunately, he has more recently developed macular oedema and is requiring ongoing Avastin injections to manage this. His visual acuity is Right 6/7.5 and Left 6/7.5+ (Figure 5, left eye post-treatment).

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Figure 5. Case 1. Left eye post-treatment

Ultimately, the patient satisfactorily completed his RTA health assessment and was able to maintain his drivers licence and return to his hobby of four-wheel driving.

Importance of timely examinations

This case amply demonstrates a number of the challenges in managing patients with diabetic retinopathy. All optometric practices will have diabetic patients and will be able to relate this case to patients they may have.

It is important that optometrists are active in the management of their diabetic patients—ensuring regular examination, developing a long-term relationship with the patients, attending to their vision and refractive needs, educating them, reinforcing need for regular screening to prevent vision loss and organising appropriate and timely referral when required.

The screening for diabetic retinopathy as part of a comprehensive eye examination is a critical part of diabetic management. This assessment should be by way of a dilated fundus examination.

Unfortunately, the circumstances surrounding the presentation in this case report are not uncommon in my practice. Whether it is the patient who wakes with acute vision loss from a vitreous haemorrhage as a result of proliferative diabetic retinopathy, or the patient who fails their vision test for their drivers licence from diabetic macular oedema, the goal of these examinations is to detect early signs of retinopathy to allow early intervention and prevent this from occurring.

Many cases of sight-threatening retinopathy are not in patients in whom the signs were missed, but rather patients who have slipped through the gaps. Many patients with potentially sight-threatening retinopathy will often be relatively asymptomatic and not understand the need for regular assessment—or simply just forget.

It is important to educate patients about the need for ongoing annual reviews, even if they appear asymptomatic. Optometric practices should have reminder systems in place to ensure their patients return for regular review as per the screening guidelines.

Importance of timely referrals

Optometrists should aim to report their findings to the patient’s GP and an endocrinologist (if involved). If managing a patient in conjunction with an ophthalmologist, the ophthalmologist should receive a diabetes report form with a summary of findings or concerns the optometrist may have.

Referral to an ophthalmologist depends on retinopathy grade and presence of diabetic macular oedema. All patients with sight threatening retinopathy—diabetic macular oedema or proliferative retinopathy, as in this patient—should be promptly referred to an ophthalmologist. Additionally, any patient complaining of reduced vision or unexplained reduced acuity should be referred to an ophthalmologist for further assessment.

Optometry Australia’s newly revised clinical guidelines for the examination and management of patients with diabetic retinopathy provide some guidance in this regard. The guidelines recommend the need for follow-up, referral and appropriate management according to retinopathy grade based on recognised disease severity scales.

The optometrist’s role extends beyond assessment to diagnose retinopathy. Optometrists must be key players and active participants within a multidisciplinary diabetes health-care team. Patients who are receiving active treatment for diabetic retinopathy with an ophthalmologist should continue to see their optometrist. Their optometrist can attend to the patient’s ongoing refractive needs, monitoring for treatment side-effects, such as raised intraocular pressure and cataract, and provide a valuable educational and support role for these patients.

CASE REPORT 2

Optometrist

This patient’s visit with me was also prompted by the need to complete a form for the RTA of NSW. These required assessments commonly reveal serious pathologies in patients who otherwise would remain untreated.

On examination, we found his vision to be RE 6/12 and LE 6/15. This was due to his background retinopathy and probably some amblyopia. His retina showed signs of drusen and some dot, blot and flame haemorrhages.

The patient, who was 67 years old, was being treated for diabetes, hypertension and cholesterol. His vessels showed crossing changes, consistent with hypertension.

He just narrowly passed the RTA standard but we referred him to Dr Michael Chilov at Retina Associates for a thorough review of his retinopathy.

Dr Chilov wrote back, outlining how he had found the patient’s blood pressure and sugar level were too high and how he encouraged him to work with his GP for better control to avoid future blindness. Dr Chilov told the patient that he wanted to see him again in one year and to attend a review at our optometric practice in six months.

Ophthalmologist

This patient illustrates many of the points raised in the first case. When I first saw him, he had mild to moderate non-proliferative diabetic retinopathy and no macular oedema. I was happy to review him in 12 months but wanted him to see optometrist Mike Jackson to monitor his progress six months following his initial consultation with me.

I have found that it can often be helpful to alternate reviews with the patient’s optometrist and my scheduled reviews. This allows the patient to maintain a relationship with their optometrist, attend to any new refractive needs, provide a further opportunity to educate the patient about diabetic retinopathy and detect any unexpected changes. Unfortunately, this patient did not follow my recommendations and did not attend follow-up despite reminders.

Optometrist

About two years later, the patient returned to our practice with another RTA form. His vision had slipped a little to RE 6/12 LE 6/18. He reported that his blood pressure was better but his limited English made me unsure. I was unable to determine how his blood sugar levels had been, but I clearly established that he had not been back to Dr Chilov.

His fundus still showed roughly the same level of retinopathy as his previous consultation, except for a tiny diamond-like embolus in the right eye, just over the macula, a Hollenhorst plaque.  The presence of a Hollenhorst plaque is significant to the patient’s health and the standard practice is to have a carotid Doppler test performed to check for blockage in the internal carotids.

Ophthalmologist

During the two-year interval between examinations, the patient had developed the cholesterol embolus and his retinopathy had progressed to the severe non-proliferative stage. (Figures 6 and 7)

When I reviewed him, I arranged for a carotid Doppler study to exclude a carotid source for the embolus. Because I was also concerned about the worsening of his diabetic retinopathy, I arranged for him to see his GP for review of his glycaemic and cardiovascular risk factor control. No active ophthalmic intervention was required as there was no diabetic macular oedema and no proliferative retinopathy.

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Figure 6. Case 2. Right fundus photograph at initial presentation demonstrating microaneurysms, grade one hypertensive retinopathy (AV nipping, copper wire reflex changes) and multiple hard drusen (intermediate and large)

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Figure 7. Case 2. Right fundus image two years later demonstrates a cholesterol emolus lodged at a vessel bifurcation superior to the macula. There is progression of the retinopathy with cotton wool spots, retinal haemorrhages and early venous beading.

Dr Anita Sharma MBBS FRACGP, General practitioner

Dr Anita Sharma has 24 years of experience as a general practitioner, with special training in treating diabetes and chronic diseases. She says that optometrists are ideally placed to advocate for optimal diabetes and health management, provided they work as part of a team.

‘Optometrists who familiarise themselves with the different classifications for diabetic retinopathy and the evidence-based review and referral schedules have a huge impact on the quality of patient care,’ she said.

Dr Sharma was keen to point out that even if the patient is being referred on to an ophthalmologist, it is essential to keep the GP informed, as a professional courtesy, for legal purposes and to achieve the best health outcomes for the patient. ‘The GP is generally the most frequently-visited health-care professional, even by the most non-compliant patient, so collaboration and communication of this information with the GP is vital,’ she said.

‘Optometrists are really well-placed to proactively identify diabetic retinopathy and refer these patients to GPs for consideration of fenofibrate and offer tactful reminders about better glycaemic control as part of “whole patient care”.’

Patients generally turn to the GP for most advice on whether to commence a therapy so optometrists should leverage off of that,’ she said.

Dr Sharma says that the level of glycaemic control, which is crucial for prevention of worsening diabetic retinopathy, is an important piece of information that is too often omitted in the correspondence between diabetes team members.

‘All members of the multi-disciplinary team should be aware of the patient’s level of glycaemic control and reiterate this point in their correspondence,’ she said. ‘This will go a long way in ensuring that action will replace clinical inertia.’




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