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The Importance of the Periphery

2 CPD in Australia | 1CD in New Zealand | 8 December 2018


 By  Dianne Pyliotis

Examining the peripheral retina is an important part of an optometric eye examination. It is critical for the detection and management of diabetic retinopathy, acute retinal pathologies, the progression of chronic retinal pathologies, management of inflammatory eye disease, identification of systemic health risk factors and diagnosis of pathologies in asymptomatic patients. 


1. Understand the differences between non-mydriatic digital fundus photography and ultra-widefield retinal imaging with respect to time management and pathology detection.
2. Identify the role the peripheral retina plays in the assessment of diabetic retinopathy and understand the supporting evidence-based research.
3. Identify the importance of peripheral retinal examinations in patients presenting with acute ocular pathology for the appropriate management implementation.
4. Understand the evidence-based research and recognise the role the peripheral retina plays in chronic ocular pathologies that affect central vision primarily (i.e. age-related macular degeneration, epiretinal membranes).
5. Recognise the importance of peripheral retinal health in asymptomatic patients, assess common peripheral retinal lesions and better manage these patients.
6. Identify the importance of peripheral retinal examinations in patients with inflammatory eye disease with respect to management.
7. Understand evidence-based research highlighting the role of the peripheral retina in systemic diseases that are not diabetes mellitus (i.e. hypertension, stroke, Alzheimer’s dementia), and recognise the importance of communicating these findings with other practitioners within the medical community.
8. Identify the importance of patient education for better health care in the community. 


In Australia today, most primary eye care practitioners only dilate symptomatic and diabetic patients, which indicates that all other patients may not be receiving the optimum peripheral retinal examination. Technological advances, such as ultra-widefield imaging, are now permitting non-dilated patients to receive a thorough retinal check.

Dilemmas with Dilation

It is common Australian optometric practice to perform non-dilated eye examinations. This is most likely due to both patient and practitioner perceptions about the inconvenience caused and extra consultation time required for dilated examinations. This results in practitioners questioning its necessity for low-risk patients. However, the established gold standard eye examination involves a dilated fundus exam (DFE) with binocular indirect ophthalmoscopy.

Non-mydriatic digital fundus photography is a common tool used by optometrists for patient screening, disease detection, photo-documentation and patient education, however the standard area of the retina captured is only 30 degrees.1 Technological advancements, mainly with ultra-widefield retinal imaging, have allowed for peripheral retinal examinations in the absence of dilation. This imaging is highly effective at ensuring all patients receive appropriate care, have previously undetected retinal pathology diagnosed and have necessary management initiated. It allows earlier detection, photo-documentation for better progression monitoring and minimises patient inconvenience.

The use of ultra-widefield imaging also helps address the continued pressure placed on optometrists regarding consultation times and numbers. Aeillo et al (2012) published that ultra-widefield imaging took less than half the time required to take  dilated, stereoscopic, standard field 35mm colour 30 degree fundus Early Treatment of Diabetic Retinopathy Study1 photographs (ETDRS photography). Additionally, ultra-widefield imaging provided comparable and consistent grading scales for the level of diabetic retinopathy (DR), highlighting the positive relationship between effective imaging and time efficiency.1

All patients require peripheral retinal examination, and hence implementing ultra-widefield imaging as part of routine eye examinations can remove the dilemmas involved with dilation.

Managing Diabetic Retinopathy

Patients with diabetes mellitus require regular eye examinations, and according to the Medicare Benefits Optometric Services schedule, a diabetic eye examination involves the “instillation of a mydriatic”.2 With this requirement in mind, it is apparent that the peripheral retinal examination is critical for diabetic eye care.

The global prevalence of diabetes among adults in 2014 was estimated to be 422 million. This disease is a major cause of blindness, among other detrimental health conditions.3 The 2012 publication from the AusDiab group reported that the prevalence of diabetes in the Australian adult population was 7.4 per cent, with over 250 adults developing diabetes every day.4 This prevalence varies across demographic and cultural groups, for example, diabetes is twice as prevalent among Indigenous Australians as it is among non-Indigenous Australians.5

Overall, between 25-44 per cent of people with diabetes have some form of diabetic retinopathy (DR) at any point in time.5 The most recent Australian DR prevalence data from the AusDiab Study found an overall DR prevalence of 25.4 per cent, with proliferative diabetic retinopathy (the most advanced form of the disease) 2.1 per cent.5 This of course, is concerning, as DR is the leading cause of preventable blindness in adults of working age, and yet it is a treatable condition.6 Optometrists are well positioned in the community to provide primary eye care for diabetics, yet up to 50 per cent of Australians with diabetes do not undergo eye examinations every two years as recommended.6

The gold standard diabetic eye examination involves seven stereoscopic standard 30 degree field fundus photographs by a trained grader in order to detect DR.5 This represents 30 per cent of the retina. However, this is rarely performed in routine practice, which may be due to time constraints. Silva et al (2012) compared ultra-widefield photography imaging with ETDRS photography and found that for the assessment of DR and diabetic macular oedema, ultra-widefield imaging system results compared favourably to EDTRS photography and clinical examination, and could be acquired more rapidly.1 Furthermore, Silva et al (2014) demonstrated that after the implementation of ultra-widefield imaging, the number of non-gradable images was less than 3 per cent, and image evaluation time was improved by 28 per cent, which consequently allowed practitioners to identify DR 17 per cent more frequently.7

Routinely performing a good peripheral retinal exam is essential. Clinical studies have shown that eyes with predominantly peripheral DR lesions have more than three times increased risk of retinopathy progression, and almost five times increased risk of progression to proliferative diabetic retinopathy.1,8 This correlation was shown to hold true, even after researchers adjusted for a patient’s diabetes type, the duration of their diabetes, average blood glucose levels and other measures.1,9 Furthermore, the greater the extent of predominantly peripheral lesions in diabetic patients, the higher the risk of DR progression and progression to proliferative diabetic retinopathy, especially with less severe non-proliferative diabetic retinopathy at baseline.7,9 This does not detract from the importance of central lesions, however these findings demonstrate that detailed peripheral retinal examination provides important information that is necessary to completely assess the risk of DR progression.9

Managing Acute Ocular Pathology

Optometrists are best positioned in the community for efficient assessment, diagnosis and triaging of sight threatening ocular conditions. Optometrists possess the expertise, and together with telemedicine, can seek the opinion of the correct retinal subspecialist ophthalmologist to determine an appropriate management strategy for the patient.

The importance of a thorough peripheral retinal exam is also well established for urgent retinal conditions such as retinal holes and tears or retinal detachments. This allows for appropriate triaging so the patient can be managed to minimise potential loss of vision.

Managing Chronic Ocular Pathology

Patients with chronic ocular pathology, such as age-related macular degeneration (AMD) or epiretinal membranes (ERM), require ongoing management and regular review to monitor disease progression. With these patients, it would be easy to focus solely on the ‘affected’ part of the eye, however it is important to remember that pathological changes can also occur in the periphery.

Using ultra-widefield imaging, Lengyel et al (2015) showed there is a range of AMD-like pathological changes in the peripheral retina, some even in patients without AMD.10 Domalpally et al (2017) compared rates of peripheral retinal changes in the AREDS 2 participants who had at least intermediate AMD (large drusen) with control subjects who did not have any intermediate AMD changes.11 It was shown that peripheral retinal changes were more prevalent in eyes with AMD than in the control eyes.11 Additionally, drusen were present in the mid and far peripheral retina in a majority of eyes with AMD, however pigmentary changes and features of advanced AMD were less frequent.11 These findings lead to the hypothesis that AMD, although it is primarily a ‘macular’ condition, still involves the whole retina, and consequently, thorough peripheral retinal checks are critical. Future longitudinal studies of peripheral changes in AMD and the impact they have on visual function may contribute to understanding AMD pathogenesis.11

Retinal tears permit the liberation of retinal pigment epithelial (RPE) cells into the vitreous, which is clinically referred to as ‘tobacco dust’. These RPE cells are dispersed throughout the vitreous by the eye’s saccadic movements and can settle on the patient’s macula, leading to epiretinal membrane (ERM) formation. For this reason, it is not uncommon for patients with ERM to have asymptomatic retinal tears, again stressing the importance of checking the peripheral retina for all patients with ERMs.12 Furthermore, most idiopathic ERMs are due to posterior vitreous detachments (PVDs) with residual vitreous cell deposition on the macula, leading to the membrane formation.12 Only 1-2 per cent of patients with a PVD have a retinal break, however without a peripheral retinal check these patients will go undiagnosed.13,14

Detecting Pathology in Asymptomatic Patients

There are countless retinal degenerations and congenital abnormalities that can only be diagnosed with a peripheral retinal examination, and they often occur in asymptomatic patients. These discoveries are important for the management of the patient. For each peripheral retinal degeneration, optometrists must determine if retinal detachment (RD) could be a consequential risk; if referral is necessary and if so the urgency of the referral; how frequently the patient should be reviewed; and whether any special advice should be given to the patient.

Rhegmatogenous retinal detachments are the most common type of RD, and occur when fluid from the vitreous cavity passes through breaks in the neurosensory retina, separating it from the underlying RPE.15 RDs are more likely to result if there is ongoing vitreoretinal traction. Consequently, if a peripheral retinal degeneration predisposes the formation of retinal breaks through enhanced vitreoretinal traction, it must be considered a risk factor for the development of a RD. Most degenerations that affect the inner retina and the vitreoretinal interface are considered risk factors for RD formation.

Common peripheral retinal conditions affecting the outer retina are not considered risk factors for RDs. Such conditions include pavingstone degeneration, reticular degeneration and congenital hypertrophy of the retinal pigment epithelium (CHRPE).

White without pressure (WWOP) occurs in 30 per cent of normal eyes and is usually bilateral.15 Although WWOP is not a risk for RD formation, it can give a false impression of a retinal break, therefore examination is critical to decrease unnecessary referrals. Microcystoid degeneration is present in all eyes and increases in extent with age.15 The cysts can form splits in between the neurosensory retinal layers, which leads to retinoschisis. Retinoschisis is present in 7 per cent of the population over 40 years of age and occurs predominantly in hyperopes.15 It results in an absolute scotoma but does not threaten vision, unlike a RD. In 0.05 per cent of cases, breaks in the inner neurosensory layers of the retinoschisis can trigger a RD.15 Differentiating between a RD and retinoschisis is imperative to patient care because treatment approaches vary significantly, ranging from observation of retinoschisis, to surgical management for RDs.16 Long term follow-up is often required in these cases, and it is here that ultra-widefield imaging can be used as an excellent monitoring tool. It permits detections of subtle changes, and good continuity of care of patients who may be under the care of more than one practitioner.16

Atrophic retinal holes are most likely caused by chronic atrophy from vascular changes, and their incidence is not related to age.15 It is very rare for an asymptomatic atrophic hole to progress to a RD, which means these patients do not require urgent referral, in contrast to those with operculated tears.15 Lattice degeneration is present in 8 per cent of eyes and has a higher incidence in myopes.15 The retina in lattice degeneration is thinner, and in combination with the strong vitreoretinal traction, makes lattice degeneration a risk for RDs. However only 1 per cent of eyes with lattice degeneration develop a RD over a 10 year period.15

Clinical asymptomatic RDs are uncommon, and account for a minority of RDs in myopes.17 In comparison to symptomatic RDs, asymptomatic RDs are less sight threatening, and are often only detected as an incidental finding during a peripheral retinal examination.17,18 Although studies have shown that the rate of progression to a clinically symptomatic RD is the same as the rate of spontaneous regression, referral for surgery remains the most common recommended management.18,19 Ahmad and West (2007) suggested that this is because the majority of patients, when presented with the known facts and the undetermined risk of progression, choose to treat their RD so that they do not need to live with the worry of progression at an unpredictable time in the future.19

Even though ocular tumours are rare, a practitioner can only ensure that a patient does not have one if they conduct a thorough retinal examination. If a mass lesion is present, it is the duty of a primary eye care provider to direct the patient onto the correct collaborative care pathway. Of the rare tumours, uveal melanomas are the most common primary intraocular malignancy in adults, and most are initially asymptomatic.20 It is only as the tumour enlarges that it may cause symptoms. It is well known that one of the most important prognostic factors is the size of the mass, with smaller tumours offering significantly better prognosis.21 Only careful examination of the peripheral retina by an experienced practitioner can detect these lesions and the earlier the detection, the more likely the patient is to have a positive outcome.

Peripheral vascular abnormalities are another group of less common conditions. Many of these abnormalities are typically asymptomatic, and can therefore go undiagnosed without a thorough peripheral retinal examination. Typical vascular abnormalities include peripheral arteriovenous abnormalities, retinal hemangiomas, retinal telangiectasiae as well as signs of retinopathy of prematurity.

Managing Inflammatory Eye Disease

In all posterior inflammatory conditions, a thorough peripheral retina exam is essential. This is to ensure that the true extent of the pathology can be determined, and thereby the correct management can be implemented.

Leder et al (2013) determined whether the patient management would change when, in addition to the normal clinical exam, ultra-widefield imaging was used for patients with non-infectious retinal vasculitis. They showed that a higher percentage of patients had disease detected and, as a consequence, management was altered, in comparison with patients who did not receive ultra-widefield imaging.22 Campbell et al (2012) performed a similar investigation for patients with non-infectious posterior uveitis. They too found that a higher percentage of patients had their management changed in comparison with those who did not receive ultra-widefield imaging.23

Detecting Systemic Disease

The retinal microvascular circulation is now easily observable thanks to advanced imaging techniques, and hence several observational studies have been conducted to classify different vasculature abnormalities and determine the risk associated with systemic disease. With ultra-widefield imaging, practitioners can capture the peripheral retinal vasculature accurately and reliably in high resolution.

Retinal arteriolar narrowing has been shown to be associated with the presence of hypertension (either current or previous), and with a 60 per cent higher risk of hypertension onset in three years as shown by the Atherosclerosis Risk in Communities (ARIC) study.24,25

Venular dilation and retinopathy are correlated with diabetes, obesity and metabolic disorders.24 The Cardiovascular Health Study (CHS) showed that diabetics with venular dilation were four times more likely to have an incident coronary heart disease event in the next five years, independent of traditional risk factors, and it also suggested that venular dilation was not significantly associated with an increased risk of incident stroke in the next five years.25 The Blue Mountains Eye Study (BMES) also showed venular dilation is associated with an increased risk of coronary heart disease in men and women aged 49-75 years of age.25

Any retinal microvascular abnormalities are related to an increased risk of cardiovascular morbidity and mortality, especially in patients younger than 75 years of age.24 Furthermore, the ARIC study showed retinopathy to be correlated a two to three times higher risk of ischaemic stroke, independent of other cardiovascular risk factors, as well as a deterioration in cognitive function.24,25

Peripheral drusen have been found to be associated with Alzheimer’s Dementia.26 Drusen are formed from extracellular deposits, which share similarities to the deposition of plaque material in the central nervous system in Alzheimer’s.26 With the use of ultra-widefield imaging, significant progression in drusen deposition in patients with Alzheimer’s was detected within two years, the same period of time in which cognitive function usually declines.26 Consequently, Aslam et al (2014) suggested that monitoring for the development and progression of peripheral retinal drusen might serve as a valuable tool in detecting and monitoring the progression of Alzheimer’s Dementia, however further research into this is required.

It is not the role of primary eye care practitioners to diagnose cardiovascular and neurological disease/conditions. However, it is the responsibility of all health care providers to be part of the community’s multidisciplinary team to ensure optimum healthcare for patients. The foundation for this is good communication between disciplines. As peripheral retinal checks allow primary eye care practitioners to identify early or predisposing risk factors for certain systemic conditions, reporting this back to the patient’s GP benefits the patient
and also promotes our skills and knowledge as optometrists to GPs.

Patient Education

There is no denying that ultra-widefield imaging of the retina stimulates a sense of awe and amazement in patients. These imaging techniques provide immediate feedback about the patient’s health, which in itself, presents a unique opportunity for better patient education about ocular health.

The ability to show diabetic patients how their diabetes has affected the retina, and threatens their vision can be a fantastic motivator for them to make major lifestyle changes with their diabetes management. Additionally, for diabetic patients with minimal diabetic retinopathy, it can motivate them to continue with their strict, good management.


Primary eye care practitioners are in a unique position to positively influence eye health outcomes. Integrating peripheral retinal assessments and using ultra-widefield imaging techniques helps us do this by facilitating better detection and diagnosis of sight threatening lesions to minimise vision loss.

Ultra-widefield imaging has the unprecedented ability to visualise and capture the peripheral retina. Therefore it plays an important role in managing and monitoring the risk of progression of acute conditions such as RDs, and chronic conditions such as diabetic retinopathy, AMD and ERMs; it ensures non-infectious uveitis and vasculitis can be correctly managed; and it aids in better management of systemic health conditions, in particular those involving the cardiovascular and neurological systems. Only through peripheral retinal examinations can asymptomatic pathology be detected, effectively triaged and then managed accordingly.

This sophisticated equipment has given practitioners the ability to screen all patients for posterior segment pathology, thereby aiding the detection and early diagnosis of pathology, and initiation of correct management. Indeed, studies have shown that a greater number of retinal lesions can be detected with the use of this technology, in comparison to traditional DFE alone.27

Integrating ultra-widefield imaging into a normal comprehensive eye examination will eliminate the negativities associated with dilation without reducing standard of care. As ultra-widefield imaging becomes more accepted and established as part of the new standard of care our ability to detect retinal disease and optimise patient management will be significantly improved.   


Dianne Pyliotis completed a Bachelor of Optometry/Bachelor of Science at the University of New South Wales in 2013 with first class honours. Immediately after graduating she began practicing at Eyewear Youwear, where she continues to work today. Eyewear Youwear recently upgraded from the original Optomap technology to the California RG model.

This education article was sponsored by OPTOS. 


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' implementing ultra-widefield imaging as part of routine eye examinations can remove the dilemmas involved with dilation '