Transforming eye health: SCC7 clinical pearls – Part 2

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In addition to a strong focus on glaucoma and diabetes, the seventh Specsavers Clinical Conference (SCC7) held from Saturday 8 to Sunday 9 September 2018 covered topics including the role that the eye can play in diagnosing systemic disease, anterior conditions such as corneal lesions and red eye, and posterior conditions such as ocular tumours and retinal lesions. Presentations were also given on when to refer paediatric patients, low-vision services, and optic nerve disease. Spectrum looks at some of the key take-home messages from the event.

Systemic disease and the eye
Dr Xavier Fagan, Ophthalmologist for Ringwood Eye Specialists and Northern Eye Consultants in Victoria, spoke about cardiovascular disease (CVD) as a major public health concern and risk to ocular health. He noted that optometrists are extremely well placed to assess vasculature as they can observe it in vivo.

Optometrists and ophthalmologists currently estimate risk for vascular disease in the eye by assessing biometric data such as age, gender, vascular co-morbidities, smoking status, BMI and glucose levels. As such, Dr Fagan identified history-taking as an extremely important component of the eye test in a primary care setting in order to understand the clinical testing required to appropriately manage patients.

He also spoke about infective diseases of the eye – in particular, the increasing rates of syphilis in the past decade. He explained that ocular manifestations of syphilis can appear non-specifically as posterior uveitis, pan uveitis, and anterior and intermediate uveitis, showing examples of syphilis presentations using OCT, DRS and other ocular imaging to illustrate clinical signs to be aware of.

The signs and symptoms of uveitis and retinal vasculitis in HSV infection were also explored, and Dr Fagan reminded optometrists to be vigilant of immunocompromised patients who are at higher risk of development of this kind of ocular disease. This could be from HIV / AIDS or iatrogenic immunosuppression for chemotherapy, transplant anti-rejection medication or auto-immune diseases.

Dr Fagan summarised that ophthalmic findings can be useful for the detection of systemic diseases, monitoring response to treatment, and showing patients the consequences of modifiable risk factors, while also being important information to communicate to other healthcare professionals involved in the care of a patient. He explained that novel deep-learning processes and pairing artificial intelligence with existing clinical knowledge will elevate eye care professionals’ ability to deliver better patient care and communicate with primary care providers into the future.

Diagnosing corneal lesions and red eyes
Dr Chameen Samarawickrama, Consultant Eye Surgeon at the Westmead and Liverpool Hospitals in New South Wales, discussed diagnosis and management of corneal lesions in primary practice. He advocated for a systematic method of obtaining information through clinical history and examination, creating lists of differential diagnoses, and using clinical pathways to decide on management. He described how this could be used to develop a consistent approach to management of anterior eye conditions and support optimal patient outcomes.

This was echoed by Associate Professor Colin Chan, Ophthalmic Surgeon at Vision Eye Institute in New South Wales. In his presentation, Assoc Prof Chan spoke about the evolution of anterior eye disease, noting that signs and symptoms may not be obvious or clearly differentiated upon initial presentation but may become clearer upon close review. He emphasised the value of frequent reviews to confirm treatment efficacy, and for optometrists to develop experience in red eye cases.

Both ophthalmologists recommended an approach that considered the ‘worst-case scenario’ (conditions that lead to loss of vision or a very poor visual outcome) first. Acute angle closure, endophthalmitis, orbital cellulitis, acute chemical injuries, and ocular penetrative or severe blunt trauma injuries were highlighted as differentials that should be eliminated by optometrists prior to treating empirically in primary practice.

Dr Samarawickrama used microbial keratitis as an example of a common presentation for which there is a range of organisms and causative factors that predispose patients to risk. Trauma (36%) and contact lens wear (34%) were listed as common causative factors. Although 71% of microbial keratitis cases in Australia are associated with gram positive bacteria, Dr Samarawickrama advised that for contact lens wearers, it is reasonable to assume infection with Pseudomonas aeruginosa until proven otherwise.

A systematic ‘front-to-back’ approach for clinical examination was outlined by Dr Samarawickrama, including key signs that may help to differentiate the diagnosis. Clinical features such as signs of blepharitis, severity of pain, size and location of the corneal lesion, whether there is an epithelial defect, the degree of anterior chamber reaction, and presence or absence of uveitis or a hypopyon were used to differentiate microbial keratitis from presentations of marginal keratitis (Figure 1).

Figure 1. The continuum between clinical features of marginal keratitis and microbial keratitis1

Typical signs and symptoms of microbial keratitis include sudden onset, small infiltrate, and patients with identifiable risk factors such as contact lens wear or trauma. It was noted that patients with a variable onset, large and / or central corneal defects, without identifiable risk factors, and those who are immunocompromised should be investigated carefully and referred for further assessment where the causative pathogen or diagnosis is questionable. Post-operative and corneal graft patients were also flagged as cases to treat conservatively due to the high risk of development of endophthalmitis or rejection, which can be confused with uveitis in early stages.

Treating bacterial infections
Dr Samarawickrama provided a useful guide on empirical treatment for cases that optometrists have provisionally diagnosed as bacterial keratitis, cautioning that all therapeutic intervention should be modulated by risk factors and signs and symptoms on a case-by-case basis, with close monitoring. He said the main aims of treatment for optometrists should be to eliminate infection, control inflammation and pain, avoid toxicity and complications with therapeutic agents, and ultimately restore vision.

Dr Samarawickrama’s recommended treatment regime for bacterial keratitis was as follows: ofloxacin 0.3% hourly day and night for 48 hours, with a review at 24 hours, then hourly by day for the next two days, followed by a tapering schedule of q.2.h. (for three days) and q.i.d. (for seven days) if signs and symptoms are improving at each review.

He highlighted the importance of regular reviews (daily to begin with and then to match the tapering schedule), emphasising that five days is a reasonable timeframe to expect improvement and that it is important to refer for further assessment if this does not occur. He discussed evidence that ofloxacin is an appropriate first-line topical agent due to reduced risk of ocular discomfort and chemical conjunctivitis compared to aminoglycoside-cephalosporins, and because it has a reduced risk of corneal precipitates compared to ciprofloxacin.

Assoc Prof Chan advised that the consequences of over-treating are often much less than under-treating, and encouraged optometrists to feel confident to treat bacterial keratitis therapeutically and monitor until all signs of active infection have resolved before tapering therapy. He warned that tapering treatment too quickly can initiate a rebound response.

A significant recommendation made by the corneal specialists was to develop close and communicative relationships with local ophthalmologists. They discussed a host of other pathogens that may be associated with microbial keratitis such as microsporidia, fusarium (fungus) and Acanthamoeba, and advised that any suspicion or lack of clarity with diagnosis should prompt urgent referral for further investigation.

Ocular tumours and retinal lesions
Associate Professor Adrian Fung, a NSW-based vitreoretinal surgery and medical retina diseases specialist and Co-Director of the Westmead Hospital Vitreoretinal Fellowship, talked about the systematic approach he uses to diagnose retinal lesions, which involves classifying the lesions based on appearance: pigmented, vascular and white.

He discussed the various optometric investigations that help to differentiate sub-types of these lesions, starting with assessment and diagnosis of naevi and melanoma. Naevi are present in 6.5% of the Caucasian population, with a one in 8,000 risk of conversion to melanoma. It was noted that melanoma is the most common primary intraocular tumour and choroidal metastasis is the most common cause of intraocular malignancy, with two-thirds of patients with choroidal melanoma having known cancer elsewhere in the body. This highlights the importance of questioning the patient about any history of cancer when retinal lesions are present.

Assoc Prof Fung described clinical features that are important to assess to differentiate the two and identify the risk of progression to melanoma. Features associated with melanoma include: thickness of the lesion (>2mm), the presence of fluid observed on fundus examination, patients with a lesion presenting with photopsia, the presence of orange pigment overlying the lesion (lipofuscin), and proximity of the lesion’s margin to the optic nerve. He explained that having two of these clinical signs gave rise to a 45% risk of growth.

It was noted that not all naevi or melanomas are pigmented and careful examination of amelanotic lesions for these clinical features should also be undertaken. Assoc Prof Fung added that while there is no clear evidence for protective factors relating to lifestyle, a family or systemic history of melanoma is a proven risk factor.

He talked about the role of OCT in better distinguishing loss of RPE (lacunae) and thinning of the outer retina in congenital hypertrophy of the RPE (CHRPE), distinguishing subretinal haemorrhage from melanoma, and identifying the location of lesions within the retina and sub-choroidal space.

A key take-home message from his presentation related to deciding on a management plan for patients with naevi. He recommended referring all indeterminate or suspicious lesions for an ophthalmological opinion in the first instance. For naevi, he recommended a three- to six-month review by optometrists, and if stable, another review six to 12 months after that, with referral to ophthalmology if there is any signs of change or growth.

Photo documentation was highlighted as integral for accurate monitoring. Inclusion of digital images and scans in Oculo referrals was noted as an important part of the transfer of care to ophthalmology. Assoc Prof Fung also raised the importance of communicating carefully to patients being referred for retinal lesions, stating that it is best to avoid terminology like ‘tumour’ which might unnecessarily alarm the patient.

Optic nerve diseases
Professor David Mackey, Head of the Centre for Ophthalmology and Visual Science at the University of Western Australia and the Lions Eye Institute, highlighted the challenges in subjective optic nerve evaluation amongst ophthalmic experts. He concluded that, due to this variability, diagnosis of optic neuropathies cannot be purely based on evaluating disc / fundus photographs. Careful history-taking (including family history), assessment and additional testing is required to differentiate between a normal optic nerve and optic neuropathy, and, if diagnosed, to determine the type of neuropathy.

Prof Mackey provided SCC7 delegates with information about hereditary optic nerve diseases such as the less commonly occurring Leber’s hereditary optic neuropathy (LHON). Clinical signs and symptoms of LHON include an acute visual loss from normal vision to legally blind occurring within days to weeks, mild swelling of the optic nerve to a complete temporal pallor, severe colour vision defects, and central field loss / scotoma. According to Medicare, in an optometric setting, assessment and management for these patients – including testing of residual visual acuity and visual field, prescription of spectacle correction, and / or the prescription of magnification aids – may be billed under the item 10942.

Although spontaneous recovery of some vision may be seen in patients over time, management is extremely important. Immediate support includes genetic counselling for both the patient and family to manage the impact to lifestyle and also to ensure awareness and considerations due to the genetic nature of the disease. Low-vision support – including applications, devices, services and coaching of eccentric fixation – for the acute reduction in vision is also required.

Prof Mackey concluded his presentation with insights into clinical trials and treatments for genetic optic nerve diseases. Current research and advances into this area have shown promise in increasing the severely limited treatment options for these diseases, however, considerations of efficacy and cost were also noted as having an impact on whether treatments are feasible to apply to patients.

Referring for low-vision services
Nabill Jacob, Clinical Relationship Manager for Vision Australia, opened his presentation with some key statistics, stating that an estimated 357,000 people in Australia are blind (10%) or have low vision (90%), and that of those, more than 70% are 65 years or older. He explained that Vision Australia assesses functional and residual vision and offer services to help the patient maintain their independence.

The comprehensive services offered by Vision Australia include:

  • Emotional support groups
  • Education and employment support
  • Seeing Eye Dogs
  • Occupational therapists
  • Aids and equipment
  • Audio books and library
  • Mobility specialists
  • Technology and training to stay connected
  • Helpful information for family and clients
  • Orthoptists
  • Early intervention, and services for children and adolescents
  • My Aged Care and National Disability Insurance Scheme to maximise funding.

Nabill noted that anyone can refer to Vision Australia, including patients, who can refer themselves. He stated that services are available to patients of all ages at any Vision Australia office across Australia, but said that Vision Australia staff can also travel to patients who have limited mobility.

When assessing whether a patient will benefit from a referral to Vision Australia, Nabill recommended optometrists use questions that are open and based around lifestyle and real-life situations. He suggested some examples, such as questions around the performance of daily tasks and tasks that are being impacted by the patient’s vision.

He also recommended patients be referred to Vision Australia when BCVA is ≤6/24 binocularly and / or when they had a visual field of less than or equal to 30 degrees binocularly, adding that patients should be referred sooner if the debilitation of low vision is impacting everyday tasks.

When making a referral, Nabill advised optometrists to include details of the patient’s concerns, measurement of vision and refraction, as well as the desired outcome from care and services provided by Vision Australia.

It was noted that the initial consultation with Vision Australia is free, and that Vision Australia will refer the patient back to the referrer for ongoing care of their eye health.

Referring paediatric patients
Professor Glen Gole, outgoing Director of Ophthalmology at Lady Cilento Children’s Hospital in Queensland, concluded SCC7 with a presentation on when to refer paediatric patients. He said that as primary eye care providers, it is imperative that optometrists are able to confidently recognise signs of sight- and life-threatening conditions in children and manage these in a timely and appropriate manner.

Prof Gole encouraged optometrists to take advantage of the fundus photography and OCT imaging readily available in all Specsavers stores, stating that these imaging techniques can be performed much earlier than subjective visual field testing and may provide objective information that is key to an important sight- or life-threatening diagnosis.

If unable to logically reach a diagnosis or management plan, he said that optometrists should make contact and engage with their local ophthalmologists. Urgent referral is required for suspicion of sight- or life-threatening conditions. Referral is also required for children who are not responding to management as expected.

Prof Gole stressed the importance of communication between the clinician, parents, child and other health professionals, and the need for any communication to be professional – inside scope of practice and factual, but also empathetic and appropriate.

Life-threatening conditions
Using OCT to assist a clinician in differentiating between optic disc drusen and papilloedema was highlighted by Prof Gole as an example of the benefits of objective imaging. True papilloedema displays an obscuration of vessels, loss of spontaneous venous pulsation and OCT disc draping. Pseudo-swelling due to drusen has no obscuration of vessels, with the disc appearing lumpy and bumpy on OCT.

For practitioners without access to an OCT, Prof Gole stressed that careful history-taking and identification of important symptoms is just as important, such as an early morning headache that progressively worsens into vomiting. This indicates urgent referral for neurological assessment.

He said that a white pupil (leukocoria) should always raise concern. Although congenital cataract is the most common cause of leukocoria, retinoblastoma must be ruled out first. Presentation is typically a white mass growing into the vitreous, however retinoblastoma can also present as a mass growing over the retina. Prof Gole said optometrists have an important role to play in ensuring potential life-threatening conditions are detected and urgently referred upon first presentation as historically, paediatric patients undergo repeated visits to health professionals before a diagnosis is reached.

Sight-threatening conditions
Prof Gole went on to describe sight-threatening conditions that are imperative for optometrists to detect. Accommodative esotropia generally presents from 18 months old to four years and older. Key signs include moderate to high levels of hyperopia (on cycloplegic refraction) or a high AC/A ratio. Prescribing the full correction and any patching for amblyopia (if present) is the gold-standard approach to management. A regular review cycle of six to eight weeks is recommended to ensure correction of esotropia, with referral indicated for children who are not responding as expected, or for any child with non-accommodative strabismus.

Other sight-threatening conditions discussed included congenital cataract, infantile glaucoma, infectious keratitis, and capillary hemangioma. Prof Gole said that if infectious keratitis is suspected in a child who is difficult to assess or non-cooperative, referral is recommended. Otherwise, first-line topical therapy can be given by an optometrist in a cooperative child with a clear diagnosis.

Prof Gole concluded that referral is indicated for all sight-threatening conditions, as early intervention leads to good visual results, reduces risk of sensory deprivation and associated impact, and rules out risks of systemic implications that can be life-threatening.

See also: Transforming eye health: SCC7 clinical pearls – Part 1


REFERENCES

  1. Samarawickrama, C. (2018). Diagnosing and Managing Corneal Lesions. Presentation, 7th Specsavers Clinical Conference.
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