Optometry Virtually Connected: In Pursuit of Knowledge

Complex Ophthalmology Cases

With optometry’s expanding roles in managing the eye health of both adults and paediatric patients, and access to state-of-the- art imaging modalities, pathology is being picked up earlier, enabling prompt treatment to follow.

By propogating a tiny tear sample with a soundwave, the behaviour of the fluid can be monitored, providing vital information on the health of the tears and potentially the substance of the tear that is abnormal

In a lively presentation, New South Wales ophthalmologist Dr Rushmia Karim presented a snapshot of some of the interesting cases referred from her optometry colleagues.

First up was a patient who presented with a classic blurred optic disc margin. These cases can range from being anomalous to a “dreaded” optic disc swelling from intracranial pathology.

Dr Karim advised delegates that it’s always best to err on the side of caution in these instances, with prompt referral and a careful history regarding symptoms.

She reported that following imaging, including red free and ultrasound, the patient was found to have optic disc drusen. “However, it’s important to investigate. Perhaps the most important aspect of this case was that the patient was asymptomatic,” she noted.

Dr Karim’s next case wasn’t quite as benign, with the patient presenting with nonspecific signs but pain on eye movements.

Early optical coherence tomography imaging showed nerve fibre layer thinning, which indicated the need for urgent neuroimaging via an MRI scan with gadolinium for diagnosis.

With the patient diagnosed with optic neuritis from multiple sclerosis, Dr Karim noted that careful counselling was required. However, she reported that having commenced treatment early, the patient was making excellent progress.

Dr Karim said identifying and managing rare cases from Coat disease, acute posterior multifocal placoid pigment epitheliopathy (APMPPE), valsalva retinopathy and FEVR are “all in a day’s work”. One case of microspherophakia (a rare abnormality of the crystalline lens) led to angle closure from lens dislocation – highlighting the fact that pressures and a slit lamp examination are still the gold standard for many diagnoses.

“With a systematic approach towards patients and their symptoms, we can trouble shoot any diagnostic dilemmas. These cases remind us that we always must be on our toes, but skills and services save sight,” Dr Karim concluded.

CATARACT SURGERY AND RETINAL DISEASE

Always insightful, ophthalmologist Dr Simon Chen spoke on cataract surgery in the presence of retinal disease (age related macular degeneration and diabetic retinopathy being the most common), describing it as “often complex”.

Optometrists, as primary eye care providers, have an important role to play in managing these patients before referral for cataract surgery and after surgery, and Dr Chen said patients will respect and value their expert guidance.

The advice optometrists offer can help patients make potentially life changing decisions about the timing of surgery, lens options (extended depth of focus multifocal intraocular lenses may not be suitable), appropriate refractive targets, and the need for pre- and post-operative treatment. Setting appropriate expectations for vision outcomes is important because the reference point these patients have is often a friend or family member without complications who has undergone cataract surgery.

Cataract patients with retinal disease tend to be more complex for a few reasons, one of which is co-morbidities associated with retinal disease such as diabetic retinopathy. Additionally, there are a lot more ‘only eyes’ in this patient group due to the longerterm consequences of retinal disease.

Dr Chen said operating on an only eye patient presents unique challenges. In the United Kingdom, a 4% complication in cataract surgery on only eyes has been reported vs 2.5% for patients with two good eyes.

This tends to be because, with a desire to protect a patient’s vision in their one eye, cataract surgery is often delayed. However, by the time surgery proceeds, the cataract is dense, resulting in more complex surgery. Additionally, patients who have lost vision in one eye due to a retinal disease like diabetic retinopathy tend to have other co-morbidities, like high blood pressure and poor lid hygiene, which can lead to postoperative complications.

With the stakes high, only eye surgery is stressful for both surgeon and patient… an anxious patient can cause a surgeon to feel more anxious.

Performing cataract surgery on patients with retinal disease requires careful planning from beginning to end. The potential for complications means surgeons need to be prepared with additional instrumentation and backup IOLs etc. in case they need to change their approach during surgery. Patients should be well-informed ahead of time so that they too are prepared for unexpected outcomes and the risk of retinal disease progression that may require future treatment.

MINIMISING THE IMPACT OF DRY EYE DISEASE

Dry eye disease is a multifactorial condition that affects the health of the tears and the ocular surface and can have a significant effect on quality of life.

Associate Professor Laura Downie is an optometrist and research academic at the University of Melbourne, and the inventor on a patent relating to a new diagnostic method for dry eye. In her presentation she reviewed the latest research evidence relating to the clinical care of dry eye disease, including the potential use of emerging innovations in clinical practice.

Healthy tears have more than 2,000 unique components. While the bulk of the tear volume is water, other components include proteins, electrolytes, growth factors and suppressors of inflammation, soluble mucins and immunoglobulins. An exquisite balance of these components gives rise to optimal tear stability, protects the cornea and other ocular structures from infection, allows them to heal rapidly if injured, and provides nutrition to the avascular cornea.

Because the tears are so complex, they are naturally perturbed by many factors. A comprehensive risk factor assessment is required, considering lifestyle factors including contemporary influences.

Two of these modern lifestyle factors are face mask wear and cosmetics. Over the past two years, the requirement for people to wear masks due to the pandemic has given rise to what’s now known as Mask Associated Dry Eye (MADE). Patients report gritty, dry, irritated eyes and even show signs of ocular surface inflammation.

Research studies show those at greatest risk are females, people who wear masks for three or more hours a day, and those with a prior dry eye history.

Assoc Prof Downie said many patients are unaware of the potential association between face mask use and dry eye disease, making this an opportunity for proactive discussion and education during consultations. She said, “ask specifically about ocular symptoms with mask use. The most important advice on alleviation is to wear a well-fitted mask. Taping the mask under the eye, the use of ocular lubricants and reducing other environmental exposures as much as feasible, (e.g., low humidity and extended digital device use) will also help.”

Cosmetics – particularly mascara, eye liner and eye shadow – are manufactured with a complex formulation of ingredients (waxes, soaps, pigments etc.) which, when worn in close proximity to the eye, have potential to migrate onto the eye lid margin. Recent research shows product application at the inner eyelash line poses the greatest risk, including reduced tear stability, primarily at the lipid layer, and increased risk of ocular infection including from Demodex which like to live in oil-rich environments. Application of make-up can cause accidental ocular surface trauma, and make-up can also cause eye lid dermatitis and ocular surface inflammation. There is potential for proinflammatory effects in the tear fi lm. While it’s best not to wear eye make-up, if that’s not possible, recommend avoid applying make-up to the inner eyelid. Patients should also be advised not to use ocular lubricants while wearing make-up because they may exacerbate migration of products into the tear film. There is ongoing research into ocular surface safe cosmetics that do not cause physiological harm to the ocular surface.

Techniques for Diagnosis 

Best practice diagnosis of dry eye disease, as described in the Tear Film and Ocular Surface Society (TFOS) International Dry Eye Workshop II (DEWS II) report, involves a step-wise approach, and there are several techniques which look at individual aspects of the condition. Reliance on the experience of the observer to interpret clinical tests leaves potential for variability.

Research underway aims to improve and speed up the identification and stratification of dry eye disease, which will better inform management and optimise patient outcomes.

The application of artificial intelligence for diagnosis of dry eye disease is an area of active research interest. This has great potential to save chair time and improve the consistency of clinical diagnosis and follow-up.

Assoc Prof Downie’s clinical team at the University of Melbourne, in collaboration with Prof Leslie Yeo’s chemical engineering team at Royal Melbourne Institute of Technology, are developing a novel diagnostic device called Acoustically Driven Microfluidic Extensional Rheometry (ADMiER), which has capacity to identify dry eye, stratify its severity and subtype the disease.

The ADMiER device measures tear viscoelasticity – or stretchiness. The research team has shown that the viscoelasticity of healthy tears differs from the viscoelasticity of tears from people with dry eye. The lower the extensional viscosity of the tears, the greater the dry eye severity. By propogating a tiny tear sample with a soundwave, the behaviour of the fl uid can be monitored, providing vital information on the health of the tears and potentially the substance of the tear that is abnormal.

Assoc Prof Downie said this technology is unique because it can handle extremely low tear volumes – for the first time it allows a microlitre of a tear sample to be analysed for its viscoelastic properties.

A clinical study of 103 participants compared ADMiER to the full eight-step TFOS DEWS II approach to dry eye diagnosis, with promising findings. Assoc Prof Downie and her team are currently undertaking further research to develop and validate ADMiER, with a long-term goal to commercialise the technology so that is available as a point-of-care device in international eye care practice