Optometrists from Sydney soaked up the latest on research and approaches to collaborative eye care management at a ‘Mad Hatter’s Tea Party’, hosted in the city’s Parliament House, by Sydney Retina Clinic.
Almost 100 optometrists gathered at the NSW Parliament House in late August to listen to presentations by Drs Hemal Mehta, Anne Lee, Thomas Pham, James Wong, Thomas Hong, Samantha Fraser-Bell and Andrew Chang, all of whom ingeniously wove themes from Alice in Wonderland into their discussions. A wide range of topics were supported by engaging case studies and helpful hints on imaging, followed by interesting questions from the audience.
Cataract and Diabetic Retinopathy
Assoc Prof Hemal Mehta spoke on the challenges of managing cataracts in patients with diabetic retinopathy (DR). These included possible progression of retinopathy, management of small pupils and the increased risk of encountering zonular damage during surgery.
Patient counselling, ideally beginning in the optometry room, is essential to set realistic expectations for the visual outcome, Assoc Prof Mehta noted. Studies show that post-surgery, patients with diabetes may not achieve the same level of visual acuity gains as non-diabetic patients.
Assoc Prof Mehta discussed the need to address existing DR and diabetic macular oedema (DMO) before surgery. Surgery is inherently pro-inflammatory and the risk of progression from one stage of DR to the next is approximately 30% in the six months after surgery. Anti-VEGF leading up to cataract surgery has been shown to reduce macular oedema, improving the visual outcome. For eyes at high risk of proliferative diabetic retinopathy (PDR), anti-VEGF treatment pre-operatively, when the fundus view is more limited, and panretinal photocoagulation (PRP) post-operatively, when the fundus view improves, can also maintain visual stability.
Assoc Prof Mehta also noted that choosing the appropriate intraocular lens (IOL) is critical. Trifocal lenses, which depend on a healthy macula, may not be ideal for patients at risk of developing DMO or significant retinopathy. Small aperture IOLs limit the peripheral fundus view, making it more difficult to apply PRP in future cases of PDR.
Anti-VEGF leading up to cataract surgery has been shown to reduce macular oedema, improving the visual outcome.
Ocular Hypertension
To accurately diagnose ocular hypertension, Dr Anne Lee emphasised the importance of thorough history-taking to rule out conditions like angle closure, pigment dispersion syndrome, and Possner-Schlossman syndrome.
Dr Lee highlighted the need to obtain baseline measurements – including pachymetry, visual fields, disc photography, and optical coherence tomography (OCT) readings – for monitoring progression. She also noted the variability in IOP readings due to differences between devices and the impact of corneal thickness.
There were two studies that Dr Lee identified as landmark studies: the Ocular Hypertension study published in 2002, which she said is still relevant in identifying risk and guiding treatment decisions; and the Laser in Glaucoma and Ocular Hypertension (LIGHT) trial.2 The six-year results of the LIGHT trial were published last year and demonstrated that selective laser trabeculoplasty (SLT) is more cost-effective and comfortable compared to initial drop therapy, with about 70% of patients maintaining target pressure without needing additional drops. This suggests that SLT could be a viable first-line treatment, particularly in young patients.
When considering treatment, Dr Lee reminded the audience of the need to consider patient-specific factors such as pregnancy, breast feeding, and medications. Since there are multiple treatment options available, and no intervention is without risk, choosing the best option for the patient relies on honest communication between the practitioner and patient.
Central Serous Chorioretinopathy
Dr Thomas Pham presented on central serous chorioretinopathy (CSR). Acute CSR ranks as the fourth most common non-surgical retinopathy and can be easily diagnosed due to its well-defined epidemiology, risk factors, and clinical signs. The pathophysiology is attributed to hyperpermeable choroidal capillaries with retinal pigment epithelium (RPE) dysfunction, and spontaneous resolution with a good visual outcome is common.
Beyond the commonly recognised Type A personality, male gender and use of corticosteroids, Dr Pham highlighted other factors that have been linked to CSR, including phosphodiesterase 5 inhibitors (in medications like Viagra), Helicobacter pylori infection, chemotherapy and organ transplant, obstructive sleep apnoea, and autoimmune diseases.
Dr Pham spoke of the challenge of treating chronic CSR, which occurs in five to 15% of cases and is characterised by symptoms persisting for longer than six months. Its management is challenging, with a median time to resolution of approximately 458 days. Complications may include macula atrophy and the development of choroidal neovascular membranes.
He discussed the options in treatment of chronic and recurrent CSR. Argon laser and photodynamic therapy (PDT) have the best evidence in treating chronic CSR. Focal PDT is particularly effective in reducing leakage by inducing vascular occlusion and decreasing vessel hyperpermeability; however, the potential side effects include scotomas and the risk of developing choroidal neovascular membranes if the treatment is too aggressive. There is also a risk of ischaemia and atrophy. Subthreshold laser can be useful, when PDT is not available, to stimulate tissue repair. Mineralocorticoid antagonists like spironolactone can also be used but have mixed success rates.
Acute CSR ranks as the fourth most common non-surgical retinopathy
Choroidal Neovascularisation and OCT
Dr James Wong presented on OCT features in choroidal neovascularisation (CNV). These include subretinal hyperreflective material (SHRM), pigment epithelial detachment (PED), subretinal and intraretinal fluid.
Dr Wong also described the evolvement of the term “macular neovascularisation” rather than CNV, recognising that neovascularisation can also come from the retinal circulation.
SHRM is a recent term used to describe exudation into the subretinal space, which is optically dense material, often consisting of fibrin, serum, red blood, and/or inflammatory cells, and vitelliform material. Dr Wong explained that it can lead to fibrosis and its presence often signifies a worse prognosis; studies show SHRM in a subfoveal location or less than one millimeter from the fovea is associated with lower vision. It may also be seen in other retinal diseases like CSR.
Dr Wong also discussed the way that OCT and imaging has changed the way we monitor and make management decisions about retinal diseases. “A lot of the decisions we make in terms of treatments are 80 to 90% based on imaging,” he said.
For the last part of his talk, Dr Wong highlighted the results of the PULSAR study, which compared 2 mg Eylea administered every eight weeks, 8 mg every 12 weeks and 8 mg every 16 weeks. All three treatment regimens resulted in visual improvement over two years, with only slight differences in visual outcomes. He observed that the higher dosage arms with less frequent treatment could potentially reduce the burden of care on patients and their carers.
Posterior Uveitis
Assoc Prof Samantha Fraser-Bell shared her approach to diagnosing posterior uveitis. Accentuating the significance of a thorough case history, she quoted Lewis Carroll: “Begin at the beginning and go on until you come to the end”. This approach involves not only assessing symptom duration and severity but also evaluating systemic signs of inflammation and disease such as fevers, joint paint and arthritis, a history of cancer or cancer treatment, and immunosuppression.
Distinguishing between infectious or non-infectious causes is vital, Assoc Prof Fraser-Bell stressed. Immunosuppression can exacerbate the disease if an infection is untreated. In non-infectious cases, it is crucial to discern whether the uveitis is an isolated ocular issue or a manifestation of a systemic condition.
Assoc Prof Fraser-Bell underscored the importance of multimodal imaging as a tool for diagnosis. Pattern recognition through imaging can reveal hallmark features of specific diseases, such as optic nerve swelling with a macular star in Bartonella infection, helping to speed up diagnosis or determine the need for additional investigations to confirm the disease.
Finally, Assoc Prof Fraser-Bell reminded attendees to always look beyond the surface; in cases that appear to be simply recurrent anterior uveitis, a dilation is warranted to rule out posterior involvement.
Assoc Prof Fraser-Bell underscored the importance of multimodal imaging as a tool for diagnosis.
Maculopathy in the Myopic Eye
Prof Andrew Chang provided insight on myopic maculopathy, using the analogy of a regular eye (or globe) as the size of a bedroom. Compared to the emmetropic eye, the myopic eye is stretched to the size of a combined living and dining room, with the same amount of retinal tissue.
Foveoschisis can develop due to the stretching of the tissue, where a break is caused by the vitreous remaining attached to the inner retinal layer while the outer layer follows the posterior staphyloma. Generally, this is asymptomatic and can be confirmed on wide-field OCT. The progression of this, Prof Chang explained, can be variable. Four to five percent of these cases can resolve; 12% may worsen with the schisis progressing to develop a full-thickness retinal detachment, needing intervention.
More centrally, severe traction can cause a macular hole, characterised by a full thickness break at the fovea. Surgical intervention has better outcomes with earlier intervention.
Prof Chang introduced the concept of a “retinal column” to illustrate how the macula’s layers, when stretched, become further apart. This causes strain on the underlying neural connections. Microperimetry is used to assess the functional impact of these structural changes.
Surgical intervention involves peeling the internal limiting membrane and creating a posterior vitreous detachment to alleviate traction and Prof Chang showed a video of this procedure. Given the delicacy of the macular tissue, there is a risk of detachment developing post-surgery.
Myopic choroidal neovascularisation (CNV) is another significant concern, occurring in approximately 10% of myopic eyes and presenting a 35% risk of developing in the fellow eye. Prof Chang said that anti-VEGF therapy has significantly improved the management of CNV, and patients often only require a few treatments for effective control.
Clinical Trials and Results
The ‘Mad Hatter’s Tea Party’ concluded with some updates on the latest retinal research given by Dr Thomas Hong.
He reiterated the results of the Eylea 8 mg PULSAR study, which demonstrated that a dosage of 8 mg has a safety profile consistent with the 2 mg.3 There were no new adverse events associated with Eylea at 8 mg but extended treatment intervals were possible at the higher dose.
Dr Hong discussed the multiple genome association studies that confirm the link between AMD and two gene loci: abnormalities on CFH on chromosome 1 and abnormalities of ARMS2/HTRA1 on chromosome 10. He introduced a clinical trial that is currently recruiting patients
with geographic atrophy to evaluate gene therapy delivered as a one-time intravitreal injection to protect the retina before advanced degeneration.
Dr Hong also discussed two other studies: a phase III trial evaluating the efficacy and safety of intravitreal Faricimab (Vabysmo) in myopic choroidal neovascularisation and a phase II trial investigating the efficacy of Tivozanib (Fotivda) eye drops in diabetic macular oedema.
Following a highly successful event, optometrists left Parliament House armed with the latest research findings and clinical pearls for eye care in practice.
Stephanie Lai graduated in optometry from the University of Auckland in 2009 and completed her Graduate Certificate in Public Health and Leadership at the Australian College of Optometry in 2022. She works as an optometrist at Dry Eye Solution Sydney, and is a regular contributor to mivision.
References
1. Kass MA, Heuer DK, Gordon MO et al. The Ocular Hypertension Treatment Study: a randomized trial determines that topical ocular hypotensive medication delays or prevents the onset of primary open-angle glaucoma. Arch Ophthalmol. 2002 Jun;120(6):701-13; discussion 829-30. doi: 10.1001/archopht.120.6.701.
2. Gazzard G, Konstantakopoulou E, Barton K, et al. LiGHT Trial Study Group. Laser in Glaucoma and Ocular Hypertension (LiGHT) Trial: Six-year results of primary selective laser trabeculoplasty versus eye drops for the treatment of glaucoma and ocular hypertension. Ophthalmology. 2023 Feb;130(2):139-151. doi: 10.1016/j.ophtha.2022.09.009.
3. Lanzetta P, Korobelnik JF, Wong TY et al; PULSAR Investigators. Intravitreal aflibercept 8 mg in neovascular age-related macular degeneration (PULSAR): 48-week results from a randomised, double-masked, non-inferiority, phase 3 trial. Lancet. 2024 Mar 23;403(10432): 1141-1152. doi: 10.1016/S0140-6736(24)00063-1.
