The trouble with retinal pathologies…
Drs Leo Sheck and Rachel Barnes with Carolyn Campbell

The trouble with retinal pathologies…

October 4, 2021 Lesley Springall

Retina Specialists’ first seminar since Dr Leo Sheck joined the team was a fascinating, interactive discussion of retinal pathologies. These real case studies clearly demonstrated how far from black and white diagnosis and treatment decisions can often be.

 

Held at Foundation on George in Auckland’s swanky Parnell suburb, optometrist attendees were wined and dined with delicious finger food before downloading an anonymous voting app to their phones. This allowed them to test their own knowledge and skills as two of Retina Specialists’ consultant ophthalmologists, Dr Sheck and Dr Rachel Barnes, quizzed them on diagnosis and treatment options for a range of cases. Most fascinating and enlightening were those cases where diagnosis or treatment choices turned out to be incorrect and, with the benefit of hindsight, where clues had perhaps been missed.

 

To test the app and break the ice in a warm and humorous way, Dr Sheck presented a series of cute baby pictures, challenging the audience to guess the sex and ethnicity of the baby, who turned out to be his adorable son. Dr Barnes kicked off the case studies proper, all prefaced by a detailed history, slit-lamp and OCT images and, sometimes, OCT-angiography and fluorescein angiography.

 

Dr Rachel Barnes presents retinal pathology case studies

 

The majority of the audience identified the first case as macular telangiectasia type 2 (MacTel 2). Acquired and bilateral, it is the most common form of MacTel, usually found in middle aged or older patients. Currently there’s no proven treatment for it, said Dr Barnes, with intravitreal anti-VEGF injections being the treatment mainstay for neovascular cases. However, a phase 3 trial involving more than 40 clinical sites in the US, Europe and Australia is currently studying the intraocular delivery of ciliary neurotrophic factor (CNTF) after a successful phase 2 trial found decreased ellipsoid zone loss, increased macular thickness and stable reading speed compared with controls. The California-based MacTel Research Group, which is conducting the CNTF phase 3 trial, has also discovered that a deficiency of the amino acid serine is linked to the accumulation of certain toxic lipids in the blood and retina, causing photoreceptor apoptosis in MacTel type 2 (Ganter ML et al, 2019), said Dr Barnes, both of which offer exciting treatment potential.

 

Attendees Jas Walia and Michael Holmes

 

Taking it in turn to present each case study, Drs Sheck and Barnes also shared some of the challenging questions they are asked by patients. This included one older male patient, with significant geographic atrophy in his right eye (6/60) and good vision in his left but the beginning of atrophy, who asked when he’d lose sight in his left eye and if he had to keep having Avastin (anti-VEGF) injections to preserve his sight. Dr Sheck shared some of the latest research from The Fight Retinal Blindness Study, which has shown a significant risk of recurrence if injections are stopped (50% in one year, 80% over five years), with 60% of recurrences being asymptomatic. Ideally, patients should continue their injections every three months, but if stopped, they should be “watched like a hawk,” said Dr Barnes and reviewed at least every two months.

 

Attendees Lydia Zhu and Roberta Gough

 

Other cases tackled included Avastin alone versus Avastin and photodynamic therapy; retina fleck disorders, a category of hereditary retinal diseases that includes fundus albipunctatus, retinitis punctata albescens, fundus flavimaculatus (Stargardt disease), familial drusen and fleck retina of Kandori, all characterised by discrete white or yellow flecks; when to treat with anti-VEGF and when not to by identifying subtle clues from OCT scans; when slow-release steroid treatment (Ozurdex) may be more effective than anti-VEGF, and the importance of counselling a patient about the potential side effects of steroid treatments such as cataract, glaucoma and intraocular infection; and ocular ischaemic syndrome (OIS) - a rare condition characterised by abnormal ocular blood vessel growth, causing pain and visual loss, associated with hypertension, diabetes and peripheral vascular disease. It’s easy to miss, said Dr Sheck, with a very poor prognosis if it becomes fully established in the eye.

 

In total, Drs Sheck and Barnes shared nine case studies, in this first of what is intended to be a biannual CPD-fuelled event. Most included details of recent studies relating to the choices under discussion, showing just what a dynamic area the world of retinal pathologies really is.