Awakening the Lazy Eye at WCPOS V 2024 as Experts Discuss Updates in Amblyopia Treatment

Day 1 of the 5th World Congress of Paediatric Ophthalmology & Strabismus (WCPOS V 2024) in Kuala Lumpur, Malaysia kicks off with expert insights into the latest strategies and future directions for managing amblyopia. 

Sequential vs simultaneous treatment

Amblyopia, commonly known as lazy eye, represents a significant challenge in pediatric ophthalmology, affecting visual development in children worldwide. In his talk, Prof. Jonathan Holmes (USA) delved into the use of glasses and patches as treatment options for anisometropic and strabismic amblyopia. Prof. Holmes discussed two approaches: the sequential method, which begins with prescribing glasses followed by graduated patching if required; and the simultaneous method where glasses and patching are initiated concurrently and weaned as able. 

He described various studies, which showed that glasses alone are effective in improving visual acuity regardless of the type of amblyopia, due to possibly an improvement in alignment and blur. 

Meanwhile, a recent study by Proudlock, et al. published in the Lancet (2024) comparing an intensive patching regimen, with and without extended optical treatment (EOT), indicated that high-intensity early patching is a more effective treatment for amblyopia than extended optical treatment (EOT) before patching, especially in younger children with less severe forms of the condition.¹

Prof. Holmes emphasized the need for a well-designed randomized controlled trial (RCT) to compare these treatment approaches. He further mentioned that the Pediatric Eye Disease Investigator Group (PEDIG) has initiated such a study, with results expected in 2025. 

“In the meantime, there is stronger evidence supporting option 1: starting with glasses, followed with patching if necessary, and starting with patching if the condition doesn’t completely resolve,” explained Prof. Holmes.

Insights into patching for deprivation amblyopia

Next, Dr. Justin Mora (New Zealand) noted that there isn’t much data available about patching for deprivation amblyopia, due to the presence of many clinical variables. These include cause of deprivation (eg. cataract, ptosis and keratitis), constant or intermittent factors (eg. head posture with ptosis) and depth of deprivation (degree of cataract, onset and timing of intervention). On top of that, there are treatment variables, which include the quality of refractive outcome and compliance. 

From 122 responses obtained from a SurveyMonkey poll he posted on a pediatric ophthalmology listserv, Dr. Mora found that the majority consensus was to target half of the waking hours for patching. He recommended continuing this regimen as long as there is ongoing improvement, as determined by accurate visual acuity testing, and considering tapering once vision has remained unchanged for 6-12 months. At this point, finding a stable maintenance level, particularly for school-age children, is advised. “Also, be realistic and give the family permission to stop if things aren’t going well, such as failure to respond, poor compliance despite good education and psychosocial stress,” added Dr. Mora.

Binocular treatment for amblyopia using smart devices

Despite the low birth rate in South Korea, the incidence of amblyopia has been increasing, noted Dr. Haeng-Jin Lee (South Korea). Although patching is effective in treating amblyopia, it involves a long duration, and there are monitoring issues and decreasing compliance overtime. As an alternative, researchers are exploring binocular vision stimulation. 

Dr. Lee explained that amblyopia occurs due to imbalance of signals between the two eyes and the lack of interaction. The binocular treatment works by reducing inhibitory signals by providing blurred stimuli to the normal eye, and stimulating both eyes similarly to induce visual improvement in the amblyopic eye. Tools that have been investigated to provide binocular treatment include: virtual reality (VR) or augmented reality (AR) devices, smart pads, smartphones and standard definition (SD) monitors. 

“VR devices equipped with head-mounted displays (HMDs) offer distinct image separation, personalized treatments based on the amblyopic eye’s visual acuity, excellent immersion and can be monitored using eye trackers,” she emphasized.

“Identifying the most suitable smart devices for amblyopia treatment is crucial. However, key treatment parameters such as blur intensity, treatment frequency and duration have yet to be firmly established. Providing a diverse range of content to engage children and sustain their attention would be ideal,” she concluded.

Challenges and management of amblyopia in Malaysia

Meanwhile in Malaysia, the prevalence of amblyopia stands at 8%.² Dr. Nurul Farhana binti Abu Bakar (Malaysia) reported that and she also highlighted numerous challenges in managing and intervening in amblyopia within the country.

A study (Diana et al., 2018) conducted at Shah Alam Hospital with 122 participants revealed a low public awareness rate (27%) regarding amblyopia. Another survey (Chen et al., 2020) involving 416 parents indicated that 67% of children did not receive necessary vision screenings or eye examinations.³

Dr. Farhana emphasized that poor cooperation between parents and children poses a significant obstacle to effective amblyopia intervention, and outlined five primary challenges. “We found five major challenges in amblyopia management in Malaysia: public awareness, shortage of human resources, time constraints in clinical practice, lack of skill and knowledge among eye care personnel and lack of facilities,” she said. 

To address those issues, an optometrists-led national program – Amblyopia and Visual Impairment Screening (AVIS) – was initiated. This national initiative aims to plan, document and support the implementation of preschool vision-screening programs. Between 2018 and 2023, AVIS successfully screened 29,033 children, marking a significant step forward in combating amblyopia in Malaysia. 

Predicting refractive error and amblyopia 

Last but not least, Prof. Chris Hammond (United Kingdom) addressed the question: Can we predict refractive error and amblyopia in children? He underscored that amblyopia is a complex trait that involves interaction between genetic and environmental factors. Knowing the family history and doing an early photo refraction could identify those risks. “Potentially, early screening of those who are at high risk will reduce the incidence of amblyopia,” he said.

Regarding anisometropia, Prof. Hammond noted the challenges of studying it due to its association with myopia, hyperopia, astigmatism and related risk factors. “While no genome-wide association studies have been conducted to date, twin and family case-reports suggest genetic factors. There is evidence linking anisometropia to poor emmetropization,” he added.

Furthermore, Prof. Hammond discussed modifiable risk factors for amblyopia, which include maternal health, diet, smoking and premature birth. “Hopefully, a greater understanding of genetics will enable future therapies for amblyopia,” he said. 

References

1. Proudlock FA, Hisaund M, Maconachie G, et al. Extended optical treatment versus early patching with an intensive patching regimen in children with amblyopia in Europe (EuPatch): a multicentre, randomised controlled trial [published correction appears in Lancet. 2024;403(10445):2694.
2. Chew FLM, Thavaratnam LK, Shukor INC, Ramasamy S, Rahmat J, Reidpath DD, Allotey P, Alagaratnam J. Visual impairment and amblyopia in Malaysian pre-school children – The SEGPAEDS study. Med J Malaysia. 2018;73(1):25-30.
3. Chen AH, Bakar NA, Lam CS. Comparison of open-ended and close-ended questions to determine signs and symptoms of eye problems among children. J Optom. 2020;13(2):81-87.

Editor’s Note: Reporting for this article occurred at the 5th World Congress of Paediatric Ophthalmology & Strabismus (WCPOS V 2024) from 11-13 July in Kuala Lumpur, Malaysia.