A study released in JAMA Ophthalmology identified three distinct axial elongation profiles—better known as “trajectories”—among different age groups of myopic patients.
Give me some background first.
Myopia-related macular degeneration is emerging as a significant cause of blindness in adults, often stemming from excessive axial elongation.
In line with this new development, myopic patients with an axial length (AL) of 30 mm or greater have been shown to be at a higher risk of developing vision impairments than those with an AL less than 24 mm.
Now, talk about the study.
This study aimed to observe the trajectories of axial elongation in patients with high myopia using cluster analysis from a participant population of both pediatric and adult patients.
Who was included in the study?
A total of 793 participants were recruited from the high myopia cohort in an ongoing study from the Zhongshan Ophthalmic Centre-Brian Holden Vision Institute.
Patients were recruited between November 2011 to October 2012 and were followed-up every other year for 8 years. Each participant had an AL measurement taken at baseline and had at least one follow-up visit.
Findings?
Three distinct axial elongation trajectories from childhood to late adulthood were identified:
- Stable progression
- Mean axial elongation rate of 0.02
- Moderate progression
- Mean axial elongation rate of 0.12
- Rapid progression
- Mean axial elongation rate of 0.38
The study found that 29.3%, 41.4%, and 29.3% of participants were in the stable, moderate, and rapid progression trajectories, respectively.
Tell me more.
Patients in the stable progression group would likely require less frequent clinic visits, but those in the rapid progression group may benefit from more frequent screenings and more aggressive interventions.
Anything else?
Younger age and longer AL at baseline were linked to faster axial growth and categorization of a faster progression trajectory.
Pathological myopic macular degeneration (MMD) was also a risk factor for faster axial growth in older adults.
Limitations?
The sample was comprised of only Chinese participants and a relatively large portion of patients from the youngest cohort, which may limit the direct applicability of the results to other populations.
A significant number of patients were lost due to the COVID-19 pandemic: 107 patients at the 6-year follow-up and 99 patients at the 8-year follow-up.
Expert opinion?
The study authors stated that, “these distinct axial elongation trajectories could prove valuable for early identification and intervention for high-risk individuals.”
Take home.
The identification of three axial elongation trajectories have the potential to advance early identification and intervention in high-risk patients.
However, studies with larger and more diverse samples—as well as with longer follow-up time—can further insights regarding axial elongation.
With more research, axial elongation trajectories could be used to personalize risk prediction and management of high myopia.