Recent findings from a study published in Contact Lens & Anterior Eye evaluated the efficacy of orthokeratology (ortho-k) lenses for myopia control in children with allergic conjunctivitis (AC) after 3 years of wear.
Give me some background.
The growing and global myopia epidemic has necessitated the development of effective therapies, such as overnight ortho-k lenses.
In fact: Previous research has indicated that ortho-k may be the best method of myopia control compared to low-dose atropine and peripheral myopic defocus spectacle lenses (PMDSL).
Now bring in allergic conjunctivitis.
AC is a common eye condition among adolescents and children with an estimated prevalence of around 30% and a risk factor for corneal adverse events (AEs) in ortho-k wearers.
Further, studies have found that AC is associated with myopia—and children with AC are more likely to develop myopia.
Talk about the study.
In this retrospective case-control study, investigators analyzed the data of patients aged 8-15 years who were fitted with ortho-k lenses in 2019 at the Aier Eye Hospital of Wuhan University in Wuhan, China.
A follow-up was conducted wherein researchers documented all corneal AEs and the increase in axial length (AL) of the eye after 3 years of wearing ortho-k lenses.
And the setup?
Patients were divided into groups with and without AC based on their medical history and physical signs at the initial fitting.
Then: The baseline data and AL elongation were compared between the two groups after 3 years.
Findings?
In total, 309 patients (47 in the AC group, 262 in the without AC [nAC] group) were included in the study.
There were no statistically significant differences between the two groups in terms of:
- Age
- Sex
- Spherical equivalent (SE)
- AL of the eye
- Environment
How did AC impact AL elongation?
After 3 years of ortho-k lens wear, the AL elongation in the AC group was 0.96 ± 0.45 mm, compared to 0.69 ± 0.45 mm in the nAC group (P<0.001).
- Meaning: The extent of AL elongation in AC patients was significantly greater than that in nAC patients.
And corneal AEs?
During the 3-year follow-up period, the duration of ortho-k lens discontinuation due to corneal AEs in the AC group was greater than that in the nAC group (P<0.05).
Further, 42.6% of patients in the AC group experienced AEs, while only 28.6% of patients without AC experienced AEs.
Any explanation for the connection between AC and ortho-k wear?
Of note, conditions like AC can cause disruption to the ocular surface, resulting in a higher risk of AEs.
- Meaning: The increased risk likely led to more frequent occurrences of corneal AEs in the AC group that resulted in extended periods of ortho-k lens wear cessation over the 3-year period.
Another potential explanation: Allergic inflammation may increase inflammatory factors such as:
- Tumor necrosis factor alpha (TNF-alpha)
- Interleukin 6 (IL-6)
- Interleukin 8 (IL-8)
Note: These factors also contribute to the development and progression of myopia via remodeling of the scleral matrix.
Expert opinion?
The study authors recommended that eye care practitioners proactively educate AC patients using ortho-k lenses on the importance of prompt follow-up and managing ocular inflammation.
“Implementing timely and effective measures to control ocular inflammation can reduce the duration of lens wear cessation, thereby allowing ortho-k lenses to more effectively control the progression of myopia,” they stated.
Limitations?
This study did not establish a control group using single-vision spectacles, so it is unclear whether the use of ortho-k lenses in patients with AC can definitively affect myopia control.
Take home.
These findings indicate that AC can impact the efficacy of ortho-k lenses for myopia control after 3 years of treatment.
Future studies could investigate whether effectively addressing ocular surface inflammation during ortho-k lens wear can improve myopia control.