While orthokeratology in children for myopia control is deemed safe and effective,¹ side effects—such as changes to the tear film and meibomian glands—are under investigation. Given the use of orthokeratology lenses carries a risk for corneal staining,² a healthy tear film is an important part of safe orthokeratology lens wear. 

In one study,² additional ocular surface disease testing was included during a baseline evaluation and after 12 months of lens use. These tests included the Ocular Surface Disease Index (OSDI) survey, baseline corneal fluorescein staining, tear break up time, tear meniscus height, meibomian gland imaging, and a dynamic tear film stability assessment. During 12 months, there was an increase in OSDI score (indicating more symptoms) and corneal staining in the lens-wearing group compared to controls. There were no significant changes in tear film stability, tear meniscus height, or meibomian gland loss.³ Another study evaluated the use of non-viscous 0.9% saline drops versus a more viscous 0.3% hyaluronic acid drop during the application of orthokeratology lenses. It was noted that the 0.3% hyaluronic acid group reported better comfort during lens wear initially, but both groups reported good comfort after one month of wear.³

Takeaway #1: Our patients using orthokeratology lenses may experience symptoms related to ocular surface disease, especially in the first month of use.

Another study conducted similar ocular surface testing for 24 months of orthokeratology lens wear.⁴ The results nearly mirrored the previous study,³ in that patients reported more ocular surface disease symptoms via the OSDI, and that meibomian gland structure was unaffected during the 6-month period. However, Wang and colleagues  noted that OSDI scores returned to baseline between 12 and 24 months of orthokeratology lens use.⁴ There was also a small increase in corneal staining with sodium fluorescein at the 1-month visit, and that low level remained stable throughout 24 months.⁴ The corneal staining was described as grade 1: “a few scattered dots of stain” in 90% of patients.⁴ There was also a 0% dropout rate during the 24-month period,⁴ which is an impressive finding when compared to the soft lens dropout rate of approximately 25% for the same period.⁵

Takeaway #2: Patients can safely wear orthokeratology lenses long-term, and patients choose to continue with orthokeratology. 

It has been suggested that analyzing the tear layer itself may give insight into potential complications with long-term orthokeratology lens wear. A third study assessed tear film components after one night of orthokeratology lens wear.⁶ The only component that resulted in a statistically different finding was lactate dehydrogenase (LD),⁶ which is a marker of corneal hypoxic stress.⁷ Both the control and orthokeratology lens-wearing groups showed higher levels of LD after a night of sleep, though the orthokeratology group had slightly higher levels. The authors concluded the effect of orthokeratology lens wear on the tear film was slight.⁶

Takeaway #3: The tear film experiences minimal change with orthokeratology lens wear compared to non-lens wearers. 

As an orthokeratology enthusiast, it is comforting to read that my preferred method of myopia control is effective and minimally impactful on the ocular surface. 

References:

1. Hiraoka T. Myopia Control With Orthokeratology: A Review. Eye Contact Lens. 2022;48(3):100-104.
2. Hui W, Xiao-Feng H, Song-Guo L, Jing-Jing W, Xuan H, Yong T. Application of orthokeratology on myopia control and its effect on ocular surface and meibomian gland function in Chinese myopic adolescents. Front Med (Lausanne). 2022;9:979334.
3. Carracedo G, Villa-Collar C, Martin-Gil A, Serramito M, Santamaría L. Comparison Between Viscous Teardrops and Saline Solution to Fill Orthokeratology Contact Lenses Before Overnight Wear. Eye Contact Lens. 2018;44(Suppl 1):S307-S311.
4. Wang X, Li J, Zhang R, et al. The Influence of Overnight Orthokeratology on Ocular Surface and Meibomian Gland Dysfunction in Teenagers with Myopia. J Ophthalmol. 2019;2019:5142628.
5. Shovlin J. A Deep Dive on Dropout. Review of Cornea and Contact Lenses. 2024 Feb 15. www.reviewofcontactlenses.com/article/a-deep-dive-on-dropout. Accessed January 13, 2024.
6. Choy CKMC, Cho P, Forster Benzie IF, Ng V. Effect of one overnight wear of orthokeratology lenses on tear composition. Optom Vis Sci. 2004;81(6):414-420.
7. Ichijima H, Imayasu M, Ohashi J, Cavanagh H. Tear lactate dehydrogenase levels. A new method to assess effects of contact lens wear in man. Cornea. 1992;11(2):114-120.

Brooke M. Messer, OD, FSLS practices at Vance Thompson Vision in West Fargo, ND. She is also a fellow of the American Academy of Optometry. She has received remuneration from Bausch + Lomb SVP, Glaukos, Heidelberg, and Tarsus.

 This editorial content was supported via unrestricted sponsorship.