Ortho-k Wear Increases Ocular Discomfort Symptoms, Decreases Tear Film Function

Within the first 3 months of wear, orthokeratology (ortho-k) lens wear increases ocular discomfort symptoms and decreases tear film function, according to a study published in Contact Lens and Anterior Eye. However, the study shows they are likely to be restored after the initial period of discomfort.

Researchers enrolled 50 participants (age range, 8–14 years; 24 women, 26 men; mean spherical equivalent, -3.05±1.29 D) in a prospective pilot study. All participants underwent an ocular surface exam and testing including ocular surface disease index (OSDI), keratography 5M, optical quality analysis system, and corneal staining. After the baseline exam, participants underwent clinical testing at 1 day, 1 week, 1 month, 6 months, and 12 months after ortho-k lens wear. 

The researchers report that the overall OSDI score, and 2 subscale scores (ocular symptoms and vision-related function) significantly increased at the 3-month visit (P < .05) and decreased to levels near baseline at 12-months (P >.05). 

The basic objective scatter index and mean tear film objective scatter index increased, peaking at 3-month visit (P < .05), and decreased after. The modulation transfer function cut-off significantly decreased at the 3-month visit (P < .05). 

During the 12-month period, the overall OSDI score, and vision-related function score were positively correlated with the basic objective scatter index and mean tear film objective scatter index (P <.05). 

After 1 week of lens wear, grade 1 corneal staining increased to 16.4 %, mostly involving the central and inferior cornea. Despite staining, patients opted to continue lens wear under careful monitoring, and treated with antibiotics and artificial tears.

“The OQAS provides a better interpretation of complaints of ocular discomfort in orthokeratology lens wear,” according to researchers. “The new parameter, TF-OSI, was more sensitive in detecting the quality and stability of the tear film compared to traditional tear film indicators (TMH, NITBUT-f, and NITBUT-av). Thus, the OQAS may be useful in tear film assessments and long-term follow-up examination of patients treated with orthokeratology lenses.”