Effects Of Long-term Monocular Orthokeratology On The Ocular Surface

Objective:To study the effects of long-term monocular orthokeratology on ocular surface.Methods: A retrospective study was conducted on patients with unilateral myopia(The contralateral eye of each patient is emmetropic.)who has been wearing an orthokeratology len for more than half a year from January 2013 to December 2015,in ophthalmology clinic,101 Hospital,Wuxi,China.The tear break-up time(BUT),basal tear secretion,central corneal thickness,corneal endothelial cell density,conjunctival congestion and corneal epithelium fluorescein staining were observed before wearing orthokeratology and at different time points during wearing orthokeratology.Results: Fifty-three young patients(53 eyes)with long-term wearing a monocular orthokeratology len were observed,whose ages were(10.43 + 1.70)years old and their SEs were(-3.37 + 1.50)D.For the myopic eyes,after 1-week treatment of monocular orthokeratology,the tear break-up time(BUT)was shortened,but there was no significant difference compared with 1-month,3-month,6-month treatment of monocular orthokeratology(P>0.05).For the emmetropic eyes,there was no significant difference in changing the BUT at above different time points(P>0.05).There was no significant difference in the value of basal tear secretion at those time points between two different kinds of eyes(The myopic eyes with orthokeratology and the emmetropic eyes without orthokeratology)(P>0.05).Compared with before wearing orthokeratology lens,there was no significant difference in both corneal center thickness and corneal endothelial cell density at those time points after wearing orthokeratology lens(P>0.05).After wearing orthokeratology lens,the corneal epithelial stain was mostly I dyed.After 1 week,1 month,3 months and 6 months respectively,the I dyed amounts were 10 eyes(18.87%),6 eyes(11.32%),8 eyes(15.09%),6 eyes(11.32%),the II dyed amounts were 1 eye(1.89%),0 eyes,0 eyes,1 eye(1.89%).The conjunctival congestion(score 1)showed up on 10 patients after wearing the orthokeratology lens.After all the 10 cases stopping wearing orthokeratology lens,but taking some antibiotics and corneal repair agents,the corneal epithelium stain disappeared and the conjunctival congestion faded away.For the emmetropic eyes,no obvious conjunctival congestion was observed during the observation period,and the corneal epithelial stain was 0.Conclusion: Continuous wearing orthokeratology can cause the decrease of the stability of tear film.And it also affects the conjunctiva and corneal epithelium by degrees.But it has no significant effect on tear secretion,corneal thickness and corneal endothelial cells.There will be no apparent ocular surface damage on non-wearing eyes.Even though wearing orthokeratology may still hurt the eye surface,however,it is mild and controllable.