The safety of orthokeratology in myopic children and analysis of related factors

Efficacy, predictability and safety of long-term orthokeratology: An 18-year follow-up study

“…Other commonly reported and less severe or innocuous effects of ortho-k are corneal staining, pigmented ring deposits, lens binding, fibrillary lines, microcysts and non-infectious corneal infiltrates, amongst others [2,10,16]. In the present sample of patients, and in agreement with previous studies [17][18][19][20][21][22][23], the most common complication was corneal staining, with an incidence of 1591.39 cases per 10,000 patient-years, followed by corneal erosion, non-infectious corneal infiltrates, pigmented ring deposits, bulbar hyperaemia, papillary conjunctivitis and conjunctivitis. Interestingly, although one third of complications occurred during the first four weeks of ortho-k, another third was distributed between the 13th and 217th months of treatment, with a higher incidence in children than adults following the 1-year mark (35.1% vs 29.4%, respectively), although this may reflect the longest duration of ortho-k treatment in children.…”

“…For instance, Charm and Cho observed an incidence between 8.3% and 25% of grade 1 corneal staining over a follow-up period of two years in a group of children aged 8 to 11 years [19]. Similarly, in a recent research, Hu and co-workers followed for one year a sample of 489 eyes of children aged 8 to 15 years, noting that adverse effects occurred twice more frequently in patients with myopia of 4 D or more than in those with <4 D of myopia, and that these complications were three times more severe in the former group [20]. The same authors also found an increased incidence of corneal staining in younger than older children, in agreement with previous research by Lipson [21].…”

“…It must be noted that for long-term users of ortho-k requiring many lens modifications over the years as their refraction progressed, the last set of records, corresponding to the last change of lens, was used to determine efficacy and predictability, albeit all records were explored to determine ortho-k safety. In addition, given that episodes of corneal staining are frequent after the first night of ortho-k and mainly related to unskilled manipulation, these instances were not included in the analysis [20]. The association between the occurrence of adverse effects and other demographic, refractive, corneal topography and lens use parameters was explored only for those patients with a duration of the ortho-k treatment longer than one year.…”

“…Corneal staining has been described as the most frequent adverse effect of ortho-k [17][18][19][20][21][22][23]. For instance, Charm and Cho observed an incidence between 8.3% and 25% of grade 1 corneal staining over a follow-up period of two years in a group of children aged 8 to 11 years [19].…”

The Biomechanical Response of the Cornea in Orthokeratology

“…As the refractive target increased, both the central and peripheral corneal stress responses increased significantly, especially in the corneal center. Although the FDA or other health authorities approve the use of ortho-k treatment in myopia up to −6.00 D in some lens designs, the safest and most successful outcome will be achieved for those patients with lower baseline levels of myopia ( Mika et al, 2007 ; Liu and Xie, 2016 ; Singh et al, 2020 ; Hu et al, 2021 ). Therefore, for patients with high myopia or for doctors who used to increase the target degrees, more attention must be paid to the possible side effects of the ortho-k lens wear, such as damage to the integrity of the cornea, since those lenses are designed with increased compressive pressure.…”