This study demonstrated that the compliance rate of ortho-k patients was low (19.7%), which is consistent with a study by Jiang et al. . As with previous studies [18, 20], this study found that most ortho-k patients were teenagers in mainland China.
There was no correlation between compliance and lens care operator. The study also showed no correlation between compliance and age. Jiang et al.  surveyed the relationship between compliance and age in patients who had been wearing ortho-k lenses for more than 1 year, and the result was the same. Sapkota K also found that the compliance of conventional contact lens wearers was not related to age . However, a study by Morgan PB et al. showed that the older the patient, the lower the compliance . The different results may be due to the different ages of the subjects in these studies. The subjects in the study by Morgan PB had a large age span (range 21–60 years), while the subjects in other studies were of a certain age group.
No correlation has been found between compliance and sex. This result is the same as that of Jiang et al.’s study . Conversely, some previous studies have shown that compliance in females is better than that in males [16, 21]. However, none of the subjects in those studies was ortho-k patients.
The study found that there was a correlation between wearing experience and the compliance with wear and care experience. The compliance of ortho-k patients wearing lenses for less than 1 year was significantly higher than that of patients wearing lenses for more than 1 year. A previous study by Jiang et al. showed that when ortho-k patients had worn lenses for more than 1 year, the compliance for wear and care behaviors had no correlation with wearing experience . This result suggests that once ortho-k patients had worn lenses for 1 year, measures should have been taken to prevent compliance from decreasing. This result is consistent with a study by Wu et al. ; although they found that wearing experience was correlated with wear and care compliance for contact lenses other than ortho-k, compliance declined rapidly over the first 2 years rather than the first year. The following two reasons may be related to the faster decline of compliance among ortho-k patients. First, most ortho-k patients were teenagers in this study and were, therefore, younger than the patients in Wu et al.’s study (range 18–69 years; mean ± SD, 32 ± 1 years). Second, Wu et al.’s study investigated fewer behaviors than we investigated. Efron found that simpler guidelines may improve patient adherence .
The study investigated compliance over different periods in the first year and found no significant difference among them. The compliance in different periods in the first year was low, which should be noticed. It suggests that compliance with wear and care behaviors is poor at the beginning. However, 96.6% of subjects thought that their wear and care behaviors were correct. The reason for this strong contrast may be the same as the result of a study by Claydon . The study showed that most non-compliant behaviors were not intentional and may have been due to the patient not remembering or understanding when ECPs illustrated the guidelines. However, none of the subjects in the study were ortho-k patients. Further studies are needed to verify this.
As shown in Table 1, during the first year, poorest compliance was with “lens case replacement according to ECPs’ recommendation” and “removal of lens deposition interval according to ECPs’ recommendation”. After wearing lenses for 1 year, compliance with these two behaviors remained poor, but compliance with “avoiding exposure of lenses to non-sterile solutions” decreased dramatically. This finding indicated that, while some non-compliance was unintentional, some patients were intentionally non-compliant. Therefore, it is important to re-examine ortho-k lenses patients’ wear and care practices to identify the wear and care behaviors that wearers are not following. A study by Jiang et al.  showed that after wearing ortho-k lenses for 1 year, compliance with “removal of lens deposition interval according to ECPs’ recommendation” and “avoiding exposure of lenses to non-sterile solutions” was poor, which is consistent with this study. However, compliance with “lens case replacement according to ECPs’ recommendation” in this study was much lower than that in the study by Jiang et al. It indicated that the behaviors with poor compliance might differ in different areas. Cho P et al. found that poor compliance behaviors could be improved by repeated education . Therefore, the behaviors with poor compliance should be determined in different areas to re-educate the patients in those specific behaviors.
One of the limitations of this study is that the specific reasons for the decline in compliance are unclear; although it has been found that the compliance of ortho-k patients will decline with wearing experience. In addition, although repeated education has been shown to improve compliance , there is a need for further studies that would investigate the other effective strategies. It will be interesting to know whether different interventional measures can prevent and improve the compliance of ortho-k patients.