DESPITE THE KNOWN increased prevalence of myopia in patients worldwide, there is still significant knowledge to be gained in myopia management.^1,2 As the eye-care community continues to learn more about myopia treatment options, many practitioners are implementing this type of care into their practices. Depending on the practitioner’s training and comfort level, an office may offer single or multiple management strategies to their patients and families.

In order to examine various treatments for myopia management, a retrospective review was performed on myopic patients who had been prescribed a myopia management strategy, and were followed over a three-year period. A focused evaluation of these specific treatment groups allows the eyecare community to gain insight regarding utilization of various myopia treatment options, as well as treatment algorithms used by this specialized practice.

STUDY DESIGN

The authors conducted a retrospective chart review of de-identified data from all patients treated in the two myopia management clinical centers from Aug. 1, 2016, to Sept. 30, 2019. To be included in the analysis, patients had to have undergone a comprehensive examination at baseline, been prescribed an optical or pharmacological intervention, and completed one year of follow-up visits at minimum.

Data captured included cycloplegic auto-refractions as well as axial length (AL) measurements. Due to the retrospective study design, informed consent was not required and a waiver was obtained from the Sterling Institutional Review Board (IRB). All children were evaluated every three months. Cycloplegic auto-refraction and AL measurements were performed at six-month intervals.

The sample comprised all evaluated patients who met the inclusion/exclusion criteria. Aside from the cost of prescribed atropine drops, which was taken in consideration, the fees were identical for all treatments, eliminating cost as a potential source of bias in selecting a treatment.

A search of all records was performed based on keywords for adverse events (AE). All events were sent for an independent masked adjudication. Detailed reports on the adjudication process and results of the full data analysis are in development for publication.

Due to the high correlation in cycloplegic spherical equivalent refraction (CSER) and AL between the right and left eyes, only the right eyes were used for analysis. Baseline age, initial spherical equivalent refractive error, and axial elongation were tested using unpaired two-sided t-tests, adjusted using the step-down Bonferroni method. Analysis of variance (ANOVA) was used for comparison of data over time within each treatment modality, between modalities, and with an age- and ethnicity-matched myopic virtual control group.

CHOOSING A MYOPIA MANAGEMENT STRATEGY

A discussion between the practitioner and each family member regarding which myopia management option(s) is/are favorable for the patient is of utmost importance. The primary factors to consider are the amount of myopic refractive error at diagnosis and the amount of astigmatism present (both refractive and corneal), as well as anterior segment ocular health.

Binocularity and accommodation can be affected in any treatment,^3,4 so it is important to obtain accurate baseline data prior to initiating myopia management. Patients’ hobbies, sports activities, and the degree to which the parents would like oversight of the nightly cleaning, disinfection, and application/removal processes and/or drop instillation should also be discussed prior to choosing the appropriate treatment strategy.

Atropine eye drops are an option for patients who have any myopic refractive error at any age. Atropine can be prescribed in various concentrations;⁵ thus, there was high variability with atropine treatments for patients in the “Retrospective Analysis of a Clinical Algorithm for Managing Childhood Myopia Progression.”⁶

While uncommon, atropine therapy alone or in high concentrations has been reported to potentially cause glare or near vision blur,⁵ and the patient will likely remain in spectacle correction during the drop therapy. Instillation of drops can be completed at home; however, families that may be hesitant to use daily pharmaceutical drops in their children’s developing eyes.

Soft multifocal contact lenses (SMFCLs) and orthokeratology are optical options, although many differences exist between the two. SMFCLs offer a range of available parameters—low- to high-minus powers, with or without astigmatism correction, and daily disposable, monthly, and quarterly replacement modalities.

The current U.S. Food and Drug Administration (FDA)-approved myopia control soft lenses are daily disposables and were tested with a minimum of 10 hours of daily wear.⁷ Soft contact lens options all require a young patient to be responsible for lens removal, proper storage, reapplication solutions, and daytime troubleshooting without adult oversight at school or during extracurricular activities.

Extensive study of orthokeratology over more than two decades has shown the benefit of personalized lens designs, correction-free or reduced dependency in daytime vision, and effective myopia management.^8-12 In addition, the limited seven to nine hours of necessary overnight wear and the steps for proper cleaning and disinfection are performed at home, allowing for parental participation and oversight.

For younger myopic children, this home-based wear means eyecare practitioners can partner with the parents as well as the patient in the event that any question or problem arises during the treatment process. For these reasons, orthokeratology as a myopia management strategy is used frequently in this practice and will be highlighted for the purpose of this article.

MYOPIC PROGRESSION ANALYSIS

The patient population was evaluated across all myopia management treatment types. It is important to analyze both refractive error and AL data to monitor the rate of myopic progression. However, with the use of orthokeratology treatment, AL monitoring can provide a more precise understanding of the patient’s true myopic progression, as the corneal surface is intentionally altered, rendering refractive error a less consistent indicator of progression.^13,14

In terms of measuring parameters, minimal progression of AL was defined as less than or equal to 0.10mm per year. It has been noted that even emmetropes in this young age group progress at approximately 0.10mm per year.¹⁵ Maintaining this amount of progression is more realistic and practical than expecting a complete halt of AL growth. For those patients treated with orthokeratology alone, minimal progression was achieved in 56%, 53%, and 56% of patients in years one, two, and three, respectively.

With regards to refractive error, orthokeratology achieved minimal progression in refractive error in 91%, 58%, and 63% of patients in years one, two, and three, respectively. In contrast, the percentage of SMFCL patients achieving minimal progression in refractive error were 64% and 39% in years one and two, respectively (year three data was not available for SMFCL). The percentage of atropine patients achieving minimal progression in refractive error were 52%, 54%, and 100% in years one, two, and three, respectively. Adding atropine to the treatment of patients wearing orthokeratology lenses (after one month of orthokeratology at minimum) was effective when progression was observed, particularly for those patients who were considered “slow responders.”^16-18

ORTHOKERATOLOGY PRESCRIBING AND SAFETY

While all modalities of treatment showed some efficacy in myopia management, orthokeratology was the most prescribed modality for the overall population (55% of the total population, or 188 of 342 children).

Throughout the three-year duration of this study, 78% of the patients fit in orthokeratology lenses did not require any changes in treatment. In contrast, 68% of patients wearing SMFCLs and 22% of patients prescribed atropine alone did not require any changes in treatment over their respective treatment periods (Figure 1). Not only does this exemplify the popularity of orthokeratology as an initial treatment option, it also shows that patients and their families chose to continue it over the study years. The most common changes included the addition or change in concentration of atropine or a switch from one lens modality to another (such as SMFCLs to orthokeratology).

The Cumulative Absolute Reduction in axial Elongation (CARE) values for the three primary treatment types were also determined in the report using an age and ethnicity matched virtual control group.² CARE represents an empirically demonstrated, evidence-based articulation of myopia control effect over time.²

The CARE value was obtained by determining the difference between projected progression in the virtual control group and the actual progression in axial elongation. For example, the cumulative three-year change in axial elongation in the orthokeratology group was 0.30mm, compared to the projected progression of 0.62mm in the virtual control group. The CARE value was obtained by determining the difference between those two values (0.62 – 0.30 = 0.32mm).

For this analysis, only the children who had started in that treatment group and had not had a second treatment added—for example, the addition of, or a combination with, atropine—were included. For the atropine CARE calculation, all concentrations and frequencies of dosage were included, even if they were changed, but not those children who had orthokeratology or SMFCL added. The CARE score for orthokeratology is the highest at 0.32 over 3 years, representing a better myopia control effect when compared to SMFCL (0.20) and atropine (0.23) (Table 1).

SAFETY DATA

For orthokeratology, current literature reveals that it is a safe and effective treatment modality for slowing myopia progression.¹⁹ In a systematic review of 170 publications (58 in English and 112 in Chinese), it was reported that the risk of microbial keratitis (MK) found in orthokeratology lenses was comparable to that of other overnight modalities.²⁰ Corneal staining has been shown as the most common benign complication associated with orthokeratology lens wear. It can be manifested during the initial phase of lens wear, yet it largely subsides over time.²¹ Meanwhile, a large-scale multicenter retrospective study reported the estimated incidence rate of MK as 7.7 cases per 10,000 patient years (95% CI, 0.9 to 27.8). This rate is comparable to those found in other orthokeratology and SMFCL studies in the literature.^22,23

All myopia management treatment modalities require extensive oversight by the practitioner in order to monitor the children’s ocular health. Proper lens fitting and training, rigorous lens care, and compliance to lens hygiene, as well as stable adherence to periodic follow-up visits, are of paramount importance to maintain optimal eye health.

CONCLUSION

Within the population of patients treated and managed during this three-year period, orthokeratology showed remarkable success in managing children’s myopia progression with highly sustained efficacy and patient acceptance. This data further exemplifies that orthokeratology treatment provides a reduction in both refractive error and, more importantly, AL elongation progression compared to expected for age and ethnicity matched children.¹⁵ As such, orthokeratology can be a life-changing treatment option for a patient’s myopia management when prescribed and monitored carefully. CLS

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