Abstract
Background An estimated 49.8% of the world population will be myopic by 2050. Multifocal contact lenses (MFCLs) and orthokeratology (OK) reduce peripheral retinal hyperopic defocus, which animal studies have shown to positively impact eye growth. MFCLs are expected to slow myopic progression by 20 – 50% and OK by 30 – 60%, making them valuable therapeutic tools. In view of the guidelines for myopia management published by the International Myopia Institute in 2019, the aim of this retrospective data analysis of a tertiary care center was to review past experience with OK and MFCLs for myopia control and gain information to update current practice.
Patients and Methods The contact lens (CL) database of the Eye Clinic of the University Hospital of Basel was searched with the label “myopia progression” between January 2012 – 2020. Patients were included if they gave informed consent, were younger than 19 years old at baseline, and had no ocular comorbidities that could potentially compromise vision. Primary outcomes were progression of spherical equivalent refraction for MFCL patients and progression of axial length (AL) for the OK group, comparing with historical data from OK trials. Secondary outcomes were the presence of risk factors for myopia, age, refractive error at baseline, follow-up duration, and adverse effects during therapy.
Results Twenty-one patients could be included, with a mean age of 12.80 ± 3.32 years (y) at baseline. The majority of patients were older than 12 years and already myopic (− 3.89 ± 2.30 diopters) when control treatment was started. Overall, follow-up ranged from 0.08 to 6.33 years (2.03 ± 1.66 y). In the patients treated with MFCLs, myopia control improved significantly when patients changed from spectacles to MFCLs. In the OK group, 14% dropped out during the first year and 2 patients had multiple AL measurements during therapy, which showed a slower growth of AL when compared to other OK trials and controls with spectacles. There were two cases of non-severe keratitis. Environmental risk factors had not been documented and only 48% of clinical records had a documented family risk assessment.
Conclusion Patients showed a slower myopia progression under MFCLs or OK, which supports their role as a treatment option in myopia management. In this regard, AL measurement is an important additional parameter to be included in the assessment of myopia progression in clinical practice. Identification of children at risk of developing high/pathologic myopia (family history, environmental risk factors) needs to improve so that the first stages of myopic shift can be recognized and targeted. Changes in lifestyle should be actively encouraged, especially when the impact of decreases in outdoor time secondary to COVID-19 is yet to become clear.
Environmental risk factors for Ixodes ricinus ticks and their infestation on lambs in a changing ecosystem: Implications for tick control and the impact of woodland encroachment on tick-borne disease in livestock
