Author reply

Abstract

We thank Dr. Brown for her interest in our article. The author was right that there was a typographical error in the text of the results. The axial length was 25.16 mm rather than 24.16 mm. The author mentioned that “it is unlikely that this very modest reduction” of the axial length “of about 1% would substantially decrease that risk” of future complications of myopia. The reduction of axial length as a percent of the total axial length may be only 1%, but the benefit may still be considerable. The actual benefit is related to the final axial length. Moreover, in actual clinical use, the reduction of axial length may be considerably more than 0.3 mm, since atropine may be employed for longer than 2 years before cessation. The risk of retinal complications may exponentially increase with increase in axial length, so it is beneficial to achieve a relatively shorter axial length wherever possible. We thank the author for pointing out the mislabeling of the Y axis in Figure 2. This should be “spherical equivalent in diopters.” The author mentioned that “few or no patients were enrolled at less than 3 D of myopia.” There were 159 right eyes among the groups that had less myopic spherical equivalents than –3D at the commencement of the study. Furthermore, this study is aimed to investigate the effect of atropine on myopia progression, so pre-myopia cases have been excluded. We agree that the use of atropine is not designed to remove the need for glasses. However, this does not imply the lack of functional benefit. The stabilization of low/moderate myopia results in an eye with lower final myopia and hence an optical system with less aberrations. With less myopic refractive errors, there is increased suitability for corneal refractive surgery such as LASIK or photorefractive keratectomy (PRK). Moreover, such refractive errors may also allow reading without glasses at presbyopic onset later in life. Pharmacological treatment, though not perfect, is nevertheless the only type of treatment in myopia that has been shown to be clinically effective in randomized controlled settings. While treatment with atropine 1% was relatively safe, it can nonetheless produce unwanted side effects such as glare, photophobia, and blurring of vision. Therefore, we have embarked on a second trial to evaluate lower concentrations of atropine with the aim of finding an optimal dose with a good efficacy and minimal functional side-effects. It is our intention thereafter to investigate the possibility of treating pre-myopic children. Atropine Treatment for MyopiaOphthalmologyVol. 116Issue 10PreviewI read with interest the article by Tong and associates1 regarding the use of long-term atropine penalization to retard the progression of myopia. The study recruited children between 6 and 12 years of age with a spherical equivalent between -1 and -6 diopters (D), who were treated with atropine 1% eye drops in one eye nightly for 2 years; there was a placebo arm. This report provides data through year 3, or 1 year after treatment was discontinued. I would like to discuss an overlooked issue in this and similar trials2 of myopia “reduction.” Full-Text PDF