PhD Student, UC Berkeley
Myopia (nearsightedness) is a condition in which the eye grows too long for its optical power. In addition to creating a dependency on glasses and/or contact lenses, myopia can lead to vision-threatening complications, such as retinal detachment and myopic maculopathy. I am currently studying how we can modify pharmaceutical treatments that are already available in clinic to optimize the myopia controlling effect while minimizing side-effects. Low concentration atropine is now widely used by pediatric optometrists and ophthalmologists to slow down progression of myopia. The lowest concentration of atropine that has been tested appears to have a significant and clinically meaningful myopia control action, with fewer side effects than higher concentrations. However, based on the mechanism of action of atropine, even this concentration may be more than what's necessary for myopia control. It has been shown that when used for other purposes, atropine is as effective when used twice per week compared to daily. Less frequent dosing would have many benefits, including a reduced risk of side-effects and slower development of tolerance, which are critical for the intended long-term treatment for myopia. This clinical study seeks to establish evidence-based dosing guidelines for the use of low dose atropine, beginning with a study of measurable clinical side effects.
Abstract: To compare daily atropine to weekend atropine as prescribed treatments for moderate amblyopia in children younger than 7 years.Prospective, randomized multicenter clinical trial (30 sites).One hundred sixty-eight children younger than 7 years with amblyopia in the range of 20/40 to 20/80 associated with strabismus, anisometropia, or both.Randomization either to daily atropine or to weekend atropine for 4 months. Partial responders were continued on the randomized treatment until no further improvement was noted.Visual acuity (VA) in the amblyopic eye after 4 months.The improvement in VA of the amblyopic eye from baseline to 4 months averaged 2.3 lines in each group. The VA of the amblyopic eye at study completion was either (1) at least 20/25 or (2) better than or equal to that of the sound eye in 39 children (47%) in the daily group and 45 children (53%) in the weekend group. The VA of the sound eye at the end of follow-up was reduced by 2 lines in one patient in each group. Stereoacuity outcomes were similar in the 2 groups.Weekend atropine provides an improvement in VA of a magnitude similar to that of the improvement provided by daily atropine in treating moderate amblyopia in children 3 to 7 years old. This article contains additional online-only material available at http://www.ophsource.com/periodicals/ophtha.
Pub.: 04 Nov '04, Pinned: 05 Jul '17
Abstract: To study the change in spherical equivalent and other ocular parameters 1 year after stopping the administration of atropine.Prospective randomized double-masked clinical trial.We assigned 400 myopic children, 6 to 12 years of age, to receive atropine 0.5%, 0.1% or 0.01% for 24 months, after which medication was stopped. Parents and children gave informed consent to participate in the research. Children were reviewed at 26, 32 and 36 months, and changes in cycloplegic spherical equivalent (SE), axial length (AL), visual acuity, pupil size, and accommodation were assessed.Of the children, 356 (89%) entered into the washout phase. At entry, there was no significant difference in age, gender, SE, or AL among the children in the various atropine groups. Over the following 12 months, myopic progression was greater in the 0.5% eyes (-0.87 ± 0.52 D), compared to the 0.1% (-0.68 ± 0.45 D) and 0.01% eyes (-0.28 ± 0.33 D, P < 0.001). AL growth was also greater in the 0.5% (0.35 ± 0.20 mm) and 0.1% (0.33 ± 0.18 mm) eyes, compared to the 0.01% eyes (0.19 ± 0.13 mm, P < 0.001). Pupil size and near visual acuity returned to pre-atropine levels in all groups, but accommodation at 36 months was less in the 0.5% eyes (13.24 ± 2.72 D) compared to the 0.1% (14.45 ± 2.61 D) and 0.01% eyes (14.04 ± 2.90 D, P < 0.001). The overall increase in SE over the entire 36 months in the 0.5%, 0.1% and 0.01% groups was -1.15 ± 0.81 D, -1.04 ± 0.83 D and -0.72 ± 0.72 D, respectively (P < 0.001).There was a myopic rebound after atropine was stopped, and it was greater in eyes that had received 0.5% and 0.1% atropine. The 0.01% atropine effect, however, was more modulated and sustained.
Pub.: 10 Dec '13, Pinned: 05 Jul '17
Abstract: To compare the safety and efficacy of different concentrations of atropine eyedrops in controlling myopia progression over 5 years.Randomized, double-masked clinical trial.A total of 400 children originally randomized to receive atropine 0.5%, 0.1%, or 0.01% once daily in both eyes in a 2:2:1 ratio.Children received atropine for 24 months (phase 1), after which medication was stopped for 12 months (phase 2). Children who had myopia progression (≥-0.50 diopters [D] in at least 1 eye) during phase 2 were restarted on atropine 0.01% for a further 24 months (phase 3).Change in spherical equivalent and axial length over 5 years.There was a dose-related response in phase 1 with a greater effect in higher doses, but an inverse dose-related increase in myopia during phase 2 (washout), resulting in atropine 0.01% being most effective in reducing myopia progression at 3 years. Some 24%, 59%, and 68% of children originally in the atropine 0.01%, 0.1%, and 0.5% groups, respectively, who progressed in phase 2 were restarted on atropine 0.01%. Younger children and those with greater myopic progression in year 1 were more likely to require re-treatment. The lower myopia progression in the 0.01% group persisted during phase 3, with overall myopia progression and change in axial elongation at the end of 5 years being lowest in this group (-1.38±0.98 D; 0.75±0.48 mm) compared with the 0.1% (-1.83±1.16 D, P = 0.003; 0.85±0.53 mm, P = 0.144) and 0.5% (-1.98±1.10 D, P < 0.001; 0.87±0.49 mm, P = 0.075) groups. Atropine 0.01% also caused minimal pupil dilation (0.8 mm), minimal loss of accommodation (2-3 D), and no near visual loss compared with higher doses.Over 5 years, atropine 0.01% eyedrops were more effective in slowing myopia progression with less visual side effects compared with higher doses of atropine.
Pub.: 15 Aug '15, Pinned: 05 Jul '17
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