Abstract
Purpose :
Topical atropine is now widely used by pediatric optometrists and ophthalmologists for controlling myopia progression; however, the optimal dosing routine is yet to be determined. This study compared the efficacy of topical 1% atropine applied daily versus every three days for controlling myopia in pigmented guinea pigs.
Methods :
To induce myopia pigmented guinea pigs (New Zealand strain, n=25) wore monocular -10 D custom-made rigid gas-permeable (RGP) contact lenses for three weeks, after which they were replaced with -15 D contact lenses for another three weeks. Ten animals were also treated with daily 1% atropine (atr. group 1), six with atropine every three days (atr. group 2), and nine with topical artificial tears as a placebo control treatment (control group). Spherical equivalent refractive error (SER) and axial length (AL) data, as well as retinal and choroidal thickness data were collected at weekly intervals using retinoscopy, ocular biometry (Lenstar), and Spectral-Domain Optical Coherence Tomography (SD-OCT), respectively.
Results :
Topical 1% atropine significantly slowed down myopia progression. Mean (±SEM) interocular differences (treated - fellow) in SER at week-0 (baseline) were similar for all groups (0.11±0.37, 0.63±0.26, & -0.29±0.31 D for control, group 1, and group 2 resp., p=0.168), but significantly different by week-6 (-13.71±0.93, -10.50±0.77, and -7.83±0.08 D, resp., p=0.0032) (Figure 1). Interocular differences in AL (Figure 2) at week-0 were also not significantly different (-0.05±0.02, 0.00±0.02, and -0.01±0.01 mm for the control, group 1, group 2 resp., p=0.1179), but were by week-6 (0.29±0.05, 0.16±0.02, & 0.08±0.03 mm, resp., p=0.0068). For the control group, the interocular differences in choroidal thickness and blood vessel area decreased over the time as expected. These changes were attenuated by topical atropine. There is no significant difference in retinal thickness among the three groups, at any time.
Conclusions :
For the negative contact lens-induced pigmented guinea pig model, administration of 1% topical atropine daily or every three days slowed myopia progression. Although further investigations are needed, these results challenge the need for daily dosing of atropine for myopia control.
This is a 2020 ARVO Annual Meeting abstract.