Abstract
Purpose :
Myopia is associated with abnormal scleral constitution and remodeling. We investigated the effect of low dose atropine eye drops on scleral thickness and pressure to evaluate ocular rigidity, and other visual parameters in emmetropes and myopes.
Methods :
Young adults (N=19, 24.4±1.2yrs) with emmetropia (SE +0.4±0.3D) or myopia (SE -2.4±1.7D) were enrolled. Lenstar LS900 was used to measure axial length (AXL), corneal thickness (CCT), anterior chamber depth (ACD) and lens thickness (LT); Spectralis SD-OCT anterior segment module to evaluate anterior scleral thickness, and wide-field posterior module to evaluate retinal and choroidal thickness. IOP was measured with GAT and iCare in the central cornea and with iCare at four scleral locations: 4mm nasal, 4mm temporal, 5mm superior and 5mm inferior from the limbus. Other tests included pupil sizes under dim, bright and near conditions, dynamic retinoscopy (MEM) and contrast sensitivity (CS, Rubin). Subjects used 1 drop of 0.05% atropine in each eye every night for 7 days. All measurements were taken: twice during Visit-1 (before and 30mins after instillation of atropine), and once during Visit-2 (1 week later, at a similar time: ±2 hours).
Results :
Pupils became significantly larger after instillation of atropine (Dim: 1.5±0.7mm, Near: 2.1±0.7mm, Bright: 2.2±0.8mm, p<0.01 all). Accommodation lags increased (0.4±0.7D, p=0.05) and CS decreased (-0.2±0.3LogCS,p=0.02) in Visit-2. Corneal IOP decreased (1.6±2.7mmHg, p=0.02), but scleral IOPs significantly increased at 5mm superior (7.2±2.7mmHg, p=0.04) and 4mm temporal (3.6±2.7mmHg, p=0.04) in Visit-2. ACD was deeper in Visit-2 (0.1±0.1mm, p=0.02), and a trend was noted for longer AXL, thicker CCT and thinner LT. Those subjects for whom temporal sclera thickened with atropine, tended to also have higher IOPs temporally (R=0.4, p=0.06). No significant effect of atropine on retinal or choroid thickness was noted for any eccentricity.
Conclusions :
Although short-term use of 0.05% atropine eye drops significantly increased pupil sizes, more variability was noted on accommodation and other visual parameters. Corneal IOP significantly decreased after 1 week use of atropine, whereas superior and temporal scleral IOP increased. Higher IOP in anterior sclera and trend for thickening in the same area with atropine use may be associated with the mechanism of atropine in myopia management.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.