Effect of Low-Concentration Atropine Eye Drops on Parapapillary Gamma Zone Development and Enlargement over 3 Years: The LAMP Study.

PURPOSE: To evaluate the longitudinal changes in the parapapillary gamma zone in children receiving 0.05%, 0.025%, or 0.01% atropine eye drops and placebo/switchover over 3 years based on the Low-Concentration Atropine for Myopia Progression (LAMP) study.

DESIGN

A secondary analysis from a randomized controlled trial.

PARTICIPANTS

Two hundred eighty children underwent spectral-domain OCT at baseline, which involved 24 equally spaced radial OCT B-scans of the optic nerve head, taken at 1-year intervals.

METHODS

Children in the LAMP study were randomized to receive 0.05%, 0.025%, 0.01% atropine, or placebo eye drops. In the second year, placebo participants switched to 0.05% atropine. At the beginning of the third year, each group was rerandomized to continued treatment or cessation (washout). The Bruch membrane opening was identified in 48 meridians in each eye. Gamma zone was defined as the parapapillary region without Bruch membrane.

MAIN OUTCOME MEASURES: Differences between treatment groups in gamma zone area changes from baseline to the 3-year follow-up visits.

RESULTS

Of 238 children included at baseline, the study included 192 (80.7%) children completing the follow-up of 3 years. The cumulative mean gamma zone area changes differed significantly between the initial 0.05%, 0.025%, and 0.01% atropine subgroups (0.09 ± 0.09 mm2, 0.19 ± 0.12 mm2, and 0.22 ± 0.17 mm2; P for trend <0.001) over 3 years. In multivariable analysis, gamma zone area enlargement was associated with 0.05% atropine (β = -0.07, P = 0.005), female sex (β = 0.05, P = 0.006), larger baseline gamma zone area (β = 0.23, P < 0.001), and larger axial elongation (β = 0.14, P < 0.001).

CONCLUSIONS

Low-concentration atropine reduced parapapillary gamma zone enlargement in a concentration-dependent manner over a 3-year treatment period. Continued 0.05% atropine treatment showed efficacy in controlling gamma zone development.

FINANCIAL DISCLOSURES: The author has no/the authors have no proprietary or commercial interest in any materials discussed in this article.