Size and position of the optic disc crescent in a white European population with myopia

Significance One of the first clinically observed changes in the retina with progressing myopia is in the form of optic disc crescents. If such a change is predictive of myopia progression, it could aid in myopia management interventions to target those at greatest risk of progression and subsequent ocular morbidity. Purpose To investigate the type, dimension and appearance of optic disc crescents and how they relate to the level of myopia. Methods Retrospective data collection analysing retinal photographs of healthy children and adults with a refractive error of ≤−0.50 D sphere and astigmatism ≤2.00 D. Crescent location, maximum crescent width and vertical disc diameter were measured from retinal images of right eyes only. Results Four-hundred eyes with a mean spherical error (SER) of −0.50 to −14.00 D (aged 7–81 years) were included (83.5% exhibited a discernible crescent). Mean (SD) maximum crescent width was 0.24 (0.24) mm. Univariate analysis showed a significant correlation between crescent width and age (r = 0.26, p