Lacquer cracks are found in the posterior fundus of 4.3% of highly myopic eyes. They represent healed and mechanical breaks of the retinal pigment epithelium, Bruch's membrane, and choriocapillaris complex. This prospective study examined the progressive course and angiographic characteristics of transitional changes in highly myopic eyes with lacquer cracks.The authors studied 66 eyes (53 patients with lacquer cracks, using general ocular examinations and fluorescein angiography once every 3 to 12 months. Follow-up ranged from 7 to 243 months (average, 72.8 months).The lacquer cracks progressed in 37 eyes (56.1%). Of these 37 eyes, the number of lacquer cracks increased in 14 eyes and turned into other myopic fundus changes in 25 eyes. These changes included patchy atrophy, diffuse atrophy, and choroidal hemorrhage with neovascular membrane (Fuchs' spot). Fluorescein angiography showed patchy atrophy beginning with a small hypofluorescent area at the peripheral end of the lacquer cracks.A high incidence of lacquer cracks progressed into advanced fundus changes during a mean follow-up period of 6 years. Even faint lacquer cracks may characterize an unfavorable prognostic course, leading to macular pathology in patients with pathologic myopia.