Myopic macular degeneration, or myopic macular degeneration (MMD), occurs in eyes with pathological myopia. With increasing age, patients often experience progressive elongation of the axial length, leading to posterior expansion of the globe, forming a posterior staphyloma. Characteristic fundus changes include the following: a choroidal atrophic crescent (commonly referred to as a myopic crescent) is observed on the temporal side of the optic disc, and in severe cases, the crescent can extend circumferentially around the disc. In the macular region, atrophy of the retinal pigment epithelium (RPE) and the choriocapillaris may be seen, often presenting as multiple patches of variable sizes that can merge into larger areas. Within the atrophic regions, exposed larger choroidal vessels and irregular pigmentation may be observed.
Due to posterior expansion of the globe, several characteristic lesions may develop in the macular area, including lacquer cracks (appearing as yellowish-white lines caused by ruptures in the Bruch's membrane), subfoveal hemorrhage, Fuchs spots (blackish, slightly elevated roundish lesions), and choroidal neovascularization (CNV). Patients often present with sudden and significant visual deterioration, visual distortion, or central scotomas due to macular hemorrhage. The presence of CNV can be evaluated with OCT or OCTA, while fluorescein angiography (FFA) aids in identifying CNV leakage.
Furthermore, the degenerative changes in the macular RPE and choroid, vitreous liquefaction, retinal schisis, and vitreomacular interface abnormalities caused by pathological myopia increase the susceptibility to complications such as macular epiretinal membranes, macular holes, and subsequent retinal detachment.
A diagnosis can often be made based on a history of myopia and the presence of characteristic fundus changes. For pathological myopic CNV, intravitreal anti-VEGF therapy is currently the primary treatment option.