metamorfopsia

Metamorphopsia is a visual symptom in which straight lines appear bent, curved, or wavy, and objects may seem smaller or larger than they are. It is not a disease itself but indicates dysfunction in the retina or the central visual pathway, most often involving the macula or fovea.

Common causes include age-related macular degeneration, diabetic macular edema, retinal vein occlusion, epiretinal membrane (macular pucker), and full-thickness macular holes. Less frequently, conditions such as central serous chorioretinopathy or inflammatory retinopathies can produce metamorphopsia. The symptom is typically unilateral when the retina is affected on one eye, but both eyes can be involved in systemic or bilateral retinal conditions.

Patients usually report distortion of objects, wavy or bent lines in central vision, and sometimes reduced visual acuity or difficulty reading. Metamorphopsia can be present suddenly or develop gradually, and its severity may change with treatment or disease activity.

Diagnosis relies on patient history and objective testing. The Amsler grid is commonly used for home monitoring to detect distortion. In the clinic, imaging and functional tests such as optical coherence tomography (OCT), fundus photography, fluorescein angiography, and microperimetry help identify macular pathology and quantify distortion.

Management targets the underlying condition. Treatments may include anti-VEGF injections for exudative age-related macular degeneration or diabetic macular edema, surgical removal of an epiretinal membrane, or pars plana vitrectomy for a macular hole. Prognosis varies with the cause and response to therapy, and persistent metamorphopsia can affect quality of life even when acuity improves.