From the Guidelines
Metamorphopsia is a visual disturbance characterized by the distortion of straight lines, curves, or irregularities, and objects may appear distorted in size or shape, typically affecting central vision. This condition is often associated with disorders of the macula, the central part of the retina responsible for detailed vision. According to the study by 1, patients with vitreomacular traction (VMT) experience similar symptoms of impaired visual function and metamorphopsia, which may be acute or chronic depending on the severity of the traction and the resulting distortion or detachment of the macula.
Causes of Metamorphopsia
The main causes of metamorphopsia include:
- Age-related macular degeneration (AMD)
- Macular holes
- Epiretinal membranes
- Central serous chorioretinopathy
- Retinal detachment As noted in the study by 1, epiretinal membranes can lead to macular traction and similar visual symptoms, including metamorphopsia, and can cause folds in the retina, distortion of the inner and outer macula, traction on retinal vessels, and even displacement of the macula.
Diagnosis and Treatment
Diagnosis of metamorphopsia typically involves an Amsler grid test, where patients identify distortions in a pattern of straight lines. Treatment depends on addressing the underlying cause and may include anti-VEGF injections for wet AMD, vitrectomy surgery for macular holes or epiretinal membranes, or laser therapy for certain conditions. Early detection and treatment are crucial to prevent permanent vision loss, as emphasized in the study by 1. Patients often notice that doorframes appear bent, text on a page seems wavy, or faces look distorted, highlighting the importance of prompt diagnosis and treatment to improve quality of life and prevent morbidity and mortality associated with vision loss.
From the Research
Definition of Metamorphopsia
- Metamorphopsia is a visual disturbance characterized by the perception of distorted shapes, where straight lines appear curved or wavy 2, 3, 4.
- It is a common symptom in various macular disorders, including age-related macular degeneration, epiretinal membrane, and central serous chorioretinopathy 3, 4, 5.
Characteristics of Metamorphopsia
- Metamorphopsia can manifest as micropsia (perceiving objects as smaller than they are) or macropsia (perceiving objects as larger than they are) 4.
- The distortion can be characterized by straight lines being recognized as bending toward a central scotoma, as seen in macular hole patients 6.
- The severity of metamorphopsia can be correlated with subjective scores and visual acuity 5.
Assessment and Quantification of Metamorphopsia
- Traditional assessment methods include the use of Amsler Grids, where patients identify irregularities in a standardized set of lines 2, 3, 5.
- Newer methods, such as M-CHARTS and preferential hyperacuity perimetry, have been developed to quantify and assess metamorphopsia 3, 6.
- These methods can be used to evaluate the severity of metamorphopsia and monitor changes over time, including after surgical treatment 6.