The Amsler grid demonstrated limited sensitivity for detecting diabetic macular edema, particularly for small edema areas, and cannot replace OCT-based examinations at recommended follow-up intervals.
The Amsler grid showed very low sensitivity for detecting very small diabetic macular edema areas.
Amsler grid sensitivity for DME detection increased substantially as edema area exceeded 0.01 mm².
DME was identified in 90 eyes out of 1,444 eyes examined in 722 diabetic patients.
OCT was used as the diagnostic gold standard against which Amsler grid performance was assessed.
The Amsler grid may serve as an adjunctive but not replacement tool for DME home monitoring in diabetic patients.
This research examined how well the Amsler grid — a simple checkerboard-like chart used to detect vision distortions — can identify diabetic macular edema (DME), a leading cause of vision loss in people with diabetes. The study enrolled 722 diabetic patients (1,444 eyes) and compared results from the Amsler grid test against OCT (optical coherence tomography), the medical gold standard for detecting fluid buildup in the central part of the retina. Ninety eyes were found to have DME, and a detailed analysis focused on 34 eyes with edema directly at the fovea (the center of the retina responsible for sharp vision). The study found that the Amsler grid's ability to detect DME depended heavily on how large the edema was. For very small areas of swelling (0.01 mm² or less), the Amsler grid only detected the problem 20% of the time — meaning 4 out of 5 affected eyes would be missed. As edema size increased, detection improved: the grid caught about 62% of cases with edema larger than 0.01 mm², and about 70% of cases with edema larger than 0.03 mm². This means even for larger edema, nearly one-third of cases could go undetected. This research suggests that while the Amsler grid is an inexpensive and accessible tool that patients can use at home, it is not reliable enough to replace regular eye clinic visits with OCT scanning for people with diabetes. It may still have a role as a supplementary monitoring aid — for example, helping patients notice significant changes between appointments — but should not be relied upon as a standalone screening method for catching early or small cases of diabetic macular edema.
Wolf S, Michelson G. (2026). Association between macular edema area on optical coherence tomography and Amsler grid sensitivity in diabetic macular edema: a cross-sectional study.. BMC ophthalmology. https://doi.org/10.1186/s12886-026-05298-3