A review that pooled 10 studies (1,890 eyes) found the grid detected wet macular degeneration in about 67% of cases when compared with healthy eyes, and 71% when compared with eyes with the dry form. Bias was judged low across studies. The authors said sensitivity may be too low for monitoring1Meta-analysis · 2023Diagnostic Accuracy of the Amsler Grid Test for Detecting Neovascular Age-Related Macular Degeneration: A Systematic Review and Meta-analysis.Although the Amsler grid is easy and inexpensive to use for detection of metamorphopsia, its sensitivity may be at levels typically not recommended for monitoring. Coupling this lower sensitivity with only moderate specificity to identify neovascular AMD in a population at risk, these findings suggest that such…JAMA Ophthalmol.
An earlier review that pooled 12 studies (903 people) found the grid detected about 78% of wet cases, and correctly cleared about 97% of healthy eyes. The true detection rate could be anywhere from about 64% to 87%. Nearly all studies compared known patients with healthy people, which tends to flatter a test2Meta-analysis · 2014 · 903 peopleDiagnostic accuracy of the Amsler grid and the preferential hyperacuity perimetry in the screening of patients with age-related macular degeneration: systematic review and meta-analysis.Results from small preliminary studies show promising test performance characteristics both for the Amsler grid and PHP to rule out wet AMD in the screening setting. To what extent these findings can be transferred to a real clinic practice still needs to be established.Eye (Lond).
In studies that followed people at high risk, the grid caught only about 42% of new wet disease over 2 years (15 eyes developed it). With so few cases, the true figure is very uncertain9Study · 2012 · 98 peopleDetection of new-onset choroidal neovascularization using optical coherence tomography: the AMD DOC Study.Time-domain OCT, supervised Amsler grid, and PHP have low to moderate sensitivity for detection of new-onset CNV compared with FA. Optical coherence tomography has greater specificity than Amsler grid or PHP. Among fellow eyes of individuals with unilateral CNV, FA remains the best method to detect new-onset CNV.Ophthalmology.
Head-to-head A trial that compares two treatments directly with each other, rather than each with a placebo. trials found the grid missed more disease than a newer machine test. In one, it flagged 26% of eyes with macular degeneration, against 68% for the machine4Clinical trial · 2005 · 117 peopleResults of a multicenter clinical trial to evaluate the preferential hyperacuity perimeter for detection of age-related macular degeneration.The PHP had greater sensitivity, although with a relatively high rate of false-positive results for healthy individuals, than the Amsler grid in detecting AMD-related lesions.Retina. In another, it flagged 34% of eyes with wet disease, against 94%3Clinical trial · 2003 · 108 peopleReplacing the Amsler grid: a new method for monitoring patients with age-related macular degeneration.The MCPT was superior to the Amsler grid in detecting AMD-related lesions in this cohort. Studies are underway to determine whether the MCPT is feasible for home monitoring to provide early detection of progression to CNV.Ophthalmology. A third found similar results for the two, with the grid flagging 80% of wet cases6Clinical trial · 2006 · 140 people[Comparison of Preferential Hyperacuity Perimeter (PHP) test and Amsler grid test in the diagnosis of different stages of age-related macular degeneration].The PHP and Amsler grid tests revealed comparable results detecting metamorphopsia and scotoma in early ARMD (30 vs. 30 %) and late ARMD (46 vs. 52 %). However, the PHP test more often revealed disease-related functional changes in the groups of geographic atrophy (87 vs. 67 %) and neovascular ARMD (84 vs. 80 %). This…Klin Monbl Augenheilkd.
A review noted that sensitivity can fall below 50%. Part of the reason may be that the brain "fills in" the blind spot5Review · 2007The Amsler chart: absence of evidence is not evidence of absence.Although alternative tests have been developed and shown to have greater sensitivity, at present no straightforward, cheap, home-based test of macular disease progression is available. The development of such a self-diagnostic tool should be a research priority.Br J Ophthalmol.
In a study of 297 people already treated for wet disease, none of three home vision tests detected active disease well. Most active cases would have been missed. The Amsler grid itself wasn't one of the three7Study · 2024 · 297 peopleHome-Monitoring Vision Tests to Detect Active Neovascular Age-Related Macular Degeneration.Results suggest that no home-monitoring vision test evaluated provided satisfactory diagnostic accuracy to identify active nAMD diagnosed in hospital eye service follow-up clinics. Implementing any of these evaluated tests, with ophthalmologists only reviewing test positives, would mean most active lesions were…JAMA Ophthalmol.
In diabetic eye swelling, a study of 722 people found the grid detected about 62% of cases, and only 1 in 5 of the smallest swellings10Observational study · 2026Association between macular edema area on optical coherence tomography and Amsler grid sensitivity in diabetic macular edema: a cross-sectional study.The Amsler grid demonstrated limited sensitivity for detecting DME, particularly for small edema areas (≤ 0.01 mm²). While it may serve as an adjunctive tool for home monitoring in diabetic patients, it cannot replace OCT-based examinations at recommended follow-up intervals.BMC Ophthalmol.
Such figures describe groups of people, so what they mean for one person depends on their own risk.
Key studies
Study
Who
What it found
Review of 10 studies, 20231Meta-analysis · 2023Diagnostic Accuracy of the Amsler Grid Test for Detecting Neovascular Age-Related Macular Degeneration: A Systematic Review and Meta-analysis.Although the Amsler grid is easy and inexpensive to use for detection of metamorphopsia, its sensitivity may be at levels typically not recommended for monitoring. Coupling this lower sensitivity with only moderate specificity to identify neovascular AMD in a population at risk, these findings suggest that such…JAMA Ophthalmol
1,890 eyes
Detected about 67% to 71% of wet cases
Review of 12 studies, 20142Meta-analysis · 2014 · 903 peopleDiagnostic accuracy of the Amsler grid and the preferential hyperacuity perimetry in the screening of patients with age-related macular degeneration: systematic review and meta-analysis.Results from small preliminary studies show promising test performance characteristics both for the Amsler grid and PHP to rule out wet AMD in the screening setting. To what extent these findings can be transferred to a real clinic practice still needs to be established.Eye (Lond)
903 people
Detected about 78%; healthy eyes cleared 97%
Study following people, 20129Study · 2012 · 98 peopleDetection of new-onset choroidal neovascularization using optical coherence tomography: the AMD DOC Study.Time-domain OCT, supervised Amsler grid, and PHP have low to moderate sensitivity for detection of new-onset CNV compared with FA. Optical coherence tomography has greater specificity than Amsler grid or PHP. Among fellow eyes of individuals with unilateral CNV, FA remains the best method to detect new-onset CNV.Ophthalmology
98 high-risk people
Caught 42% of new wet disease
Trial, 20054Clinical trial · 2005 · 117 peopleResults of a multicenter clinical trial to evaluate the preferential hyperacuity perimeter for detection of age-related macular degeneration.The PHP had greater sensitivity, although with a relatively high rate of false-positive results for healthy individuals, than the Amsler grid in detecting AMD-related lesions.Retina
150 people
Grid flagged 26% of disease; machine flagged 68%
What we don't know
How well the grid works in real home use, since most studies compared known patients with healthy people, under supervision.
Whether the grid helps people keep their vision when used between eye exams.
Written by AI from the studies listed, without review by a clinician, and graded with the GRADE method. It can be wrong, so check the studies it cites. Education, not medical advice.