Scientific Online Resource System

Bulgarian Review of Ophthalmology

M-CHARTS method for quantitative assessment of metamorphopsia in patients with ERM

Gergana Milanova



The idiopathic epiretinal membrane (iERM) is a fibrocellular membrane proliferating on the inner surface of the retina in the area of the macula. The contraction of this membrane causes a disorder in vision, which results from the occurring fibrous remodeling. Metamorphopsia is the main symptom and cause of impaired quality of vision in patients with iERM. The Amsler grid is commonly used to detect metamorphopsia, but it is impossible to quantify its severity. To overcome this limitation, Matsumoto et al. developed charts, called M-CHARTS, to quantify the severity of metamorphopsia.


The aim of the present study is to make a quantitative assessment of metamorphopsia in a group of patients diagnosed with idiopathic epiretinal membrane using M-CHARTS and to establish the existence of a relationship between the severity of metamorphopsia and visual acuity.

Materials and Methods :

 The study was conducted at Dr. Ivanovi Eye Hospital in Burgas and was previously approved by the Commission for Scientific Research Ethics of the Medical University of Varna.The study included 20 patients diagnosed with epiretinal membrane. Each patient underwent a complete ophthalmological examination, and metamorphopsia was assessed with Amsler’s grid and M-CHARTS.


Using M-CHARTS, the minimum visual angle of the dotted lines required for disappearance of metamorphopsia was measured in 20 eyes of 20 patients with iERM, thereby quantifying the degree of metamorphopsia. Using Spearman’s correlation coefficient to assess the relationship between metamorphopsia and visual acuity, it was found that there was no significant relationship between metamorphopsia scores and visual acuity.


 The use of M-CHARTS is a simple and useful method for quantitative tracking of metamorphopsia in patients with ERM, which can be used as a tool necessary in the search and finding of the optimal treatment strategy and control of functional visual outcomes.



idiopathic epiretinal membrane (iERM), metamorphopsia, M-CHARTS

Full Text


Bu SC, Kuijer R, Li XR, Hooymans JM, Los LI. Idiopathic epiretinal membrane. Retina. 2014;34(12):2317-35. doi: 10.1097/IAE.0000000000000349.

Krishna Chandran AM, Coltrini D, Belleri M, Rezzola S, Gambicorti E, Romano D, et al. Vitreous from idiopathic epiretinal membrane patients induces glial-to-mesenchymal transition in Müller cells. Biochim Biophys Acta Mol Basis Dis. 2021;1867(10):166181. doi: 10.1016/j.bbadis.2021.166181.

da Silva RA, Roda VMP, Matsuda M, Siqueira PV, Lustoza-Costa GJ, Wu DC, et al. Cellular components of the idiopathic epiretinal membrane. Graefes Arch Clin Exp Ophthalmol. 2022;260(5):1435-44. doi: 10.1007/s00417-021-05492-7.

Midena E, Vujosevic: Metamorphopsia: an overlooked visual symptom. Ophthalmic Res. 2016;55:26-36. doi: 10.1159/000441033.

Forster R. Metamorphopsie. Ein Symptom partieller Schrumpfung der Retina (Retinitis circumscripta). Berlin, Ophthalmologische Beiträge, 1862.

Knapp H. Ueber isolirte Zerreissungen der Aderhaut in Folge von Traumen auf dem Augapfel. Arch Augenheilk. 1869;1:6-29.

Wundt W. Zur Theorie der raumlichen Gesichtswahrnehmungen. Philosophische Studien. 1898;14:1.

Arimura E, Matsumoto C, Okuyama S, Takada S, Hashimoto S, Shimomura Y. Retinal contraction and metamorphopsia scores in eyes with idiopathic epiretinal membrane. Invest Ophthalmol Vis Sci. 2005;46(8):2961-6. doi: 10.1167/iovs.04-1104.

Simunovic MP. Metamorphopsia and its quantification. Retina. 2015;35(7):1285-91. doi: 10.1097/IAE.0000000000000581.

Hanumunthadu D, Lescrauwaet B, Jaffe M, Sadda S, Wiecek E, Hubschman JP, et al. Clinical update on metamorphopsia: epidemiology, diagnosis and imaging. Curr Eye Res. 2021;46(12):1777-91. doi: 10.1080/02713683.2021.1912779.

Iuliano L, Fogliato G, Gorgoni F, Corbelli E, Bandello F, Codenotti M. Idiopathic epiretinal membrane surgery: safety, efficacy and patient related outcomes. Clin Ophthalmol. 2019;13:1253-1265. doi: 10.2147/OPTH.S176120.

Pareja J, Coronado A, Contreras I. Epiretinal membrane surgery in daily clinical practice: results of a proposed management scheme. J Ophthalmol. 2019;2019:8246858. doi: 10.1155/2019/8246858.

Hartmann KI, Schuster AK, Bartsch DU, Kim JS, Chhablani J, Freeman WR. Restoration of retinal layers after epiretinal membrane peeling. Retina. 2014;34(4):647-54. doi: 10.1097/IAE.0000000000000003.

Okamoto F, Okamoto Y, Hiraoka T, Oshika T. Effect of vitrectomy for epiretinal membrane on visual function and vision-related quality of life. Am J Ophthalmol. 2009;147(5):869-74, 874.e1. doi: 10.1016/j.ajo.2008.11.018.

Okamoto F, Okamoto Y, Fukuda S, Hiraoka T, Oshika T. Vision-related quality of life and visual function after vitrectomy for various vitreoretinal disorders. Invest Ophthalmol Vis Sci. 2010;51(2):744-51. doi: 10.1167/iovs.09-3992.

Kinoshita T, Imaizumi H, Okushiba U, Miyamoto H, Ogino T, Mitamura Y. Time course of changes in metamorphopsia, visual acuity, and OCT parameters after successful epiretinal membrane surgery. Invest Ophthalmol Vis Sci. 2012;53(7):3592-7. doi: 10.1167/iovs.12-9493.

Arimura E, Matsumoto C, Nomoto H, Hashimoto S, Takada S, Okuyama S, et al. Correlations between M-CHARTS and PHP findings and subjective perception of metamorphopsia in patients with macular diseases. Invest Ophthalmol Vis Sci. 2011;52(1):128-35. doi: 10.1167/iovs.09-3535.

Amsler M. L'examen qualitative de la fonction maculaire. Ophthalmologica. 1947;114:248-61.

Amsler M. Earliest symptoms of diseases of the macula. Br J Ophthalmol. 1953;37(9):521-37. doi: 10.1136/bjo.37.9.521.

Okamoto F, Sugiura Y, Okamoto Y, Hiraoka T, Oshika T. Associations between metamorphopsia and foveal microstructure in patients with epiretinal membrane. Invest Ophthalmol Vis Sci. 2012;53(11):6770-5. doi: 10.1167/iovs.12-9683.

Matsumoto C, Arimura E, Okuyama S, Takada S, Hashimoto S, Shimomura Y. Quantification of metamorphopsia in patients with epiretinal membranes. Invest Ophthalmol Vis Sci. 2003;44(9):4012-6.

Murase A, Asaoka R, Inoue T, Nagura K, Arasaki R, Nakamura K, et al. Relationship between optical coherence tomography parameter and visual function in eyes with epiretinal membrane. Invest Ophthalmol Vis Sci. 2021;62(6):6. doi: 10.1167/iovs.62.6.6.



Font Size

About The Author

Gergana Milanova
SOBAL Burgas / MU Varna

Department of Ophthalmology and Visual Sciences, Faculty of Medicine;

Specialized Eye Hospital, Burgas