J Korean Ophthalmol Soc.  2020 Jul;61(7):765-771. 10.3341/jkos.2020.61.7.765.

Fusion and Suppression in Patients with Unilateral Idiopathic Epiretinal Membrane

• Cho IH
• Park UC
• Kim SJ
• Ryoo NK
• Yu HG

• KMID: 2504316
• DOI: http://doi.org/10.3341/jkos.2020.61.7.765

Abstract

Purpose
To investigate the presence of fusion and suppression in patients with unilateral idiopathic epiretinal membrane (ERM).
Methods
Thirty-five patients with unilateral idiopathic ERM received a full ophthalmologic exam including best corrected visual acuity (BCVA). Patients were divided into suppression and non-suppression groups according to the results of 4 Prism Dioptre Base-out Test and Worth 4 Dot test. Age, symptoms, duration of ERM, BCVA, average M-chart score, results of Titmus test and optical coherence tomography parameters were compared between the two groups. Factors associated with suppression were also evaluated.
Results
Eleven (31%) of 35 patients had suppression. The BCVA (0.18 ± 0.12 vs. 0.29 ± 0.12 p = 0.019) and stereopsis (2.25 ± 0.27 vs. 2.66 ± 0.62, p = 0.009) were significantly lower in the suppression group than the non-suppression group. Median age was older (63.21 ± 9.64 vs. 70.82 ± 6.80, p = 0.013) and duration of ERM (7.86 ± 3.69 vs. 18.54 ± 14.92 months, p = 0.004) was longer in the suppression group than the non-suppression group. Average M-chart score was higher in the suppression group. However, not all the patients suffered from metamorphopsia, including the suppression group when using binocular vision.
Conclusions
Unilateral suppression is common in unilateral idiopathic ERM and influences the patient’s stereopsis. Suppression was significantly correlated with age, duration of symptoms and metamorphopsia.

Keyword

Epiretinal membrane; Metamorphopsia; Suppression; Sensory fusion; Stereopsis