Prognostic Value of the Crowding Phenomenon in Amblyopia

Abstract

Abstract: : Purpose: To determine the prevalence and the prognostic value of the crowding phenomenon in patients with amblyopia. Methods: Patients with amblyopia (best corrected linear visual acuity difference of at least 2 lines) were included if they complied with treatment and had isolated optotype visual acuity measured at the beginning of treatment. Significant crowding was defined as at least 2 lines of difference between linear and isolated initial visual acuity. The prognostic value of the crowding phenomenon in amblyopia was evaluated by comparing outcomes between patients with significant crowding (group1) and those with insignificant or no crowding (group 2). Results: The average ages and the types of amblyopia were similar for each group.The average number of lines of visual acuity improvement after amblyopia treatment was 2.5 lines for group 1 (crowding) and 1.3 lines for group 2 (no crowding). (p = .03) Seven of 10 patients (70%) in group 1 improved by at least 2 lines, compared to 6 of 12 patients (50%) in group 2. (p = .42) Sixteen of 22 patients (73%) in the study had a best recorded visual acuity after treatment that was equal to or better than their initial isolated visual acuity. Conclusion: Significant crowding was present in 12/22 amblyopic patients, and it is associated with a better visual outcome after amblyopia treatment. Most patients with amblyopia can achieve a linear visual acuity after treatment equal to or better than their isolated visual acuity prior to treatment.

Keywords: 313 amblyopia