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Anisometropic Amblyopia: Distribution of Refractive Errors and Clinical Characteristics of Patients from an Eye Hospital
Ann Optom Contact Lens 2020;19:11-17
Published online March 25, 2020
© 2020 The Korean Optometry & Contact Lens Study Society

Soo-Yeon Cho, MD, Dae Hee Kim, MD, Ungsoo Samuel Kim, MD, PhD, Seung-Hee Baek, MD, PhD

Strabismus & Pediatric Ophthalmology Center, Kim's Eye Hospital, Seoul, Korea
Correspondence to: Seung-Hee Baek, MD, PhD
Strabismus & Pediatric Ophthalmology Center, Kim's Eye Hospital, #136 Yeongsin-ro, Yeongdeungpo-gu, Seoul 07301, Korea
Tel: 82-2-2639-7811, Fax: 82-2-2633-3976
Received August 16, 2019; Revised October 10, 2019; Accepted October 19, 2019.
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Purpose: To investigate clinical characteristics and visual prognosis of anisometropic amblyopia patients in a secondary referral eye hospital in Seoul, South Korea.
Methods: Medical records of 561 patients with anisometropic amblyopia between 3 and 12 years of age were retrospectively reviewed and 450 patients who followed up ≥ 2 times were included for comprehensive analysis. Amblyopia was defined as best corrected visual acuity difference of ≥ 0.2 logarithm of the minimum angle of resolution (logMAR) between the sound and amblyopic eyes. Anisometropia was defined by ≥ 1 diopter (D) difference in spherical equivalents (SE), or ≥ 1.5 D difference of cylindrical error in any meridian between the eyes. Baseline clinical characteristics, best corrected visual acuity and cycloplegic refraction of both eyes at the first visit were collected. According to the SE of amblyopic eyes, patients were categorized into hyperopia (SE ≥ 1 D), emmetropia (-1 < SE < +1) and myopia groups (SE ≤ -1 D). Treatment success was defined as achieving interocular logMAR visual acuity difference < 0.2. Treatment success rates and time to reach treatment success were compared among the SE groups.
Results: Median age of patients was 5.0 years. Median follow-up period was 25.8 months. The proportions of hyperopia, emmetropia and myopia groups were 68.9%, 14.4%, and 16.7%, respectively. Emmetropia group showed anisometropia mostly due to cylindrical error difference between the eyes, rather than SE difference. Treatment success rates were the highest in emmetropia group (95.4%), followed by hyperopia group (85.8%) and then myopia group (77.3%, p = 0.010). Among the patients who fulfilled the success criteria, median time to reach treatment success was the shortest in emmetropia group (3.0 months) followed by hyperopia group (3.6 months) and then myopia group (4.0 months, p < 0.001).
Conclusions: Hyperopia was the most common refractive error of the amblyopic eyes in anisometropic amblyopia patients who presented to an eye hospital in Seoul. Treatment success rate was the best in emmetropia group, followed by hyperopia group, and then by myopia group. Time to reach treatment success was the shortest in emmetropia group.
Keywords : Anisometropic amblyopia; Astigmatism; Hyperopia; Myopia

March 2020, 19 (1)