Part time patching treatment outcomes in children with amblyopia with and without fusion maldevelopment nystagmus: An eye movement study

Matteo Scaramuzzi; Jordan Murray; Jorge Otero-Millan; Paolo Nucci; Aasef G Shaikh; Fatema F Ghasia

doi:10.1371/journal.pone.0237346

Part time patching treatment outcomes in children with amblyopia with and without fusion maldevelopment nystagmus: An eye movement study

PLoS One. 2020 Aug 13;15(8):e0237346. doi: 10.1371/journal.pone.0237346. eCollection 2020.

Authors

Matteo Scaramuzzi^{1

2

3}, Jordan Murray¹, Jorge Otero-Millan⁴, Paolo Nucci³, Aasef G Shaikh^{5

6}, Fatema F Ghasia^{1

5}

Affiliations

¹ Cole Eye Institute, Cleveland Clinic, Cleveland, OH, United States of America.
² Department of Neuroscience, Unit of Ophthalmology, Istituto Giannina Gaslini, Genoa, Italy.
³ DISCCO, University of Milan, Milan, Italy.
⁴ Department of Neurology, The Johns Hopkins University, Baltimore, MD, United States of America.
⁵ Daroff-Dell'Osso Ocular Motility Laboratory, Cleveland, OH, United States of America.
⁶ Case Medical Center, Case Western Reserve University, Cleveland, OH, United States of America.

Abstract

Purpose: We investigated how the abnormalities of fixation eye movements (FEMs) of the amblyopic eye were linked with treatment outcomes following part-time patching therapy in children with amblyopia.

Methods: We recruited 53 patients, with at least 12 months of patching, and measured FEMs at the end of treatment. Subjects were classified based on FEM waveforms (those without nystagmus = 21, those with nystagmus without fusion maldevelopment nystagmus (FMN) = 21, and those with FMN = 11) and based on clinical type of amblyopia (anisometropic = 18, strabismic = 6, and mixed = 29). The treatment outcomes such as duration of treatment of receiving part-time patching therapy, visual acuity and stereo-acuity deficits at the end of treatment were determined. Bivariate contour ellipse area (BCEA), fast (fixational saccade/quick phases), and slow (inter-saccadic drifts/slow phases) FEMs of the fellow and amblyopic eye were analyzed.

Results: Anisometropic group had less residual amblyopia (0.23±0.19logMAR acuity) compared to strabismic/mixed (0.36±0.26) groups (p = 0.007). Treatment duration in patients without nystagmus was lower (12.6±9.5months) compared to nystagmus without FMN (25.6±23.2) and FMN (29.5±20.4) groups (p = 0.006). Patients without nystagmus had better stereopsis at the end of treatment (2.3±0.84logarcsecs) compared to nystagmus without FMN (2.6±0.84) group (p = 0.003). The majority of patients with FMN (8/11) had absent stereopsis. BCEA of the amblyopic eye was higher in patients with greater residual visual acuity deficits in patients without nystagmus. No such association was seen in Nystagmus no FMN and FMN groups. Increased amplitude of fast FEMs, increased eye position variance and eye velocity of slow FEMs were seen in patients who had received longer duration of part time patching therapy and in those with greater residual amblyopia, and poor stereopsis at the end of treatment.

Conclusions: Assessment of FEM waveforms and fast and slow FEM characteristics are important measures while describing fixation instability in amblyopia. Several FEM abnormalities were associated with stereo-acuity and visual acuity deficits and treatment duration in patients with amblyopia treated with part time patching therapy.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Amblyopia / complications*
Amblyopia / physiopathology
Amblyopia / therapy*
Child
Child, Preschool
Eye Movement Measurements
Eye Movements
Humans
Infant
Nystagmus, Pathologic / complications*
Nystagmus, Pathologic / physiopathology
Retrospective Studies
Treatment Outcome

Grants and funding

Supported by grants from Blind Children’s Center, RPB Unrestricted Grant CCLCM-CWRU, CTSC Pilot Grant Program and Cleveland Clinic RPC Grant (FG) and Departmental NEI T32 grant (JM). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.