The Effect of Combined Patching and Citalopram on Visual Acuity in Adults with Amblyopia: A Randomized, Crossover, Placebo-Controlled Trial.

Alice K Lagas,Bruce R Russell,Robert R Kydd,Benjamin Thompson,Joanna M Black

doi:10.1155/2019/5857243

Alice K Lagas, Bruce R Russell + Show 3 more

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https://doi.org/10.1155/2019/5857243

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Abstract

Nonhuman animal models have demonstrated that selective serotonin reuptake inhibitors (SSRIs) can enhance plasticity within the mature visual cortex and enable recovery from amblyopia. The aim of this study was to test the hypothesis that the SSRI citalopram combined with part-time patching of the fellow fixing eye would improve amblyopic eye visual acuity in adult humans. Following a crossover, randomized, double-blind, placebo-controlled design, participants completed two 2-week blocks of fellow fixing eye patching. One block combined patching with citalopram (20 mg/day) and the other with a placebo tablet. The blocks were separated by a 2-week washout period. The primary outcome was change in amblyopic eye visual acuity. Secondary outcomes included stereoacuity and electrophysiological measures of retinal and cortical function. Seven participants were randomized, fewer than our prespecified sample size of 20. There were no statistically significant differences in amblyopic eye visual acuity change between the active (mean ± SD change = 0.08 ± 0.16 logMAR) and the placebo (mean change = −0.01 ± 0.03 logMAR) blocks. No treatment effects were observed for any secondary outcomes. However, 3 of 7 participants experienced a 0.1 logMAR or greater improvement in amblyopic eye visual acuity in the active but not the placebo blocks. These results from a small sample suggest that larger-scale trials of SSRI treatment for adult amblyopia may be warranted. Considerations for future trials include drug dose, treatment duration, and recruitment challenges. This study was preregistered as a clinical trial (ACTRN12611000669998).

Highlights

Disruptions to binocular vision such as strabismus or anisometropia during the critical period of visual development can cause a neurodevelopmental disorder of vision called amblyopia [1, 2]
Amblyopia is typically diagnosed on the basis of a monocular visual acuity loss that cannot be explained by ocular pathology combined with an amblyogenic factor [1]
We explored the effects of 2 weeks (14 days) of the selective serotonin reuptake inhibitor (SSRI) citalopram combined with fellow fixing eye patching on visual acuity, stereopsis, and visually evoked retinal and cortical responses in adults with amblyopia

Summary

Introduction

Disruptions to binocular vision such as strabismus (an eye turn) or anisometropia (unequal refractive error between the two eyes) during the critical period of visual development can cause a neurodevelopmental disorder of vision called amblyopia [1, 2]. Current treatments for amblyopia in childhood involve the provision of refractive correction followed by patching or penalization of the fellow fixing eye to promote use of the amblyopic eye These treatments are effective [6,7,8,9,10,11,12], but efficacy appears to decline with increasing age in children [13,14,15,16], possibly due to a decline in neural plasticity as the visual cortex matures and exits the critical period for visual development [17,18,19,20].

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