Design of the Monitored Occlusion Treatment of Amblyopia Study (MOTAS).
OBJECTIVE
The effectiveness of occlusion therapy for the treatment of amblyopia is a research priority. The authors describe the design of the Monitored Occlusion Treatment for Amblyopia Study (MOTAS) and its methodology. MOTAS will determine the dose-response relation for occlusion therapy as a function of age and category of amblyopia.


METHODS
Subjects progress through up to three study phases: (1) Assessment and baseline phase: On confirmation of eligibility, and after parental consent, baseline visual functions are determined, and spectacles prescribed as necessary; (2) Refractive adaptation phase: Subjects wear spectacles full time and return to clinic at 6 weekly intervals until 18 weeks, by which time all improvement due to refractive correction is complete; (3) Occlusion phase: All subjects are prescribed 6 hours of occlusion per day. Daily occlusion is objectively monitored using an occlusion dose monitor (ODM).


METHODS
visual acuity (logMAR charts), log contrast sensitivity (Pelli-Robson chart), and stereoacuity (Frisby) are assessed at 2 weekly intervals until gains in visual acuity cease to be statistically verifiable.


CONCLUSIONS
Four methodological issues have been addressed; firstly, baseline stability of visual function; secondly, differentiation of refractive adaptation from occlusion; thirdly, objective measurement of occlusion dose and concordance; fourthly, use of validated outcome measures.
Department of Ophthalmology, Imperial College of Science, Technology and Medicine, London, UK.
C E
CE
Stewart
A R
AR
Fielder
D A
DA
Stephens
M J
MJ
Moseley
D000550:Amblyopia / Q000503:physiopathology / Q000628:therapy*; D002648:Child; D002675:Child, Preschool; D002985:Clinical Protocols; D005139:Eyeglasses; D006801:Humans; D012029:Refraction, Ocular; D013997:Time Factors; D014792:Visual Acuity