Article for CME creditThe minimum occlusion trial for the treatment of amblyopia
Section snippets
Materials and methods
The medical records of all patients treated for amblyopia between 1990 and 1996 at the University of Iowa Hospitals and Clinics were reviewed. Only patients that met the following criteria were included in the study:
- •
Documentation in the medical record of one or more occlusion trials,
- •
Younger than 10 years of age during the occlusion trial,
- •
Visual acuity assessed by optotype acuity tests,
- •
Absence of any organic ocular condition that could result in visual impairment,
- •
At least 75% or more compliance
Results
Sixty-four patients were included in the study group. There were 31 females and 33 males. The mean age at the onset of the occlusion trial was 2 years 10 months (range, 2.0–9.5 years). The amblyopia was classified as anisometropic amblyopia in 32 patients (50%) and strabismic amblyopia in 32 patients (50%).
There were 81 occlusion trials that included one FTO interval without improvement followed by a second FTO interval (Fig 1). Visual acuity improved after the second FTO interval in 25 (31%)
Discussion
We determined the probability of visual acuity improvement in amblyopia patients with additional intervals of occlusion therapy who initially do not respond to treatment. Our study demonstrates that a clinically significant percentage of patients who initially did not respond to FTO did have an improvement in their acuity with a second or third interval of FTO. As may be predicted, the greater number of consecutive occlusion intervals without improvement corresponded to a decreased probability
References (12)
- et al.
Anisometropic amblyopia
Ophthalmology
(1991) - et al.
Compliance and results of treatment for amblyopia in children more than 8 years old
Am J Ophthalmol
(1986) - et al.
The sensitive period for strabismic amblyopia in humans
Ophthalmology
(1993) - et al.
Full-time occlusion therapy for amblyopia
Am Orthopt J
(1980) - et al.
Practical management of amblyopia
J Pediatr Ophthalmol Strabismus
(1986) Occlusion therapy for strabismic amblyopia
Aust N Z J Ophthalmol
(1994)
Cited by (16)
A randomized trial of levodopa as treatment for residual amblyopia in older children
2015, OphthalmologyCitation Excerpt :Placebo group participants and parents may have been more compliant with patching than they had been previously because they were being monitored in a research study. Nonetheless, the observation that some participants continued to improve with patching even after apparent VA stability was achieved should be considered by clinicians and parents when deciding to stop patching.20,21 Our finding of a lack of efficacy for levodopa must be viewed in the context of the study eligibility criteria: children 7 to 12 years of age with residual amblyopia from anisometropia, strabismus, or both, after a period of treatment with patching.
Recurrence of Amblyopia after Occlusion Therapy
2006, OphthalmologyCitation Excerpt :Long travel distances and rescheduled appointments occasionally necessitated less than FTO for a brief time; however, no patient was prescribed <8 hours of occlusion per day during treatment to improve VA. A patient was judged to have reached optimal vision in the amblyopic eye when the VA in that eye equaled or surpassed the vision in the normal sighted eye, or the VA improved as noted in the eligibility criteria followed by ≥3 FTO intervals without improvement in VA (Table 1).6 Once optimal VA was achieved, we recommended a progressive decrease in the daily duration of occlusion by approximately 50% every few months until occlusion was completely stopped or the patient had a recurrence of amblyopia.
Window to other specialties: Visual clarity defects
2006, Anales de Pediatria ContinuadaAmblyopia
2006, LancetCitation Excerpt :Until recent trials,67,68 the amount of patching prescribed has been entirely a matter of individual preference. Some researchers have argued for full-time occlusion, recommending at least three cycles69 of a week of full-time occlusion per year of age. Others have preferred to patch less intensively (a few h per day), recognising that treatment could take longer than expected but could be just as effective with the advantage of being less disruptive.
Amblyopia treatment outcomes
2005, Journal of AAPOSAmblyopia characterization, treatment, and prophylaxis
2005, Survey of OphthalmologyCitation Excerpt :Invest Ophthalmol Vis Sci 44[Suppl]:S200, 2003) and parents of children with no previous history of patching preferred a part-day/full-week patching schedule over an all-day/part-week schedule.521 Although some studies report an effect of age at initial visit on outcome, based on univariate measures,185,507 many do not,42,95,98,206,258,290,366,572 including a study with a maintenance-free long-term follow-up of 1.1–9.8 years. 323 One ATS study reports a small age effect,214 but other ATS studies none.3,5