August 26, 2019
2 min read

Six-hour occlusion as effective as full-time for severe amblyopia

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Six hours of occlusion is as effective as full-time occlusion in the treatment of severe amblyopia, and 2-hour occlusion is as effective as 6 hours for moderate amblyopia, according to a retrospective study.

“Our population achieved outcomes comparable to the Pediatric Eye Disease Investigators Group (PEDIG) studies, albeit after a longer duration of treatment,” the authors wrote. “The ‘plateau’ in visual acuity improvement noted after 32 weeks’ treatment in moderately amblyopic eyes and after 48 weeks of treatment in severely amblyopic eyes may guide clinicians in terms of planning duration of treatment.”

Researchers examined 877 electronic patient records (EPR) at the Gloucestershire Eye Unit from June 1, 2013, to June 1, 2017, in the largest ever reported series of amblyopia treatment according to PEDIG protocols. Severe amblyopia was defined as cases with logMAR visual acuity of 0.7 to 1.3 in the affected eye, with moderate amblyopia defined as acuity of 0.3 to 0.6. Patients 7 years old or older, with meridional and deprivation amblyopia, with visual acuity better than 0.3 or worse than 1.3 in the worse seeing eye or who had been treated with atropine were excluded.

Of the 288 children identified with severe amblyopia, 40% achieved best-corrected visual acuity greater than 0.4 logMAR at 32 weeks, increasing to 55% at 48 weeks. Moderate cases saw similar success, with 71% of the 589 cases with moderately amblyopic eyes achieving best-corrected visual acuity better than 0.3 LogMAR at 32 weeks. The average number of lines of visual improvement was 2.1 for moderately amblyopic eyes and 4.2 for severe cases.

Results were similar in the previous PEDIG studies, which found 67% of severely amblyopic eyes achieved best-corrected visual acuity better than 0.4 and 81% of moderately amblyopic eyes had best corrected visual acuity better than 0.3, with average lines of visual acuity improvements of 4.8 and 2.4, respectively.

“With increasing uptake of the EPR as part of routine practice, there may be opportunity to collate a national amblyopia database of treatment outcomes,” the authors wrote. “Such outcomes could provide a useful benchmark applicable to the general patient population.”– by Eamon Dreisbach


Holmes JM, et al. Ophthalmology. 2003;doi:10.1016/j.ophtha.2003.08.001.

Repka MX, et al. Arch Ophthalmol. 2003;doi:10.1001/archopht.121.5.603.

Disclosures: Please see the full study for a list of the authors’ relevant financial disclosures.