Combining bifocal wear and atropine use may offer an effective therapy option in amblyopia. Photo: Jasleen Jhajj, OD.

Refractive correction is key for amblyopia therapy, but studies have noted that other variables such as optical aberrations, pupil size and accommodation may influence the success of such treatments.

Noting that most hyperopic anisometropic amblyopic children have greater accommodative lag in their amblyopic eye when viewing monocularly, researchers recently investigated the effects of wearing a bifocal lens in the amblyopic eye with defective accommodation in combination with atropine in the sound eye. They reported that this combination seemed to be an effective therapy during the study’s six-month duration.

In the proof-of-concept study, the researchers randomly assigned children aged four to eight to bifocal + atropine (n=16) or atropine only (controls, n=19). They performed the following measurements before initiating treatment and at six months: visual acuity, prism and cover test, stereoacuity, contrast sensitivity, accommodation, retinoscopic refraction and subjective refraction. Accommodation was measured at nine to 11 months.

The researchers reported significantly more visual acuity improvement in the amblyopic eye of the intervention group vs. the control group (3.3 vs. 2.6 logMAR lines). Stereoacuity and contrast sensitivity changes weren’t significantly different between the two groups. In both, the researchers observed decreased differences in accommodative gain between the amblyopic and sound eye after treatment (0.62 vs. 0.79 in the atropine group and 0.69 vs. 0.82 in the atropine + bifocal group).

They concluded that amblyopia therapy has a beneficial effect on accommodation and that bifocal wear in the amblyopic eye is “feasible for the treatment of amblyopia.” They added that “this therapeutic strategy may be advantageous in treating hyperopic anisometropic amblyopia” though further studies are needed to establish efficacy in this patient population.

Tejedor J, Gutiérrez-Garmona FJ. Bifocal use in hyperopic anisometropic amblyopia treated with atropine: a proof-of-concept randomized trial. Eye. September 20, 2022. [Epub ahead of print].