Determination of optical penalization by vectographic fixation reversal

Optical penalization for distance is a useful alternative to occlusion for treating amblyopia, and as maintenance therapy following occlusion. It is particularly useful in cases of patching noncompliance. The major key to patient acceptance is choosing the minimal amount of penalization necessary, while still ensuring that the patient actually switches fixation to the amblyopic eye. We have found the vectographic letter slide reliable for identifying the fixing eye for distance vision. Thirty-four patients were treated for anisometropic or strabismic amblyopia with distance optical penalization without the use of cycloplegic agents. Twenty-two patients had improvement of their visual acuity, and 10 patients remained the same during an average follow-up period of 22.5 months. The average visual acuity improved from 20/40 to 20/32. The dominant eye required an average of only +1.25 diopters of fogging for the patient to switch fixation to the amblyopic eye, significantly less than the arbitrary +3.00 diopters advocated by some clinicians.