FULL-TIME ATROPINE, INTERMITTENT ATROPINE, AND OPTICAL PENALIZATION AND BINOCULAR OUTCOME IN TREATMENT OF STRABISMIC AMBLYOPIA

Objective: The purpose of the study is to evaluate the monocular and b inocular outcome of three types of ''penalization'' (blurring of the s ound eye) treatment of amblyopia: traditional full-time atropine or op tical penalization and a new intermittent atropine regimen involving a tropine instillation 1 to 3 days a week. Design: The study design was a retrospective study. Participants: A total of 163 patients with stra bismic amblyopia treated by full-time atropine (n = 38), intermittent atropine (n = 73), or optical (n = 52) penalization participated. Main Outcome Measures: Logarithm of the minimum angle of resolution (logMA R) visual acuity, and binocularity index were determined. Results: All th ree forms of penalization produced statistically significant mean reduction in amblyopia (1.7-2.7 logMAR lines) and mean improvement in binocularity by the end-of-treatment or long-term follow-up visit or b oth, with minimal mean loss after discontinuation or slight mean impro vement on these measures at long-term mean followup of 1.9 to 4 years across groups. Few patients achieved high-grade stereoacuity. Complian ce was high. Comparable efficacy was found for all three treatment gro ups after controlling for age, depth of amblyopia, and binocularity at the initial visit. Initial-visit amblyopia depth was strongly and sig nificantly associated with amblyopia depth at both post-treatment visi ts. Pretreatment and post-treatment binocularity showed a similar stro ng relationship. Surprisingly, however, there was no consistent or sig nificant association found between depth of amblyopia and binocularity in any visit combination. Posttreatment measures of these two variabl es also were not associated with initial-visit age or refractive error at any clinically significant level. Mean treatment duration was 1.1 to 2.9 years and was not found to be associated with visual outcome. A mblyopia reversal was found in one (full-time atropine) case at a clin ically important level. Conclusions: The authors confirmed previous re ports of penalization's efficacy as a primary treatment of moderate am blyopia (20/100 or better acuity) and, in some cases, relatively sever e amblyopia (> 20/100) and also confirmed its ability to significantly improve mean binocularity. Amblyopia and binocularity appear to respo nd to treatment independently and, within the postinfancy age range of ?he sample studied, the responses appear to be independent of initial -visit age. The high acceptability to patients and parents of atropine penalization, and particularly of the intermittent regimen introduced here, suggests the need for prospective-study-based re-evaluation of the relative merits of penalization and occlusion as the standard of c are for mild-to-moderate amblyopia.