Do bifocals reduce accommodative amplitude in convergence excess esotropia?

Abstract

In several patients, excessive convergence is secondary to the extra accommodative effort required due to the presence of a primitive NPA deficit. In these subjects, the prognosis can be made on the basis of NPA measurement, and treatment with bifocal lenses will always be required to compensate. Furthermore, the parents of these small patients should be informed, even before the prescription of bifocals, that prospective surgery of medial rectus muscles will not eliminate the need for bifocals.

Esotropia

“…Ludwig et al (1989) reported that the esotropia recurred or surgery was required to correct a distance esotropia in 40-60% of their patients when bifocals were discontinued. Whether accommodation problems arise from the use of bifocals or, as suggested by one report (Fresina et al 2010), may be pre-existing remains uncertain. Whether accommodation problems arise from the use of bifocals or, as suggested by one report (Fresina et al 2010), may be pre-existing remains uncertain.…”