Stangler-Zuschrott E
Klin Monbl Augenheilkd. 1976 Jun;168(6):775-83.
Based on 15 case reports it can be shown, that the onset of a convergent squint is even possible in the age of presbyopia, independent of the patient's refraction. The clinical picture resembles that of a divergence paralysis or the convergent strabismus of the Bielschowsky type. In 13 cases the decompensation of a previous esophoria may have caused this distance-esodeviation; a divergence paralysis is not probable. In two cases change of orthophoria to esotropia could be observed. Therefore we share the opinion of v. Graefe, that an increased tonicity of the internal recti induced for compensation of weak convergence in aged individuals may cause esotropia. Treatment with prisms for distant vision is easy and effective. No case required surgery.