Many excellent papers1-9 have been written recently concerning the type and amount of surgery to be done for the more perfect correction of intermittent exotropia. To satisfy my own curiosity and to add further clarity to this field, I reviewed 451 consecutive cases of exotropia done on the ward service of the Massachusetts Eye and Ear Infirmary. These included: (1) overcorrected esotropias, (2) constant exotropias, (3) alternating exotropias, (4) exotropias which have as their basis reduced vision and resultant deviation, and (5) intermittent exotropias with (a) convergence insufficiency and (b) divergence excess.
Only in this last category was it possible to find any definite relationship between type and amount of surgery and the degree of stereopsis.
Method of Selection of Cases
In Category 5, intermittent exotropia, I have used Costenbader's classification3 for delineating divergence excess, and only this will be covered in this paper. The characteristics for divergence
JOHNSON DS. Some Observations on Divergence Excess. AMA Arch Ophthalmol. 1958;60(1):7-11. doi:10.1001/archopht.1958.00940080021002