Preoperative prismatic correction in patients with strabismus convergence concomitants
Ohtsuki, H.; Nakayama, M.; Okayama, H.; Fujiwara, Y.; Hasebe, S.; Watanabe, Y.
Nippon Ganka Gakkai Zasshi 90(12): 1707-1713
1986
ISSN/ISBN: 0029-0203 PMID: 3825796 Document Number: 272470
The therapeutic effectiveness of preoperative prismatic correction on postoperative late results after a period of average 1.5 year was evaluated in 60 patients with strabismus convergence concomitans without amblyopia and nystagmus. The prismatic correction was carried out for seven to ten days before operation. An additional prismatic correction was needed for some patients who overconverged more than 10 prism diopters or more. When a constant small angle esotropia of less than 10 prism diopters with a peripheral fusion was obtained, we based the surgical amounts on a degree of prism diopters for correcting distant deviations. The combined res./rec. operation was took place on the dominant eye. The mechanism of overconvergence was discussed on the base of haploscopic findings. 1. Successful surgical alignments of the eyes could be achieved for 49 patients (82%) with a residual angle of squint 0 to 8 prism diopters (eso, or exo.). 2. There was a significant positive correlation between the change of angle of squint under final prismatic correction and the post-operative obj. angle of squint (r = 0.534, p < 0.01). 3. There was a significant negative correlation between the change of angle of squint for the first prismatic correction and the surgical effect in percentage (r = 0.5543, p < 0.01). 4. It was revealed that an additional prismatic correction induced more statistically significant and favorable surgical results than when no prismatic recorrection was carried out (p < 0.02). From a retrospective study it is concluded that the preoperative prismatic correction has an important therapeutic and prognostic values to obtain optimal surgical results. The suppressionsscotome may play the role to cause a prismatic compensation, in which case no peripheral fusion is found before prismatic correction.