[Strabismus Sursoabductorius (put into the Context of eighteen Years of Strabismus Surgery Analysis)].

AIM: To familiarize with the form of combined horizontal and vertical deviations and its development and put it into the context of eighteen years of strabismus surgery analysis.

MATERIAL AND METHODS: During the period from 1996 to 2014, there were at the Department of Ophthalmology, 2nd Medical Faculty, Charles University and Faculty Hospital Královské Vinohrady, Prague, Czech Republic, E.U., operated on 2 248 patients due to the eye position misalignment. The surgery of dynamic (comitant) strabismus (esotropia, exotropia, vertical deviations and their combinations) was altogether performed in 81.7 % of patients. Out of them, horizontal-vertical deviations comprised 12.9 % - it was the strabismus sursoadductorius in 211 patients. Strabismus sursoabductorius (SAB) comprised 3.5 %; the initial type without excess of divergence (I-SAB) was established in 39 patients, and in other 43 patients it was the type already with the excess of divergence (E-SAB). The remaining surgeries were dealing with paralytic strabismus (14.7 %), and torticollis due to horizontal and torsional nystagmus (3.6 %).

RESULTS: In the clinical picture of SAB dominated the elevation of the eyeball in abduction as well as in adduction, which was at the same time insufficient, negatively influencing the second phase of convergence. The divergent part of the deviation for far vision was on average in I-SAB 12 prisms (prism diopters)(), and in E-SAB 30 . The age of the patients at the time of the surgery was on average 12 years in I-SAB and 19.5 years in E-SAB. The difference between both evaluations was significant (p < 0.005), confirming the developmental relation. The I-SAB with the increasing age changes into the E-SAB. Between the two forms of this vertical-horizontal deviation was not significant difference in the minimal deviation at near (I-SAB 2.5 and E-SAB 4.0 ). In the vertical part of the deviation was the difference even smaller (I-SAB 5.0 and E-SAB 6.0 ). The simple binocular vision was maintained in less than half of the patients with I-SAB and roughly in one-fifth of the patients with E-SAB. In I-SAB, the stereopsis was confirmed in one half of the patients, and it was rare (1/10) in E-SAB. The examination on the Hess screen confirmed extorsion, but excluded incomitant relationship as well. This sursoabduction includes in itself some separate signs of dissociated vertical deviation (DVD), and adduction activity of overactioning inferior rectus muscle (IOOA), but does not represent either of these clinical entities. Recession of the inferior oblique muscle with its eventual simultaneous resection (anteposition) of the insertion at the level of inferior rectus muscle, in E-SAB supplemented by recession of the lateral rectus muscle was found as the ultimate surgical solution. The stereoscopic functions after the surgeries restored in part only, they were present altogether in two-thirds of patients with I-SAB and in two-fifths of patients with E-SAB. Substantially improved the convergence. The vertical deviation improved and eventual residual divergence was corrected by means of prisms.

CONCLUSIONS: The author expresses his own theory of this deviations appearance. Presumed decompensated exophoria was transformed into intermittent form of exotropia, which was probably accompanied by appendant abduction of the inferior oblique muscle, because it was overacting at the same time. Insufficient adduction and convergence corresponded with that. In further development, the horizontal deviation developed into the excess of divergence with the maintenance of the inferior oblique muscle overacting (hyperfunction) and above-mentioned motility disorders. Post-operative position of the inferior oblique muscle insertion weakened its function in elevation and, simultaneously, the function of abductor transformed to function of adductor, and thereby decreased the divergence part of pathological misalignment of the eye position.

KEY WORDS: strabismus sursoabductorius, vertical deviation, horizontal deviation, exotrophia, hypertrophia, comitant strabismus, inferior oblique muscle recession.