Outcomes of three different vertical rectus muscle transposition procedures for complete abducens nerve palsy.

PURPOSE: To compare the efficacy of three different vertical rectus muscle transposition (VRT) techniques performed as a sole procedure to correct ocular alignment and improve abduction in cases of complete abducens nerve palsy. METHODS: The medical records of patients with complete abducens nerve palsy who underwent one of three different VRT procedures without simultaneous medial rectus weakening over a period of 20 years were retrospectively reviewed. The following procedures were used: full-tendon transposition (FTT), FTT with 4 mm resections before reinsertion (FTTR), and FTT with myopexy sutures (FTTM). We recorded the pre- and postoperative alignments, limitations of adduction and abduction, and complications. Follow-up was at least 6 months. RESULTS: A total of 26 patients (age range, 8-74 years) were included: 25 unilateral and 1 bilateral. Follow-up ranged from 6 to 21 months. Among 25 patients having unilateral surgery, the mean changes in esotropia were: 36.0(Δ) for FTT (n = 9), 46.4(Δ) for FTTR (n = 7), and 41.3(Δ) for FTTM (n = 9). Mean improvements in abduction grading were 0.94 for FTT (9 eyes), 1.64 for FTTR (7 eyes), and 1.41 for FTTM (11 eyes). For both measures the means were not significantly different. Three patients (2 FTT and 1 FTTM) had new postoperative vertical tropias >3(Δ). Only 1 patient (with FTTR) had an overcorrection. CONCLUSIONS: FTTR corrected the most esotropia and improved abduction to the greatest degree, with the advantages of a low risk of creating a new vertical deviation and avoiding the risks of extra scleral sutures.

Two mathematical models for the correction of carbohydrate and protein interference in the determination of uronic acids by the m-hydroxydiphenyl method.

The most common method in the routine determination of uronic acids, the m-hydroxydiphenyl reaction, recently adapted to rapid microplate analysis, has as a main inconvenience, in any one of their modalities, interferences due to the frequent presence of proteins and neutral carbohydrates in the samples. Corresponding corrections in the literature are unsatisfactory when applied to complex matrices, and further adaptation to the microplate analysis is not free from additional problems. With particular reference to hyaluronic acid, the interactions between the principal reactants and the interfering materials are studied kinetically under realistic conditions, and simple mathematical models are proposed which satisfactorily describe the experimental results and allow adequate corrections to be made.