Superior Rectus Recession with Modified Hang-loose Technique in Rabbits

Hang-loose technique(HLT) is a reliable recession method in strabismus surgery. However, the loop length and the parallel of the anterior muscle border may not be sustained when the muscle was recessed behing the equator. This study was designed to assess the postoperative status of the large-recessed superior rectus muscle using the HLT and a modification of HLT(M-HLT) respectively in rabbits. Some of the recessed muscles with both techniques showed forward creeping. The average creeping was 0.5 mm on M-HLT and 1.1 mm on HLT in 7 mm recession group, and the difference was statistically significant(p=0.023). In 8 mm recession group, the average creeping was 1.0 mm on M-HLT and 1.8 mm on HLT. The difference was statistically significant(p=0.012). Although the parallel of the anterior muscle border was better on HLT than on M-HLT, the difference was not significant statistically. According to our result, M-HLT may be an useful alternative method in the cases of large recession with HLT.

Large recession of one lateral rectus muscle

A large recession of one lateral rectus muscle for exotropia is an infrequently used procedure. In this prospective study, 27 patients (3 to 19 years, mean age of 7) with moderate-angle exodeviation (18-35delta) were treated with large recession (8mm-9mm) of one lateral rectus muscle on their non preferred eye. Initially, there was underaction of the lateral rectus muscle. Within 6 weeks, the lateral rectus muscle regained full abduction, incomitance resolved, and the deviation was eliminated or reduced to a small phoria. Since surgery is confined to the deviating eye alone, operating time, length of anesthesia, and postoperative discomfort is reduced. The average amount of prism diopters needed for correction following operation for 8mm, 8.5mm and 9mm were 20.4delta, 26.4delta, and 31.3delta respectively and esthetically satisfactory results (within 10delta exodeviatior) were obtained in 90.I% of the patients.