Surgical management of Helveston syndrome (Triad exotropia)

Purpose To evaluate and compare different surgical approaches for the treatment of Helveston syndrome and provide further information for preoperative planning. Methods From February 2008 to December 2018, data of 52 patients with Helveston syndrome were retrospectively reviewed. Different surgical approaches were selected based on the extent of A-pattern exotropia, dissociated vertical deviation (DVD), and both superior oblique muscle overaction (SOOA) with fundus photograph intorsion. Eye position, A-pattern, DVD, superior oblique muscle function, and binocular vision function were evaluated pre- and postoperatively. The average follow-up duration was 20.5 months. Results Nine cases underwent simultaneous horizontal deviation correction with bilateral superior rectus recession, 24 underwent simultaneous horizontal deviation correction with bilateral superior oblique muscle lengthening, and 19 underwent two stages of horizontal deviation correction with superior oblique muscle lengthening, and later bilateral superior rectus recession. A-pattern, DVD, SOOA, and fundus intorsion were all collapsed in all patients postoperatively. Forty-five patients had an orthophoric eye position with considerably aligned ocular movements postoperatively. The total success rate was 86.5%. Postoperatively, eight of the 10 patients with diplopia experienced a recovery of binocular single vision and three had a recovery of rudimentary stereopsis (Titmus 3000–400 s of arc). The compensatory head posture of patients improved significantly postoperatively. Conclusions The surgical planning of Helveston syndrome should be designed based on the degree of the A-pattern, SOOA, DVD, and the intorsion in fundus photographs, and the appropriate approach should be selected to improve patient satisfaction.

Combined Recession–Resection of The Superior Rectus Muscle in the Treatment of Dissociated Vertical Deviation.

Purpose This is retrospective study that evaluates the use of combined recession-resection of the superior rectus muscle in the treatment of dissociated vertical deviation (DVD) Methods The medical records of 21 patients with bilateral DVD were retrospectively reviewed. Preoperative data were extracted for age, gender, BCVA (logMAR), amblyopia, angle of stereopsis, previous strabismus surgeries and angle of deviation. All included patients received resection of 2.5 mm of the superior rectus muscle prior to its recession in an amount determined by the maximum DVD angle. The main outcome measure was postoperative angle of DVD at the end of six postoperative months and success was identified as absence of manifest DVD . Results The mean angle of preoperative DVD was 18.09 PD in the right eye and 16.76 PD in the left ‎eye‎. The mean amount of SR recession was 8.9 ‎±1.4 ‎mm in the right e‎‎ye and 8.7 ‎±1.5 in the left ‎eye with symmetrical surgery performed in only 7 patients. Mean postoperative angle of DVD was ‎5.96‎ in the right eye and ‎5.86 ‎in the left eye. Surgical success was achieved in 15 patients (71%). Conclusions Combined recession-resection of the superior rectus muscle seems to be an effective technique in the management of DVD and could represent a good alternative to other surgical procedures.

Simulation of complex strabismus surgical procedures on goat eyes

Purpose: To describe the possibility of complex strabismus surgical simulation on goat eyes. Methods: The goat eyes were procured from local slaughterhouse with retained extra ocular muscle tissues. The obtained eyes were inspected for globe integrity, muscle quality, muscle length, and the surrounding teno-conjunctival layers. The included eyes were then segregated for surgical simulation based on their insertion and orientation (as oblique or recti), and they were mounted on a mannequin head, with a fixation suture at free end to simulate the resting tension. Additionally, as per necessary, extra muscles were also transplanted along desired sites to simulate human extra ocular muscle anatomy. Results: The inferior oblique, superior oblique, and all other four recti were successfully simulated in varying proportions in more than 50 eyes. Primarily, by simulating the lateral rectus, inferior rectus, and the inferior oblique muscle, staged weakening procedures of inferior oblique were successfully practiced (Fink’s recession, Park’s recession, Elliot and Nankin procedure, total anterior positioning, and antero-nasal trans-position or Stager’s procedure). Similarly, by simulating superior rectus, inferior rectus, lateral rectus, and the medial rectus muscles, half width transposition, full width transposition, and other complex procedures were practiced (Knapp’s procedure, augmented Knapp’s, Nishida’s procedure, Faden operation, and Y splitting procedure). Furthermore, by simulating superior oblique and the superior rectus muscles, superior oblique tuck, posterior tenectomy, loop tenotomy, and Harada Ito procedures were successfully practiced. Conclusions: On goat eyes, the complex strabismus surgical procedures can be successfully simulated and practiced after re-organizing the existing muscles in different patterns.

Modified superior oblique intrasheath tenectomy in A-pattern with superior oblique overaction

Background To evaluate the effect of modified superior oblique intrasheath tenectomy (MSOIT) on superior oblique overaction (SOOA) with A-pattern. Methods We retrospectively reviewed the data of 66 patients (130 eyes) with SOOA and A-pattern underwent MSOIT at the nasal border of the superior rectus under an operating microscope between January 1, 2004 and December 31, 2018. The superior oblique (SO) tendon fibres were resected, and the sheath was preserved in all patients. The preoperative and postoperative SOOA, objective torsion, ocular motility, and A-pattern deviation findings were compared. The correlation between the preoperative A-pattern deviation and the corrected deviation was analysed. The average follow-up period was 33.45 ± 29.88 (range: 12–122) months. Results The mean SOOA deviation improved from 2.95 ± 0.54 to 0.34 ± 0.55 (P < 0.001), while the A-pattern deviation difference between upgaze and downgaze improved from 23.15 ± 7.59 prism diopters (PD) to 3.50 ± 2.90 PD (P < 0.001). The average objective fundus intorsion value improved from + 2.96 ± 0.58 to + 0.38 ± 0.60 (P < 0.001). The magnitude of correction in A-pattern was significantly correlated with the preoperative severity of A-pattern (r = 0.812, P < 0.001). Conclusions MSOIT at the nasal border of the superior rectus (SR) under an operating microscope is safe and yields beneficial outcomes in patients with SOOA and A-pattern.

AN UNSUSUAL CASE OF ISOLATED EXTRAOCULAR MYOCYSTICERCOSIS: MASQUERADING AS A SUPERIOR RECTUS MUSCLE ABSCESS

Human cysticercosis is caused by the larval form of the swine tapeworm Taenia solium.It can affect the central nervous system, the eye, skeletal muscles and subcutaneous tissues. In the orbit, cysticercosis can lodge into any extraocular muscle or other adnexal structures and are usually found as part of a generalized systemic infestation and very rarely seen with isolated infestation of a single extraocular muscle.Hence, sometimes as it was in our case,it is very difficult to differentiate an isolated extraocular muscle cysticercosis from extraocular muscle abscess or lymphoma. So,we, at our institute report a rare and unusual case of isolated right superior rectus muscle cysticercosis which presented with ptosis and painless swelling of the right upper eyelid, which was in fact discovered later masquerading as a superior rectus abscess.

Characterization of the position of the extraocular muscles and orbit in acquired esotropia both at distance and near using orbital magnetic resonance imaging

PurposeAge-related distance esotropia (ARDE) involves acquired esotropia at distance and phoria at near. However, distance-independent esotropia (DIE) exists esotropia both at distance and near. Thus, we examined the orbital magnetic resonance imaging (MRI) findings for DIE to assess differences in its characteristics.MethodsThis study was a retrospective case-control study. We evaluated the efficacy of the standard coronal MRI in patients with acquired esotropia and control patients with optic neuritis. Cases with strabismus in the control group were excluded. DIE was defined as having esotropia both at distance and near, and an angle of more than 10 prism diopters at near. The condition of the lateral rectus-superior rectus band, position of rectus muscles, and the volume ratio of the globe to the whole orbit (G/WO) were examined.ResultsThe DIE group consisted of 12 eyes of 6 patients (77.3±7.7 years); ARDE group, 38 eyes of 19 patients (73.1±6.8 years); and control group, 34 eyes of 17 patients (70.9±4.3 years). The ratio of abnormality of the lateral rectus-superior rectus bands was higher in the DIE and ARDE groups than in the control group (p<0.01). The vertical angle of the lateral rectus deviated downwards in the control (-7.5±5.1°), ARDE (-12.2±9.1°), and DIE groups (-18.8±5.7°) (p<0.05). The tilting angle of the lateral rectus was tilted temporally in the control (-12.2±9.1°), ARDE (-20.0±8.6°) and DIE groups (-28.6±5.4°) (p<0.01). G/WO was higher in the DIE (0.28±0.01) and ARDE groups (0.27±0.02) compared to the control (0.25±0.03) group (p<0.01).ConclusionIn comparison with the ARDE and control groups, the DIE group presented with abnormalities of the lateral rectus-superior rectus band, malposition of the lateral rectus, and differences in the G/WO. The DIE group showed a more severe form of ARDE.