Federico G. Velez

Partial rectus muscle–augmented transpositions in abduction deficiency

PURPOSE Lateral posterior fixation sutures increase the effect of full rectus extraocular muscle transpositions. Partial rectus muscle transposition may be indicated to minimize the risk of anterior ischemia when multiple rectus muscles require surgery to achieve ocular alignment. PURPOSE To report a modification of full vertical rectus muscle transposition with lateral posterior fixation sutures for use in patients at risk for anterior segment ischemia. METHODS Ten cases of unilateral split rectus muscle transposition augmented with lateral posterior fixation sutures were analyzed. Five patients had Duanes syndrome with esotropia in primary position, and five patients had sixth-nerve palsy. RESULTS Seven patients had a history of ipsilateral rectus muscle surgery, and three patients underwent simultaneous surgery on ipsilateral horizontal rectus muscles. In Duanes syndrome patients, the preoperative angle of deviation at distance was 15.8 +/- 5.8 prism diopters (PD) (range, 10 to 25) compared with 3.2 +/- 4.4 PD (range, 0 to 8) postoperatively (P =.005). In patients with sixth-nerve palsy, the preoperative angle of deviation at distance was 45.2 +/- 23.9 PD (range, 16 to 80) compared with -5 +/- 14.1 PD (range, -30 to 5) postoperatively (P =.004). Postoperative binocular single visual fields enlarged in seven of seven patients. CONCLUSION Partial rectus muscle-augmented transposition allows surgery on multiple ipsilateral rectus muscles in (1) Duanes syndrome patients with esotropia, marked cocontraction, and/or limitation to both horizontal rotations and in (2) sixth-nerve palsy patients with ipsilateral medial rectus tightness. Augmented partial rectus muscle transpositions improve ocular alignment and may enlarge binocular single fields in patients with persistent deviations despite previous muscle surgery.

Extraocular muscle damage associated with endoscopic sinus surgery : An ophthalmology perspective

Background Orbital complications associated with endoscopic sinus surgery are well documented. Damage to the medial rectus muscle results in complicated strabismus and disturbing diplopia. The aim of this study was to characterize the types of extraocular muscle injury and the number of muscles involved that may complicate endoscopic sinus surgery and correlate its occurrence to factors in the surgical procedure itself. Methods A retrospective chart review was performed of 14 patients with strabismus after endoscopic sinus surgery. Operative notes of the surgical procedure, pathology reports of the intraoperative specimens, postoperative pattern of strabismus, the extraocular muscle involved, and the type of muscle injury characterized by orbital imaging were reviewed in each patient. Results In our series, not only the medial rectus muscle but also the inferior rectus and the superior oblique muscles were damaged with multiple muscles being involved in one patient. Extraocular muscle injury varied from hematoma, entrapment of muscle in the fractured orbital wall, damage to the oculomotor nerve entry zone, muscle transection, and partial or complete muscle destruction with entrapment in scar tissue. Use of the microdebrider causes extensive irreparable muscle damage. Conclusion Extraocular muscle damage complicating endoscopic sinus surgery can produce therapeutically challenging complicated strabismus.

Nonsurgical Management of Congenital Eyelid Malpositions Using Hyaluronic Acid Gel

Purpose: To report our preliminary experience using hyaluronic acid gel fillers as a nonsurgical alternative in the management of congenital eyelid malpositions. Methods: In this retrospective interventional case series, 5 patients (10 eyes) with congenital eyelid malpositions, including eyelid retraction, ectropion, euryblepharon, epiblepharon, and abnormalities associated with a shallow orbit, with resultant lagophthalmos and/or keratopathy and tearing were evaluated before and after injection with hyaluronic acid gel (Restylane) in the pretarsal and/or septal regions of the affected eyelid(s). Pretreatment, posttreatment, and follow-up photographs were analyzed for eyelid position and degree of eyelid closure and lagophthalmos, and slit-lamp evaluation of the degree of keratopathy. Results: All 5 patients demonstrated significant improvement of eyelid position and degree of keratopathy. The mean improvement in lagophthalmos was 4.5 mm (range, 2–7 mm). The average volume of hyaluronic acid gel used was 0.5 ml per eyelid. Complications were minor, including transient edema and ecchymosis at the sites of injection. Of the 10 eyelids injected, only one had increased astigmatism after injection. Conclusions: Hyaluronic acid gel shows promise as a safe and effective nonsurgical treatment for the management of certain eyelid malpositions, disorders traditionally requiring surgical intervention if aggressive ocular lubrication fails. This treatment is particularly useful in such patients who are commonly premature with poor general health and serves as a temporizing measure by allowing the much needed tissue expansion to take effect over time.

Management of vertical deviations after vertical rectus transposition surgery

PURPOSE To describe options for the management of vertical deviations after vertical rectus muscle transposition surgery (VRT). METHODS Retrospective case series including 7 children who underwent VRT for esotropic Duane syndrome and developed the complication of a vertical deviation. RESULTS Eighty-two consecutive children underwent VRT for Duane syndrome. Seven eyes of 7 patients (4 boys, 3 girls) were found to have induced vertical deviations postoperatively. Average length of follow-up was 12.7 months (range, 3-28 months). Median induced vertical deviation was 10.1(Delta) (range, 8-12). All patients required only one additional surgery to ameliorate the vertical deviation. At final follow-up, the mean vertical tropic deviation was 0. Six patients were operated on within 4 days of VRT. Surgical strategies included recession of one vertical rectus muscle and repositioning of a posterior fixation suture. CONCLUSIONS In children undergoing VRT for esotropic Duane syndrome, the complication of a vertical deviation occurred in 8.5% of cases. The vertical deviation was completely ameliorated in each case by one surgical procedure involving recession of one of the transposed muscles.

Functional burden of strabismus: decreased binocular summation and binocular inhibition.

IMPORTANCE Binocular summation (BiS) is defined as the superiority of visual function for binocular over monocular viewing. Binocular summation decreases with age and large interocular differences in visual acuity. To our knowledge, BiS has not heretofore been well studied as a functional measure of binocularity in strabismus. OBJECTIVE To evaluate the effect of strabismus on BiS using a battery of psychophysical tasks that are clinically relevant and easy to use and to determine whether strabismus is associated with binocular inhibition in extreme cases. DESIGN Case-control study. SETTING University-based eye institute. PARTICIPANTS Strabismic patients recruited during 2010 to 2012 from a preoperative clinic and control participants with no history of eye disease other than refractive error. INTERVENTION A battery of psychophysical and electrophysiological tests including Early Treatment Diabetic Retinopathy Study visual acuity, Sloan low-contrast acuity (LCA) (2.5% and 1.25%), Pelli-Robson contrast sensitivity, and sweep visual evoked potential contrast sensitivity. MAIN OUTCOME AND MEASURE Binocular summation was calculated as the ratio between binocular and better-eye individual scores. RESULTS Sixty strabismic and 80 control participants were prospectively examined (age range, 8-60 years). Mean BiS was significantly lower in the strabismic patients than controls for LCA (2.5% and 1.25%, P = .005 and <.001, respectively). For 1.25% LCA, strabismic patients had a mean BiS score less than 1, indicating binocular inhibition (ie, the binocular score was less than that of the better eyes monocular score). There was no significant difference in BiS for contrast thresholds on Early Treatment Diabetic Retinopathy Study visual acuity, Pelli-Robson contrast sensitivity, or sweep visual evoked potential contrast sensitivity. Regression analysis revealed a significant worsening of BiS with strabismus for 2.5% (P = .009) and 1.25% (P = .002) LCA, after accounting for age. CONCLUSIONS AND RELEVANCE Strabismic patients demonstrate subnormal BiS and even binocular inhibition for LCA, suggesting that strabismus impairs visual function more than previously appreciated. This may explain why strabismic patients who are not diplopic close 1 eye in visually demanding situations. This finding clarifies the visual deficits impacting quality of life in strabismic patients and may represent a novel measure by which to evaluate and monitor function in strabismus.

Binocular visual function in patients with Boston type I keratoprostheses.

Purpose: To report the postoperative binocular function of patients with Boston type I keratoprostheses implantation for unilateral visual impairment. Methods: Seventeen patients who underwent implantation of a Boston type I keratoprosthesis and had a best-corrected visual acuity better than 20/50 in the contralateral eye before surgery were evaluated. All subjects prospectively underwent sensory testing of binocular function including Bagolini lenses, Worth-4-dot test, stereoacuity at distance and near, and double Maddox rods. In addition, an assessment of ocular rotations and alignment was performed on each subject. Results: Twenty patients with best-corrected visual acuity better than 20/50 in the contralateral eye at the time of keratoprothesis surgery were identified. Seventeen of the 20 patients underwent binocular visual testing, with 16 of 17 (94%) demonstrating binocular function. Second-degree fusion at near was demonstrated via the Worth-4-dot test in 13 of 17 (76%) patients. Third-degree fusion at near was demonstrated in 7 of 17 (41%) patients. Patients with better postoperative sensory binocular function tended to be of younger age (P = 0.05) and have better postoperative visual acuity (P = 0.006). Five patients were found to have some degree of ocular misalignment. Overall, patients with strabismus had worse binocularity (P = 0.04). Conclusions: Implantation of the Boston type I keratoprosthesis in patients with good preoperative visual acuity in the fellow eye is associated with useful binocular function in greater than 90% of patients.

Surgical treatment of strabismus secondary to glaucoma drainage device.

OBJECTIVE To describe surgical strategies in a series of patients with diplopia following implantation of a glaucoma drainage device. METHODS Retrospective review of 9 consecutive patients who underwent strabismus surgery because of strabismus and diplopia after implantation of a glaucoma drainage device. RESULTS Seven patients with marked limitation to ocular rotations and incomitant strabismus underwent surgery on the eye with the implant. Two patients with mild limitation to ocular rotations of the involved eye underwent surgery on the contralateral eye. All patients had a large fibrous capsule surrounding the implant plate, adjacent muscles, and sclera. Intraocular pressure was not elevated postoperatively. Postoperative diplopia in the primary position was eliminated in 5 patients and markedly improved in 3 patients. CONCLUSIONS Strabismus following implantation of a glaucoma drainage device is an uncommon but serious complication. Restoration of ocular alignment is a complex undertaking requiring strabismus and glaucoma surgical expertise. Multiple surgical complications may occur. Surgical intervention may require complete removal of the fibrous capsule surrounding the implant and involved adjacent structures. Size reduction of the implant plate is helpful and did not interfere with postoperative intraocular pressure control in this study. Surgery on the contralateral eye is an option in patients with mild restriction.

Abducens nerve ocular neuromyotonia following non-sellar or parasellar tumors.

Ocular neuromyotonia is an uncommon disorder resulting from episodic involuntary discharge of ocular motor nerves producing sustained contraction of their respective ocular muscles. Ocular neuromyotonia manifests in brief spells of diplopia occurring spontaneously or after eccentric gaze holding. In most cases, ocular neuromyotonia follows months or years after radiotherapy to the sellar and parasellar region and involves the oculomotor nerve. We report two unusual cases of abducens nerve ocular neuromyotonia that followed radiation therapy of tumors in areas other than the sellar or parasellar region.

Postoperative Drift in Patients with Thyroid Ophthalmopathy Undergoing Unilateral Inferior Rectus Muscle Recession

ABSTRACT Background: Extraocular muscles of patients with thyroid ophthalmopathy (TO) may respond differently to strabismus surgery than those of other strabismic patients. This study reports postoperative alignment changes in patients with TO compared with patients with non-restrictive strabismus following unilateral inferior rectus muscle recession (IRR). Methods: We reviewed records of patients with and without TO who underwent unilateral IRR. Group A had adjustable muscle sutures, while Group B had permanent or semi-adjustable sutures. Controls were patients undergoing adjustable unilateral IRR for other indications. Results: Mean preoperative hypotropias were 17 ± 9, 21 ± 7, and 11 ± 4 PD for groups A (n = 13), B (n = 14), and controls (n = 19), respectively. Postoperative day one (POD1) measurements after adjustment were 1.2 ± 2.5, 3.7 ± 4.9, and 0.3 ± 2.4 PD, respectively, representing overall undercorrections in all cases (the preoperative deviation was given a positive (+) value and overcorrections were deemed negative (−) deviations). Dose response from linear regression analysis of thyroid patients compared with control patients for IRR was 3.26 PD/mm (SE 0.18) vs 2.38 PD/mm (SE 0.18) (p = 0.001). Mean final measurements were −0.7 ± 5.6 (overcorrection), 2.7 ± 5.7, and 1.7 ± 5.7 PD of hypotropia, respectively. Final overcorrections occurred in 23%, 14%, and 16% of patients, for adjustables, permanent sutures, and control subjects, respectively. Drifts from POD1 measurements after adjustment to final measurements were −1.9 ± 4.3, −1.0 ± 4.6, and 1.4 ± 5.9 PD respectively (p = 0.05 for comparison between Group A and controls). Conclusions: TO patients with adjustable sutures drift toward postoperative overcorrection.

Assessment of torsion after superior rectus transposition with or without medial rectus recession for Duane syndrome and abducens nerve palsy

BACKGROUND Superior rectus transposition with or without medial rectus recession has been advocated for the treatment of abducens nerve palsy and esotropic Duane syndrome. Early reports have focused mainly on postoperative ocular alignment, but there is concern that superior rectus transposition may induce torsional misalignment. The purpose of this study was to evaluate torsional outcomes after superior rectus transposition surgery using prospective preoperative and postoperative torsional assessments. METHODS Prospective measurements were performed on all patients undergoing superior rectus transposition. Preverbal infants were assessed using fundus torsion evaluating the position of the fovea relative to the optic nerve; older children/adults underwent double Maddox rod (DMR) assessment of torsion. RESULTS A total of 11 subjects met the study inclusion criteria. The etiology of strabismus was an abducens nerve palsy (n = 7) or Duane syndrome (n = 4). For the subjects evaluated by fundus torsion (n = 4), there was no significant change in torsion for 3 (75%). For those subjects undergoing DMR (n = 7), there was a significant change in subjective torsion (4.7 ± 3.8°excyclotorsion vs 0.0° ± 5.0° excyclotorsion; P = 0.004). Esotropic deviation improved significantly for all subjects (39(Δ) ± 23(Δ) vs 6.5(Δ) ± 13(Δ); P = 0.001) and no significant mean vertical deviation postoperatively, although 1 patient had a clinically significant postoperative hypertropia measuring 14(Δ). Abduction also improved significantly (-4.2 ± 0.9 vs -2.8 ± 1, P = 0.0001). CONCLUSIONS In this patient series, superior rectus transposition with medial rectus recession did not have clinically significant induction of torsional diplopia as a result of the procedure.