Rectus Muscle Surgery Research Articles

Hornhautendothelzellzahl nach Augenmuskeloperationen an zwei und mehr geraden Augenmuskeln

The short-term impact of eye muscle surgery on the blood-aqueous barrier has been described by iris fluoresceinangiography and laser tyndallometry. The aim of this study was to investigate the long-term effects of eye muscle surgery on the oxygen supply of the anterior segment of the eye by determination of the corneal endothelial cell density. We investigated the corneal endothelial cell density of 32 patients with unilateral rectus muscle surgery pre- and postoperatively (24 cases of primary surgery on 2 horizontal muscles, 4 revision surgeries on 2 horizontal muscles, and 4 primary eye muscle surgeries on the 2 vertical recti including: 3 transpositions of the lateral halves of the vertical recti additional to recession of the medial rectus and one complete transposition of the two vertical recti). Exclusion criteria were previous intraocular surgery and retinal detachment surgery. Mean age at surgery was 37.5 +/- 16.3 (14.5 to 79.9) years. Mean follow-up time was 5.0 +/- 2.2 (1.9 to 10.1) months. The corneal endothelial cell density (CECD) was quantified by means of a specular microscope (EM-1000, Tomey). The intraocular difference in CECD was not statistically significant either pre- or postoperatively. Mean values were 84 +/- 297 (731 to 700) vs. 52 +/- 357 (600 to 800), p = 0.64. In the subgroups of patients with revision surgery and those with primary eye muscle surgery involving the vertical recti, there was also no significant intraocular difference of CECD. Based on the corneal endothelial cell density, there was no evidence of a chronically decreased oxygen supply of the anterior segment even after complex eye muscle surgery.

The Role of Botulinum Toxin A in Augmentation of the Effect of Recession and/or Resection Surgery

The aim of this study is to assess the effectiveness of intraoperative botulinum toxin A (BTA) injection as an adjunct to the surgical treatment of large-angle esotropia or exotropia. Ten patients were included in the study. Mean age of the patients was 27+/-20 years. Of these 10 patients, 7 were esotropic and 3 exotropic. The average preoperative esodeviation was 73.6+/-16.5 prism diopters and exodeviation was 76.7+/-5.8 PD. Five units of BTA were injected intraoperatively into one of the recessed horizontal rectus muscles in all of the patients. The average follow-up was 14+/-10 months (range, 8 to 40 months). The average final deviation in the esotropia group was 13+/-9.6 PD of esotropia. The average final deviation in the exotropia group was 4.7+/-5 PD of exotropia. The final deviation of the 70% patients was within 10 PD of esotropia or exotropia. The results of this study suggest that the combination of BTA injection with recession may increase the expected correction of a conventional horizontal rectus muscle surgery.

Changes of the Lid Fissure After Surgery on Horizontal Extraocular Muscles

To evaluate the effect of isolated medial and lateral rectus muscle surgery on eye lid position. Prospective, interventional case series. We recruited 36 patients with strabismus with surgery performed on one horizontal extraocular muscle only. The width of the lid fissure and the position of the upper and lower lids in relation to the pupil center were measured before and 3 months after surgery. Regression analysis was used to evaluate the surgical effect. Recessions induced a widening of and resections a narrowing of the lid fissure, mainly because of changes of the lower lid position. The effect was statistically significant (change in lid fissure width, = 0.13 x surgical dose in millimeters; r(2) = .35; P = .0001). Patients should be informed about changes in lid fissure width after operations on horizontal extraocular muscles. If adequately integrated into the surgical plan, this side effect may alleviate pre-existing interocular differences in lid configuration.

Strabismus Surgery Under Augmented Topical Anesthesia

Recently, topical lidocaine 2% jelly had been used in phacoemulsification and trabeculectomy surgeries. The purpose of this study is to evaluate the efficacy and stability of one-stage adjustable suture using topical lidocaine jelly 2% in combination with intravenous nalbuphine (Nubain). Forty adult patients aged 16 to 46 years (median, 24 years) underwent adjustable rectus muscle surgery under topical lidocaine jelly 2% and intravenous 10 mg nalbuphine given 10 minutes before surgery. Adjustment was performed on the operating table before conjunctival closure. The stability of adjustment was studied by comparing the postadjustment deviation to that at 1 day, 1 week, and 3 weeks postoperatively. Success was defined as alignment within 10 prism diopters on distant fixation. Analgesia was assessed using Verbal Description Scale. Changes in vital signs were recorded during surgery to evaluate the oculocardiac reflex. Forty rectus muscles were recessed, 22 muscles were resected, 3 muscles were tucked, and 2 muscles were retrieved. During the operation, 35 patients expressed no pain, 3 patients complained of discomfort, and 2 patients complained of distressing pain and required an additional 10 mg of intravenous nalbuphine. Thirty-eight patients (95%) were successfully aligned during the first postoperative day, 37 patients (92.5%) after 1 week, and 36 patients (90%) after 3 weeks. Intraoperative cardiac monitoring did not record positive oculocardiac reflex in any patient. Lidocaine jelly in combination with intravenous nalbuphine is an effective topical anesthesia strategy that provides for the patient's comfort and the surgeon's ability to fine-tune ocular alignment on the operating table.

Vertical Deviations Improved With Release of Postoperative Inferior Oblique Muscle Inclusion

In repeat surgery involving the horizontal extraocular muscles, it is frequently noted that the anterior fibers of the inferior oblique muscle are inadvertently caught in the lateral rectus muscle insertion. It is theorized that releasing the IO muscle inclusion (IOI) will decrease the total amount of vertical deviation associated with the horizontal misalignment in primary position. The current study shows the impact of this release on the vertical deviation. A retrospective noncomparative analysis was used to evaluate the impact of eliminating the IOI. The subjects were 45 patients with residual horizontal strabismus found to have IOI at the time of surgery. Each patient was managed with release of the entrapped muscle along with the appropriate horizontal muscle surgery. Release of the IOI muscle reduced the ipsilateral vertical deviation an average of 3.5 PD ( P > 0.001) in cases of hypotropia and 5.8 PD ( P > 0.001) in patients with hypertropia, with stability of alignment for a minimum of 2 years. Inadvertent IOI is commonly encountered in reoperative strabismus for horizontal deviations, involving partial or complete capture of the IO muscle fibers at the time of original lateral rectus muscle surgery. It is concluded that the simple release of the IO muscle fibers included in the attachment of the lateral rectus muscle will have a significant impact on reducing the vertical deviation and may avoid the need for additional vertical muscle surgery.

Clinical features and surgical treatment of congenital ocular muscle palsy characterized with double elevator dysfunction

To investigate the clinical features of congenital ocular elevator muscle palsy and to evaluate the efficacy of surgical treatment. Pre- and post-operative eye position, superior rectus muscle and inferior oblique muscle function, clinical features were examined and analyzed in 11 patients with congenital double elevator palsy of ocular muscles. When fixated with the nonparetic eye, ten of 11 patients showed hypotropia and pseudoblepharoptosis in the primary position; One of 11 patients fixated with the paretic eye and showed hypotropia in the primary position. All cases were a monocular elevation deficiency in abduction and adduction, and showed pseudoblepharoptosis. In ten patients fixated with the nonparetic eye, two of 10 were undergone inferior rectus recession on paretic eyes; six of 10 were undergone inferior rectus recession and superior oblique tenectomy on paretic eyes; two of 10 were applied inferior rectus recession and superior oblique tenectomy on paretic eyes, superior rectus recession was performed on healthy eyes in six months postoperation. The patient fixated with the paretic -eye were undergone superior rectus recession and inferior oblique tenectomy on healthy eyes. Seven patients with exotropia had lateral rectus muscle surgery performed at the time of their vertical operation. Strabismus were complete corrected in 81.8% (9/11) of patients in our study and 18.2% (2/11) of patients were partial corrected. The functions of superior rectus muscle and inferior oblique muscle were not corrected. Nine patients showed complete correction of the psuedoptosis, one patient showed partial correction of the psuedoptosis, one patient did not showed any improvement of the pseudoptosis. We conclude that superior rectus muscle and inferior oblique muscle insufficiency are the primary factors in the etiology of congenital double ocular elevator palsy. Vertical rectus recession and superior oblique tenectomy on paretic eyes is an effective way of surgical treatment the disease.

Vertical rectus muscle surgery for nystagmus patients with vertical abnormal head posture

Purpose To characterize the results of vertical rectus muscle recession, or recession and resection surgery for vertical abnormal head posture (VAHP) due to null-point nystagmus. Method This is a retrospective, noncomparative, consecutive case series of patients who underwent vertical rectus muscle recession alone, recession then resection, or combined recession/resection surgery for VAHP due to null-point nystagmus. The primary outcome measure was the amount of residual VAHP. Results Twenty patients with VAHP due to null-point nystagmus were studied. The mean follow-up interval after surgery was 49 months (median: 44 months; range 9 to 124 months). Preoperative VAHP ranged from 10° to 45°, and the total amount of bilateral vertical rectus muscle recession, or recession and resection surgery, ranged from 8.5 to 20.0 mm per eye. After recession alone, 5/11 had residual VAHP ≤ 5°. The remaining six underwent subsequent resection or plication for residual VAHP > 10° that resulted in residual VAHP ≤ 5° in each case. After combined recession/resection, 6/9 had residual VAHP ≤ 5° and the remaining three had VAHP < 10°. Conclusion Large amounts of vertical rectus muscle surgery are indicated to successfully correct the VAHP associated with nystagmus with a vertical null point. Combined recession/resection of the appropriate vertical rectus muscles, instead of recession alone, appears to be a more effective procedure.

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 Duane's 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 Duane's 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) Duane's 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.

Accessory lateral rectus muscle in a patient with congenital third- nerve palsy

Purpose To report a case of accessory lateral rectus muscle in a patient with congenital third-nerve palsy. Design Observational case report. Methods An 18-year-old boy with left exodeviation, ptosis, pupil dilation, and limited adduction, supraduction, and infraduction of his left eye. Left lateral rectus muscle recession and medial rectus muscle resection were done. An orbital computed tomographic (CT) scan was obtained. Result Intraoperatively, an accessory muscle was found under the lateral rectus muscle. Postoperatively, the orbital CT scan showed accessory lateral rectus muscle located in the medial side of the lateral rectus muscle. Conclusion Accessory lateral rectus muscle was demonstrated in a patient with congenital third-nerve palsy using lateral rectus muscle surgery and an orbital CT scan.

Astigmatism induced by simultaneous recession of both horizontal rectus muscles.

Changes have been reported in the refractive state of the eye after various types of strabismus surgery. This study investigates the effect of large simultaneous recession of both horizontal rectus muscles on the refractive state of the eye. Twenty-six eyes (13 patients) were refracted 1 to 2 weeks before and 6 to 8 weeks after large horizontal rectus muscle recessions for the purpose of damping nystagmus. The preoperative refraction was mathematically subtracted from the postoperative refraction, and the induced refractive changes were averaged and statistically analyzed. The relation between the amount of recession and the induced astigmatism was also investigated. A statistically significant change in astigmatism in the with-the-rule direction was induced with this procedure (+ 0.70 diopter cylinder, axis 90.0 degrees, P <.0002). With the narrow range of amounts of recession performed, there was no demonstrable relation between the amount of recession and the amount of induced astigmatism. Recession of both horizontal rectus muscles, the same as has been reported for recession of one horizontal rectus muscle and recession-resection surgery on both horizontal rectus muscles, tends to induce a change in astigmatism in the with-the-rule direction.

Astigmatism induced by simultaneous recession of both horizontal rectus muscles

Purpose Changes have been reported in the refractive state of the eye after various types of strabismus surgery. This study investigates the effect of large simultaneous recession of both horizontal rectus muscles on the refractive state of the eye. Methods Twenty-six eyes (13 patients) were refracted 1 to 2 weeks before and 6 to 8 weeks after large horizontal rectus muscle recessions for the purpose of damping nystagmus. The preoperative refraction was mathematically subtracted from the postoperative refraction, and the induced refractive changes were averaged and statistically analyzed. The relation between the amount of recession and the induced astigmatism was also investigated. Results A statistically significant change in astigmatism in the with-the-rule direction was induced with this procedure (+ 0.70 diopter cylinder, axis 90.0°, P < .0002). With the narrow range of amounts of recession performed, there was no demonstrable relation between the amount of recession and the amount of induced astigmatism. Conclusions Recession of both horizontal rectus muscles, the same as has been reported for recession of one horizontal rectus muscle and recession-resection surgery on both horizontal rectus muscles, tends to induce a change in astigmatism in the with-the-rule direction.

Strabological results in patients with macular translocation surgery and counterrotation of the globe as a secondary procedure

INTRODUCTION Age-related macular degeneration is the most common cause of irreversible loss of visual acuity, including the ability to read, in elderly patients. One of the surgical treatment options is macular translocation with 360° retinotomy. The orthoptic results of torsional muscle surgery as a second procedure are demonstrated. MATERIALS AND METHODS Between January 1999 and December 2000, the macula was rotated upward by 12?45° in 10 eyes following complete artificial detachment and a 360°retinotomy. In these patients, torsional surgery was carried out as a second procedure. Depending on the resulting cyclotorsion, we performed surgery on the oblique muscles only in four patients with a cyclotropia of 12?20° and a combination of oblique muscle surgery with surgery of two or four rectus muscles in the remaining six eyes (cyclotropia over 21°). The pre- and postoperative diagnostic techniques included visual acuity, reading vision and the orthoptic status. RESULTS Due to the unilateral ectopia of the macula, all patients presented postoperative strabismus with a vertical deviation of 2?10° and a subjective cyclotropia between 12° and 40°. After surgery on the oblique muscles, the patients showed a residual cyclotropia of 0?6°. In patients in whom surgery on the oblique muscles was accompanied by rectus muscle surgery, the remaining cyclotorsion was 5?13°. Four patients excluded the non-operated fellow eye, six patients experienced double vision under binocular conditions and thus required prescription of additional prism glasses. CONCLUSION Macular translocation causes diplopia under binocular conditions because of the unilateral ectopia of the macular region with cyclotropia and vertical deviation. These problems can be resolved or reduced by oblique muscle surgery or in combination with additional surgery on the rectus muscles, depending on the range of the cyclotorsion. Performing the torsional surgery as a second procedure after macular rotation with an exact preoperative measurement of the subjective cyclodeviation appears to be useful.

Treatment of A-pattern Esotropia with Marked Mongoloid Slanting Palpebral Fissures

Background: The association of oblique palpebral fissures and A- or V-pattern has not been clarified. We report two cases of A-pattern esotropia with marked mongoloid slanting palpebral fissures associated with vertical displacement of the horizontal rectus muscle. Cases: Case 1 was a boy with Prader-Willi syndrome. He showed A-pattern esotropia with upward slanting palpebral fissures. Severe superior oblique muscle overaction was observed. Case 2 was a girl with meningocele. She also showed A-pattern esotropia with upward slanting palpebral fissures. Observations: In case 1, weakening surgery of the superior oblique muscles did not improve the A-pattern. Coronal images of computed tomography showed one-half-muscle-width upward displacement of both lateral rectus muscles. After downward transposition surgery of the lateral rectus muscles, the preoperative A-pattern of 25 prism diopters (PD) was successfully corrected to 10 PD. In case 2 also, upward displacement of both lateral rectus muscles was shown by computed tomography. The preoperative A-pattern of 26 PD was corrected to 4 PD postoperatively after upward transposition surgery of the medial rectus muscles. Conclusions: The vertical displacement of horizontal rectus muscles was considered the principal cause of A-pattern in these cases associated with marked mongoloid slanting palpebral fissures.

Early reoperation after vertical rectus muscle surgery

Purpose: Adjustable suture strabismus surgery has a success rate between 90% and 94%. In some patients, undesirable deviations are noted in the first week after surgery. In this article, we describe a method of reoperation in the first week of the initial repair in an outpatient clinical setting. Methods: A retrospective review of clinical records from 1990 to 1998 identified 7 patients who underwent reoperation of the original surgical procedure in a clinic setting. All patients had vertical deviations that were overcorrected and had a reversal of their diplopia. Results: Follow-up ranged from 3 months to 59 months. All patients were free of diplopia and were either orthophoric or had small phoric deviations. Conclusions: Proper identification of patients with strabismus as a result of overcorrected adjustable sutures and prompt reoperation in the first week after surgery are possible and prevent the need for repeat anesthesia in the operating suite. (J AAPOS 2001;5:217-20)

Late overcorrections in inferior rectus muscle surgery for vertical squint correction

The aim of this study was to evaluate postoperative results in 21 patients with vertical strabismus and diplopia who underwent surgery on the inferior rectus. Postoperative results were obtained 1, 3, and 6 months after surgery. We concluded that inferior rectus recession may have unpredictable outcome despite the use of adjustable sutures. Whenever surgery on this muscle is considered, patients must be left undercorrected to avoid late overcorrections.

Anterior transposition of the superior oblique tendon in the treatment of oculomotor nerve palsy and its influence on postoperative hypertropia.

To determine whether postoperative hypertropia after anterior transposition of the superior oblique tendon without trochleotomy could be avoided with a simplified surgical approach. Eight patients with oculomotor nerve palsy (one patient was bilaterally affected) were retrospectively identified as having undergone anterior transposition of the superior oblique tendon without trochleotomy or vertical rectus muscle surgery between March 1992 and September 1998. The superior oblique tendon was cut at the medial border of the superior rectus muscle and placed 1-3.5 mm anterior to the medial insertion of the superior rectus muscle in each of these patients. Resection of the superior oblique tendon was not performed. The lateral rectus muscle was weakened, and no vertical rectus muscles were resected. Preoperative deviations with the uninvolved eye fixating in primary position ranged from 20-90 prism diopters (delta) of exotropia (mean: 49.3 delta) and from 0-20 delta of hypotropia (mean: 11.25 delta). Postoperative horizontal deviations in the primary gaze position ranged from 12 delta of exotropia to 20 delta of esotropia. Six cases were aligned within 10 delta of exotropia or esotropia. Postoperative vertical deviations in the primary gaze position ranged from 2 delta of hypertropia to 8 delta of hypotropia. Six cases were aligned within 2 delta of deviation. Significant postoperative restrictive hypertropia, or new postoperative paradoxical ocular movements, did not occur in any patient. Patients who underwent follow-up >4 months maintained stable eye alignment. Transposition of the superior oblique tendon without simultaneous resection or trochleotomy, or additional surgery to the vertical rectus muscle simplifies the surgical technique and eliminates subjective decision making regarding the amount of resection.

Strabismus surgery under subconjunctival anesthesia: technique and evaluation by patient and his surgeon

In adults, eye muscle surgery can be performed under local anesthesia without retrobulbar injection. We wanted to know how patients and surgeons perceive this procedure. 50 patients and 3 surgeons were interviewed with a questionnaire after operation on one or two straight eye muscles, including revisions in 11 cases. The patients were sedated with benzodiazepines. The conjunctiva was anesthetized with tetracaine eye drops. During the operation, mepivacaine was irrigated under the muscle insertion using a blunt needle. The patients perceived little or no pain during the operation. This corresponded to the surgeon's judgement. 96% of the patients would prefer local over general anesthesia in case of a second operation. The technique can be recommended for surgery of rectus muscles in adults, even in the case of revision.

The results of adjustable suture technique in paediatric strabismus surgery.

Adjustable suture technique (AST) has been shown to be an effective treatment method in adult strabismus. The application of AST is not well studied in children due to potential poor cooperation during adjustment and the concern that the adjustment process can not be completed. The present series evaluates the efficacy and safety of this technique in a preselected group of children between 7 and 15 years of age. A retrospective review of 89 consecutive children undergoing AST was completed to assess: (1) the ability to perform and complete adjustment in children; (2) the frequency of need to perform adjustment; and (3) accuracy of surgical alignment. Only patients with horizontal rectus muscle surgery were included. All children successfully completed the AST on the first post-operative day. Of the 89 patients, 24 (27%) required further adjustment by the AST. The mean follow-up period was 13.1 months. Fifty-three patients (60%) had previous strabismus surgery (range 1 to 5 operations). Sixty-six (74%) patients achieved successful alignment. Complications included slipped muscles in 1 case and difficulty in recession of the lateral rectus muscle in 1 patient. Twenty-seven per cent of the patients required post-operative adjustment. The AST achieved an overall 74% successful alignment. Application of the AST should be considered in children with horizontal deviations over age 7 years, especially in the reoperations of esotropia.

Bilateral recession of superior rectus muscles: Its influence on A and V pattern strabismus

Purpose: To determine whether bilateral superior rectus recession modifies A and V pattern strabismus. Patients and Methods: Three patients with V patterns and eight patients with A patterns underwent bilateral superior rectus recession with neither oblique muscle surgery nor vertical displacement of the horizontal rectus muscles. Another three patients with A patterns underwent simultaneous superior oblique tenotomy and superior oblique recession. Results: Two of the patients with V patterns demonstrated an increase in the V pattern after surgery; one was unchanged. Five of the patients with A patterns converted to V patterns after surgery. In the remaining three patients the pattern was eliminated. The three patients who underwent superior oblique tenotomy along with superior rectus recession had large shifts toward V pattern (mean shift, 40 Δ). Conclusion: Bilateral superior rectus recession tends to increase V patterns and reduce A patterns. Superior rectus recession may be synergistic with superior oblique tenotomy in collapsing an A pattern.

Rectus muscle recession and resection without scleral sutures

Purpose: To eliminate the risk of scleral perforation during strabismus surgery in susceptible patients, we introduce a technique to allow predictable rectus muscle recession and resection without the placement of scleral sutures. Methods: Three patients with thin sclera underwent rectus muscle surgery by use of a double-arm suture technique that avoids placement of sutures directly into the sclera. Two of the patients had esotropia and underwent bilateral lateral rectus muscle resections and a unilateral recess/resect operation, respectively. One of the patients had exotropia and underwent bilateral lateral rectus muscle recessions. Results: All three patients achieved postoperative alignment to within 15 PD of orthotropia and had no evidence of slipped or lost muscle when examined 2 months postoperatively. The appearance of the ocular surface was excellent in all three cases. Conclusions: Predictable and secure rectus muscle recession and resection can be performed without the placement of scleral sutures in patients in whom scleral suturing may be hazardous.