Vertical transposition of the horizontal recti (Knapp procedure) for the treatment of double elevator palsy: effectiveness and long-term stability

Observation on the curative effect of horizontal rectus transposition combining recess-resect treatment on monocular elevation deficiency with horizontal strabismus

Purpose

To explore the clinical effect of horizontal rectus transposition combining recess and resect treatment on monocular elevation deficiency (MED) with horizontal strabismus.

Methods

Ten patients (10 eyes) scheduled to undergo horizontal rectus transposition combining recess-resect surgery to treat MED with horizontal strabismus in the ME Department of Ophthalmology of the First Affiliated Hospital of Guangxi Medical University between July 2016 and February 2022 were included in the study. The degree of vertical and horizontal prism strabismus, the grading of upper movement of the paralyzed eye, and the improvement of binocular vision were evaluated before and after the surgery.

Results

Horizontal rectus transposition combined with recess and resect treatment was used to treat 10 patients with MED combined with horizontal strabismus. A good curative effect was seen in eight patients. The differences in the degree of vertical strabismus, the degree of horizontal strabismus, and the movement function of the paretic eyes before and after surgery were significantly different (all P < 0.05). The binocular haplopia function in six patients was reconstructed in the primary position after surgery.

Conclusion

Horizontal rectus transposition combining recess-resect is easy to perform, and the number of recti involved in the surgery is small. This approach can effectively correct the eye position, improve eye movement, and reconstruct binocular vision in patients with MED by combining horizontal strabismus.

Combined Rectus Muscle Transposition With Posterior Fixation Sutures (Augmented Knapp Procedure) for the Surgical Treatment of Double Elevator Palsy

PURPOSE

To evaluate the surgical results of full horizontal tendon rectus muscle transposition to the superior rectus muscle insertion, augmented by posterior fixation sutures, in patients with double elevator palsy.

METHODS

In this retrospective comparative study, 17 patients treated by the augmented Knapp procedure (study group) were compared with 28 patients treated by the standard Knapp procedure (control group). Pre-operative and postoperative vertical deviation in primary position, ocular motility, binocular function, and rate of reoperation were evaluated.

RESULTS

The mean preoperative near and distance deviations (hypotropia) decreased by 93% and 97% in the study group and 68% and 69% in the control group, respectively. The improvement in near and distance deviation was statistically more significant in the study group than the control group (P = .001 for each parameter). The mean preoperative elevation deficiency in abduction and adduction improved by 64% and 66% in the study group and 37% and 39% in the control group, respectively. The improvement in elevation deficiency in abduction and adduction was statistically significantly greater in the study group than the control group (P = .001 and .04, respectively). Reoperation was required in 15 patients (54%) in the control group and 2 (12%) in the study group during the follow-up period of 26 ± 4 months.

CONCLUSIONS

The postoperative improvement in near and distance deviation and elevation deficiency in abduction and adduction was significantly better in the augmented Knapp procedure than the standard Knapp procedure. This procedure demonstrated a stronger effect in the treatment of double elevator palsy. [J Pediatr Ophthalmol Strabismus. 2022;59(1):17-23.].

Single horizontal rectus muscle vertical augmented transposition with posterior fixation suture in management of monocular elevation deficiency

We describe successful management of three cases of acquired monocular elevation deficiency (MED) with superior transposition of the lateral rectus augmented with a posterior fixation suture with or without simultaneous inferior rectus muscle weakening. In each case, the lateral rectus muscle was transposed superiorly to the superior rectus muscle along the spiral of Tillaux, with maintained distance between the original lateral rectus muscle poles and the limbus. Augmentation was achieved with a posterior fixation suture 8 mm posterior to the muscles' insertion. At the time of lateral rectus transposition, simultaneous inferior rectus recession by 5.5 mm was performed in case 1 whereas simultaneous botulinum toxin injection was performed in case 3. With regards to all three cases, the mean age was 32 years [10-46 years] and the mean follow-up period was 10 months. The mean hypotropia was reduced from 35 prism diopters (PD) (range: 20 to 60 PD) to 4.67 PD (range: 0 to 14 PD) with a mean correction of 32.57 ± 9.34 PD after 9 months. In our experience, full-tendon-width transposition of the lateral rectus to the superior rectus with posterior fixation suture corrects primary position hypotropia in MED and does not always require simultaneous inferior rectus recession. When transposing the lateral rectus muscle along the spiral of Tillaux, the measured distance of the original muscle insertion point to the limbus must be maintained in order to prevent recession of the muscle.

Comparison of different tendon transposition techniques for the treatment of monocular elevation deficiency type 2

PURPOSE

To compare results of three different tendon transposition techniques (Knapp procedure and two modified techniques) for the treatment of type 2 monocular elevation deficiency (MED) patients.

METHODS

The medical records of patients with MED type 2 operated on at a single institution from 2000 to 2016 were reviewed retrospectively. Patients were divided into three vertical transposition groups: (1) full tendon width, (2) augmented surgery; and (3) partial tendon width. Surgical success was defined as no severe limitation of upgaze, hypotropia of <6^Δ, and no hypertropia in primary position. Pre- and postoperative vertical deviations in the primary position and limitations in elevation levels were compared.

RESULTS

A total of 39 patients were included. The pre- and postoperative deviations in the full-tendon group were 22.50^Δ ± 4.17^Δ and 3.50^Δ ± 1.27^Δ, respectively; in the augmented surgery group, 23.75^Δ ± 4.78^Δ and 1.75^Δ ± 1.14^Δ; and in the partial-tendon group, 20.50^Δ ± 3.98^Δ and 4.12^Δ ± 2.78^Δ. Corrected vertical deviations were 19^Δ, 23^Δ, and 16^Δ, respectively. The pre- and postoperative limitation of elevations were -2.80 and -0.80 in the full-tendon group, -3.20 and -0.90 in the augmented surgery group, and -2.37 and -1.12 in the partial-tendon group. The pre- and postoperative vertical deviation improvements and limitations of elevation were statistically significant (P < 0.05) in all groups. Success was achieved in 29 patients (74%).

CONCLUSIONS

In this study cohort, all three procedures were reasonably effective in improving vertical deviations and limitation of elevation.

Single Horizontal Muscle (Medial or Lateral Rectus) Transposition and Inferior Rectus Recession in Monocular Elevation Deficit: A Novel Surgical Technique

PURPOSE

To describe a novel surgical technique for the treatment of monocular elevation deficit and report its short-term outcomes.

METHODS

This was a prospective interventional case series. It was an institutional-based study of 5 patients with monocular elevation deficit. A single horizontal rectus muscle was transposed to 2 mm from the insertion of the superior rectus muscle along the spiral of Tillaux, augmenting it with a non-absorbable suture taken 8 mm behind its insertion. The main outcome measures were primary position hypotropia and elevation deficit at 8 months postoperatively.

RESULTS

The mean age was 12.4 years (range: 6 to 26 years). Four patients underwent lateral rectus transposition and one underwent medial rectus transposition. Inferior rectus recession was done in all patients. The mean follow-up period was 8 months (range: 6 to 12 months). The mean hypotropia reduced from 34.6 prism diopters (PD) (range: 20 to 48 PD) preoperatively to 0.8 PD (range: -4 to 8 PD) at 8 months postoperatively. Additionally, 3 patients had exotropia with a mean of 12 PD (range: 2 to 20 PD) and 2 had esotropia with a mean of 28.5 PD (range: 12 to 40 PD); 1 underwent lateral rectus recession and 1 medial rectus recession. Three patients did not require any horizontal muscle surgery. The mean elevation deficit in abduction, straight up gaze, and adduction improved from 4.4, 3.2, and 2.8 to 2.0, 2.0, and 1.8, respectively. The mean depression deficit was 0.5. No adverse effects were noted.

CONCLUSIONS

Single horizontal muscle transposition with inferior rectus recession allows sparing of at least one horizontal muscle and achieves adequate elevation effect and primary position deviation correction, at least in the short-term follow-up. [J Pediatr Ophthalmol Strabismus. 2019;56(3):183-187.].

Surgical Management in Type 1 Monocular Elevation Deficiency

PURPOSE

To evaluate the outcome of surgical treatment in patients with type 1 monocular elevation deficiency.

METHODS

Patients who were diagnosed as having type 1 monocular elevation deficiency by forced duction test and exaggerated traction test between 2000 and 2016 were retrospectively reviewed. Epidemiologic and clinical features of the patients were noted. The efficacy of ipsilateral inferior rectus recession to vertical misalignments and limitation of elevation were evaluated. The clinical features of the patients who did not achieve surgical success after inferior rectus recession were determined. The surgical and functional results of contralateral superior rectus recession were evaluated for patients who had residual hypotropia under inferior rectus recession.

RESULTS

Thirty-nine patients were included in the study. Preoperatively, vertical deviations were 20.53 ± 4.50 prism diopters (PD) for near and 22.21 ± 5.12 PD for distance. After inferior rectus recession, the amount of vertical deviation corrected was 15 ± 1.14 PD for near and 17.01 ± 2.00 PD for distance. Ten (25.64%) patients did not achieve surgical success (> 6 PD residual hypotropia). Nine patients (preoperative inferior rectus recession measurements = 28.77 ± 7.25 PD for near and 27 ± 7.44 PD for distance) underwent contralateral superior rectus recession as a second surgery. After contralateral superior rectus recession, 7 of 9 (77.78%) patients achieved surgical success. The limitation of elevation significantly improved after both surgeries (Wilcoxon test, P < .05). No diplopia or other complications after surgeries were reported.

CONCLUSIONS

Inferior rectus recession is the first surgical option for patients with type 1 monocular elevation deficiency. Contralateral superior rectus recession is an effective alternative surgical treatment for residual hypotropia after ipsilateral inferior rectus recession. [J Pediatr Ophthalmol Strabismus. 2018;55(6):369-374.].

Clinical features and surgical treatment of double elevator palsy in young children

AIM

To describe the clinical features of congenital double elevator palsy (CDEP) and to evaluate various surgical outcomes between the standard Knapp and augmented Knapp procedures, based on improvements in primary eye position and ocular motility.

METHODS

Twenty-two patients with CDEP at Shanghai Children's Hospital were enrolled from July 2014 to January 2018. The forced duction test (FDT) was negative in 21 patients, aged 8mo to 12y (mean 5.4y). Patients were divided into two treatment groups: 16 patients underwent the standard Knapp procedure (group A), with or without horizontal squint procedure; and 5 patients underwent the augmented Knapp procedure (Foster procedure; group B). One patient underwent inferior rectus recession in the affected eye and superior rectus recession in the sound eye because of a positive FDT. The pre- and postoperative vertical deviations in the primary position and ocular motility were compared in the two groups.

RESULTS

Twenty-one eyes of the 22 patients (95%) were aligned within 10 prism diopters (PD), and all patients (100%) reached ≥25% elevation improvement after surgery. The average corrected vertical deviation in group B was statistically better than that of group A. For group A, the vertical deviation in the primary position decreased from 24.75Δ±8.35Δ to 4.56Δ±8.07Δ after surgery, for an improvement of 23.06Δ±6.51Δ (P<0.05). In group B, the decrease was from 35.00Δ±5.00Δ (range 30Δ-40Δ) to 1.00Δ±2.24Δ, for an improvement of 34.00Δ±4.18Δ (P<0.05). There were significant differences between the pre- and postoperative elevation in each group (group A, P<0.05; group B, P<0.05). The average scale of improved elevation in group B (1.80±0.45) was not significantly better than that of group A (1.69±0.87; Z=-0.732, P=0.548). The average follow-up periods lasted 21mo in group A and 18mo in group B.

CONCLUSION

For vertical deviations <30Δ, the standard Knapp procedure can be chosen. For deviations greater than 30Δ-40Δ, the Foster procedure should be chosen. Because of our early interference, the inferior rectus (IR) muscle did not show mechanical restriction. Monocular elevation deficiency (MED) should be diagnosed early so that complications will be reduced and the procedure will be easier for the surgeon.

Modified Nishida's procedure for monocular elevation deficiency

Monocular elevation deficiency (MED) is a frequent cause of hypotropia. Knapp's procedure is a well-documented and established procedure for treating MED. Modified Nishida's procedure (no split-no tenotomy transposition) has been described as equivalent to vertical rectus transposition in abducens nerve palsy. We report our results using the latter procedure in 3 cases of MED.

To assess the efficacy of vertical muscle surgery for management of hypotropia in monocular elevation deficiency type II

AIM

To assess the efficacy of vertical muscle surgery for management of hypotropia in monocular elevation deficiency (MED) type II. Knapp's is described as standard procedure for management of MED type II. However, it is not graded and has unpredictable amount of correction. Besides this, there is drift towards overcorrection with time and limitation of movements in extreme adduction and abduction. MED is a vertical misalignment for which vertical muscle surgery is also described but limited literature is available.

METHODS

Thirteen fresh cases of MED type II with hypotropia >20 PD and age >4 years were included in our interventional study. All cases underwent superior rectus resection and inferior rectus recession (vertical R&R) depending upon amount of preoperative deviation. Success was defined as hypotropia <5 PD at 1-year follow-up.

RESULTS

Twelve patients (92.30 %) were aligned to within 5 PD. Six patients (46.15 %) had gain in elevation. Bell's phenomenon was improved in six patients (46.15 %). There was no limitation in down gaze in any patient. None gained stereopsis.

CONCLUSION

Vertical R&R is a good alternative for MED type II with predictable amount of correction especially in patients with higher preoperative deviation. It spares horizontal muscles for correction of any associated horizontal deviation.

Comparison of augmented and nonaugmented modified Knapp procedure for the treatment of nonrestrictive double elevator palsies

PURPOSE

To compare surgical results of augmented and nonaugmented modified Knapp procedure, for the treatment of nonrestrictive double elevator palsies (DEP).

METHODS

The medical records of patients with congenital DEP were reviewed retrospectively. Patients were divided into three treatment groups: standard transposition (group A), Foster transposition (group B), and resection transposition (group C). Pre- and postoperative vertical deviation in primary position, ocular motility, and binocular vision were compared.

RESULTS

Thirty patients were enrolled. The pre- and postoperative deviations in group A were 34.7^Δ ± 8.6^Δ and 6.5^Δ ± 6.5^Δ; in group B, 38.6^Δ ± 14.6^Δ and 5.7^Δ ± 9.3^Δ; and in group C, 43.1^Δ ± 10.3^Δ and 8.5^Δ ± 6.1^Δ. The corrected vertical deviation of group B (32.9^Δ ± 5.7^Δ) and group C (34.6^Δ ± 5.0^Δ) were greater than that of group A (28.1^Δ ± 3.6^Δ; P = 0.03, 0.002). The pre- and postoperative measures of upgaze in group A were -3.7 and -1.8; in group B, -4.0 and -1.3; and in group C, -3.6 and -2.0. The average improved upgaze in group B (2.6 ± 0.5) was statistically significantly better than that in group A (1.9 ± 0.6) and group C (1.5 ± 0.5; P = 0.03, 0.002). There was no significant difference in the surgical effect on downgaze in three groups (P > 0.05). The surgical outcome was satisfactory in 19 (63.3%) patients with preoperative vertical devation of ≤40^Δ.

CONCLUSIONS

All transpositions are reasonably effective in treating vertical deviations of <35^Δ without obviously limiting downgaze in DEP. Augmented procedures could correct greater vertical deviation of 30^Δ-40^Δ. The Foster transposition demonstrates the strongest effect in improving upgaze.

Surgery for Supranuclear Monocular Elevation Deficiency

PURPOSE

We report a novel approach to surgery for monocular elevation deficiency (MED).

METHODS

A retrospective review of 5 patients undergoing surgery for supranuclear MED between 2003 and 2014. All patients had intact Bell's phenomenon, hypotropia, limited elevation above the primary position, and negative forced duction testing of the paretic eye. Preoperatively all patients preferred chin-up head posture and three had pseudoptosis or ptosis. One of the 5 had prior vertical muscle surgery. Surgery correction for the MED consisted of near maximal superior rectus recession on the contralateral sound eye.

RESULTS

Compensatory chin-up head position and alignment in primary position was improved in all patients. Average age at surgery was 5.3 years. Average superior rectus recession was 9.7 mm. Mean follow-up was 4.8 years (range 12 months to 11.5 years). The vertical deviation of the paretic eye in primary position postoperatively was orthotropic for 2, hypotropic for 2, and overcorrected for 1.

CONCLUSIONS

In cases of supranuclear MED (double elevator palsy) contralateral superior rectus recession based on the innervational principle is a simple and reliable alternative surgical approach compared to published results of the Knapp transposition procedure. Additionally, it holds the possibility for decreased complications and less complicated future surgical treatment options.

Monocular elevation deficiency: a case series of surgical outcome

BACKGROUND

Inferior rectus recession, Knapp procedure, partial tendon transposition, and combined procedure are different surgical procedures in the management of monocular elevation deficiency (MED). Only a few studies have been published on the management of this problem. In this study, we report our experience with patients with MED focusing on the indications and types of surgery in the south of Iran.

METHODS

In this case series, a computerized database review on 4773 patients with strabismus was performed and 18 patients diagnosed as having MED who had undergone strabismus surgery were enrolled.

RESULTS

Of the 18 patients, 13 had only hypotropia and 5 had horizontal deviation as well. Preoperative vertical deviation was between 15 and 60 prism diopter (mean±SD=25.8±10.7 PD). Fourteen patients had positive forced duction test on elevation. Seventeen patients had ptosis twelve of them had true ptosis and the remaining 5 had pseudoptosis). The mean postoperative follow-up was 24.4 months. Four patients underwent Knapp procedure, 12 patients underwent inferior rectus recession, and for 2 patients a combined procedure was performed. The mean postoperative hypotropia was 6.1±7.9 PD. Twelve out of the 18 patients were corrected to within five PD of orthophoria and no one was found with overcorrection.

CONCLUSION

Although MED is etiologically multifactorial, satisfactory surgical results can be achieved by judicious selection of the surgical technique based on the results of the forced duction test.

Surgical treatment in patients with double elevator palsy

PURPOSE

To evaluate the effectiveness of surgical treatment performed in patients with double elevator palsy (DEP).

METHODS

Patients diagnosed with congenital DEP between April 2003 and March 2007 were included in the study. The cases with positive traction test had inferior rectus (IR) recession followed by full tendon width muscle transposition Knapp surgery or partial tendon width transposition operation, while those without positive traction test underwent transposition procedure alone. Transposition surgery was combined with recession and resection of horizontal rectus muscles in patients with exotropia according to the amount of horizontal deviation. Eyelid surgery was applied in patients with ptosis following strabismus surgery.

RESULTS

The average age of 13 patients was 14+/-32.5 years (range, 3-60 years). Five patients (38%) were female and 8 patients (62%) were male. The mean preoperative hypotropia was decreased from 29.2+/-3.5 prism diopters (PD) (range, 16-45 PD) to 2.6+/-2.8 PD (range, 0-6 PD) postoperatively. The median amount of horizontal deviation in patients with exotropia (n=4) was 30 PD (range, 25-45 PD) preoperatively; it was reduced to 2 PD (range, 0-8 PD) postoperatively. Mean follow-up period was 14.1+/-2.8 months (range, 6-31 months). Five patients (38%) underwent eyelid surgery, and all achieved cosmetically satisfactory results.

CONCLUSIONS

Transposition surgery alone or combined with IR recession is an effective procedure in treatment of double elevator palsy. In patients with moderate horizontal deviations, recession and resection of horizontal rectus muscles combined with transposition provide correction of the horizontal deviation at the same time.

Congenital monocular elevation deficiency

OBJECTIVE

The pathophysiology of monocular elevation deficiency is poorly understood. The goal of this study was to determine the appearance of the extraocular muscles and the oculomotor nerve.

DESIGN

Observational case series.

PARTICIPANTS

Six patients with monocular elevation deficiency.

METHODS

Ophthalmologic examination and thin-sectioned magnetic resonance imaging (MRI) at the brainstem level as well as across the orbit in 6 patients were performed.

MAIN OUTCOME MEASURES

Ocular alignment and movement, extraocular muscles, and the oculomotor nerve on MRI.

RESULTS

One out of 6 patients with monocular elevation deficiency showed focal thickening of the inferior rectus muscle near the orbital apex. The 5 remaining patients showed normal extraocular muscles and the oculomotor nerves on MRI.

CONCLUSIONS

Focal thickening of the inferior rectus muscle may partially explain the cause of restricted gaze. In addition, the finding of normal oculomotor nerves might support an underlying deficit in the unilateral center for upgaze as the etiology of monocular elevation deficiency.

Double elevator palsy, subtypes and outcomes of surgery

PURPOSE

To describe the clinical manifestations of subtypes of double elevator palsy and to report the outcomes of surgery in these patients.

METHODS

This retrospective study was conducted on hospital records of patients with double elevator palsy at Labbafinejad Medical Center over a ten-year period from 1994 to 2004. Patients were classified into three subgroups of primary elevator muscle palsy (9 subjects), primary supranuclear palsy with secondary inferior rectus restriction (4 subjects) and pure inferior rectus restriction (7 subjects) according to forced duction test (FDT), force generation test (FGT) and Bell's reflex. Patients in the first group underwent Knapp procedure, the second group received Knapp procedure and inferior rectus recession simultaneously and in the third group vertical recess-resect or mere inferior rectus recess operation was performed. Success was defined as final residual deviation ≤5 PD and ≥25% improvement in restriction after all operations.

RESULTS

Overall 20 subjects including 10 male and 10 female patients with mean age of 12.6±9.3 (range 1.5-32) years were operated during the mentioned period which included 9 cases of primary elevator muscle palsy, 4 patients with primary supranuclear palsy and secondary inferior rectus restriction, and 7 subjects with pure inferior rectus restriction. Mean follow-up was 22.0±20.0 (range 3-63.5) months. Mean pre and postoperative deviation was 32.0±8.0 PD and 3.8±8.0 PD (P<0.001) respectively, and mean restriction before and after the operation(s) was -3.5±0.7 and -2.3±1.2 (P<0.001), respectively. Success rate was 77% for correction of deviation and 80% for improvement in muscle restriction.

CONCLUSION

Surgery for double elevator palsy must be individualized according to FDT, FGT and Bell's reflex. The outcomes are favorable with appropriate surgical planning.

Management of congenital elevation deficiency due to congenital third nerve palsy and monocular elevation deficiency

PURPOSE

To document the presentation and management of congenital III nerve palsy and monocular elevation deficiency to single ophthalmologist over a 14-year period. Surgical management was reviewed and visual outcome was analysed.

METHODS

A retrospective study was conducted of all patients presenting during a period between 1992 and 2006 to the private practice of a paediatric ophthalmologist, with either congenital III or monocular elevation deficiency. For patients requiring surgical intervention pre- and post-surgical data were documented and analysed.

RESULTS

A total of 19 congenital III and 13 monocular elevation deficiency patients were identified. There were eight surgical patients in each congenital III nerve palsy group and in the monocular elevation deficiency group. The congenital III group had a preoperative mean exotropia for near of -36 prism dioptres (PD) compared with postoperative mean exotropia for near -16 PD. Preoperative mean hypotropia for near of -19 PD was improved to postoperative mean hypotropia of -5 PD. The monocular elevation deficiency group had preoperative mean esotropia for near of +6 PD compared with postoperative mean exotropia for near -5 PD. Preoperative mean hypotropia for near of -15 PD was improved to postoperative mean hypotropia of -7 PD. At last follow up both groups had a majority of mild or no amblyopia noted.

CONCLUSION

Superficially, congenital III and monocular elevation deficiency may appear similar, both frequently having ptosis and hypotropia as features. Careful clinical assessment of the horizontal alignment and the result of forced duction testing will usually allow them to be distinguished. Congenital III more frequently requires surgery for exotropia as well as surgery for hypotropia and monocular elevation deficiency more often requires surgery just for hypotropia. The ptosis surgery is similar for either diagnosis in this study. Significant cosmetic improvement, as well as excellent visual acuity outcomes can be achieved.

Review of the inverse Knapp procedure: indications, effectiveness and results

PURPOSE

To evaluate the indications and results of inverse Knapp procedures performed at one institution over a 10 year period between 1987 and 1996.

METHODS

The records of patients who had undergone inverse Knapp procedures were retrospectively reviewed. Demographic data were collected, pre- and post-operative orthoptic assessments were evaluated, and pre- and post-operative binocular single vision (BSV) charts and Hess charts were scored.

RESULTS

Twenty-one patients were identified and records were available in 17. The main indication for the operation was orbital trauma. The mean vertical deviation in primary position and downgaze improved from 16.06 prism dioptres (PD) to 7.35 PD and 26.45 PD to 6.66 PD respectively. The pre-operative average score for BSV was 42%, increasing to 62% post-operatively. The Hess chart error scores improved on average from 848.8 pre-operatively to 296.4 post-operatively. Further operations were required for 8 patients.

CONCLUSIONS

Inverse Knapp procedure is an uncommon strabismus operation but an extremely useful one in selected cases. We recommend it for the treatment of marked inferior rectus weakness, congenital or acquired, for post-traumatic inferior rectus underaction with or without orbital blow-out fracture and for residual large hypertropia in patients with poor binocular functions. The extent of inferior rectus underaction should be assessed very carefully to avoid overcorrecting.

Augmented Hummelsheim procedure for paralytic strabismus

PURPOSE

To report a modification of the Hummelsheim procedure for use in the management of paralytic strabismus.

METHODS

Eight patients with paralytic strabismus secondary to third nerve palsy (n=1), sixth nerve palsy (n=3), combined cranial nerve palsy (n=1), or extraocular muscle damage (n=3) were treated using a modification of the Hummelsheim transposition procedure. The procedure involves half-tendon transpositions of the adjacent rectus muscles to the insertion of the paralyzed muscle, coupled with resection of the transposed halves. Further augmentation was achieved by surgical or pharmacologic weakening of the ipsilateral (n=6) or contralateral (n=1) antagonist. One patient underwent the procedure bilaterally. All patients underwent at least 6 weeks of follow-up.

RESULTS

The mean preoperative primary position deviation in the seven unilateral cases was 54 prism diopters (delta) (range: 25-85 delta). Preoperative forced ductions were positive in four cases. Resections varied from 4-8 mm. Ipsilateral antagonist recession varied from 0-14 mm. The mean change was 52 delta (range: 25-85 delta). Five cases were aligned within 15 delta of orthotropia at 6 weeks. No cases of anterior segment ischemia or induced vertical deviation were noted.

CONCLUSION

The modified Hummelsheim procedure appears capable of correcting large angles of strabismus associated with muscle palsy of various etiologies. It is safe, amenable to adjustable sutures, and relatively tissue- and vessel-sparing. Additional study is required to understand more fully the procedure's component effects and its interaction with ocular rotation.

Surgical management of ocular motor cranial nerve palsies

This article reviews the various surgical treatment approaches currently used in the management of ocular motor cranial nerve palsies. Regardless of the approach, the final goal is improved alignment, especially in the primary and reading positions.

Dissociative phenomena in congenital monocular elevation deficiency

INTRODUCTION

Monocular elevation deficiency is characterized by unilateral limitation of elevation in both adduction and abduction and is usually present at birth. Dissociative phenomena such as dissociated vertical deviation are well recognized in association with conditions such as congenital esotropia but much less so in association with conditions such as congenital monocular elevation deficiency.

METHODS

All 129 patients given the diagnosis of monocular elevation deficiency or double elevator palsy in the Pediatric Ophthalmology and Strabismus Clinic at the University of Iowa Hospitals and Clinics between 1971 and 1995 were reviewed. After those with history of trauma, myasthenia gravis, thyroid eye disease, orbital lesions, Brown syndrome, or monocular elevation deficiency with acquired onset were excluded, 31 patients with congenital monocular elevation deficiency remained for retrospective study.

RESULTS

First diagnosed at median age 2.6 years (although all were noted by parents at less than 6 months of age) with mean follow-up of 5.0 years (up to 15.5 years), 9 of 31 (29%) developed dissociated vertical deviation in the eye with monocular elevation deficiency, all of whom had undergone strabismus surgery 0 to 9.7 years previously (mean 3.5 years). Those who developed dissociated vertical deviation were generally younger, were followed up longer, and had more accompanying horizontal strabismus than did those who did not develop dissociated vertical deviation. The results did not reach significance.

CONCLUSION

The current study demonstrates that dissociated vertical deviation occurs in association with monocular elevation deficiency.

Unilateral congenital ptosis with ipsilateral superior rectus muscle overaction

PURPOSE

Congenital ptosis may be accompanied by weakness of the ipsilateral superior rectus muscle. We report the finding of a hypertropia of the ipsilateral eye in patients with isolated unilateral congenital ptosis that became manifest only in upgaze.

METHODS

Seventy consecutive patients with congenital ptosis were recalled and 58 reexamined. Examination included assessment of visual acuities, palpebral apertures, levator muscle function, and an orthoptic examination. Particular attention was paid to the assessment of upgaze.

RESULTS

Thirty-eight patients had an isolated unilateral congenital ptosis. Four patients had bilateral ptosis, six had upgaze deficits, and ten others had a variety of other syndromes associated with ptosis. Seventeen of the 38 patients with isolated unilateral congenital ptosis were found to have an ipsilateral hypertropia on upgaze. The size of the vertical deviation varied from 5 to 30 prism diopters and, in the more severe cases, produced a cosmetic problem that became more noticeable after successful ptosis surgery. In one of these patients, a superior rectus muscle posterior fixation suture was effective in reducing the hypertropia.

CONCLUSION

Of a number of possible causes for the ipsilateral hypertropia in upgaze in patients with unilateral congenital ptosis that we observed either a misdirection syndrome within the superior division of the oculomotor nerve or an exaggerated Bell's reflex is the most likely.

Effectiveness of inferior transposition of the horizontal rectus muscles for acquired inferior rectus paresis

Full inferior transposition of the horizontal recti (inverse Knapp procedure) was performed on four patients with unilateral inferior rectus muscle weakness. The patients were followed up over time to determine the medium- and long-term effectiveness of the procedure. All of the patients had single binocular vision without the use of prisms in the primary position of gaze and three in the reading position after a mean postoperative follow-up interval of 21/2 years. The mean primary position preoperative vertical deviation was 20.3 delta and the mean primary position postoperative vertical correction was 19.5 (range, 16 to 24) delta. The field of binocular single vision was assessed quantitatively and scored 2.4% preoperatively compared with 52.3% postoperatively. There was no decrease in the effect of the procedure over time. Additional surgery may still be required to correct symptomatic residual vertical down-gaze diplopia.