Anterior segment ischemia and retinal detachment after vertical rectus muscle surgery

PURPOSE: The authors describe the clinical course of a woman who developed two complications following vertical strabismus repair: anterior segment ischemia (ASI) and retinal detachment. METHODS: A 62 year-old woman is described. She presented with new onset proptosis and left hypertropia with significant diplopia in all fields of gaze. This presentation, her 15 year history of thyroid disease, and preoperative computed tomography (CT) of the orbits were consistent with Graves' ophthalmopathy. Vertical strabismus repair was carried out by recessing the left superior rectus muscle and resecting the left inferior rectus muscle. RESULTS: The diplopia was eliminated. The patient developed significant postoperative ASI and iatrogenic rhegmatogenous retinal detachment in the left eye due to unsuspected globe perforation. She was treated with systemic corticosteroids and radial scleral buckling. CONCLUSIONS: Severe ASI following strabismus surgery is a well recognized complication, with age, thyroid ophthalmopathy, and manipulation of the vertical rectus muscles as risk factors. The retinal detachment soon after strabismus surgery was difficult to detect, possibly due to diminished visualization of the posterior segment as a result of ASI.     

Anterior segment ischemia after three rectus muscle surgery

Nine patients underwent simultaneous or staged detachment of the vertical and medial rectus muscles in the treatment of sixth nerve palsy or Duane's retraction syndrome. In five adult patients (34, 35, 41, 45, and 65 years of age), clinically significant anterior segment ischemia developed postoperatively. Known medical risk factors were present in only one case. With the exception of corectopia, there were no apparent sequelae and all involved eyes returned to preoperative visual acuity within 9 weeks of surgery. Anterior segment ischemia may be a frequent complication of strabismus surgery in adult patients when the superior, inferior, and medial rectus muscles are detached from the globe.     

Anterior segment ischemia following augmented 2-muscle transposition surgery

Anterior segment ischemia (ASI) rarely complicates surgery on fewer than three rectus muscles. We have encountered two women in their early sixties who developed ASI following augmented transposition of the vertical rectus muscles as described by Foster. Both had undergone intracranial surgery.     

Anterior ischemia after posterior segment surgery

Anterior segment ischemia is a rare complication of posterior segment surgery with a broad spectrum of presentations. Most frequently, it follows a mild self-limited course. Cases that are more prominent usually result from a co-incidence of precipitating factors. Recognition of precipitating factors and appropriate action can avoid anterior segment ischemia. Management includes nonspecific steps, such as topical medications (ie, corticosteroids and cycloplegics) and face-mask and eye-mask oxygen delivery, as well as specific steps related to the underlying cause (eg, removal of an encircling scleral buckle).     

Anterior segment ischemia after strabismus surgery with microvascular dissection.

Anterior segment ischemia is a rare but well-known complication of extraocular muscle surgery.(1) Several surgical techniques have been used to prevent this complication in high-risk patients. A number of studies have suggested that microvascular dissection and preservation of the anterior ciliary vessels during strabismus surgery may reduce the risk of ischemic complications. (2-4) We present a case in which anterior segment ischemia occurred despite the use of this vessel-sparing technique.     

Outcomes of half-width vertical rectus transposition augmented with posterior fixation sutures for sixth cranial nerve palsy

AIM: To describe the experience with half-width vertical muscles transposition (VRT) augmented with posterior fixation sutures. METHODS: The clinical charts of all patients, who underwent half-width VRT augmented with posterior fixation sutures for sixth cranial nerve palsy from January 2003 to December 2018, were retrospectively reviewed. For each patient, pre- and post-operatively, the largest measured angle was used for the calculations, usually resulting with the angle for distance, except in young infants, where measurements were made at near fixation using the Krimsky test. RESULTS: Fifteen patients met the inclusion criteria for the study, of them 9 (60.0%) had also medial rectus muscle recession at the time of surgery. Mean follow-up period was 21.4±23.2mo (range 1.5-82mo). Preoperative mean esotropia was 51.3±19.7 prism diopter (PD; range 20-90 PD). Postoperative mean deviation on final follow-up was 7.7±20.2 PD (range -40 to 35 PD; P=0.018). In all patients with preoperative abnormal head position, improvement was noted. Ten (66.7%) patients had improvement in abduction and 10 (66.7%) patients reported improvement in their diplopia, by final follow-up. The addition of medial rectus recession was correlated with a larger change in postoperative horizontal deviation compared to baseline (P=0.026). Two (13.3%) patients developed a vertical deviation in the immediate postoperative period which had resolved in one of them. CONCLUSION: Half-width VRT augmented with posterior fixation suture, with or without medial rectus muscle recession, is an effective and safe procedure for esotropia associated with sixth cranial nerve palsy. A major improvement in the angle of deviation is expected. Most patients will have improvement in their abnormal head position and diplopia.     

Botulinum toxin augmented bilateral lateral rectus recession versus three muscles surgery in large-angle intermittent exotropia

AIM: To report the surgical outcomes of correcting large angle intermittent exotropia in adult patients by bilateral lateral rectus muscle recession with intraoperative use of botulinum toxin and to compare the results with those of bilateral lateral rectus muscle recession and unilateral medial rectus resection. METHODS: The medical records of patients who underwent surgical correction of large angle intermittent exotropia [exotropia >50 prism dioptre (PD)] were retrospectively reviewed. Two groups of patients were identified; Group I (21 patients) had bilateral lateral recti recession augmented with intraoperative botulinum toxin A (BTA) injection into the recessed muscles and group II (30 patients) were treated by bilateral lateral recti recession with unilateral medial rectus muscle resection. Preoperative data were extracted for age, gender, refraction, type of exotropia, angle of stereopsis and angle of deviation. The main outcome measures were the postoperative angle of deviation and stereoacuity angle by Titmus test measured at the end of one year of postoperative follow up. RESULTS: By the end of the first postoperative year, 10 patients in group I (47.6%) and 20 patients in group II (66.7%) achieved esotropia/esophoria <5 PD or exotropia/exophoria <10 PD. The difference in surgical success rate was not statistically significant (P=0.1) but there was a statistically significant higher rate of undercorrection in group I (P=0.03). On the other hand, 3 patients in group I (14.3%) and 5 patients in group II (16.7%) had improved stereopsis; this difference in the sensory outcome was not statistically significant (P=0.8). In the BTA augmented surgery group, good stereoacuity and smaller preoperative angle of deviation were associated with significantly higher surgical success rate (P=0.004, 0.01 respectively). CONCLUSION: BTA augmented bilateral lateral recti recession is associated with higher rate of undercorrection as compared to bilateral lateral recti recession with unilateral medial rectus resection in the correction of large angle intermittent exotropia. The surgical success rate in BTA augmented surgery group is observed to be higher in patients with preoperative smaller angle of deviation and in patients with good stereoacuity.     

Anterior segment ischemia following pterygium surgery

A 60-year-old woman developed anterior segment ischemia 1 week after an uneventful pterygium excision in the left eye. Corrected visual acuity fell from 20/20 to 20/200. Ophthalmic examination found keratic precipitates on the corneal endothelium, ++ cells in the aqueous humor, and necrosis of the lower half of the iris with posterior synechiae resulting in a fixed and distorted pupil. On therapy of topical corticosteroid eyedrops hourly and atropine eyedrops three times a day, the iridocyclitis resolved in 2 weeks. At the final examination 3 months after the surgery, the corrected visual acuity was 20/20. The atrophy of the lower half of the iris and posterior synechiae in the lower half of the pupil, giving the fixed and distorted pupil, were noted as sequelae. Iris fluorescein angiography revealed filling defects in the lower half of the iris but no leakage from iris vessels. Systemic evaluation was unremarkable except for mild hypertension. Doppler studies of carotid, ophthalmic, and central retinal arteries were normal. Mitomycin C, β-irradiation and rectus muscle fixation sutures were not used. Only conjunctival dissection or episcleral cauterization were seen as possible causes of interference with the anterior segment blood supply. We believe this is the first report of anterior segment ischemia following pterygium surgery.     

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.     

Anterior segment ischemia following extraocular muscle surgery

An experimental study was conducted on rhesus monkeys using the technique of anterior segment fluorescein angiography to determine the changes that occur in the iris circulation following surgery on extraocular recti muscles in various combinations and to investigate the safe time limit to perform further surgery on the remaining recti muscles. Based on the results, the probable blood supply to the iris and its clinical significance is discussed. It is concluded that the often quoted clinical safe period of 6 weeks is not enough from the angiographic point of view, as the iris circulation is not fully normalized by that time.     

Vertical muscle transposition augmented with lateral fixation.

INTRODUCTION: Full vertical rectus muscle transpositions have been shown to be an effective treatment for lateral rectus palsies and type I Duane syndrome. This operation is usually accompanied by mechanical or botulinum toxin treatment of one or both medial rectus muscles. This series evaluates the effect of augmenting the transposed muscles with lateral fixation sutures. METHODS: Transposition of the vertical rectus muscles to the lateral rectus muscle was performed in 23 eyes of 21 patients; transposition to the medial rectus muscle was performed in one eye of one of these 21 patients. A lateral fixation suture of 5-0 Dacron polyester filament was placed in the sclera 16 mm posterior to the limbus and adjacent to the lateral rectus muscle, incorporating one fourth of the transposed vertical rectus muscle. Of the 21 patients, five had type I Duane syndrome with a face turn and esotropia in the primary position, seven had a unilateral lateral rectus palsy, two had bilateral lateral rectus palsy, four had an ipsilateral lateral rectus palsy combined with a contralateral lateral rectus paresis (a recess resect procedure was performed on the paretic eye along with the augmented transposition on the paralyzed eye), two had gaze palsies, and one had a unilateral lateral rectus palsy with recurrent esotropia after a transposition procedure performed 16 years previously. Lateral fixation sutures alone were used in the last case listed. Postoperative diplopia-free fields were measured when possible (10 cases). RESULTS: In most cases (19/23 eyes), alignment was achieved in the primary position with the use of the augmented transposition procedure alone. On average,20 degrees of binocular fusion into the abducted field was obtained. No postoperative limitation of adduction in the transposed eye was noted. Among the patients with Duane syndrome, 80% had elimination of the face turn; one patient had 5 degrees of residual face turn. The one patient with previous transposition surgery alone had an 80% (16 PD) reduction of the recurrent esotropia after placement of lateral fixation sutures. After augmented transpositions, induced vertical deviations in the primary position were uncommon (4/20 patients) and not greater than 2 PD. Significant lid fissure changes were not seen. CONCLUSIONS: The addition of lateral fixation sutures to full vertical rectus muscle transpositions improves the tonic abducting force of the procedure for patients with lateral rectus palsy and type I Duane syndrome without compromising adduction.     

Inferior oblique inclusion after lateral rectus surgery

A retrospective and prospective study evaluated the clinical characteristics of patients with inadvertent incorporation of the inferior oblique muscle to the lateral rectus muscle after lateral rectus surgery. Nineteen cases were included in the study (12 retrospectively in the preceding 18 months and 7 during the prospective 5-month period). Thirteen cases with the inferior oblique inclusion occurred after a lateral rectus resection and 6 occurred after a lateral rectus recession. Most patients demonstrated a vertical deviation in the affected eye preoperatively. Nine had hypotropia and 8 had hypertropia. Deficient elevation in adduction in all patients was found on motility testing. After reoperation, despite freeing the inferior oblique from the lateral rectus, most patients had a persistent vertical deviation. Inadvertent inferior oblique inclusion can be avoided by inspecting the under surface of the lateral rectus and freeing any inferior oblique attachment before reattaching the lateral rectus to the globe during either resection or recession.Dedicated to Dr. G.K. von Noorden on the occasion of his 60th birthday