Inferior Rectus Restriction Research Articles

Strabismus and oculomotor disorders induced by injection anesthesia for cataract surgery

To analyze diagnostic and treatment outcomes in patients with strabismus and oculomotor disorders induced by injection anesthesia for cataract surgery. The study included 11 patients (7 women and 4 men) aged 61 to 85 years (the mean age of 66±7.1 years) who complained of diplopia in the early post-op period after cataract phacoemulsification and elastic IOL implantation under retrobulbar anesthesia. Prior to further surgical treatment, all of the patients underwent functional multispiral computer tomography of the orbits. Prismatic spectacle correction was also used independently or in addition to surgical treatment. Eight out of eleven patients underwent one- or two-step surgical treatment (3 and 5 cases, respectively). In 2 patients, hypotropia did not exceed 10 prism diopters, and thus, diplopia could be compensated with prismatic spectacle correction alone. In 5 cases, binocular vision was achieved throughout the whole field of gaze. In 3 cases, surgical treatment enabled elimination of heterotropia in the primary gaze and compensation of diplopia within a radius of 40º from the center of gaze and within the entire horizontal range of eye-movement in the downward gaze. The limitation of ocular mobility decreased from 2.36 to 0.55 points leading to an associated decrease in the area of binocular diplopia - from 98% to 29%. In one case, spectacle occlusion was used. The inferior rectus restriction is the morphological substrate of anatomical and functional changes induced by retrobulbar anesthesia. As treatment options for restrictive vertical strabismus and binocular diplopia, both surgical (extraocular muscle surgery) and optical (prismatic correction, occlusion) methods should be considered.

Surgical management of monocular elevation deficiency combined with inferior rectus restriction.

To evaluate the results of ipsilateral inferior rectus (IR) recession, when performed alone or in combination with contralateral superior rectus (SR) recession in patients with monocular elevation deficiency (MED) and IR tightness. The medical records of patients with MED and tight IR muscle were retrospectively reviewed. Patients underwent either ipsilateral IR recession alone (IR group) or combined with contralateral SR recession (IR+SR group). Pre- and postoperative ocular motility and alignment and fundus torsion were analyzed. Abnormal head posture was recorded. All patients were followed for at least 6 months. A total of 23 patients were identified. Mean patient age at time of surgery was 9.8 ± 8.7 years (range, 3-45 years). Ten patients underwnet ipsilateral IR recession 5-8 mm; 13 patients, 4 mm ipsilateral IR recession combined with 5-12 mm contralateral SR recession. Both groups experienced marked improvement in ocular alignment in the primary position (P = 0.34). However, there was a statistically better ocular alignment in both upgaze (P=0.03) and downgaze (P < 0.01) in the IR+SR group, with a lower degree of fundus intorsion (P < 0.01). An ipsilateral head tilt developed in 70% of patients in the IR group and in 54% of patients in the IR+SR group. In this patient cohort, combined contralateral SR recession with ipsilateral IR recession reduced postoperative IR underaction and achieved better ocular alignment in upgaze and downgaze.

Unmasking Bilateral Inferior Rectus Restriction in Thyroid Eye Disease: Using Degree of Cyclotropia

PurposeThyroid eye disease (TED) frequently causes strabismus and diplopia. Though the condition involves multiple extraocular muscles in both eyes, the inferior rectus (IR) muscle is particularly susceptible. TED may be so asymmetric as to mask the involvement of the contralateral IR. The purpose of this study was to determine if the degree of preoperative cyclotropia measured with an objective test could be used to predict the extent of bilateral IR disease and assist in surgical planning.MethodsAdults with TED involving the IR and demonstrating cyclotropia were enrolled. Preoperative and postoperative sensorimotor exam included quantification of cyclotropia using double Maddox rod test (DMR). Forced ductions were done intraoperatively. Degree of cyclotropia was compared to results of duction tests and surgical outcome.ResultsTwelve participating patients demonstrated excyclotropia on DMR test preoperatively (mean 16 ± 9°). Unilateral IR recession was planned based on the results of preoperative ocular rotations and forced duction testing in eight cases. The remaining four underwent bilateral IR recession. Four of the unilateral recession cases presented with reversal of the hypotropia, obvious limitation of elevation in the unoperated eye, and persistent symptomatic excyclotropia at the first postoperative visit. The mean excyclotropia of the bilateral cases was 21 ± 5°, compared to 5.5 ± 3° in the unilateral group (P < 0.005).ConclusionsPrism diopters of hypotropia, limitation of elevation, and forced duction testing evaluate muscle function relative to its yoke and may underestimate contralateral IR involvement in the case of asymmetrical disease. Duction testing and forced ductions are qualitative and subjective. Results suggest that degree of excyclotropia correlates well with severity of IR restriction, and that amounts exceeding 15° infer bilateral IR involvement.

Strabismus after regional anesthesia for cataract surgery

Background: An adult strabismus clinic in a regional eye centre provided an opportunity to estimate the risk of postoperative diplopia from regional anesthesia after cataract surgery and to describe the management of these patients.Methods: Retrospective cohort analysis. All cases were referred over a 22-month period (November 1997 to September 1999) for investigation of postoperative diplopia after cataract surgery.The surgical and anesthetic records were reviewed to determine the number and location of injections, and the volume and type of regional anesthesia.The evolution and management of patients' diplopia was studied prospectively.Results: Twenty-one patients (12 women and 9 men aged 63 to 88 [median 76] years) were ascertained with postoperative diplopia. In II cases the right eye was affected, and in 10 cases, the left eye.Vertical diplopia occurred most commonly from inferior rectus restriction (16 cases). Three cases resolved without treatment, which indicated that the diplopia was transient. Four patients declined treatment, five required prism in eyeglasses only, and nine required strabismus surgery. One patient required surgery and prism in eyeglasses. Two patients required more than one strabismus operation to relieve the diplopia. For the period of data collection, we estimate the risk of nontransient postoperative diplopia from regional anesthesia as 2.6 cases per 1000 cataract procedures (95% confidence interval 1.9-4.7).Interpretation: Patients should be forewarned of the risk of diplopia after cataract surgery with regional anesthesia.The treatment of the diplopia may require prism in eyeglasses or strabismus surgery or both.

Fixation Duress in the Pathogenesis of Upper Eyelid Retraction in Thyroid Orbitopathy: A Prospective Study

Upper eyelid retraction in thyroid eye disease may be caused by proptosis, levator and Müller's muscle infiltration with fibrosis or individual fiber enlargement, excessive sympathetic innervation, abnormal adhesions between levator palpebrae muscle and surrounding tissues, or fixation duress. Fixation duress refers to upper eyelid retraction while fixating with an eye with inferior rectus muscle restriction due to excessive simultaneous firing of the ipsilateral superior rectus and levator palpebrae muscles. The authors prospectively examined six patients with strabismus and thyroid eye disease associated with inferior rectus restriction and upper eyelid retraction in whom the eyelid retraction was suspected clinically to be a result of fixation duress. All six patients underwent recession of both inferior recti ranging from 3 to 6.5 mm (mean, 4.5 mm) to improve the ocular motility and alignment, reduce the diplopia, and mitigate the upper eyelid retraction. Reduction of upper eyelid retraction measured as the preoperative versus postoperative difference in corneal light reflex-upper eyelid margin measurements was achieved in all patients postoperatively, ranging from 1.5 to 5.5 mm (mean, 3.2 mm). Only one patient showed significant residual retraction to warrant consideration of upper eyelid surgery. Fixation duress plays a significant role in upper eyelid retraction of thyroid eye disease in a subset of patients with restriction of the inferior rectus muscle. In this selected group of patients, the upper eyelid retraction may be reduced or eliminated upon proper recession of the tight inferior rectus muscle(s).

Congenital Double Elevator Palsy: Vertical Saccadic Velocity Utilizing the Scleral Search Coil Technique

Four patients with congenital double elevator palsy were studied who had clinically brisk elevation of the affected eye from downgaze to the midline position of rest, but severely limited or absent elevation above primary position. Forced duction tests were negative and Bell's phenomenon was present preoperatively in all patients. To clarify why upgaze saccades clinically seemed intact below but not above midline, vertical saccadic velocities were measured using the scleral search coil technique. The tracings of three cases suggest sufficient superior rectus function to generate a normal upward saccadic trajectory. A supranuclear lesion is the most likely etiology of the inability to elevate the eye well above primary position in these three patients. In a fourth patient, the reduced ability to elevate the affected eye above primary position is caused by a superior rectus paresis with decreased upward saccadic velocities. We suggest at least three distinct groups of patients present clinically as double elevator palsy: primary inferior rectus restriction, primary superior rectus paresis or palsy, and congenital supranuclear elevation deficiency.

Superior oblique overaction in patients with true Brown's syndrome.

The charts of all patients with the diagnosis of congenital Brown's syndrome seen between July 1983 and June 1984 were examined retrospectively. In the past, overaction of the ipsilateral superior oblique (OAISO) was felt by most authors to be absent or minimal. Our study revealed that separate observers consistently documented the presence of an OAISO in about one-fifth of the selected patients. The presence of OAISO has not been emphasized previously and still remains controversial. We felt that an extremely tight superior oblique might cause an OAISO. We therefore statistically compared its presence to the presence of a downshoot. The presence of an OAISO to abnormal head tilt, abnormal chin position, amblyopia, and abnormal stereo was also compared statistically. Finally, we emphasize a technique of forced ductions that differentiates Brown's syndrome from an inferior oblique palsy, but which also alerts the examiner to the presence of an inferior rectus restriction or other posteriorly located restrictions.

Elevating the hypotropic globe.

Twelve consecutive cases are reviewed of unilateral hypotropia due to various causes. In most of them the presenting complaint was of ipsilateral blepharoptosis. Some patients had undergone previous ineffective surgery. The surgical techniques employed and the results obtained are discussed, with emphasis on the necessity to test for inferior rectus restriction. Some interesting sensory results are also noted.