Double Maddox Rod Research Articles

Novel superior oblique anterior fiber plication with or without adjustable sliding knot for extorsion

PurposeTo report a novel surgical technique to correct excyclotropia, consisting of a superior oblique anterior fibers plication (SOAFP) with or without a hemihangback anterior knot, allowing access for postoperative adjustment. MethodsA retrospective interventional case series was conducted. Fourteen patients, 21-92 years of age, underwent SOAFP (18 eyes, 14 eyes on adjustable), at the Mayo Clinic in Rochester, Minnesota. SOAFP was the only procedure performed in 12 eyes; in 6 it was performed in conjunction with up to four horizontal rectus muscle recession, resection, and/or plication. Ocular alignment was assessed with prism and alternate cover and double Maddox rod tests; preoperatively, at initial and final (closest to 6-8 weeks) postoperative visits. ResultsPreoperative torsion ranged from 2° to 30° of extorsion (mean, 10.14 ± 7.01). A SOAFP of 2–30 mm (mean, 8.93 ± 5.63) was performed. At the initial postoperative examination, mean intorsional shift was 11.18 ± 7.37, accounting for 1.86° ± 1.04° of correction per millimeter of plication. Three eyes were adjusted after the initial visit to obtain a stronger plication effect targeting of 5° intorsion. At the final visit, 61 ± 23 days postoperatively, mean extorsion was 1.21° ± 2.29°, ranging from 5° of extorsion to 3 of intorsion. Mean final intorsional shift was 9.14 ± 7.53°, accounting for a 1.16 ± 0.50° of correction per millimeter of plication. Of our 14 patients, 13 had improvement in diplopia. ConclusionsIn our study cohort, SOAFP allowed for targeted and easily adjustable correction of extorsion.

Long-Term Surgical Outcomes of Bilateral Symmetrical Superior Oblique Nasal Tenotomy in Patients of Large A-Pattern Exotropia.

To report the long-term outcomes of bilateral symmetrical superior oblique (SO) nasal tenotomy in patients with large A-pattern exotropia (≥25 prism diopter [PD]). This retrospective study was conducted on 15 patients (aged: 4-28 years) of large A-pattern exotropia. An A-pattern was defined as >10 PD difference between up and down gaze at 6 m by use of the alternate prism cover test. Objective ocular torsion was assessed by fundus photography and subjective torsion by double Maddox rod test. All patients underwent horizontal muscle surgery according to the primary position horizontal deviation and bilateral symmetrical SO nasal tenotomy for A-pattern. Surgical success was defined as postoperative A-pattern of ≤10 PD, the absence of vertical and torsional diplopia, and the absence of V-pattern. The minimum follow-up period was 24 months. A total of 15 patients of large A-pattern exotropia (7 males and 8 females) with a mean age of 17.09 ± 7.9 years were included in the study. All patients had bilateral SO overaction of grade +3 or +4 with a mean preoperative A-pattern of 30.3 ± 3.9 PD. At 24 months of follow-up, esotropia in down gaze (V-pattern) was present in four patients with a mean of 11.25 ± 2.5 PD, (range, 10-15 PD). The rest of the 11 patients maintained successful alignment with a mean A-pattern of 3.18 ± 1.17 PD, (range, 2-5 PD). There was significant A-pattern collapse with a mean of 31 ± 9.1 PD after 2 years of follow-up, which was significantly associated with preoperative A-pattern (Pearson correlation, r = 0.7; t[15] = 4.0; P = 0.002). The mean of pre- and postoperative objective ocular torsion was found to be -0.5 ± 4° and -4.8 ± 3.8° with a mean extorsion effect of 4.67 ± 3.85°. There was a statistically significant difference between pre- and postoperative ocular torsion (°) (t [30] = 5.42; P < 0.001), the change in ocular torsion was significantly associated with preoperative torsion (Pearson correlation, r = 0.5; t [30] = 7.2; P < 0.001). None of the patients had subjective torsion on the double Maddox rod test pre- and postoperatively. Bilateral symmetrical SO nasal tenotomy is effective in cases with large A-pattern (>25 PD). The reduction of A-pattern and postoperative change in fundus torsion have a positive correlation with preoperative A-pattern and preoperative torsion, respectively.

A Survey to Identify Screen Test Usage by Certified Orthoptists Across the United States of America

ABSTRACT Purpose To ascertain the use of screen tests for assessing strabismus under binocular viewing conditions by certified orthoptist colleagues around the United States of America. Methods A link to an online survey was distributed to all 440 registered members of the American Association of Certified Orthoptists in early 2022. A total of 135 certified orthoptists responded. Results Of the 135 respondents, 51% were from a public practice, 36% were private practice and 13% from a mixture of both. A large proportion of respondents did not use binocular screen tests to measure strabismus such as the Lancaster red/green test (85%) or Hess screen test (93%), although one respondent reported using the Harms screen test. Most respondents reported using single or double Maddox rods (75%), synoptophore (44%) and prisms (14%) in their practice to quantify strabismus clinically. Conclusion There is limited use of screen tests in private and public practice in the USA. The ergonomic requirements of such tests are prohibitive to their implementation in modern clinical practice.

A simple marking system for accurate intraoperative monitoring and adjustment of cyclotorsion strabismus surgery.

Ocular cyclotorsion is treatable only with surgery. The surgical procedure must be tailored individually to the specific etiologies causing the horizontal and vertical strabismus and its torsional components. An adjustable surgical approach is often used for postoperative or intraoperative adjustments. However, the methods currently used have some limitations. In this study, we propose a simple intraoperative marking system for all cyclotorsion correction surgery. The proposed marking system used three sets of surface markers: external horizontal markings, ocular horizontal markings, and surgical torsion markings, drawn in sequence. We retrospectively analyzed the surgical results using this novel marking system in this single-center, single-surgeon study. Fifteen patients with cyclotorsion who underwent treatment using the proposed marking system as an intraoperative aid between August 2019 and August 2021 were included. The medical charts were thoroughly reviewed, and the pre-and postoperative subjective and objective cyclotorsion were analyzed. Among the study subjects (10 males, 5 females; age range: 6-89 years), 13 had excyclotorsion and 2 incyclotorsion. Preoperative mean net subjective cyclotorsion measured by the double Maddox rod (DMR) test was 6.0° (standard deviation: 10.8°) and mean net disc-to-fovea angle (DFA) was 20.23° (13.21°). The postoperative net DMR and DFA were 0.2° (2.1°) and 14.09° (5.97°), respectively. The mean absolute net DMR and DFA being treated were 9.8° (4.8°) and 9.76° (4.61°). Overall, the proposed intraoperative marking system is a simple and quantitative method to assess, monitor, and adjust the torsional aspect for all strabismus surgeries.

Pearls & Oy-sters: Vertical Diplopia and Ocular Torsion: Peripheral vs Central Localization.

We describe a case with torsional deviation of the eyes from a brainstem lesion. Torsional eye movement refers to changes in the position of the eyes in the roll plane around the visual axis. When the head is tilted laterally (that is, rolled toward the shoulder), the eyes roll in the opposite direction as part of the torsional vestibulo-ocular reflex known as the ocular counter-roll. Pathologies that affect the otolith-ocular pathway can lead to a torsional deviation of the eyes as part of the ocular tilt reaction (OTR) that also causes vertical deviation of the eyes (skew deviation) and head tilt. Lesions caudal to the pontomedullary junction (such as the labyrinth, eighth cranial nerve, or vestibular nucleus) result in an OTR with ipsiversive torsional deviation, whereas lesions rostral to the junction result in an OTR with contraversive torsional deviation. Furthermore, torsional deviation of the eyes in the OTR is conjugate (incyclotorsion in the higher eye and excyclotorsion in the lower eye), whereas torsional deviation from ocular palsy in peripheral lesions is disconjugate (e.g., exyclotorsion only in the higher eye with superior oblique palsy). Therefore, the pattern of torsional eye deviation can be helpful in localizing the lesion. Several techniques including fundus photography, double Maddox rod testing, optical coherence tomography, and video-oculography are used to measure torsional eye position.

Modified Harada-Ito Procedure with Intraoperative Adjustable Sutures Using a Mendez Ring for Excyclotorsion

Purpose: We report a case of using a modified Harada-Ito procedure with intraoperative adjustment via a Mendez ring in a patient with bilateral superior oblique palsy, resulting in satisfactory postoperative outcomes.Case summary: A 47-year-old male patient presented with bilateral diplopia after cerebral hemorrhage. Bilateral superior oblique palsy was diagnosed, and double Maddox rod tests confirmed 20° of excyclotorsion in both eyes. After 6 months of observation, surgical correction was attempted. To check the amount of cyclodeviation, a modified Harada–Ito procedure was performed on the superior oblique muscle after marking at the 6 and 12 o'clock positions of the corneal limbus. Following the procedure, a Mendez ring was placed on the limbus to check for the amount of incyclotorsion. Thirty degrees of incyclotorsion was aimed at both eyes, and a 5-mm resection of the right superior oblique tendon was performed for additional correction. There was no complaint of diplopia at 6 months postoperatively, and no deviation was observed.Conclusions: A modified Harada-Ito procedure with intraoperative adjustment using a Mendez ring effectively corrected excyclotorsion with torsional diplopia.

Development and Preliminary Validation of a Virtual Reality Approach for Measurement of Torsional Strabismus.

Double Maddox rod (DMR), the gold-standard method for in-office measurement of cyclodeviation, requires an examiner and specialized equipment. The objective of this study was to develop a virtual reality (VR) technique for measurement of cyclodeviation and validate this against the DMR. A VR-DMR was implemented using a smartphone and commercially available VR viewer. The app displayed a line to each eye and accepted touch inputs from the user to rotate the lines into perceived alignment. VR-DMR cyclodeviation measurements were compared with traditional DMR (T-DMR) cyclodeviation measurements in adults with and without strabismus and children without strabismus. Thirty-one subjects were studied (age 5-88 years, 20 with strabismus). VR-DMR had similar test-retest reliability as T-DMR. VR-DMR was highly correlated with T-DMR (r2 = 0.94, linear regression slope 1.12) with a slight positive bias (linear regression y intercept 1°). VR-DMR was preferred by 54% of subjects with 29% having no preference. A VR method of ocular cyclodeviation measurement using sensory techniques was implemented using commercially available hardware. VR measurements compared favorably with gold-standard DMR measurements, and user feedback was positive. The VR methodology has application for in office and home use by nonexperts for purposes of strabismus monitoring.

Clinical observation of anterior tucking of the superior oblique tendon for correction of excyclotropia in adults

Objective: To investigate the clinical effect of anterior 1/3 superior oblique tendon tucking in acquired symptomatic excyclotropia adults. Methods: Retrospective case series. Seven patients (7 eyes) with acquired symptomatic excyclotropia who underwent an anterior 1/3 superior oblique tendon tuck procedure in Tianjin Eye Hospital from January 2019 to December 2019 were included. There were 5 male patients and 2 female patients, with an average age of (49±12) years old. All the patients had a history of a closed head injury. There was torsional diplopia in primary position, and eye movement examination showed paralysis of the superior oblique muscle in the affected eye, without obvious hyperactivity of the inferior oblique muscle. The anterior 1/3 tendon of the superior oblique muscle was tucked during surgery according to the relaxation of the superior oblique tendon in the forced duction test. The paired-sample nonparametric rank sum test was used to analyze the preoperative and postoperative (at 1 day after surgery and the last follow-up) excyclotropia angle. Results: The mean tuck amount was (7.7±1.8) mm (range, 6.0 to 10.0 mm). During operation, patients complained that excyclotropia improved markedly. The excyclotropia angle with the double Maddox rod test improved significantly from preoperative 10° (8°, 15°) to 2° (0°, 3°) at 1 day (Z=-2.379; P<0.05) and 2° (2°, 5°) at the last follow-up (Z=-2.375; P<0.05). The follow-up period was (112+38) days. All patients had no complaints of excyclotropia at the last follow-up. Conclusions: The anterior 1/3 superior oblique tendon tucking can effectively improve clinical symptoms in the primary position in adults with acquired excyclotropia and diplopia. The short-term postoperative results seem to be stable, without significant regression. (Chin J Ophthalmol, 2021, 57: 685-688).

Surgical Outcomes of Nonadjustable Modified Harada-Ito Surgery.

PurposeThis study aimed to investigate the surgical outcomes of nonadjustable Harada-Ito surgery under general anesthesia.MethodsTwenty-two patients who underwent nonadjustable modified Harada-Ito surgery under general anesthesia were reviewed retrospectively. Among them, 21 out of the 22 patients who were followed up for 6 months after surgery were included in this study. Subjective cyclotorsion (double Maddox rod test) and objective cyclotorsions (fundus photography) were measured. Success of the surgery was defined as follows: success (the patients do not acknowledge diplopia at any direction), partial (the patients feel diplopia at a specific direction, but they do not feel discomfort in routine life), and fail (the patients feel diplopia in primary gaze, hence requiring a thorough investigation).ResultsThe mean age of the patients (18 male and 3 female) was 56.5 years (range, 40–77 years). Based on the alternate prism cover test, the patients had 4.2 ± 3.0 prism diopters of vertical deviation. The corrected amounts of cyclotorsion based on the double Maddox rod test and fundus photography were 14.8° ± 7.5° and 9.8° ± 7.9°, respectively, and were significantly different between the two methods (p = 0.006). After the surgery, 20 out of the 21 patients (95.2%) completely recovered from diplopia in the primary gaze. However, among the 20 patients, seven complained of diplopia in the secondary gaze (down gaze, four patients; head tilt gaze, three patients). The success group had a smaller preoperative subjective excyclotorsion than the partial and fail groups (12.6° ± 2.5° and 21.0° ± 8.9°, respectively; p = 0.046).ConclusionsNonadjustable modified Harada-Ito surgery under general anesthesia has favorable success rate, and preoperative subjective excyclotorsion can be a prognostic factor in patients with bilateral superior oblique palsy.

The use of OCT in the assessment of ocular torsion

Measurement of ocular torsion is an essential part of evaluation, differential diagnosis and management of patients with strabismus. Conventionally, double Maddox rod testing (DMRT) and dilated fundus photography are used to measure ocular torsion. DMRT depends upon reliable patient response. Fundus photography requires dilation and analysis. Heidelberg ocular coherence tomography (OCT) provides an assessment of torsion as a disk-foveal angle (DFA) easily obtained without dilation, but this has not been clinically validated. We studied the correlation between DMRT, fundus photography, and OCT methods of measuring torsion.

Modified Anterior Superior Oblique Tuck: A Case Series

ABSTRACT Purpose Selection of the ideal procedure to correct symptomatic excyclotropia depends on several factors including the degree of torsion and associated vertical, horizontal and pattern deviation. Selective tuck of the anterior temporal torsional fibers of the superior oblique (SO) tendon is an alternative procedure to the classical Harada-Ito. The purpose of this study is to report its stability and results. Methods Retrospective review of all consecutive patients with symptomatic excyclotorsion of at least 5º (degrees) treated by selectively splitting and tucking the anterior temporal fibers of the SO tendon. Torsion in primary position was measured using the double Maddox Rods. Patients with additional symptomatic vertical or horizontal diplopia underwent simultaneous surgery on other extraocular muscles. Results Five patients were studied. Mean age was 60 ± 8 years (47–67). Mean postoperative follow-up was 10 ± 8 months (3–21). The mean preoperative torsion of 11º±4º (7º-15º) significantly decreased to 3º±2º (p = .03) at the first postoperative visit (16 ± 9 days) and 3 ± 2º during the last visit (P = .03). The procedure corrected 1.4º±0.9º per mm of tuck. Postoperatively no patient complained of torsion. No undesirable vertical or horizontal deviations were noted. Conclusion This technique is a simple alternative to manage symptomatic excyclotorsion, with significant and stable relief of moderate amounts of torsion and without inducing unexpected vertical or horizontal deviation.

Dose Effect and Stability of Postoperative Cyclodeviation After Adjustable Harada-Ito Surgery

To report the dose-response relationship of adjustable Harada-Ito surgery, and postoperative stability of cyclodeviation. Retrospective cohort study. Twenty patients underwent a unilateral adjustable Harada-Ito advancement of the anterior fibers of the superior oblique tendon, with or without resection. The surgical dose was calculated as resection plus advancement plus adjustment. Cyclodeviation was measured using double Maddox rods at preoperative and postoperative time points. We assessed dose effect by calculating change in cyclodeviation from preoperatively to postadjustment and evaluated the dose-response relationship by Spearman rank methods. Postoperative stability of cyclodeviation was assessed by comparing postadjustment measurements with 1-day and 6-week measurements, and also 1- and 5-year measurements, when available. Change in cyclodeviation from preoperatively to postadjustment ranged from 7 to 20 degrees of incyclo effect. There was a dose effect of 1.3 degrees per mm (rs= 0.52, P= .019). Postoperative incyclodeviation unwound a mean of 3.6 degrees ± 2.5 degrees between postadjustment and day 1. Overall change between postadjustment and the 6-week window was 6.5 ± 2.9 degrees in an excyclo direction. Unwinding continued with a mean change of 0.2 ± 2.6 degrees between the 6-week and 1-year windows, and of 0.4 ± 2.1 degrees between 1-year and 5-years windows. Adjustable Harada-Ito advancement of the anterior fibers of the superior oblique tendon has a dose response of 1.3 degrees per millimeter, but its effect regresses over time. Based on our data, an immediate postoperative target incyclodeviation of 7 degrees is reasonable.

Differentiating Acute and Subacute Vertical Strabismus Using Different Head Positions During the Upright-Supine Test

Accurate clinical differentiation between skew deviation and fourth nerve palsy (4NP) is critical in the acute and subacute settings. To determine the sensitivity and specificity of the upright-supine test to detect vertical misalignment changes using different head positions for the diagnosis of acute or subacute skew deviation vs 4NP. This multicenter study enrolled consecutive patients from Coimbra University Hospital Centre, Coimbra, Portugal, and Michigan State University, Lansing, within 2 months of presenting with vertical diplopia and diagnosed as having skew deviation or acquired unilateral 4NP. The study used nonmasked screening and diagnostic test results from June 1, 2013, to December 31, 2016. Data were analyzed from January 1, 2017, to June 30, 2017. A 50% or greater change in vertical misalignment between the upright and supine positions, with the head centered and tilted to either side. Measurements included the alternate prism and cover (APC) test, the double Maddox rod test, the APC test change index ([measurement upright - measurement supine] / [measurement upright + measurement supine]), and the APC test sensitivity and specificity. Of the 37 included patients, the mean (SD) age was 58 (14) years, and 26 (70%) were male. We enrolled 19 patients (51%) with skew deviation and 18 (49%) with 4NP. Eighteen patients with skew deviation (95%) showed additional ocular motor and/or neurological signs. When moving to the supine position, only 1 patient with skew deviation (5%) showed more than a 50% decrease of hypertropia with the head centered (APC test: sensitivity, 5%; specificity, 100%). Three patients with 4NP (17%) showed more than a 50% decrease of hypertropia with the head tilted toward the hypertropic eye, and 10 patients with 4NP (56%) showed more than a 50% increase of hypertropia with the head tilted toward the hypotropic eye. Change indexes were different between the skew deviation and 4NP groups for head tilt to the hypotropic eye (difference, -0.33 prism diopters; 95% CI, -0.43 to -0.20; P < .001). Cyclotorsion worsened in the supine position only in patients with skew deviation (hypertropic eye: difference, -7.6 prism diopters; 95% CI, -13.00 to -0.75; P = .01; hypotropic eye: difference, 8.2 prism diopters; 95% CI, 0 to 15.75; P = .03). The upright-supine test with the head centered is not a sensitive method to separate acute or subacute skew deviation from 4NP. Conversion of an incomitant vertical deviation in the upright position to a comitant vertical strabismus in the supine position in all head positions, as well as the absence of additional ocular motor and/or neurologic signs, may constitute a more useful clue.

Test-retest variability of cyclodeviations measured using the double Maddox rod test

The double Maddox rod test is often used to measure cyclodeviations and to monitor change over time. The purpose of this study was to estimate test-retest reliability and the amount of cyclodeviation that would be considered real change using 95% limits of agreement. We retrospectively studied 86 clinically stable patients with double Maddox rod measurements 5-175days apart (median, 69days). The range of cyclodeviation at the first measurement was 6° incyclodeviation to 15° excyclodeviation. We calculated the half width of the 95% limits of agreement to be 4.7°, which means that a change of ≥5° in cyclodeviation would be considered a real change. The threshold of 5° should be used when assessing change between two measurements made with double Maddox rods.

Adjustable Bilateral Superior Oblique Tendon Advancement for Bilateral Fourth Nerve Palsy

Bilateral fourth nerve palsy may be symmetric or asymmetric with combined vertical and excylotropic deviations and so there may be an advantage to independent adjustment of vertical and torsional components. We report a surgical technique that allows such independent adjustment. Retrospective interventional case series. Fifteen patients, aged 17-73 years, underwent adjustable bilateral superior oblique tendon advancements for bilateral fourth nerve palsy: 11 symmetric (≤2 prism diopters [pd] hyperdeviation in straight-ahead gaze) and 4 asymmetric. Motor alignment was assessed with double Maddox rods and prism and alternate cover tests preoperatively, pre- and postadjustment, and 6weeks postoperatively. Preoperative torsion ranged from 7 to 30 degrees excyclotropia (mean 17 ± 7 degrees) and hyperdeviation from 0 to 10 pd. Preadjustment torsion ranged from 5 degrees excyclotropia to 40 degrees incyclotropia, and hyperdeviation from 0 to 8 pd. Twelve of the 15 patients (80%) were adjusted to a target of 0 pd hyperphoria and 10 degrees incyclotropia (actual mean 9 degrees incyclotropia, range 2-13 degrees incyclotropia). At 6weeks postoperatively there was expected excyclodrift (to mean 4 degrees excyclotropia, range 0 degrees incyclotropia to 15 degrees excyclotropia), but 13 (87%) had 5 degrees or less excyclotropia and 14 (93%) had 2 pd or less hyperdeviation. Mean torsional correction from preoperative to preadjustment was 31 ± 14 degrees (P < .0001), and from preoperative to 6weeks was 13 ± 6 degrees (P < .0001). Adjustable bilateral superior oblique tendon advancement allows independent control of torsional and vertical components of the deviation, and therefore may be useful in cases of bilateral superior oblique palsy.

Modified Harada-Ito Procedure in Acquired Superior Oblique Palsy with Exotropia

Superior oblique palsy is the most common isolated cranial nerve palsy and is commonly associated with exotropia. Modified Harada-Ito procedure can be used to correct excyclotorsion in symptomatic patients. We report a case of acquired superior oblique palsy with exotropia undergoing modified Harada-Ito procedure. A 33 years old man presented with torsional diplopia. On examination there was 10 degrees of left excyclotorsion on double Maddox rod with 25-diopter of exotropia on primary gaze and 20-diopter on lateral gaze suggestive of lateral incomitancy. He underwent a Fells modification of Harada-Ito procedure with bilateral rectus recession. Three months postoperative, he was orthophoric. Modified Harada-Ito procedure is a successful procedure in overcoming torsional diplopia. It is important to identify lateral incomitancy to prevent overcorrection of the horizontal deviation.

Comparison of Double Maddox Rod Test and Bagolini Striated Lens Test for Superior Oblique Palsy

Comparison of Double Maddox Rod Test and Bagolini Striated Lens Test for Superior Oblique Palsy

A technique for standardizing disk foveal angle measurement

Ocular torsion can been measured by perimetry, double Maddox rod, Bagolini glasses, indirect ophthalmoscopy lens, slit-lamp biomicroscopy, synoptophore, and fundus photography. Wide variations have been reported in the measurement of the disk foveal angle (DFA) using fundus photography. We describe a technique for measuring the DFA, formed by a horizontal line extending from the center of the optic disk and a line from the center of disk to the fovea, using Microsoft PowerPoint and ImageJ software.

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.

Measurement of Ocular Cyclotorsion in Superior Oblique Palsy Using a Single Maddox Rod

To describe a modified technique to measure ocular cyclotorsion using only 1 Maddox rod and compare it with the traditional double Maddox rod test (DMR). Ocular cyclotorsion was prospectively measured in 48 consecutive patients with superior oblique palsy. Four measurements were taken; 2 using 2 Maddox rods: (A) a red rod in front of the affected eye and a white rod in front of the fellow eye and (B) red rod in front of the sound eye and red in front of the affected eye. Two additional sets of measurements were taken using 1 red Maddox rod in front of 1 eye only, where horizontal lines in the room served as a reference: (C) the red rod in front of the affected eye and (D) the red rod in front of the sound eye. Mean ocular cyclotorsion in 48 patients was 6.7°, 6.8°, 6.6°, and 6.1° in measures A, B, C, and D, respectively. The agreement between A and C did not differ statistically, whereas the agreement between B and D was statistically different (P < 0.0001). There was high repeatability in both comparisons. Ocular cyclotorsion may be measured using a single Maddox rod instead of two. It is simpler to conduct than the DMR.