Mean Horizontal Deviation Research Articles

Characteristics and type of strabismus associated to macular diplopia. Treatment outcomes

ObjectiveTo study the clinical characteristics of macular diplopia, treatment, and outcome. MethodsRetrospective descriptive study of cases referred to the ocular motility section of a tertiary hospital with diplopia, diagnosed with macular diplopia between 2022−23. The etiology of the macular pathology and the type of associated strabismus were recorded. The result was considered good if the diplopia improved or was eliminated with the medical or surgical treatment. Follow-up time from the onset of diplopia until data collection was recorded. Resultsa total of 19 cases comprised the sample (63.2% women), mean age: 67.16 years. Amblyopia (21.1%), high myopia (47.4%), epirretinal membrane (ERM) (36.8%), neovascular membrane (26.3%), macular hole (10.5%), and lamellar (15.8%), and age macular degeneration (5.3%) were registered. The 47.4% had vertical diplopia, horizontal: 5.3 and 47.4% mixed. The mean horizontal deviation was: 7.3 PD (prism diopters) and vertical: 6.22 PD. Ocular extorsion was observed in 26.3%, and intorsion: 5.3%. Torticollis was present in 15.8%. The treatment consisted of strabismus surgery + Botox (15.8%), strabismus surgery (47.4%), medical treatment with Fresnel prims or Scotch cellophane (36.8%). A 68.4% presented a good result at the end of the study. The mean follow-up was 55.58 months. ConclusionsMisregistration of macular photoreceptors is the most common cause of binocular diplopia in patients with ERM or other macular pathologies. Most complains of vertical or mixed diplopia. Sensorimotor evaluation of these patients should be thorough. Early diagnosis prevents unnecessary prescription of prism glasses. Surgical and/or medical treatment achieves good results in most cases.

Características y estrabismos asociados a la diplopía macular. Resultados del tratamiento

ObjectiveTo study the clinical characteristics of macular diplopia, treatment, and outcome. MethodsRetrospective descriptive study of cases referred to the ocular motility section of a tertiary hospital with diplopia, diagnosed with macular diplopia between 2022-23. The etiology of the macular pathology and the type of associated strabismus were recorded. The result was considered good if the diplopia improved or was eliminated with the medical or surgical treatment. Follow-up time from the onset of diplopia until data collection was recorded. ResultsA total of 19 cases comprised the sample (63.2% women), mean age: 67.16 years. Amblyopia (21.1%), high myopia (47.4%), epirretinal membrane (ERM) (36.8%), neovascular membrane (26.3%), macular hole (10.5%), and lamellar (15.8%), and age macular degeneration (5.3%) were registered. The 47.4% had vertical diplopia, horizontal: 5.3 and 47.4% mixed. The mean horizontal deviation was: 7.3 PD (prism diopters) and vertical: 6.22 PD. Ocular extorsion was observed in 26.3%, and intorsion: 5.3%. Torticollis was present in 15.8%. The treatment consisted of strabismus surgery+Botox (15.8%), strabismus surgery (47.4%), medical treatment with Fresnel prims or Scotch cellophane (36.8%). A 68.4% presented a good result at the end of the study. The mean follow-up was 55.58 months. ConclusionsMisregistration of macular photoreceptors is the most common cause of binocular diplopia in patients with ERM or other macular pathologies. Most complains of vertical or mixed diplopia. Sensorimotor evaluation of these patients should be thorough. Early diagnosis prevents unnecessary prescription of prism glasses. Surgical and/or medical treatment achieves good results in most cases.

Teprotumumab for Thyroid Eye Disease-related Strabismus.

To assess and quantify teprotumumab's effect on thyroid eye disease-related strabismus by change in measured horizontal and vertical deviations and change in extraocular motility. We reviewed a series of patients with thyroid eye disease-related strabismus treated with teprotumumab. Exclusion criteria included age under 18 years, strabismus of alternate etiology, or thyroid eye disease-related reconstructive surgery during the treatment course. Primary outcomes were absolute (prism diopters) and relative (%) differences in horizontal and vertical deviations in primary position at distance, as well as change in ductions of the more affected eye. Secondary outcomes included incidence and timing of strabismus surgery postteprotumumab. Thirty-one patients were included, with mean age 63 years and thyroid eye disease duration 10 months. After teprotumumab, there was 6 prism diopters (39%) mean reduction in vertical deviation ( p < 0.001), without significant change in mean horizontal deviation ( p = 0.75). Supraduction, abduction, adduction, and infraduction significantly improved in the more restricted eye ( p < 0.01, p < 0.01, p = 0.04, and p = 0.01, respectively). Thirty-five percent of patients underwent strabismus surgery posttreatment, at an average 10 months after last infusion. Teprotumumab produced a statistically significant reduction in vertical but not horizontal strabismus angles in primary position at distance. Extraocular motility in all 4 ductions also improved. A substantial minority of patients still required strabismus surgery following teprotumumab.

Long-term results of strabismus surgery for treatment of esotropia in patients with Möbius syndrome

To evaluate the surgical results of Möbius syndrome esotropia following bilateral medial rectus recession with and without bilateral Hummelsheim procedure. The medical records of patients with Möbius syndrome operated on by a single surgeon from 1993 to 2022 were studied retrospectively. For each patient, age, sex, and ocular deviation before and after surgery were retrieved. Success was defined as a horizontal deviation of up to 15Δ and vertical deviation of <10Δ. Eleven patients were included. Average patient age at the time of surgery was 4 years. Eight patients with esodeviation up to 70Δ underwent bilateral medial rectus recession; 3 patients with esotropia >70Δ underwent recession plus bilateral Hummelsheim procedure. The mean esodeviation before surgery was 52.5Δ in the first group and 86.6Δ in the second group. The mean horizontal deviation at early follow-up was esotropia of 7.4Δ in the first group and of 15Δ in the second group. The early success rate was 87% in the first group and 67% in the second group. Long-term follow-up revealed exoshift in 43% of the patients in the first group and all 3 patients in the second group. In our small patient cohort of patients with Möbius syndrome, bilateral medial rectus recession corrected esodeviations of up to 70Δ. In more severe cases (>70Δ), adding bilateral Hummelsheim procedure was beneficial.

Horizontal recti-down displacement for unilateral dissociated vertical deviations – A case series

This is a case series of 3 patients of comitant horizontal deviations with unilateral dissociated vertical deviations (DVD) who underwent half tendon down displacement of horizontal recti during recession resection surgery. Out of these 3 patients, 2 had exotropia and 1 had esotropia. The mean horizontal deviation preoperatively was 31.6 ± 7.6 prism diopters (PD) and post-operatively was 3.0 ± 2.6 PD. Mean preoperative DVD was 11.3 ± 1.1 PD which had a near-complete resolution in all patients. No increase in DVD of the other eye was noticed in any of the patients. None of the patients required second surgery for correction of horizontal deviation or DVD. The DVD was corrected in all patients with no complications. Half tendon down displacement with recession and resection surgery of horizontal recti is effective in the correction of unilateral DVD in selected patients.

A randomized clinical trial on the accuracy of guided implant surgery between two implant-planning programs used by inexperienced operators

Statement of problemVarious static implant planning software packages have been developed for the purpose of static computer-assisted implant surgery. However, how different software programs affect the accuracy of implant placement is unclear. PurposeThe purpose of this clinical study was to evaluate and examine the difference in posterior implant positioning between the planned and placed positions when inexperienced operators, following a fully guided implant surgery protocol, used 2 static implant planning software packages. Material and methodsTwenty-four participants who needed single posterior implant placement were randomly divided into 2 groups based on the used implant planning software program (coDiagnostiX, n=12; Implant Studio, n=12). The dataset of the placed implant position, generated by digitizing the implant impression, was superimposed on the planned implant position. The number of horizontal, angular, and vertical deviations of the placed implants were measured for each software package and statistically analyzed with the independent t test (α=.05). ResultsThe coDiagnostiX group presented with a mean horizontal deviation at the entry point (DE) of 1.07 ±0.36 mm, mean angular deviation (DA) of 3.52 ±1.64 degrees, and mean depth deviation (DD) of −0.71 ±0.29 mm, while the mean DE, mean DA, and mean DD in the Implant Studio group were 0.97 ±0.33 mm, 3.77 ±2.16 degrees, and −0.84 ±0.30 mm, respectively. Statistically, no significant differences were found between coDiagnostiX and Implant Studio programs for all these results (P>.05). ConclusionsAcceptable accuracy of implant positioning can be expected by inexperienced operators if they follow the guidelines of either of the 2 software packages. Both the coDiagnostiX and Implant Studio programs showed similar results, with a shallower than planned implant depth of 0.71 and 0.84 mm, respectively.

Study of reliability and validity of VOG Perea® and GazeLab® and calculation of the variability of their measurements

Abstract Objective To determine the reliability and validity of VOG Perea® (VP) and GazeLab® (GL), their correlation and concordance with cover test (CT), and define the margins of variability of the measurement of angle deviation in primary position. Methods Forty-four orthotropic patients were included. Alternating prism CT, an examination with VP, and GL were performed. Intraclass correlation coefficient (ICC) was calculated to determine the reliability, and mean comparison was used to study validity. Correlation coefficient (R) between CT and each video-oculographer was calculated. Bland-Altman diagrams were used to determine concordance. All measurements were expressed in prismatic dioptres (PD). Results The mean horizontal deviation was −0.571 PD with CT; 0.22 PD with VP and 0.4 PD with GL. ICC was 0.246 [95% CI (−0.402–0.595)] in GL and 0.984 [95% CI (0.970–0.992)] in VP. Mean comparison between CT and GL was −0.9286 [CI 95% (−1.822 −0.0355)] (P = .042) and −0.8423 [95% CI (−1.7190–0.03450)] (P = .0593) for CT-VP. Correlation coefficient for VP was R = 0.5704 [95% CI (0.319–0.747)] (P = .0001) and R = 0.4539 [95% CI (0.174–0.666)] (P = .0025) for GL. Margins of variability for a single horizontal measurement in primary position with VP were ±5.22 PD and ±2 DP for GL. Conclusion Both VP and GL are reliable and valid devices. Margins of variability for a horizontal measurement are 5.22 PD in VP and ±2 PD in GL.

Estudio de la fiabilidad y la validez de los videooculógrafos VOG Perea® y GazeLab® y cálculo de los márgenes de variabilidad

ObjectiveTo determine the reliability and validity of VOG Perea® (VP) and GazeLab® (GL), their correlation and concordance with cover test (CT), and define the margins of variability of the measurement of angle deviation in primary position. MethodsForty-four orthotropic patients were included. Alternating prism CT, an examination with VP, and GL were performed. Intraclass correlation coefficient (ICC) was calculated to determine the reliability, and mean comparison was used to study validity. Correlation coefficient (R) between CT and each video-oculographer was calculated. Bland-Altman diagrams were used to determine concordance. All measurements were expressed in prismatic dioptres (PD). ResultsThe mean horizontal deviation was −0.571 PD with CT; 0.22 PD with VP and 0.4 PD with GL. ICC was 0.246 (95% CI: [−0.402]-0.595) in GL and 0.984 [95% CI: 0.970-0.992)] in VP. Mean comparison between CT and GL was −0.9286 (CI 95%: [−1.822]-[0.0355], P=.042) and −0.8423 (95% CI: [−1.7190]-0.03450, P=.0593) for CT-VP. Correlation coefficient for VP was R=0.5704 (95% CI: 0.319-0.747, P=.0001) and R=0.4539 (95% CI: 0.174-0.666, P=.0025) for GL. Margins of variability for a single horizontal measurement in primary position with VP were±5.22 PD and±2 DP for GL. ConclusionBoth VP and GL are reliable and valid devices. Margins of variability for a horizontal measurement are ±5.22 PD in VP and±2 PD in GL.

Evolving trends in strabismus following retinal surgery: is there still a role for botulinum toxin?

ABSTRACT Purpose Ocular motility disturbances following retinal detachment surgery are well documented, resulting in ocular misalignment and disabling diplopia. Interestingly, there has been a downward trend over the last decade across the United Kingdom with the evolution of refined vitrectomy techniques and instrumentation. We aim to report our updated experience on factors influencing botulinum toxin outcomes in view of the trend toward vitrectomy. Methods The Moorfields strabismus service carried out a follow-up retrospective study of all subjects that received botulinum toxin for retinal surgery-related strabismus at our center over an eleven-year period. All new onset constant or intermittent strabismus following retinal detachment surgery were included. Botulinum toxin response was stratified to good and poor. Results 32 patients fulfilled our criteria, with a mean follow-up of 20 months. The majority were vitrectomised eyes (62%), presented with diplopia (60%) and exotropia (66%). All isolated and combined vertical deviations (18%) were noted among cryobuckled eyes only. Baseline largest mean horizontal deviation was 49 and 51 prism diopters (PD) among the good and poor responders, respectively. A statistically and clinically significant reduction in the horizontal angle of deviation was noted among the good (p < .0001) responders, requiring a mean of six injections, in comparison to the poor responders (p = .03). Of the good responders, five patients (16%) with decompensated phorias regained fusion control. A small number of complications (15%) were noted, the most marked being intractable diplopia in a good responder (3%) with failure to fuse. Conclusions Botulinum toxin is a useful treatment modality, particularly when surgical options are limited. It can restore binocularity in patients with preexisting fusion potential. Ocular cosmesis can be achieved but requires ongoing injections. Barriers to fusion restoration include multiple retinal surgeries, persistent macula pathology and central-peripheral retinal rivalry. This highlights the need for rigorous baseline macula assessment to allow a tailored approach when considering botulinum toxin therapy for strabismus.

Ocular characteristics of patients with cerebral palsy

Aim: The purpose of this study is to report the ophthalmic characteristics and treatment results of our cerebral palsy (CP) patients. Materials and Methods: We explored the charts of 62 CP patients who were followed by our tertiary referral pediatric ophthalmology and strabismus department between 1998-2018 retrospectively. Patient demographics, strabismus type, preoperative deviation, type of surgery, visual acuities (VA), fundus findings, first surgery time, additional surgeries and anomalies and follow-up time were recorded. Results: Mean age and follow-up time were 34.1 and 42.6 months respectively. Most of the subjects (80.6%) had bilateral VA less than 20/200. The ratio of patients without fixation and follow was 11.2% in right eye and 14.5% in left eye. Fifty eight percent of patients had normal fundus findings. The most leading finding was bilateral optic disc pallor in abnormal fundus patients (33.8%). Fifty-six (90.1%) patients had strabismus (esotropia (ET) (50%), exotropia (XT) (35.5%), vertical deviation (4.8%). Mean horizontal deviation was 25.64±8.41 (8-40) prism diopter (PD) in ET and 25.4±9.39 (12-40) PD in XT. We performed strabismus surgery to 20.9% of patients. The most frequent surgery type was bilateral medial rectus recessions. Mean first surgery time was 35.6 months. Four (30.7%) patients who had previous strabismus surgery needed additional surgery. The most frequent additional surgery types were medial rectus advancement (50%) and inferior oblique myectomy (50%). Prematurity (19.3%), epilepsy (12.9%) and corpus callosum dysplasia and periventricular leukomalacia (12.9%) were the leading encountered additional anomalies. Conclusions: CP patients are mostly accompanied with esotropia. The management of CP patients may be challenging due to need of additional surgeries.

Partial scleral buckle removal during strabismus surgery after retinal detachment repair

To describe outcomes after partial scleral buckle removal at the time of strabismus surgery. The medical records of consecutive patients with symptomatic diplopia who underwent strabismus surgery after scleral buckling by two surgeons were reviewed retrospectively. All patients underwent forced duction testing and had a segment of the scleral buckle removed intraoperatively. Pre- and postoperative ocular motility and alignment were compared. The outcome was considered successful if residual horizontal deviation was ≤8Δ, vertical deviation ≤2Δ, and cyclotropia <5°. A total of 12 patients (mean age, 51years; range, 14-71years) with a mean horizontal deviation of 16Δ (range, 2Δ-40Δ) and mean vertical deviation of 10Δ (range, 2Δ-20Δ) were included. Three patients underwent 2 strabismus surgeries. All patients underwent intraoperative removal of a segment of the scleral buckle near a muscle being advanced or recessed at the time of surgery. An adjustable suture technique was used in 13 of 15 surgeries (86%). Orthotropia was achieved in 7 patients (58%); surgical success, in 11 (92%). Subjective resolution of diplopia was achieved in all patients, in 2 with the aid of prisms. Mean follow-up was 12.4months (range, 1-75). No patient had retinal redetachment. In this case series, removal of a segment of the scleral buckle facilitated advancement or recession of a rectus muscle and was associated with good outcomes without retinal redetachment.

Uncertainty Analysis of Bivariate Design Flood Estimation and its Impacts on Reservoir Routing

The bivariate hydrological quantile estimation may inevitably induce large sampling uncertainty due to short sample size. It is crucial to quantify such uncertainty and its impacts on reservoir routing. In this study, a copula-based parametric bootstrapping uncertainty (C-PBU) method is proposed to characterize the bivariate quantile estimation uncertainty and the impact of such uncertainty on the highest reservoir water level is also investigated. The Geheyan reservoir in China is selected as a case study. Four evaluation indexes, i.e. area of confidence region, mean horizontal deviation, mean vertical deviation and average Euclidean distance, are adopted to quantify the quantile estimation uncertainty. The results indicate that the uncertainty of quantile estimation and the highest reservoir water level increases with larger return period. The 90% confidence interval (CI) of highest reservoir water level reaches 1.56 m and 2.52 m under 20-year and 50-year JRP respectively for the sample size of 100. It is also indicated that the peak over threshold (POT) sampling method contribute to uncertainty reduction comparing with the annual maximum (AM) method. This study could provide not only the point estimator of design floods and corresponding design water level, but also the rich uncertainty information (e.g. 90% confidence interval) for the references of reservoir flood risk assessment, scheduling and management.

Surgical management of strabismus following choroidal melanoma plaque brachytherapy

To characterize intraoperative findings, surgical approach, and postoperative outcomes inpatients undergoing strabismus surgery following plaque brachytherapy for ocular melanoma. The records of all patients who underwent plaque brachytherapy for choroidal melanoma between May 2007 and June 2016 were reviewed retrospectively to identify those who subsequently required strabismus surgery. Of the 461 patients who underwent plaque brachytherapy during the study period, 13 (2.8%) met inclusion criteria. Visual acuity of the affected eye was 20/40 or better in 9 patients (69%). Preoperative horizontal deviation ranged from 0Δ to 52Δ; vertical deviation, from 2Δ to 25Δ. At final follow-up mean horizontal deviation ranged from 0 to 4Δ; vertical deviation, from 0Δ to 12Δ. Intraoperatively, all muscles directly adjacent to the treated area appeared macroscopically thicker than normal despite being functionally underacting. Magnetic resonance imaging showed enlarged muscles adjacent to the plaque radiotherapy. Microscopic examination of muscles in 2 patients showed reactive enlargement of the muscle fibers, granulation tissue, and inflammation. Persistent strabismus after plaque brachytherapy is rare. Typical findings include enlarged, underacting rectus muscles adjacent to the area of the plaque, restrictive connective tissue, and incomitant strabismus. Previously disinserted muscles may be found in abnormal locations. In this patient cohort scar tissue removal in conjunction with tightening procedures on the muscle adjacent to the plaque combined with recession of the antagonist muscle frequently resulted in good anatomical outcome.

Accuracy of a direct drill-guiding system with minimal tolerance of surgical instruments used for implant surgery: a prospective clinical study.

PURPOSEA recently introduced direct drill-guiding implant surgery system features minimal tolerance of surgical instruments in the metal sleeve by using shank-modified drills and a sleeve-incorporated stereolithographic guide template. The purpose of this study was to evaluate the accuracy of this new guided surgery system in partially edentulous patients using geometric analyses.MATERIALS AND METHODSFor the study, 21 implants were placed in 11 consecutive patients using the direct drill-guiding implant surgery system. The stereolithographic surgical guide was fabricated using cone-beam computed tomography, digital scanning, computer-aided design and computer-assisted manufacturing, and additive manufacturing processes. After surgery, the positional and angular deviations between planned and placed implants were measured at the abutment level using implant-planning software. The Kruskal-Wallis test and Mann-Whitney U test were used to compare the deviations (α=.05).RESULTSThe mean horizontal deviations were 0.593 mm (SD 0.238) mesiodistally and 0.691 mm (SD 0.344) buccolingually. The mean vertical deviation was 0.925 mm (SD 0.376) occlusogingivally. The vertical deviation was significantly larger than the horizontal deviation (P=.018). The mean angular deviation was 2.024 degrees (SD 0.942) mesiodistally and 2.390 degrees (SD 1.142) buccolingually.CONCLUSIONThe direct drill-guiding implant surgery system demonstrates high accuracy in placing implants. Use of the drill shank as the guiding component is an effective way for reducing tolerance.

Predictability of horizontal versus vertical muscle surgery outcomes in thyroid eye disease.

Surgical repair of vertical muscles in thyroid eye disease (TED) is believed to yield more unpredictable results than horizontal muscle surgery. The purpose of this study is to determine if the short-term outcomes for strabismus surgery in TED are equally predictable for horizontal and vertical muscle surgery. We retrospectively reviewed the charts of 27 consecutive patients who underwent strabismus surgery for TED from a single surgeon's practice. Eligibility for inclusion in the study included biochemically stable thyroid disease for at least a year and stable orthoptic measurements for at least 6months prior to surgery. Nine patients had surgery only on vertical rectus muscles, three only on horizontal, and fifteen on both vertical and horizontal rectus muscles. Mean follow-up was 2.4±5.2months. In primary gaze at 6m, a mean horizontal deviation of 16.6±22.3 PD, and a mean vertical deviation of 19.7±14.1 PD were measured pre-operatively. Post-operatively, this measured 2.3±8.4 PD horizontally and 2.1±7.8 PD vertically (p=0.933). There was no statistically significant difference between post-operative horizontal and vertical deviations in elevation, depression, adduction, and abduction. Nine patients required reoperation to attain satisfactory ocular alignment; seven of these cases involved repeat surgery on vertical muscles, while two cases required operation on both horizontal and vertical muscles. Results suggest that surgical outcomes of both horizontal and vertical muscle surgery are equally predictable in stable TED; however, reoperation rates were higher for vertical muscles compared to horizontal muscles.

Clinical Features and Outcomes of Strabismus Treatment in Third Cranial Nerve Palsy during a 10-Year Period.

Purpose:To evaluate the demographics and management outcomes of strabismus surgery in patients with third cranial nerve palsy.Methods:This retrospective study includes subjects with third cranial nerve palsy. We evaluated age, sex, laterality, severity of involvement, etiology, frequency of clinical findings, and types and results of treatments.Results:52 patients including 29 male and 23 female subjects with mean age of 21.1±15.5 years were studied between January 1999 and January 2009. Etiologies of third nerve palsy included congenital in 16 (30.8%), trauma in 26 (50%) and other causes in 10 (19.2%) patients. In 24 patients (46.2%), the palsy was complete. The most common type of strabismus was exotropia associated with hypotropia (40%). Medical treatment was used in 25 (48%) and surgical treatment in 46 (88.4%) subjects. One time strabismus surgery was performed in 30 (65.2%), 2 times in 11 (24%) and 3 times in 5 (10.8%) subjects. The most common operation was large horizontal recession and resection in 78.2% of cases. Mean horizontal deviation in primary position was 66±29 prism diopters (PD) before surgery decreasing to 21±19, 13±12 and 6±8 PD after first, second and third surgery, respectively. Corresponding figures for mean vertical deviation were 13±15, 7±12, 4±6 and 1±2 PD, respectively. Abnormal head posture was 10-30° in 11 (21.1%) cases before treatment which completely resolved after surgery.Conclusion:Surgical management of strabismus in patients with third nerve palsy is difficult and challenging, however the majority of patients achieve ideal results with appropriate and stepwise surgical plans.

Treatment for diplopia in patients with myasthenia gravis

The purpose of this study was to describe the treatment experiences and outcomes of patients with myasthenia gravis (MG) whose initial presenting symptom was diplopia A retrospective review was performed on a group of patients with MG whose initial presenting symptom was diplopia. The mean age of onset was 45.5 ± 16.9 years, and the mean follow-up period was 45.4 ± 39.7 months. Exotropia with vertical heterotropia was the most common type of deviation. The mean horizontal deviation was 20.1 ± 17.9 prism diopters, and the mean vertical deviation was 14.8 ± 11.1 prism diopters. Limitation of eye movement was found in 20 patients (71.4 %) during the follow-up period. After conventional treatment for MG, six patients (21.4 %) showed a good response with resolution of diplopia. Four patients (14.3 %) showed a partial response to treatment. Eighteen patients (64.3 %) showed minimal or no response; among them, ten (35.7 %) had an angle of deviation of 15 prism diopters or more. Six patients underwent strabismus surgery. Four were symptom free, and satisfactorily aligned after surgical treatment. One patient had intermittent diplopia despite the small amount of deviation, and one patient experienced recurrence of exotropia with diplopia during the 10-year follow-up. In multivariable analysis, the only factor associated with the need for strabismus surgery was the initial angle of deviation (p = 0.016). Patients with MG who have a larger angle of deviation at presentation tend to require strabismus surgery after stabilization of the disease. Strabismus surgery is one treatment option for patients with MG who have a large angle of deviation and respond poorly to conventional treatment.

Horizontal deviation as diagnostic and prognostic values in isolated fourth nerve palsy

Background/AimsTo investigate the causes of isolated fourth nerve palsy (IFNP) and the association among aetiology, prognosis and ocular deviation.MethodsA total of 126 consecutive cases of IFNP was retrospectively reviewed. According...

Ocular alignment and results of strabismus surgery in neurologically impaired children.

To evaluate ocular alignment and surgical results of strabismus surgery in neurologically impaired children. Files of 33 neurologically impaired squint children were evaluated. Twelve patients had cerebral palsy(CP), 4 had CP with mental retardation, therest had mental-motor retardation of unknown cause. Cycloplegic refractions, type and angle of strabismus, surgeries performed were recorded. Mean follow-up was 34.0±16.5 months. Twenty-three patients had esodeviation, the remaining had exodeviation. In 19 patients, angle of deviations measured at different visits were highly variable. Twelve patients with stable angle of deviations or with unstable but high angle deviations had horizontal muscle surgery. Mean horizontal deviation decreased from 43.75±10,69 D to 12.83±8.38 D with surgery. In neurologically impaired strabismic children, surgery is effective in patients with stable deviations or unstable but high angle deviations. Decision for surgery should be made after a long follow up period.

Horizontal Misalignment in Patients with Unilateral Superior Oblique Palsy

To determine the frequency and distribution of horizontal misalignment in patients with unilateral superior oblique palsy (SOP) and to determine the indications for combining horizontal with vertical strabismus surgery. Patients included in the study had a vertical heterophoria or tropia that fit Parks three-step test for SOP and had no previous strabismus surgery or other ocular motility disturbance. Ocular motility and alignment were recorded. Outcomes between patients who had vertical surgery alone and those who had combined vertical and horizontal surgery were compared using the Student's t test. Of 205 patients, 121 (59.0%) had a horizontal misalignment in addition to vertical strabismus. Ninety-six patients (46.8%) required strabismus surgery. Of these, 29 had 8 prism diopters (PD) or more horizontal deviation. Twenty-two had vertical combined with horizontal surgery (V+H group). Although their initial deviation was greater, these patients had better surgical outcomes than patients who had vertical surgery alone (V group). The V+H group had a final mean horizontal deviation of 2.18 PD compared with 6.85 PD in the V group (P < .01). Postoperative vertical alignment in the V+H group was also superior with a final mean vertical deviation of 3.7 versus 6.8 PD for the V group (P = .12). These results indicate that horizontal misalignment is common in patients with SOP. Patients with 8 PD or more horizontal deviation benefited from surgical correction of the horizontal deviation in addition to the vertical surgery.