Clinical characteristics of surgically treated adult strabismus

Strabismus Surgery for Psychosocial Reasons-A Literature Review

Introduction

Strabismus surgery may be undertaken for visual benefit, to improve or eliminate diplopia symptoms, or to restore or improve binocular single vision (BSV). In patients without visual symptoms or expected visual benefit, strabismus surgery may still be undertaken if the presence of strabismus causes the patient psychosocial symptoms. To evaluate strabismus surgery undertaken for psychosocial reasons, evidence of postoperative outcomes in this specific cohort is needed.

Methods

A systematic search of the literature was conducted (1946-2023) to identify evidence where postoperative outcomes were reported for adult patients (age 18 years and above) who had undergone strabismus surgery for psychosocial reasons.

Results

Sixty-nine papers were included in the literature review. Most sources of evidence included patients within heterogeneous cohorts of strabismus surgery outcomes, with a range of symptoms and differing surgical aims.

Discussion

In adults who underwent strabismus surgery for psychosocial reasons, improved postoperative ocular alignment and/or improved health related quality of life (HRQoL) were common. Strabismus surgery outcomes appeared to be measured satisfactorily at three months postoperatively. Additional surgical outcomes, including an expanded field of vision, unexpected BSV, improved binocular summation, improved task performance and improved eye movements have been reported, but not fully investigated. There was a lack of consensus on how postoperative success should be defined and measured. A core outcome set for strabismus has been suggested and there is potential to add to the available evidence by investigating which outcome measures are most relevant to those with strabismus and psychosocial symptoms. There is a growing need for robust evidence in this specific subgroup of patients due to a lack of evidence specifically reporting postoperative outcomes in adults with strabismus and psychosocial symptoms.

Binocular Function in Adults before and after Strabismus Surgery

PURPOSE

To evaluate the state of binocular vision, the amount and direction of the ocular deviation before and after strabismus surgery in adult patients and to monitor the occurrence of postoperative complications.

METHODS

The retrospective study of 58 adult patients with selected types of strabismus who were surgically treated in the Eye Department of the Tomas Bata Regional Hospital in Zlín. We evaluated the amount and the degree of the primary ocular deviation and the binocular alignment before and after surgery,  as well as the state of binocular vision after surgery and the occurrence of postoperative complications.

RESULTS

The average deviation in convergent strabismus before surgery was +23.46 degrees, after surgery +6.6 degrees, in divergent strabismus it was -21.5 degrees, after surgery -1.48 degrees, for vertical strabismus before surgery +12.5 degrees and +3.75 degrees after surgery and in paralytic strabismus +20 degrees before surgery and +3 degrees postoperatively. Preoperatively there was effectively no binocular vision in up to 63.9% of patients, superposition occurred in 31%, fusion in 5.1%. No patient had stereopsis before surgery. After surgery, superposition was present in 39.7%, fusion in 31% and stereopsis in 6.9% of patients. Only 22.4% of patients experienced no binocular vision after surgery. Of the selected 21 patients out of 58 with an observation period of at least 3 years, we observed an improvement or development of binocular vision functions after surgery in 12 patients and no improvement of binocular vision functions in 9 patients. In the first group, 58.3% had a stable deviation throughout the follow-up period. While in the second group the deviation was stable in only 33.3%. We can assume that the improvement in binocular vision function after strabismus surgery, leads to a greater longer-term stability of postoperative deviations.

CONCLUSION

Strabismus surgery in adult patients is an effective and safe method, which is not only a cosmetic procedure used to adjust the position of the eyes, but also enables us to induce or improve the state of binocular vision functions.

Adults with Longstanding Strabismus: Psychosocial and Functional Impacts and Reasons behind Surgery Delay

Purpose

The aims of the study were to determine the reasons behind surgical correction delay in adult patients with strabismus, reveal motivations for seeking treatment, and study the psychosocial and functional impacts of strabismus on patients using an Arabic version of the Adult Strabismus-20 (AS-20) questionnaire. Methods and Patients. This study included 79 patients aged ≥18 years and had strabismus for at least one year prior to surgical correction and 40 controls without known visual defects. After a comprehensive ophthalmic exam during their preoperative visit, a validated questionnaire was administered to patients to collect sociodemographic data, reasons for surgery delay, and motivations for seeking treatment now. A translated version of the AS-20 questionnaire was then presented to patients and controls. Total AS-20 (and its subscales: psychosocial and function) scores were calculated and analyzed. All relationships between sociodemographic characteristics, the onset of deviation, presence of diplopia, type and size of deviation, and the changes in the scores of AS-20 (and its subscales) were investigated.

Results

A total of 79 adult patients with strabismus (cases) and 40 subjects with normal vision (control group) were included in this study. The mean age (SD) was 34.10 (11.5) years for cases (range: 18–61) and 34.20 (11.2) years for controls (range: 18–65) (p=0.964). About half (55.7%, n = 44) of the patients were males compared to (57.5%, n = 23) of the controls. The reasons for strabismus surgery delay reported by the patients were the following: surgery was not offered by an ophthalmologist (35.4%), surgery was offered but declined by the patient due to fear from surgical complications (22.8%), nonaffordability (17.7%), surgery was offered but refused because patients thought they were too old for surgery or patient was not bothered by appearance (15.2%), and patient never sought care (8.9%). The reasons for seeking surgical treatment after this delay were as follows: for cosmetic issues (27.8%), a better understanding of strabismus surgery and its potential complications (20.3%), pressure from family and friends (16.5%), improved economic status (13.9%), relationship/marriage prospects (13.9%), and to improve chances of getting a job (7.6%). When compared to control, patients have significantly lower mean scores of total AS-20 (50.57 vs. 88.01) and its psychosocial (49.59 vs. 87.84) and functional (51.55 vs. 88.19) subscales. AS-20 total score was significantly lower among females and in patients with large deviation size (>25 PD). The psychosocial subscale of AS-20 was significantly lower in females, patients with younger age of onset, and those with large deviation size (>25 PD). Female gender, large deviation size, vertical deviation, and having diplopia correlated significantly with a lower functional score.

Conclusion

Strabismus has a profound psychosocial and functional impact on affected individuals, especially females and patients with large deviation sizes. Many adult patients with strabismus tend to delay surgical correction; most of these delays could be avoided by better public education, increased awareness among health care providers, and changing health insurance policies to cover the costs of strabismus surgery.

Extraocular muscle resection, recession length and surgery outcome modelling in strabismus treatment: a pilot study

Background

Many surgical formulas have been developed and proposed based on the experience of surgeons to improve the predictability of strabismus surgery. However, the consent among strabismus surgeons regarding the dose effect of the extraocular muscle (EOM) recession or resection was not achieved yet and the disagreement about the appropriate amount of strabismus surgery still exists.

Objective

Our study aimed to propose an instrument for EOM resection (RsL) and recession length (RcL) estimation before the surgery and second to elaborate an postoperative angle of deviation (PAD) predictive model using simple potential predictors.

Methods and Analysis

The analytical prospective clinical study was conducted from April 2016 to July 2019, on a sample of 216 patients (aged between 2–58) with concomitant strabismus who underwent strabismus surgery in Clinical Republican Hospital ‘Timofei Mosneaga’and Children Hospital ‘Em Cotaga’ from Republic of Moldova. The correlations of patients’ age, strabismus type, amblyopia degree, RsL, RcL, preoperative angle of deviation (PreAD) with PAD were estimated using Pearson’s correlation analysis. Multiple linear regression analysis, multicollinearity analysis and residual analysis were performed.

Results

The EOM RsL was predicted using strabismus type, patient’s age, PreAD and EOM RcL. EOM RcL, in turn, was estimated by the similar covariates set, instead of RcL being RsL. PAD modelling showed the PreAD, EOM RsL and EOM RcL predictive ability for strabismus surgery outcome prediction.

Conclusion

In our study, we propose four mathematical models as potential instruments for EOM RsL, EOM RcL and PAD modelling in esotropia and exotropia surgery.

Survival analysis of adult and children intermittent exotropia using a matched case-control design

To compare the surgical outcomes of adult intermittent exotropia (X(T)) patients and matched control children X(T) patients including survival analysis. Fifty-two adult X(T) patients and 129 matched control children X(T) patients were included. Clinical characteristics, survival analysis, and surgical dose-response curves were evaluated and compared between the two groups. The weighted Cox proportional hazards regression analysis was used in order to find risk factors for the recurrence. Using Kaplan-Meier survival analysis, the cumulative probability of survival rate considering recurrence as event of Adult group were 93.97% for one year, and maintained at 88.44% for two, three. four, and five years after surgery. In contrast, those of the Child group were 83.6%, 76.5%, 65.6%, 56.23%, and 40.16% for one, two, three, four, and five years after surgery, respectively. The Adult group had a better event-free survival curve than the Child group as analyzed by a Log-rank test (p = 0.020). According to multivariate weighted Cox regression analysis, the younger age at operation and the larger preoperative angle were significant risk factors for recurrence.

Clinical profiles and surgical outcomes of adult esotropia

OBJECTIVE

The aim of this study was to describe the clinical features and surgical outcomes of teenage and adult patients with esotropia undergoing strabismus surgery with adjustable sutures.

METHODS

Seventy-three patients were included in this retrospective, cohort study. Patients were stratified into group 1 (35 with childhood-onset esotropia [CET]) and group 2 (38 with adult-onset esophoria-tropia [EPT]). Preoperative immediate, 2-week, and 4-6-month postoperative measurements of ocular alignment, as well as fusional testing, were performed. Postoperative success was defined as distant (6 m) and near (33 cm) alignment within 12 prism diopters (PDs) of orthotropia in the primary position at 2 weeks and at 4-6 months with a single surgery.

RESULTS

Patients with CET more frequently had hyperopia and amblyopia and were more likely to present for surgery because of psychosocial strabismus-related problems. Patients with EPT predominantly had myopia and were more likely to experience diplopia and asthenopia. In group 1, the mean preoperative distance deviation improved from 30 PDs to 4 PDs at 2 weeks and to 4 PDs at 4-6 months (p < 0.001). In group 2, mean preoperative distance alignment improved from 22 to 3 PDs at 2 weeks and to 3 PDs at 4-6 months (p < 0.001). The mean objective, single-surgery success rate at 2 weeks was 88% and 97% in groups 1 and 2, respectively. At 4-6 months, postoperative success was 71% in group 1 and 80% in group 2. The majority of patients reported subjective improvement.

CONCLUSIONS

There are distinct preoperative differences between CET and EPT patients. Adjustable, strabismus surgery in this cohort is safe and effective in achieving subjective and objective success.

Factors associated with surgical success in adult patients with exotropia

PURPOSE

To report the results of surgical treatment for intermittent or constant comitant exotropia in adults and to examine the factors associated with the surgical outcome.

METHODS

The medical records of consecutive patients older than 18 years of age at the time of surgery for intermittent or constant comitant exotropia and with at least 1 year's follow-up were retrospectively reviewed. Surgical success was defined as postoperative esodeviation of <5^Δ, orthotropia, or exodeviation of <10^Δ. Overcorrection (defined as esodeviation >5^Δ) and recurrence (exodeviation of >10^Δ) were considered surgical failure. Preoperative patient characteristics, surgical procedures performed, and early postoperative ocular alignment were evaluated as potential factors associated with the surgical outcome.

RESULTS

A total of 39 patients were included, of whom 28 (72%) achieved surgical success, 7 (18%) showed overcorrection, and 4 (10%) had recurrence. Alignment at postoperative week 1 was the only significant factor correlated with surgical results. Surgical outcome was best with early postoperative alignment of <10^Δ of esotropia.

CONCLUSIONS

Early postoperative overcorrection of <10^Δ resulted in more favorable surgical outcomes in adults undergoing surgery to treat exotropia.

Incorporating Health-related Quality of Life Into the Assessment of Outcome Following Strabismus Surgery

PURPOSE

To evaluate changes in health-related quality of life (HRQOL) in adult strabismus patients classified as surgical failures by standard motor and diplopia criteria.

DESIGN

Prospective cohort study evaluating outcomes.

METHODS

Adults undergoing strabismus surgery in a single clinical practice, with preoperative and 1-year-postoperative Adult Strabismus-20 HRQOL questionnaires, were included. Motor and diplopia criteria were applied to classify outcomes (success, partial success, or failure). For those classified as failure, the medical record of the 1-year examination was reviewed to determine whether the patient reported subjective improvement. We evaluated improvement in HRQOL, defined as exceeding 95% limits of agreement on at least 1 of the 4 Adult Strabismus-20 domains. We compared proportions exceeding 95% limits of agreement in those reporting subjective improvement vs those who did not.

RESULTS

Forty of 227 patients (18%) were classified as failure by motor and diplopia criteria, with 39 of 40 able to exceed Adult Strabismus-20 95% limits of agreement. Overall, 21 of 39 (54%) showed improved HRQOL by exceeding 95% limits of agreement on at least 1 of the 4 Adult Strabismus-20 domains (54% vs predicted 10% by chance alone; P < .0001). Twenty-five patients (64%) reported subjective improvement, of whom 16 (64%) showed improved HRQOL exceeding 95% limits of agreement.

CONCLUSIONS

Many apparent surgical failures report subjective improvement, often reflected in improved HRQOL scores. We propose incorporating quantitative HRQOL criteria into the assessment of strabismus surgery outcomes, defining success as either meeting motor and diplopia criteria or showing improvement in HRQOL beyond test-retest variability.

Impact of strabismus surgery on health-related quality of life in adults

PURPOSE OF REVIEW

Adult strabismus can cause many symptoms, which have generally been divided into functional complaints and social complaints. The validity of surgical correction has historically been based on the restoration of functional improvement. In the absence of this expectation, surgery was labeled cosmetic. Yet, many studies have revealed the immense impact of ocular misalignment on psychosocial variables. The purpose of this article is to review the potential functional and psychosocial benefits of strabismus surgery and to summarize the development and status of questionnaires to help quantify these benefits.

RECENT FINDINGS

Functional benefits of strabismus surgery have been recently summarized with a meta-analysis. Several questionnaires have been evaluated to assess the functional and psychosocial factors in adult strabismus. Two strabismus-specific questionnaires, the Amblyopia and Strabismus Questionnaire and the Adult Strabismus-20, reveal improvements in adults following surgery. The appropriate patient population, impact of comorbidities on the scores, and the timing of the administration of the questionnaire postoperatively still need to be determined.

SUMMARY

Future studies of the impact of strabismus surgery in adults will need to report not only objective motor results, but also the impact on health-related quality of life to encompass all the benefits of strabismus surgery.

Goal-determined metrics to assess outcomes of esotropia surgery

PURPOSE

To report outcomes of esotropia surgery with a goal-determined tool.

METHODS

A goal-determined outcomes analysis tool was devised to address a quality improvement initiative at Boston Children's Hospital. Surgeons preoperatively ranked four possible goals for intervention: enhancement of binocular potential, restoration of eye contact (reconstructive), management of diplopia, and resolution of torticollis. Criteria for success were goal specific; the primary outcome measure was surgical success at 2-4 months. Secondary outcomes included appraisal of risk factors and a comparison of outcomes with this methodology versus traditional criteria for success based on motor alignment. No patients were excluded based on diagnosis, systemic and ocular risk factors, or intervention performed.

RESULTS

A total of 824 patients underwent esotropia surgery from 2006 to 2012 and returned for evaluation at 2-4 months' follow-up. Of these, 777 had sufficient documentation for inclusion: 372 procedures were performed primarily to improve binocular potential; 238, to restore eye contact; 124, to resolve diplopia; and 43, to remediate torticollis. Excellent (71%) or good (13.7%) results were obtained in 84% of cases. Without associated risk factors, 75% had excellent and 14% had good outcomes. Risk factors were present in 444 (57%). Success diminished with prior strabismus surgery (P = 0.004), preoperative angle ≥50(Δ) (P = 0.002), and surgery before 12 months of age (P = 0.003). Patients having surgery to remediate diplopia had the best outcomes (excellent, 79%; good, 8%). Preoperative ranking of goals allowed demonstration of better results than would have been reported with requirement of "traditional" motor alignment criteria (P = 0.009).

CONCLUSIONS

Goal-determined methodology can be useful for monitoring outcomes of esotropia surgery in diverse populations.

Comparing outcome criteria performance in adult strabismus surgery

PURPOSE

To evaluate the performance of motor, diplopia, and health-related quality of life (HRQOL) criteria when analyzing outcomes of adult strabismus surgery.

DESIGN

Cohort study.

PARTICIPANTS

We studied 159 adults undergoing 171 strabismus surgeries.

METHODS

All patients underwent clinical assessment preoperatively and 6 weeks postoperatively, including completion of Adult Strabismus-20 HRQOL questionnaires. Preoperatively, strabismus was classified as either diplopic (n = 117), nondiplopic (n = 38), or atypical diplopic (n = 16). To assess performance of motor, diplopia, and HRQOL criteria, success was defined a priori and applied separately and in combinations. For success: (1) motor criteria, <10 prism diopters by simultaneous prism cover test; (2) diplopia criteria, none or only rare in primary distance and for reading; (3) HRQOL criteria, exceeding previously reported 95% limits of agreement (LOA).

MAIN OUTCOME MEASURES

Surgical success rate when applying motor, diplopia, and HRQOL criteria alone and in combinations.

RESULTS

Overall, success rates were 90% for motor criteria, 74% for diplopia criteria, and 60% for HRQOL criteria. Combining criteria, the highest success rate was for motor plus diplopia criteria (67%) and the lowest success rate was when combining motor, diplopia, and HRQOL criteria (50%).

CONCLUSIONS

Applying motor criteria alone yields the highest success rates when evaluating outcomes in adult strabismus surgery, but motor criteria do not fully represent the patient's postoperative status. Combining diplopia criteria with motor criteria provides a more clinically relevant standard for judging the success of adult strabismus surgery. For HRQOL criteria, exceeding 95% LOA at 6 weeks postoperatively seems to be a difficult hurdle to clear for some individual patients, and evaluating change in HRQOL score may be more useful in cohort studies.

Comparison of the stability of postoperative alignment in sensory exotropia: adjustable versus non-adjustable surgery

Purpose

To compare the success rates and stabilities of postoperative alignment between adjustable and the non-adjustable surgeries in the treatment of sensory exotropia.

Methods

A retrospective analysis was performed on all patients with sensory exotropia who had undergone unilateral lateral rectus recession and medial rectus resection (R&R) between January 1998 and August 2005. Thirty-four patients underwent conventional R&R, and 20 patients underwent R&R with adjustable suture of the lateral rectus. The surgical results between the two groups were analyzed with regard to the preoperative and post-operative deviation angles and the postoperative drift. The postoperative deviation angle was measured on postoperative day 1 as well as at two weeks, three months, six months and the final visit after surgery.

Results

There were no statistically significant differences in the mean preoperative and postoperative deviation angles between the two groups. In 30 (88%) patients in the non-adjustable group and 15 (75%) patients in the adjustable group, postoperative deviation was less than 15 prism diopters (PD) at the three month follow-up. There was no significant difference in the mean postoperative drift between the two groups.

Conclusions

Strabismus surgery with adjustable sutures did not show a significantly better result than surgery without adjustable sutures in the treatment of sensory exotropia. Considering the amount of postoperative exodrift in both groups, we postulate that the immediate ocular alignment after surgery for sensory exotropia should be orthophoric or 5-6 PD of esodeviation.

Factors affecting sensory functions after successful postoperative ocular alignment of acquired esotropia

PURPOSE

We sought to evaluate the sensory status of patients with acquired esotropia who were able to re-establish stable alignment by optical correction and surgery and to determine the possible predictors of the different sensory outcomes.

METHODS

Thirty-four successfully aligned esotropic patients were included in the study. Preoperative evaluation comprised history taking, measurement of visual acuity, evaluation of the sensory status (using the Worth 4-Dot test, and the Titmus Stereo test), measurement of ocular deviation, cycloplegic refraction, and fundus examination. All patients underwent successful surgical alignment to within 10 prism diopters (Delta) of orthotropia. At each postoperative follow-up visit, the sensory functions and ocular alignment were assessed. Statistical analysis of the results was performed.

RESULTS

Among the 34 patients included in the study, 62% achieved fusion, 17% had diplopia, 15% had suppression, and 6% had a variable response to the Worth 4-Dot test at 6 months after surgery. Stereopsis was achieved in 32% as determined by the Titmus Stereo test. Statistical analysis revealed a significant relationship between the sensory status and the duration of strabismus (P=.00002), the age at surgery (P=.00289), and postoperative ocular alignment (P=.02211).

CONCLUSION

Early surgical and optical ocular alignment of strabismic patients is advisable to achieve fusion and stereopsis.

Disruption and reacquisition of binocular vision in childhood and in adulthood

PURPOSE OF REVIEW

This article reviews the most recent studies that address the loss of and restoration of binocular vision in childhood and adulthood and summarizes recent changes in treatment approaches.

RECENT FINDINGS

Studies during the last two years support the idea of continued plasticity of the binocular visual system throughout life. Children and adults with strabismus onset following binocular vision maturation are susceptibility to a permanent disruption of stereopsis and sensory fusion. Plasticity of the binocular visual system, however, also means continued restorability of function. Despite a rather short critical time interval for restoration of normal function (three months in children and 12 months in adults), peripheral or extramacular binocular visual function can be restored in most patients whose onset of disruption follows binocular maturation.

SUMMARY

Stereoacuity loss can occur in the visually mature patient who develops strabismus later in life and delay of treatment can be deleterious to the restoration of normal macular binocular vision. However, despite any delay of treatment, most patients with strabismus acquired following binocular vision maturation will manifest some stereoacuity or sensory fusion following eye realignment. These findings suggest all patients with strabismus need to have their eyes aligned, either surgically or optically, to maximize their binocular vision outcome.

The management of strabismus in adults--II. Patient and provider perspectives on the severity of adult strabismus and on outcome contributors

PURPOSE

As part of a larger study intended to evaluate the management of strabismus in adults, we documented and compared patient and provider perspectives on the various factors that may contribute to treatment outcome and value of strabismus care.

METHODS

By completing a questionnaire, 170 patients with strabismus (ages 19 to 87 years) and 11 strabismus specialists who performed surgery on these patients each indicated the relative weight of several disease- and treatment-related contributors to the outcome and value of care. In addition, each respondent rated the severity of the strabismus before and after surgery.

RESULTS

Overall severity ratings improved as a result of surgery. The improvement perceived by the physicians was 5.1 +/- 1.7 on a 10-point scale and was larger than the 2.6 +/- 3.6 points improvement perceived by the patients ( P < 0.001). Patients and physicians expressed different views on the relative contributions to outcome and value (overall P < 0.001). Both groups indicated "the condition," "the physician," and "the procedures" as the largest contributors, but "condition" was perceived as more important by the physicians than by the patients ( P < 0.001), and "physician" was more important to the patients than to the physicians ( P < 0.001).

CONCLUSION

Although in approximate agreement on the main contributors to outcome and value, discrepancies exist between perspectives of patients and physicians on the relative weights of those contributors. Public information, education, and counseling may bring these perspectives better in line and ultimately improve both quality and patient satisfaction.

Factors influencing stereoacuity outcomes in adults with acquired strabismus

PURPOSE

Functional improvements of binocular vision after strabismus surgery in adults are common but not well understood. In a prospective study, factors associated with stereoacuity outcome in patients with strabismus acquired following binocular vision maturation were investigated.

DESIGN

Prospective data collection.

METHODS

Twenty-three patients aged 14 to 85 years with acquired strabismus were enrolled. Random dot stereoacuity was quantified using a battery of tests including the Randot Preschool Stereoacuity test, the Randot (version 2) shapes test, and the Randot Butterfly test.

RESULTS

Ninety-six percent of patients achieved measurable stereoacuity following successful eye realignment. Better median stereoacuity is achieved in patients with the following characteristics: < or =12 months of constant strabismus (60 vs 400 seconds of arc with >12 months' strabismus, P < .001); a presurgical capacity for fine to moderate stereopsis (60 vs 400 seconds of arc with coarse or no measurable stereopsis, P < .005); a presurgical capacity for macular fusion (60 vs 400 seconds of arc with no measurable macular fusion capacity, P < .001); and postsurgical orthotropia (100 seconds of arc) or intermittent orthotropia (100 seconds of arc vs 2000 seconds of arc with 5 to 8 prism diopters (PD) of postsurgical residual strabismus, P < .05).

CONCLUSION

Surgical correction of acquired strabismus is associated with recovery of stereopsis. Factors associated with stereoacuity outcomes include duration of strabismus and presurgical binocular vision capacity. A postsurgical correction of orthotropia or intermittent orthotropia supports better stereoacuity than a larger residual angle of strabismus subtending up to 8 PD of deviation.

Adjustable and non-adjustable strabismus surgery: a retrospective case-matched study

Adjustable suture strabismus surgery was introduced to improve results in unpredictable strabismus cases. However, its usage is increasing and in some centres is routine. The present authors propose that the routine use of the adjustable suture technique can only be justified if it can be shown to confer an advantage to the patient. In a retrospective analysis of matched data, they compared the results of their adjustable with non-adjustable strabismus surgery. The adjustable suture procedures performed during a 5-year period, on non-thyroid eye disease patients, were matched to non-adjustable cases according to the type and aetiology of strabismus and the magnitude of deviation. Pairs were matched as closely as possible according to age and strabismus surgery history. All cases were incomitant. The surgical results of the two groups were analysed with regard to the pre-operative and post-operative angles of deviation, the post-operative drift, and a successful outcome, pre-defined by carefully selected criteria. Twenty-six cases were analysed in each of the two groups. Mean pre- and post-operative angles of deviation showed no significant difference between the two groups. 'Success' rates were 81% in the adjustable group and 88% in the non-adjustable group. Given that the success rate of the two techniques is similarly high, a much larger study is required to detect a difference in results, with statistical significance. The authors conclude that there is currently insufficient evidence that patients, without thyroid eye disease, benefit from the longer and potentially uncomfortable procedure of adjustable suture strabismus surgery to support its rapidly growing use and that a prospective randomised controlled trial is indicated.

Relationships between visual acuity and anomalous head posture in patients with congenital nystagmus

PURPOSE

To determine whether patients with congenital nystagmus and an anomalous head posture have better binocular visual acuity than such patients without an anomalous head posture.

PATIENTS AND METHODS

This was an observational case series of prospectively collected data for 125 patients with clinical and oculographically confirmed congenital nystagmus. Clinical data were tabulated using computer software. Statistical analyses compared binocular visual acuity with and without the presence of a clinically evident anomalous head posture and visual acuity with and without associated sensory disease.

RESULTS

The mean visual acuity was 20/42 (log of the minimal angle of resolution [MAR], 0.32) in patients with an anomalous head posture and 20/83 (logMAR, 0.62) in patients with no anomalous head posture (P < .001). Among patients with disease of the sensory system, those with an anomalous head posture had a mean visual acuity of 20/55 (logMAR, 0.44) and those without an anomalous head posture had a mean visual acuity of 20/108 (logMAR, 0.73; P < .001).

CONCLUSIONS

Visual acuity was found to be significantly better in patients with congenital nystagmus who had an anomalous head posture versus those without such a head posture. Our findings indicate that the presence of an anomalous head posture in a patient with congenital nystagmus correlates with good vision and thus may be considered a positive prognostic sign in a preverbal child.

The management of strabismus in adults--I. Clinical characteristics and treatment

INTRODUCTION

This is the first in a series of articles intended to evaluate the management of strabismus in adults, including clinical outcomes and the quality, cost, and value of treatment from the perspectives of patients and health care providers. Here we present clinical characteristics, complexity of surgery, treatment success, and resolved complaints in a group of adult patients who underwent strabismus surgery.

METHODS

This is a multicenter retrospective study analyzing the type and amount of ocular misalignment before and after surgery in adult patients with strabismus onset before (BVM, or age < 9 years) or after (AVM, or age >/= 9 years) visual maturation. Success was evaluated in terms of alignment, motility, and the presence of diplopia; subjective success was measured in terms of resolved complaints. The complexity of surgery was determined using the Intensity/Complexity Index and compared with success rates.

RESULTS

Data are reported on 299 patients (90 BVM and 145 AVM) whose eyes were successfully aligned in 63% of the BVM cases and 81% of the AVM cases. Subjective complaints resolved at similar rates in the BVM and AVM subgroups. Successful alignment was not correlated with complexity of surgery, but motility and sensory success rates were correlated with complexity of surgery.

CONCLUSION

Within each of the BVM and AVM subgroups, this study of adult strabismus showed similar surgical success rates compared with published data. This qualifies these patient groups as clinically typical of adults undergoing strabismus surgery. Additional studies will expand on health value analyses.

Double Vision

When evaluating a patient with a complaint of double vision, it is important to distinguish monocular versus binocular diplopia, which are differentiated by asking the patient to cover each eye separately. In the setting of binocular double vision, one of the two images disappears when either eye is covered, because diplopia is the result of ocular misalignment. On the other hand, monocular double vision resolves when the affected eye is covered, but remains when the opposite eye is occluded. Causes of monocular diplopia include cataract, refractive error, and retinal disease, which can be managed accordingly by an ophthalmologist. However, an unusual form of monocular double vision can occur in the setting of cortical dysfunction. Cerebral polyopia describes the perception of multiple images and arises from an occipital disturbance. It can occur with migraine headaches and can be accompanied by a homonymous hemianopia. Palinopsia refers to the persistence of an image that is no longer in view (visual perseveration or stroboscopic effect) and results from an occipital lesion as well. The exact mechanism of polyopia and palinopsia are uncertain and both conditions are extremely rare. The majority of this discussion will focus on binocular double vision and its management. The main treatment objective of binocular diplopia is to restore the largest area of single binocular vision. Ideally, patients would be able to achieve single vision in all fields of gaze, but this is not always possible. The majority of patients are treated with either prism lenses or eye muscle surgery.