Fusion after surgical alignment of longstanding strabismus in adults

Improvement of stereopsis following strabismus surgery in adults: a retrospective analysis

OBJECTIVE

Adults who undergo strabismus surgery, in addition to cosmesis, could benefit from improved stereopsis. This improvement is associated with the performance of motor skill tasks in young adults; they reduce the risk of tripping or falling during everyday locomotion and improve reading efficiency. This study aimed to assess stereopsis level after strabismus surgery in adults who underwent strabismus surgery for any reason.

METHODS

Retrospective observational study of adult patients who underwent strabismus surgery at our institution between 2010 and 2022.

RESULTS

One hundred and thirty-two patients were included. Postoperatively, 48% had a stereo acuity better than 100 seconds of arc, and only 21.5% had no stereopsis. The most significant factor influencing improved stereopsis after surgery was the angle of strabismus postoperatively (p = 0.018). There was a statistically significant correlation between fusion at a distance and the stereo acuity (p = 0.0337). There was no statistically significant correlation between the stereo acuity level and the strabismus angle of deviation, the strabismus direction (vertical, horizontal, or combined), or the type (esotropia or exotropia) before or after the surgery. Although not statistically significant (p = 0.6579), the underlying cause categories were correlated with the stereo level. Patients with neurological causes demonstrated higher levels of stereopsis, followed by TED, whereas patients with childhood strabismus have the lowest probability of regaining stereopsis after surgery.

CONCLUSIONS

Although long-standing strabismus reduces the potential for binocularity, surgery may be beneficial and improve stereopsis regardless of the cause of strabismus.

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.

Functional changes in the visual cortex in preoperative and postoperative patients with intermittent exotropia: study protocol for a non-randomised case-control clinical trial

INTRODUCTION

Intermittent exotropia (IXT) is the most common type of divergent squint. IXT is primarily a cortical neurologic dysfunction disorder, occurring as a result of the insufficient maintenance of sensory and motor fusion. Recent reports have demonstrated the relationship between IXT and visual cortical impairment. We planned to assess blood oxygen level-dependent (BOLD)-functional magnetic resonance imaging (fMRI) in patients with IXT during the preoperative and postoperative follow-ups to evaluate the functional changes in the visual cortex.

METHODS AND ANALYSIS

A total of 90 Chinese subjects will be recruited, and their ages will be between 18 and 40 years old. The subjects will include the surgical treatment (ST) group (45 subjects with IXT who will undergo surgery) and the HC group (45 age-matched, sex-matched and education-matched healthy volunteers). The assessments will include the following aspects: fMRI and general ophthalmic examinations, optometry measurements and strabismus-related tests, such as the ocular deviation, binocular vision test and Newcastle Control Score (NCS). Each subject will complete the resting-state BOLD-fMRI, and the sequences will include echo planar imaging (EPI) pulse and 3-dimensional brain volume (3D-BRAVO) to acquire high-resolution images. The follow-up schedule will be 6 and 12 months after the surgery. The primary outcome will be determined by cortex changes in BOLD-fMRI in the ST group before and after surgery. We will also compare the HC group with the preoperative subjects in the ST group. The secondary outcomes will be changes in strabismus-related examinations, such as binocular visual function and NCS.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the Medical Ethics Committee of Beijing Tongren Hospital. We plan to publish the results of this study in a peer-reviewed journal article.

TRIAL REGISTRATION NUMBER

ChiCTR2100048852.

Causes of concomitant strabismus surgery delay in teenagers and adults

To reveal the reasons for strabismus surgery delay and motivations for seeking surgical treatment in adulthood. Prospective survey among 91 adult patients, suffering from concomitant strabismus acquired in the childhood that underwent delayed strabismus surgery. The mean age of participants was 24 years (from 16 to 58 years); 48 females (52.7%), and 43 males (47.3%). Strabismus surgery has been delayed for about 20 years in adult patients who could potentially benefit of it in childhood. The most common reasons for strabismus surgery delay, reported by patients, included the following: lack of awareness about surgery (37.4%); surgery was recommended but declined by patients' parents/guardians in their childhood (6.6%); fear of surgery (17.6%); eye specialists affirmation that surgery would not lead to strabismus improvement (27.5%); previous poor surgical experience (6.6%); and non-affordability (4.4%). The main motivations for seeking strabismus surgery in adulthood among our patients were the following: appearance improvement (38.5%), strengthening of self-confidence (30.8%), better social relationship (16.5%), better job opportunities (7.7%), and advice from family and friends (6.6%). About 80% of strabismus surgery delays in teenagers and adults were caused by lack of awareness regarding strabismus surgery and even the misconception among primary health-care practitioners and some eye doctors who considered that surgery would not lead to strabismus correction. The main reasons for seeking strabismus surgery in adulthood were: esthetical ones, self-confidence strengthening, and building better social relationship. All factors mentioned below confirmed the negative impact of oculomotor disorders on patient's psychological condition. The focus on patient's individual concerns and needs was especially important for recovery and well-being of adult patients with strabismus and formed a central feature of patient centered medical approach.

Fixation stability after surgical treatment of strabismus and biofeedback fixation training in amblyopic eyes

Background

Visual fixation may be affected in amblyopic patients and, moreover, its stability may be associated with the effects of amblyopic treatments on visual performance in patients with strabismus. Therefore, fixation stability is a relevant biomarker that might predict the recurrence of amblyopia after a therapeutic intervention. Microperimetric biofeedback fixation training (BFT) can stabilize visual fixation in adult patients with central vision loss. It was the purpose of the present study to evaluate the effects of BFT on fixation stability in adult amblyopic patients after surgical intervention to treat strabismus.

Methods

Participants were 12 patients with strabismus (mean age = 29.6 ± 8.5 years; 6 females) and 12 healthy volunteers (mean age = 23.8 ± 1.5 years; 9 females). The protocol included ophthalmological and microperimetric follow-ups to measure fixation stability and macular sensitivity. BFT was applied monocularly to four amblyopic eyes either on the spontaneous preferential retinal locus or to a fixation area closer to the anatomical fovea after surgical treatment of strabismus.

Results

Baseline measurements showed significantly altered microperimetric average threshold in amblyopic eyes compared to fellow eyes (p = 0.024) and compared to control eyes (p < 0.001). Fixation was unstable in amblyopic eyes compared to control eyes (p < 0.001). Fixation stability did not significantly change after surgical alignment of strabismus (p = 0.805). BFT applied to operated eyes resulted in a more stable fixation with improvements of about 50% after three months of training.

Conclusions

Fixation stability improvements following BFT highlight its potential use in adult amblyopic eyes after the surgical alignment of the strabismus. Future investigations may also consider applying this method in combination with standard treatments to improve vision in amblyopic patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-02020-3.

A Post-Surgical Stereovision Surprise in an Adult With an Exotropia Since Infancy Previously Managed, at Two Years With Surgery

Aim

To describe an unexpected sensory outcome in an adult male who is seeking ocular re-alignment for a psychosocially symptomatic large non-specific exotropia with suppression. The primary diagnosis was infant onset exodeviation of unclear diagnosis, was managed with bilateral strabismus surgery at two years of age, little memory of follow-up.

Result

Measurable binocular single vision (BSV) was demonstrable following surgery at 17 years of age, albeit slowly between two weeks and six months postoperatively and subsequently enhanced. His newly acquired sub-optimal BSV led to symptomatic occupation-associated asthenopia. Following two subsequent operations over a 15-year period, he has stable, symptom-free ocular realignment within three prism diopters of orthophoria and performing tasks that require extended periods of near-vision activity.

Conclusion

Delayed high levels of stereovision were unexpectedly achieved in an adult with infant onset exotropia with pre-operative sensory suppression that was surgically aligned to near orthophoria. The re-establishment of BSV in such a clinical scenario has to attain a level that is robust enough to meet an individual's social and occupational needs.

Surgical planning of horizontal strabismus using multiple output regression tree

Strabismus is an eye disease that affects about 0.12%-9.86% of the population, which can cause irreversible sensory damage to vision and psychological problems. The most severe cases require surgical intervention, despite other less invasive techniques being available for a more conservative approach. As for surgeries, the treatment goal is to align the eyes to recover binocular vision, which demands knowledge, training, and experience. One of the leading causes of failure is human error during the measurement of deviation. Thus, this work proposes a new method based on the Decision Tree Regressor algorithms to assist in the surgical planning for horizontal strabismus to predict recoil and resection measures in the lateral and medial rectus muscles. In the presented method, two application approaches were taken, being in the form of multiple single target models, one procedure at a time, and the form of one multiple target model or all surgical procedures together. The method's efficiency is indicated by the average difference between the value indicated by the method and the physician's value. In our most accurate model, an average error of 0.66 mm was obtained for all surgical procedures, both for resection and recoil in the indication of the horizontal strabismus surgical planning. The results present the feasibility of using Decision Tree Regressor algorithms to perform the planning of strabismus surgeries, making it possible to predict correction values for surgical procedures based on medical data analysis and exceeding state-of-art.

The Study of Perceptual Eye Position Examination and Visual Perceptual Training in Postoperative Intermittent Exotropes

The aim of this study was to investigate perceptual eye position (PEP) and to evaluate the effect of dichoptic visual perceptual training in postoperative intermittent exotropia [X(T)]. We enrolled 30 non-strabismus children (control group) and 54 postoperative X(T) children [divided into training group (33 patients) and non-training group (21 patients)]. All subjects received measurements of PEP, and the postoperative X(T) children were measured both in the third postoperative day and the third postoperative month. All patients in training group received 3-month dichoptic visual perceptual training based on a unique virtual reality platform. The results showed that the postoperative X(T) children with normal eye position still had an abnormal PEP. After a period of visual perceptual training, the PEP pixels in postoperative children dramatically decreased. The results revealed that PEP could evaluate fixation disparity and binocular visual function perceptively and precisely, and the dichoptic visual perceptive training may rebuild binocular visual function.

Predictive factors of stereopsis outcomes following strabismus surgery

Purpose:

To determine the predictive factors of post-operative stereopsis in patients with strabismus.

Method:

In this retrospective study, records of patients who received surgical treatment for strabismus were reviewed. All types of strabismus were included. Pre- and post-treatment stereoacuity were measured using the Titmus Stereo Fly test, and predictive factors of stereopsis were evaluated.

Results:

A total of 194 patients (132 females and 62 males) with a mean age of 14.8 ± 8.4 years were included. There was a statistically significant improvement in stereopsis following surgery (p value < 0.001). Patients with a higher amount of deviation at baseline had poorer stereopsis on the final examination (p value < 0.001). Stereopsis improvement was more prominent in the pure horizontal strabismus group, compared to combined horizontal and vertical deviations. Baseline and the final stereopsis were higher in the “exotropia” group as compared to the “esotropia” group (p value = 0.003 and 0.0155, respectively); however, the within group change of stereopsis was not significantly different between these two groups (p value = 0.144). Post surgical residual deviation was associated with a poorer stereopsis (p value = 0.002, r = 0.251). A longer duration of strabismus before surgery was associated with poorer final stereopsis levels (p value = 0.026). The presence of amblyopia before surgery was associated with poorer stereopsis on last examination (p value < 0.001 for both correlations).

Conclusion:

Based on the result of this study, final stereopsis after strabismus surgery could be affected by the type, duration, and the amount of deviation before surgery, amblyopia, and post operative ocular deviation.

Late Surgical Correction of Longstanding Constant Strabismus in Adults: Is Fusion Possible in All Successfully Aligned Patients?

PURPOSE

To determine whether late surgical correction provides fusion in adults who have constant strabismus beginning in early childhood.

MATERIALS AND METHODS

This was a prospective study that included 34 consecutive adults with a history of early onset strabismus who had not previously undergone surgery. They were tested with the Bagolini striated glasses (BSG), Worth four-dot (W4D) test, cover test, and four-prism diopter (4-PD) test, preoperatively, and 6 weeks after surgery.

RESULTS

The mean age was 23.8 years, 17 patients had esotropia and 17 patients had exotropia. Preoperatively, all patients demonstrated a manifest horizontal deviation ranging from 30^∆ to 60^∆ and had suppression. At 6 weeks postoperatively, 33 patients had a horizontal manifest deviation of <15^∆ (range, 2^∆-14^∆; median, 6^∆), and none were orthotropic as determined by the cover test together with the 4-PD test. All of these 33 patients achieved anomalous retinal correspondence (ARC) with the BSG at near, and 25 (75%) had ARC with the W4D test at near.

CONCLUSIONS

Although our study has limited number of patients its findings suggest it is possible to develop ARC after surgery in almost all adult patients with childhood-onset strabismus associated with suppression, and who have not previously been operated upon, if satisfactory alignment is achieved in adulthood.

Does successful surgical correction of childhood large angle exotropia in adults make any difference to binocularity and quality of life?

Background/Aim: Strabismus surgery could achieve motor alignment and improve health-related quality of life (HRQOL) in adults with large angle exotropia, but whether it could improve binocularity and whether the binocularity is associated with HRQOL are unknown. The aim of this study is to evaluate the binocularity and HRQOL following successful surgical correction of childhood large angle exotropia in adults. Methods: Consecutive adults with childhood large angle exotropia (≥90 prism diopters) who underwent strabismus surgery in the Department of Ophthalmology and Vision Science, Eye and ENT Hospital, Shanghai Medical School, Fudan University were enrolled. Static and dynamic stereopsis tests were performed before surgery and 1 month after surgery. At the same time, Adult Strabismus-20 (AS-20), and Amblyopia and Strabismus questionnaire (A&SQ) were investigated. Results: A total of 29 adults achieved successful alignment: 18 intermittent exotropes (IXT) and 11 constant exotropes (CXT). One month after surgery, stereopsis was demonstrated better in all types of tests (p < .05 for all comparisons). Twelve patients gained normal stereopsis. More patients in IXT group gained normal stereopsis than in CXT group (x² = 7.62 p = .008). All HRQOL scores showed statistically significant improvement after surgery (p < .05 for all comparisons). IXT group had more changes of the composite score (t = 2.24, p = .03) and the functional score (t = 2.92, p = .007) of AS-20, and the functional score (t = 3.06, p= .005) of A&SQ than CXT group. Only the change of the functional score of A&SQ was demonstrated a statistically significant correlation with the normal stereopsis (t = 2.67, p = .02). Conclusions: The stereopsis and HRQOL in adults with childhood large angle exotropia can be improved after successful surgical correction. More patients in IXT group gained normal stereopsis correlated with better functional aspects of HRQOL.

Long-term Surgical Outcomes of Initial Postoperative Overcorrection in Adults with Intermittent Exotropia

Purpose

To evaluate the relationship between initial postoperative overcorrection and long-term surgical success in exotropia patients.

Methods

The medical records of 46 patients who underwent surgery for intermittent exotropia after the age of 18 were enrolled. Enrolled patients also had at least 2 years of postoperative follow-up. Based on the initial postoperative deviation at distance measured by prism and the alternating cover test at 1 week, patients were assigned to one of the following groups: group A included patients who demonstrated any esodeviation, while group B included patients who showed orthophoria to exodeviation of 10 prism diopters. The records were analyzed to determine the preoperative deviation with stereoacuity and postoperative deviations with stereoacuity at the follow-up examinations at the following intervals: 1 week; 1, 3, and 6 months; and 1 and 2 years. A comparison between groups for demographic data and preoperative and postoperative angles of deviation was performed using analysis of variance.

Results

Of the 46 patients with intermittent exotropia included in this study, 18 (39%) belonged to group A, while 28 (73%) belonged to group B. The postoperative angle of deviation for distant fixation until 2 years of follow-up showed statistically significant differences in each group (p < 0.003 in all comparisons). The amount of exodrift until 2 years in group A (from −9.7 ± 6.1 to 1.6 ± 3.7) was greater than that in group B (from 2.0 ± 2.7 to 6.8 ± 5.6). The long-term surgical success rate within 2 years of surgery was significantly better in group A than in group B (p = 0.027). The number of patients with intermittent diplopia and the duration of diplopia were greater in group A (n = 8) than in group B (n = 2).

Conclusions

Long-term surgical success was achieved in 89% of patients who were initially overcorrected. Overcorrection of an average of 10 prism diopters at the first postoperative week was found to be associated with a more favorable long-term surgical outcome.

The Functional Benefits of Strabismus Surgery

When performed prior to visual maturity, strabismus surgery can result in the development or recovery of binocularity. When strabismus surgery is performed after visual maturity, the functional benefits of the surgery should be dichotomized according to whether the onset of the strabismus was before or after visual maturity. If the onset was after visual maturity, patients typically are diplopic. Specific success rates for eliminating diplopia vary according to the nature of the strabismus; however, overall the success rate is quite high. There is a common misperception that surgery in adults for strabismus that began prior to visual maturity is merely cosmetic. Numerous studies contradict this misconception. Even if the strabismus has been longstanding, most adults will experience some improvement in binocular function after strabismus surgery. In esotropic patients, this improvement typically takes the form of an expansion of binocular visual fields; however, some patients may also regain stereopsis. There are many psychosocial benefits to adult strabismus surgery. This is reflected in the finding that the majority of adults surveyed with strabismus would trade a portion of their life expectancy to be rid of their strabismus.

Straightening the Eyes Doesn't Rebalance the Brain

Surgery to align the two eyes is commonly used in treating strabismus. However, the role of strabismic surgery on patients' binocular visual processing is not yet fully understood. In this study, we asked two questions: (1) Does realigning the eyes by strabismic surgery produce an immediate benefit to patients' sensory eye balance? (2) If not, is there a subsequent period of "alignment adaptation" akin to refractive adaptation where sensory benefits to binocular function accrue? Seventeen patients with strabismus (mean age: 17.06 ± 5.16 years old) participated in our experiment. All participants had normal or corrected to normal visual acuity (LogMAR < 0.10) in the two eyes. We quantitatively measured their sensory eye balance before and after surgery using a binocular phase combination paradigm. For the seven patients whose sensory eye balance was measured before surgery, we found no significant change [t₍₆₎ = -0.92; p = 0.39] in the sensory eye balance measured 0.5-1 months after the surgery, indicating that the surgical re-alignment didn't by itself produce any immediate benefit for sensory eye balance. To answer the second question, we measured 16 patients' sensory eye balance at around 5-12 months after their eyes had been surgically re-aligned and compared this with our measurements 0.5-1 months after surgery. We found no significant change [t₍₁₅₎ = -0.89; p = 0.39] in sensory eye balance 5-12 months after the surgery. These results suggest that strabismic surgery while being necessary is not itself sufficient for re-establishing balanced sensory eye dominance.

Strabismus in Adults Older Than 60 Years

PURPOSE

To describe the epidemiology of adult strabismus, its etiology, and treatment methods in patients 60 years and older presenting to a tertiary care center.

METHODS

This retrospective chart review study of patients with strabismus was performed at the Ratner Eye Center, University of California-San Diego. Data collected included demographics, etiology of misalignment, alignment in the primary position, binocularity, previous surgical intervention, and treatment methods.

RESULTS

A total of 291 patients were included. The majority of patients (87.9%) had an acquired underlying etiology of misalignment (neurological, non-neurological, thyroid eye disease, or myotoxic). The most common presenting complaint was diplopia (77%). A total of 38.8% of patients had previous strabismus surgery. Surgical interventions were pursued in 32% of patients.

CONCLUSIONS

This article provides insight into the epidemiology of strabismus in patients older than 60 years. The characterization and greater understanding of strabismus in this age group can be used to enhance prevention, diagnosis, and treatment of these patients. [J Pediatr Ophthalmol Strabismus. 2016;53(6):365-368.].

Sensory eye balance in surgically corrected intermittent exotropes with normal stereopsis

Surgery to align a deviated or strabismic eye is often done for both functional as well as cosmetic reasons. Although amblyopia is often an impediment to regaining full binocularity in strabismics in general, intermittent exotropes, because their deviation is intermittent, have no amblyopia and some degree of stereopsis. Binocular function, including a balanced ocular dominance, could be expected to be normal after surgical correction if normal levels of stereopsis and visual acuity are postsurgically achieved. Here we used a binocular phase combination paradigm to quantitatively assess the ocular dominance in a group of surgically corrected intermittent exotropes who have normal stereo and visual acuity as defined clinically. Interestingly, we found significant interocular imbalance (balance point < 0.9) in most of the surgically treated patients (8 out 10) but in none of the controls. We conclude that the two eyes may still have a residual sensory imbalance in surgically corrected strabismus even if stereopsis is within normal limits. Our study opens the possibility that a further treatment aimed at re-balancing the ocular dominance might be necessary in surgically treated intermittent exotropia to provide more efficient binocular processing in the long term.

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.

To evaluate stereoacuity in patients with acquired esotropia and to determine factors associated with favourable outcomes

AIM

To evaluate stereoacuity in patients with acquired esotropia and determine the factors associated with favorable outcomes.

MATERIALS AND METHODS

A total of 68 subjects aged 6 years and above were included in the study. Thorough clinical evaluation including binocular status examination using the Bagolini-striated glass test, The Netherland Organization (TNO), and Randot stereo test were done. The subjects were divided into two groups 1 and 2, based on the amount of deviation. Statistical analysis of the result was performed.

RESULT

The duration of misalignment in the group with deviation less than or equal to 8 prism diopters (PD) was 1.49 ± 0.86 years, whereas in the group with deviation more than or equal to 10 PD was 4.64 ± 2.99 years (P = 0.000). Among the subjects in group 1, 89.5% achieved fusion and 52.6% had stereoacuity on both TNO and Randot, whereas in group 2 40% achieved fusion and 3.3% stereopsis on both TNO and Randot (one case with only coarse stereopsis). A subanalysis within group 1 revealed a statistically significant difference for the duration of misalignment (P = 0.02), but a marginal difference for the amount of deviation (P = 0.3).

CONCLUSION

A horizontal deviation up to 8 PD was compatible with stereopsis. Also, the duration of constant misalignment affects the attainment of stereopsis despite successful realignment.

Does restoration of binocular vision make any difference in the quality of life in adult strabismus

BACKGROUND

To report the effect of restoration of binocular functions in adult strabismus on the health-related quality of life (HRQOL).

METHODS

61 adults undergoing strabismus surgery completed Adult Strabismus-20 (AS-20) and Amblyopia and Strabismus (A&SQ) HRQOL questionnaires preoperatively and postoperatively. Patients were grouped according to their responses to binocular tests as binocular vision positive (BVP) and binocular vision negative (BVN) groups. Changes in AS-20 and A&SQ scores of the overall group and the subgroups were evaluated.

RESULTS

Motor success was 90%, and 43% of the cohort showed measurable level stereopsis and central fusion on the Worth four-dot test or on the synoptophore. HRQOL scores (composite, psychosocial and functional) of the cohort measured by AS-20 and A&SQ showed significant improvement after surgery (AS-20: 42,40,45 vs 85,86,84, AS&Q: 46,52,38 vs 76,75,78, p<0.05 for all comparisons). But the BVP (n-26) group was not found superior to the BVN (n-35) group both functionally and psychosocially (p>0.05). Only after the exclusion of the amblyopic patients, functional superiority of the BVP group (n-20) over the BVN group (n-20) was disclosed (AS-20: 45 vs 31, A&SQ: 28 vs 16, p<0.05), while the composite and psychosocial subscale score improvements were not different (AS-20: 44,40 vs 34,38, A&SQ: 30,38 vs 20,37, p>0.05 for all comparisons).

CONCLUSIONS

The restoration of binocular vision is possible in adults with a long-term history of strabismus and both AS-20 and A&SQ questionnaires are sensitive to detect additive effect of binocular vision on functional aspects of the quality of life. To increase this sensitivity, questionnaires can be modified to include items inquiring tasks that require fine stereopsis.

The prevalence of reoperation and related risk factors among patients with congenital esotropia

PURPOSE

To determine the prevalence rate and related risk factors of reoperation among patients with congenital esotropia.

METHODS

One hundred fifty-seven children with congenital esotropia were divided into two groups after at least one operation: children with deviation within 10 PD (n = 89; success group) and those with deviation greater than 10 PD or history of reoperation (n = 68; failure group). The relationship of risk factors such as age at first operation and primary congenital esotropia of less than 30 or more than 50 PD and accompanying factors such as inferior oblique muscle overaction (> +1), dissociated vertical deviation, lateral rectus muscle underaction, and A-V pattern with reoperation were studied. Final sensory status of children 5 years and older was evaluated by Worth 4-dot and Titmus tests.

RESULTS

Reoperation was indicated in 32.4% of children who had residual esotropia greater than 15 PD after 3 months following their first operation. Congenital esotropia greater than 30 PD (P = .002) and lateral rectus muscle underaction of −1 to −2 (P < .005), were statistically different between the two groups. Initial operation at younger than 3 years was more likely to achieve gross stereopsis in children 5 years and older (P = .032).

CONCLUSION

Congenital esotropia greater than 30 PD and lateral rectus muscle underaction were found to be risk factors of reoperation.

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.

Outcome of surgery in long-standing infantile esotropia with cross fixation

BACKGROUND

This is a retrospective study to determine the outcomes of the surgical correction in long-standing infantile esotropia with cross fixation.

METHODS

Medical charts of a group of patients with esotropia who had cross fixation and underwent surgery for strabismus between January 1991 and December 2004 were reviewed. The mean follow-up time was 4.7 years. Binocularity was measured by the Worth 4-dot test and Titmus stereo test. Twenty-six patients underwent surgery for strabismus. Twenty-one patients aged 8 to 26 years with a minimum 3-year postoperative follow-up were included. Five patients were excluded because they were lost to follow-up after surgery.

RESULTS

Bimedial recession and resection of one lateral rectus muscle were performed in all patients. Recession of the inferior oblique muscle with anteriorization was performed in patients who had inferior oblique overaction. Orthotropia was attained in 14 patients, whereas residual esotropia was diagnosed in 5 patients. Two patients were diagnosed as having exotropia. Two patients required a second surgery for dissociated vertical deviation. Overall, 9 of the 21 patients had indications of binocular function and 12 remained the same in their stereoacuity.

CONCLUSION

Surgical correction of long-standing infantile esotropia with cross fixation in young adults may improve binocular function and allow long-term alignment stability.

Strabismus surgery on the elderly and the effects on disability

It is widely believed that strabismus surgery in elderly adults has low value and is of limited benefit. In this study, consecutive patients older than 65 years of age who had undergone strabismus surgery were asked to complete a telephone questionnaire rating their before-surgery and after-surgery severity of various problems, including specific health, daily functioning, social interactions, concerns about the future, self-image, and job-related problems. Of the 56 patients identified, 37 completed the survey. Problem ratings improved significantly on all 5 of 6 items after surgery, with specific health and daily tasks yielding the greatest improvement. For all items, the number of patients who indicated an improvement was greater than the number of patients who indicated no change or deterioration with surgery. This study further details the benefits of strabismus surgery in the elderly.

Surgical outcome of single-staged three horizontal muscles squint surgery for extra-large angle exotropia

PURPOSE

To report the surgical outcomes of 24 patients undergoing single-staged three horizontal muscles squint surgery for extra-large angle exotropia.

PATIENTS AND METHODS

Prospective case series of 24 consecutive patients with primary exotropia>60 prism diopters (PD) at distant and underwent single-staged three horizontal muscles squint surgery from 2003 to 2006. Surgery consisted of bilateral lateral rectus recession of 9.0 mm for 50 PD exotropic correction. For every 5 PD remaining angle exceeding 50 PD, we additionally performed 1.0 mm of unilateral medial rectus resection. The mean follow-up period was 15.8 months (range 6.0-38.0 months; SD 9.5 months).

RESULTS

The mean age at surgery was 31.2 years old (range 7-78 years old, SD 18.2 years old). The mean distant preoperative deviation was 71.3 PD (range 60-85 PD, SD 7.7 PD). No limitation of eye movement or diplopia was found. The success rate was higher in the intermittent group (88.2%) than the constant group (42.9%) (P=0.02) and in cases with preoperative deviation of <80 PD (84.2%) compared with those with deviation>or=80 PD (40.0%) (P=0.042).

CONCLUSION

Measurement of preoperative deviation and the surgery for extra-large angle exotropia made management of this condition difficult. Single-staged three horizontal muscles squint surgery can be one of the options. Further researches on management of exotropia of >80 PD are warranted.

Functional benefits of sensory and motor evaluation before strabismus surgery

Evaluating the sensory and motor status of your strabismus patient is an important part of the preoperative examination. However, not all clinicians follow the same protocol for this assessment. Many rely on personal experience to determine what tests to do. Is this enough? Interpreting the evidence regarding the proper preoperative exam for strabismus patients and incorporating it into your practice can help to enhance your postoperative results.

Changes in the functional binocular status of older children and adults with previously untreated infantile esotropia following late surgical realignment

BACKGROUND

Most studies of infantile esotropia concern patients diagnosed in infancy and treated throughout childhood. This prospective study addresses changes in the functional binocular status of older children and adults with previously untreated infantile esotropia, following late surgical realignment.

SUBJECTS AND METHODS

Seventeen patients aged 8 years or more with a history of untreated esotropia occurring within the first 6 months of life were included in this study. All had monocular optokinetic asymmetry, a visual acuity of 20/30 or better in the worse eye, and binocular function assesment preoperatively and postoperatively. All were surgically aligned within 8(Delta) of orthotropia. None had neurologic disease.

RESULTS

Preoperatively, all 17 patients demonstrated a monocular response to Bagolini lenses, while postoperatively 15 (88%) of the 17 demonstrated binocular function with Bagolini lenses (in that they could constantly perceive the major part of both arms of the X generated by the Bagolini lenses) and 13/17 (76%) demonstrated an increase in the binocular field. All 17 had no sensory fusion, either preoperatively or postoperatively, when tested with the Worth 4-Dot test or synoptophore, and no stereopsis with the Titmus stereo test.

CONCLUSIONS

Older children and adults with previously untreated infantile esotropia derive some functional benefits following late surgical realignment. The degree of binocular function may be lower than that achieved in patients aligned before 24 months of age.

The cost utility of strabismus surgery in adults

PURPOSE

Cost-utility analysis evaluates the cost of medical care in relation to the gain in quality-adjusted life years (QALYs). Our purpose was to develop a cost model for surgical care for adult strabismus, to estimate the mean cost per case, to determine the associated gain in QALYs, and to perform cost-utility analysis.

METHODS

A cost model incorporated surgery, pre- and postoperative care, and a mean of 1.5 procedures per patient. The gain in QALYs was based on the improvement of utility on a scale from 0 (death) to 1 (perfect health). Utility was measured through physician-conducted interviews employing a time tradeoff question (seeking to estimate the portion of life expectancy a patient would be willing to trade for being rid of disease and associated effects). The interviews were conducted before and 5 to 8 weeks after surgery in 35 strabismic patients (age 19-75 years).

RESULTS

The cost model resulted in an estimated total cost of 4,254 dollars per case. A significant improvement of utility was found: 0.96 +/- 0.11 postoperatively versus 0.85 +/- 0.20 preoperatively (p = 0.00008). Based on the mean life expectancy (36.0 years) of these patients, and discounting outcomes and costs by 3% annually, this resulted in a mean value gain of 2.61 QALYs after surgery and a cost-utility for strabismus surgery of 1,632 dollas/QALY.

CONCLUSIONS

In the United States, treatments <50,000 dollars/QALY are generally considered "very cost-effective." Strabismus surgery in adults falls well within this range.

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--III. The effects on disability

INTRODUCTION

This is the third article in a series on the various facets of the management of strabismus in adults. Here, we give a broad overview of the types and severity of disability and provide initial validation of an instrument (questionnaire) to assess these disability aspects.

METHODS

After undergoing strabismus surgery, 101 patients from 6 centers completed a 6-item questionnaire in which they rated both the before-surgery and after-surgery severity of problems associated with their strabismus, ranging from specific health, daily functioning, social interaction, concerns about the future, and self-image to job-related difficulties.

RESULTS

The before-surgery outcomes showed significant variation across the 6 types of problems (P < 0.001), with "specific health" and "daily tasks" yielding the highest problem rating. Patients with diplopia reported more severe problems with "daily tasks" (P = 0.004) and "concerns about the future" (P = 0.026) than patients without diplopia. Overall, all problem ratings declined after surgery (P < 0.001), but patients who were not successfully aligned were left with higher problem ratings on "specific health" (P = 0.005), "daily tasks" (P = 0.003), and "social interaction" (P = 0.024).

CONCLUSIONS

The results indicate a wide range of disability aspects in adult patients with strabismus, with moderate differences between patients with or without diplopia. Improvements in disability after surgery, as reflected by these ratings, should be taken into account when assessing the health value of adult strabismus management.

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.

Predictive factors underlying the restoration of macular binocular vision in adults with acquired strabismus

PURPOSE

To investigate whether macular binocular vision can be permanently lost following acquired strabismus and to identify predictive factors underlying its restoration.

SUBJECTS AND METHODS

Twenty-three patients with strabismus acquired after binocular vision maturation were enrolled. Factors studied included duration of eye misalignment, age at treatment, pre-surgical strabismus type, pre-surgical diplopia, and pre-surgical capacity for binocularity. The restoration of macular binocular vision was evaluated between 1 and 3 years following successful eye re-alignment and was defined as 60 seconds of arc stereopsis or better on the Titmus circles and/or the Preschool Randot Stereoacuity test.

RESULTS

Sixteen of 23 (70%) or 7/23 (30%) of patients achieved macular binocular vision following successful surgical eye realignment using the Titmus circles versus the Preschool Randot Stereoacuity test. Patients with < or =12 months constant eye misalignment were more likely to achieve macular binocular vision following treatment than patients with >12 months constant eye misalignment.

CONCLUSIONS

Macular binocular vision continues to be susceptible to permanent loss in adult patients. Factors that are predictive of the restoration of macular binocular vision include duration of constant eye misalignment and the pre-surgical capacity for binocularity.

Binocularity following surgical correction of strabismus in adults

PURPOSE

This is a retrospective study to determine the pre- and postoperative binocular status of adults who have undergone surgical correction of strabismus.

METHODS

A list of all consecutive adult patients who underwent surgery for strabismus between June 1990 and December 2001 (surgery by MBM) was compiled and their medical charts were reviewed. Patients who had at least 6 weeks postoperative follow-up were included if their charts were available for review and if information on binocularity was recorded. Binocularity was measured by the Titmus stereo test (Stereo Optical Co., Inc., Chicago), and/or the Worth 4-Dot test for distance (Scioto Medical Products, Powell, OH [discontinued]), and/or the Worth 4-Dot near test (Gulden Ophthalmics, Inc., Elkin Park, PA). Improvements or decreases in stereo acuity were noted 6 weeks postoperatively and at the final office visit. Prism management was incorporated pre- and/or postoperatively in some of our patients. A total of 112 patients underwent surgery for strabismus. Of these, 72 patients, aged 16 to 80 years, were included; 24 were excluded as their charts did not contain any information on stereo acuity 6 weeks postoperatively or were lost to follow-up after surgery, and 16 were excluded because their charts were unavailable from storage.

RESULTS

The mean follow-up for the study patients was 16.5 months (range 6 weeks to 79 months). Overall, 30 of the 72 patients improved in binocular function (42%), 38 remained the same (53%), and 4 decreased (5%). If you exclude those patients with 40 sec of stereo acuity preoperatively whose stereopsis, by definition, could not improve further, and look only at the 59 surgical patients who could improve, then 51% improved. A variety of surgical procedures was performed, the most common being a bilateral medial rectus recession. Eleven patients required a second surgical procedure and two required a third surgical procedure.

CONCLUSION

The benefits of surgical correction of strabismus in adults include improvement in binocular function as seen in 51% of the patients in the study.

Binocularity following surgical correction of strabismus in adults

INTRODUCTION

This is a retrospective study to determine the preoperative and postoperative binocular status of adults who have undergone surgical correction of strabismus.

METHODS

A list of all consecutive adult patients who underwent surgery for strabismus between June 1990 and December 2001 (surgery performed by M.B.M.) was compiled, and their medical charts were reviewed. Patients were included if their charts were available for review and if information on binocularity was recorded. Binocularity was measured by the Titmus stereo test, Worth 4-dot test, or synoptophore. Improvements or decreases in stereo acuity were noted 6 weeks postoperatively and at the final office visit. Prism management was incorporated preoperatively and/or postoperatively in some of our patients. A total of 112 patients underwent surgery for strabismus. Of these, 72 patients, aged 16 to 80, were included; 24 were excluded because their charts did not contain any information on stereo acuity at least 6 weeks postoperatively or they were lost to follow-up after surgery, and 16 were excluded because their charts were unavailable from storage.

RESULTS

A variety of surgeries were performed, the most common being a bilateral medial rectus recession. Eleven patients required a second surgery, and two required a third surgery. Overall, 30 (42%) of the 72 patients improved in binocular function, 38 (53%) remained the same, and 4 (5%) had decreases in their stereo acuity.

CONCLUSION

The benefits of surgical correction of strabismus in adults include improvement in binocular function, as seen in 42% of the patients in the study.

Prism adaptation in visually mature patients with esotropia of childhood onset

OBJECTIVE

To investigate the role of prism adaptation in the visually mature population with esotropia onset before visual maturation.

DESIGN

Retrospective, noncomparative case series.

PARTICIPANTS

Eighty-five patients, 26 prism adapted for near (PAN) and 59 prism adapted for distance (PAD), were included in the study.

METHODS

Patients included in this study were older than 9 years and had esotropia with an onset before age 9. Mean follow-up was 30 months (range = 6 weeks-164 months). All patients had prism adaptation and subsequent surgical correction. Surgical success was defined as peripheral fusion on the Worth 4-dot test and < or = 8(Delta) deviation at near and distance on the simultaneous prism and cover test.

MAIN OUTCOME MEASURES

Response to preoperative prism adaptation and postoperative alignment and sensory results were examined.

RESULTS

Twenty-six of the 85 patients had previous surgical esotropia correction. In the PAD group, 41 were responders. Seventeen of these had built their deviation > or = "0" > 10(Delta) with prism adaptation. All responders had surgery for their prism-adapted angle. Postoperatively, 34 of 41 (83%) responders and 6 of 18 (33%) nonresponders had fusion. In the PAN group, 17 were responders. Nine of these built their deviation with prisms. Postoperatively, 16 of 17 (94%) responders and builders and 1 of 9 (11%) nonresponders had successful surgery with sensory and motor fusion.

CONCLUSIONS

Adults with esotropia onset before visual maturation can be prism adapted and surgically treated with a predictable outcome of sensory and motor fusion. Those prism adapted for near with response can be successfully treated with surgery for the near deviation. Prism adaptation also aids in determining those who would benefit from larger amounts of surgery.

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.

Surgical correction of large-angle exotropia in adults

AIM

A retrospective and longitudinal review of the outcome of strabismus surgery for adults with large- and very-large-angle manifest exodeviations, using two-, three- and four muscle horizontal recti surgery with adjustable sutures.

METHODS

A total of 26 consecutive adult patients undergoing surgery for socially noticeable strabismus comprising five primary, 16 consecutive, and five secondary constant exotropias with a mean near deviation of 58 prism dioptres and a mean distance deviation of 55Delta were evaluated preoperatively and at various time intervals postoperatively. Surgery involved two muscles in seven cases, three muscles in 13 cases, and four muscles in six cases; and 25 of 26 had adjustable sutures. There was a horizontal preoperative ocular movement deficit in 17 that was asymmetrical in four cases.

RESULTS

Binocularity was restored in eight patients (31%), 20 (77%) were within 10Delta of orthotropia, and 24 (92%) were happy with their cosmesis. Two had symptomatic asymmetrical ocular motility deficits postoperatively following a two-muscle procedure and one required reoperation. A total of 19 patients undergoing three- or four-muscle surgery were asymptomatic postoperatively. A total of 22 patients had follow-up of 8 months or more.

CONCLUSION

In adults with large-angle manifest exodeviations, adjustable suture surgery involving three or more horizontal recti successfully restores primary position alignment, a high degree of patient satisfaction, and can be expected to be associated with a low incidence of symptomatic postoperative asymmetrical ocular movement deficits.

Postoperative stereoacuity following realignment for chronic acquired strabismus in adults

BACKGROUND

There is controversy regarding whether or not visually mature individuals can permanently lose stereoacuity and under what conditions stereoacuity can be regained. Some have proposed a critical duration of misalignment in adults beyond which recovery of fine stereoacuity is not possible, despite successful surgical alignment.

METHODS

Twenty-one adult patients (median age 59 years) with large-angle acquired strabismus and who were successfully surgically aligned after 7 to 501 months of misalignment were studied. Subjects had no evidence of motor or sensory fusion since the onset of strabismus, on preoperative exam, or by history. Stereoacuity was measured using 1 or more of the Frisby, Preschool Randot and Titmus tests, at 8 weeks and at 12 months. Data from tests with monocular clues were not used.

RESULTS

At total of 67% of patients with chronic acquired strabismus and no preoperative fusion regained measurable stereoacuity and 44% regained fine stereoacuity of at least 60 seconds of arc. Of 10 patients with no or subnormal stereoacuity 8 weeks postoperatively, 6 (60%) showed improvement at the 12-month visit. Misalignment for up to 4 years did not preclude the development of postoperative stereoacuity.

CONCLUSIONS

Although a minority of adult strabismus patients may permanently lose stereoacuity despite successful alignment for acquired strabismus, the majority do show recovery. Such recovery of stereoacuity may take several months to occur. In our adult series, duration of misalignment did not predict failure to recover stereoacuity.

The value of adult strabismus correction to the patient

OBJECTIVES

To look at the value of adult strabismus correction to the patient, to consider what is known, and to define the challenges and opportunities for helping these patients.

METHOD

The benefits of adult strabismus correction leading to the establishment of binocularity, expansion of visual field, and improved psychosocial health are presented and supported by published studies.

RESULTS

Adults with strabismus can benefit from its correction.

CONCLUSION

There is a tremendous need to educate the medical community and the lay public that adults with strabismus can be helped with restoration of their eyes to a position of alignment for normal function.

The clinical spectrum of early-onset esotropia: experience of the Congenital Esotropia Observational Study

PURPOSE

To describe historical and presenting features of infants with the onset of esotropia in early infancy to provide a better understanding of the clinical spectrum of the disorder.

DESIGN

Prospective multicenter cohort study.

METHODS

Eligibility criteria included age at enrollment 4 to < 20 weeks and an esotropia at near measuring at least 20 prism diopters (pd). Historical information was elicited from the parent or guardian. The esotropia was measured at near and characterized as constant, variable, or intermittent.

RESULTS

175 infants were enrolled. Their average age at enrollment was 97 +/- 26 days. The esotropia was characterized as constant in 56% of the patients, variable in 25%, and intermittent in 19%. Forty-nine percent of the deviations were > or = 40 pd. Most of the larger angle deviations were constant whereas the majority of the smaller angle deviations were intermittent or variable. The majority of patients first seen after 12 weeks of age had constant deviations (65%), whereas the majority seen before 12 weeks of age had intermittent or variable deviations (57%). At enrollment, amblyopia was diagnosed in 19% of patients.

CONCLUSION

The clinical presentation of esotropia in early infancy shows more variation in the esotropia's size and character than has been previously appreciated. Only a minority of the infants who are diagnosed to have esotropia before 20 weeks of age have the commonly accepted profile for congenital esotropia of a large-angle constant deviation. Amblyopia frequently develops, so an evaluation for amblyopia should be an integral part of the examination of an infant with esotropia.