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

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.

Correlation of Strabismus Surgical Outcomes Graded by Goal-Determined Metric With Patient Satisfaction Survey

PURPOSE

Although strabismus surgery outcomes can be objectively measured, patient perception of results may differ. We present surgical outcomes graded by a prospective, "goal-determined metric" and compare these outcomes to results of a patient satisfaction survey.

DESIGN

Validity analysis comparing a clinical "goal-determined metric" to patient satisfaction.

METHODS

Goal-determined metric outcomes (2018-2021) for 2 surgeons treating esotropia or exotropia for diplopia control or reconstructive goals were collected. Inclusion required completion of postoperative examination 2-6 months after surgery and a satisfaction survey.

RESULTS

Record review identified 275 patients; 228 (median age 41 years [interquartile range 13-59]) met inclusion criteria. For the entire cohort, 87% were graded as "excellent" outcomes, and 78% of patients were overall "very satisfied." Agreement between patients' and surgeons' grading was 75% to 79% for all reconstructive surgery and for treatment of diplopia from esotropia. Agreement was lower, although not statistically different, for treatment of diplopia from exotropia (64%, 95% CI 43%-80%; P = .184). Preoperative risk factors, concurrent vertical or oblique surgery, and sex did not affect outcomes or satisfaction. Performance of activities requiring distance viewing improved more than performance of activities at near after esotropia-diplopia surgery (odds ratio 3.0, 95% CI 1.5-6.4; P = .004). For reconstructive cases achieving "much better" eye alignment, 62% and 72% (previously esotropic and exotropic) reported enhanced self-confidence.

CONCLUSIONS

Outcomes graded by goal-determined metric correlated well with many aspects of patient satisfaction. Patient-perceived improvement in appearance was important regardless of goal. Greater improvement in performance of activities requiring distance rather than near viewing characterized treatment of diplopia from esotropia.

Binocular Summation With Quantitative Contrast Sensitivity Function: A Novel Parameter to Evaluate Binocular Function in Intermittent Exotropia

Purpose

Intermittent exotropia (IXT) is the most common form of strabismus. Surgery can potentially improve binocular function in patients with IXT. We aimed to evaluate binocular function using a novel parameter-binocular summation ratio (BSR), measured using quantitative contrast sensitivity function (CSF) in patients with IXT before and after surgery.

Methods

Prospective study of 63 patients with IXT and 41 healthy controls were consecutively enrolled and underwent quantitative CSF testing binocularly and monocularly. BSR was calculated by dividing the CSF of the binocular value by the better monocular value. Forty-eight patients with IXT underwent strabismus surgery. BSR, stereoacuity, fusion ability, and strabismus questionnaires were assessed pre-operatively and 2 months postoperatively.

Results

Sixty-three patients with IXT (median age = 9 years) compared with 41 healthy controls showed a worse mean BSR based on all CSF metrics at baseline (the area under the log CSF [AULCSF], spatial frequency [SF] cutoff, and contrast sensitivity at 1.0-18.0 cpd SF). All 48 patients with IXT showed successful alignment after surgery, and there were significant improvements in BSR based on the AULCSF, SF cutoff, and contrast sensitivity at 6.0, 12.0, and 18.0 cpd SF, respectively. The distance stereoacuity and fusion ability also improved after surgery, and a better BSR was associated with better stereoacuity and fusion. For strabismus questionnaires, the psychosocial subscale scores improved postoperatively, whereas the functional subscale scores did not change.

Conclusions

BSR based on quantitative CSF can characterize binocular function across a range of spatial frequencies and can be used as a supplemental measurement for monitoring binocularity in patients with IXT in clinical settings.

Factors affecting quality of life in keratoconus

PURPOSE

To identify the factors affecting the quality of life (QoL) in adults with keratoconus, using the disease-specific Keratoconus Outcomes Research Questionnaire (KORQ).

METHODS

In this cross-sectional study, 574 patients with keratoconus completed the 29-item KORQ (18-item activity limitations and 11-item symptoms subscales) and demographic information. Based on mean corneal curvature to grade keratoconus severity, participants were categorised into four groups: mild <48 dioptres [D]; moderate: 48 to 53 D; advanced: 54 to 55 D and severe: >55D. Rasch analysis was used to assess the psychometric properties and to score the KORQ. Multivariable regression was performed to determine the independent impact of age, sex, laterality, severity and duration of keratoconus, education, employment status and mode of treatment for keratoconus on activity limitations and symptoms.

RESULTS

Mean (SD) age was 24.5 (5.1) years. 304 (53%), 160 (28%), 26 (4%) and 84 (15%) belonged to keratoconus groups 1, 2, 3 and 4, respectively. Rasch analysis demonstrated the 'activity limitations' and 'symptoms' KORQ subscales to possess good psychometric properties. Statistically significant associations were found between activity limitation score and the following measures: visual acuity (VA) in the better-seeing eye (r = -0.10, p = 0.01); VA in the worse-seeing eye (r = -0.09, p = 0.04) and ocular aberrations (r = -0.13, p = 0.008) in the worse-seeing eye. Statistically significant associations were also found between symptoms score and mean corneal curvature in the better-seeing eye (r = -0.10, p = 0.02). In regression models, female sex was associated with 21% worse symptom score than male (β = -0.33, 95% CI, -0.09, -0.59, p = 0.01) and working people experienced clinically and statistically significantly greater trouble from symptoms compared to those not working (β =0.44, 95% CI, 0.17, 0.70, p = 0.001).

CONCLUSIONS

People with keratoconus have poorer QoL in terms of activity limitations if they have poorer VA and greater wavefront aberrations, and in terms of symptoms if they are female and employed.

Primary and secondary superior rectus recessions to correct vertical deviations in Graves' orbitopathy patients

PURPOSE

Patients with vertical strabismus and consecutive diplopia due to Graves' orbitopathy (GO) might need recession of the rectus superior muscle. The aim of this retrospective analysis is to provide dose-effect values and motility analysis for these patients.

METHODS

Dose-effect relations (deviation reduction in primary position per amount of recession in mm), monocular excursions and size of the field of binocular single vision (BSV) were evaluated in three different groups of patients. Group 1 (n = 33) patients with primary fibrosis of superior rectus muscle undergoing recession of the ipsilateral rectus superior, Group 2 (n = 14) superior rectus muscle recession after recession of inferior rectus on the contralateral eye and Group 3 (n = 15) simultaneous ipsilateral superior rectus recession and contralateral inferior rectus muscle recession. Surgery was performed using the dose-effect for inferior rectus recession of 4 prism dioptre (PD,Δ ) reduction/per mm recession and the intraoperative traction test.

RESULTS

Restoration of BSV in the central 20° of gaze could be reached in 88%, 79% and 67% of patients in the three groups, respectively. Restoration of BSV in downgaze (up to 30°) was a little less successful, 79%, 57% and 53%, respectively. The median dose-effect was 3.2Δ reduction/mm recession in Group 1 (Spearman correlation r = 0.75, p < 0.0001) and 3.3Δ /mm in Group 2 (n.s.) and 4Δ /mm in Group 3 (r = 0.67, p = 0.016). The basis for the improvement was the symmetrization of ductions.

CONCLUSION

If superior rectus recession is necessary in GO, higher dosing around 3Δ reduction/per mm recession should be applied. In case of large deviations, combined vertical surgery (inferior rectus and superior rectus contralateral) is required and reasonable (low cyclotorsion). Single-step or two-step procedures lead to similar results.

Adjustable Sutures in the Treatment of Strabismus: A Report by the American Academy of Ophthalmology

PURPOSE

To review the scientific literature that evaluates the effectiveness of adjustable sutures in the management of strabismus for adult and pediatric patients.

METHODS

Literature searches were performed in the PubMed database through April 2021 with no date limitations and were restricted to publications in English. The searches identified 551 relevant citations, of which 55 were reviewed in full text. Of these, 17 articles met the inclusion criteria and were assigned a level of evidence rating by the panel methodologist. The search included all randomized controlled studies regardless of study size and cohort studies of 100 or more patients comparing the adjustable versus nonadjustable suture technique, with a focus on motor alignment outcomes or reoperation rates.

RESULTS

The literature search yielded no level I studies. Of the 17 articles that met the inclusion criteria, 11 were rated level II and 6 were rated level III. Among the 12 studies that focused on motor alignment outcomes, 4 small randomized clinical trials (RCTs) did not find a statistically significant difference between groups, although they were powered to detect only very large differences. Seven of 8 nonrandomized studies found a statistically significant difference in motor alignment success in favor of the adjustable suture technique, both overall and in certain subgroups of patients. Successful motor alignment was seen in both exotropia (in 3 studies that were not limited to children) and esotropia (in 1 study of adults and 2 of children). The majority of included studies that reported on reoperation rates found the rates to be lower in patients who underwent strabismus surgery with adjustable sutures, but this finding was not uniformly demonstrated.

CONCLUSIONS

Although there are no level I studies evaluating the effectiveness of adjustable sutures for strabismus surgery, the majority of nonrandomized studies that met the inclusion criteria for this assessment reported an advantage of the adjustable suture technique over the nonadjustable technique with respect to motor alignment outcomes. This finding was not uniformly demonstrated among all studies reviewed and warrants further investigation in the development and analysis of adjustable suture techniques.

Psychometric properties of the Dutch version Adult Strabismus-20 Questionnaire (AS-20)

PURPOSE

Strabismus often has an impact on a patient's quality of life (QoL). The Adult Strabismus-20 questionnaire (AS-20) is an instrument developed to assess the strabismus-specific QoL. The aim was to investigate several psychometric properties of the Dutch-AS-20 among adult patients with strabismus.

METHODS

Patients with any type of strabismus completed the Dutch-AS-20, the EuroQol five-dimensional questionnaire (EQ-5D-5L) and the Amblyopia and Strabismus Questionnaire (A&SQ) (N = 286). Psychometric properties were evaluated with the use of item response theory (IRT) analysis (graded response model) and by determining the internal consistency, test-retest reliability after two weeks, targeting and measurement precision. Construct validity of the AS-20 was tested against the EQ-5D-5L and the A&SQ.

RESULTS

Principal component analysis indicated a psychosocial and function subscale. After collapsing underutilised response options for 10 items, subsequent fit analysis showed that the function subscale benefitted from removal of two items. Differential item functioning (DIF) was detected on four items for age and gender subgroups, but with minimal impact on the total score. Internal consistency (Cronbach's alpha 0.93 psychosocial and 0.87 function subscale) and test-retest reliability (ICC 0.91 psychosocial and 0.88 function subscale) were sufficient. Targeting and measurement precision of both subscales was appropriate for patients with low to moderate levels of visual and psychosocial functioning but suboptimal for patients with high levels of visual and psychosocial functioning. Correlations were between 0.4 and 0.7 for (subscales of) the Dutch-AS-20 and the A&SQ or EQ-5D-5L, confirming expected construct validity.

CONCLUSIONS

The 18-item Dutch-AS-20 has sound psychometric properties to assess the strabismus-specific QoL among Dutch adult patients with low to moderate levels of visual and psychosocial functioning. Care must be taken when interpreting the results due to lower measurement precision at the higher end of both subscales. In future longitudinal studies, properties to assess treatment effects should be evaluated.

A prospective study of treatments for adult-onset divergence insufficiency-type esotropia

PURPOSE

To describe 10-week and 12-month outcomes following treatment for divergence insufficiency-type esotropia in adults.

METHODS

In this prospective observational study, 110 adults with divergence insufficiency-type esotropia, with a distance esodeviation measuring 2^Δ to 30^Δ and at least 25% larger at distance than near, and binocular diplopia present at least "sometimes" at distance, were enrolled at 28 sites when initiating new treatment. Surgery, prism, or divergence exercises/therapy were chosen at the investigator's discretion. Diplopia was assessed at enrollment and at 10-week and 12-month outcome examinations using a standardized diplopia questionnaire (DQ). Success was defined as DQ responses of "rarely" or "never" when looking straight ahead in the distance, with no alternative treatment initiated.

RESULTS

Of the 110 participants, 32 (29%) were prescribed base-out prism; none had received prior treatment for esotropia. Success criteria were met by 22 of 30 at 10 weeks (73%; 95% CI, 54%-88%) and by 16 of 26 at 12 months (62%; 95% CI, 41%-80%). For the 76 (68%) who underwent strabismus surgery (82% of whom had been previously treated with prism), success criteria were met by 69 of 74 at 10 weeks (93%; 95% CI, 85%-98%) and by 57 of 72 at 12 months (79%; 95% CI, 68%-88%).

CONCLUSIONS

In this study cohort, both base-out prism as initial therapy and strabismus surgery (usually following prism) were successful in treating diplopia for most adults with divergence insufficiency-type esotropia when assessed during the first year of follow-up.

Current trends of strabismus surgery in a tertiary hospital

OBJECTIVE

To analyze the strabismus surgeries and the outcomes during a year and a half in a tertiary hospital.

MATERIAL AND METHODS

A retrospective study of patients who underwent strabismus surgery. The mean age, sex, diagnosis, diplopia, surgery, anesthesia, adjustable sutures, results, reoperations and follow up time from surgery were analyzed. A good outcome was considered when the final horizontal deviation was less than 10prism diopters (pd) and the vertical deviation less than 5pd without diplopia.

RESULTS

A total of 153 cases were operated on, mean age: 43.14 ±25.58years (61.4%: women). 74.5% of patients were ≥18years (33.33% ≥60). Diplopia was present in 51% of patients. The most frequent deviation was horizontal: 83.6%. The most frequent diagnosis was cranial nerve palsies: 32% (VI nerve: 12.4%), restrictive strabismus: 7.2%, and the aged related distance esotropia: 6.5%. Adjustable sutures were used in 19.7% of cases and topical anesthesia in 65.4%. Good outcomes was present in 79.2% of cases at the end of follow-up. Reoperations were needed in 25.5%. Follow-up evolution time was 11.87 months ±6.5. The sex female (P=.012) and the oblique superior surgery (P=.017) were associated with bad outcome.

CONCLUSION

The adult strabismus surgery was three times more frequent than the children strabismus surgery. The third of the adults that were operated on were ≥60 years. The cranial nerve palsies were the most frequent diagnosis. Adjustable sutures were rarely used. Good outcomes were obtained in most of the patients at the end of follow-up.

Factors influencing the self-reported sense of deviation in adults with successful surgical outcomes for strabismus

BACKGROUND

To determine whether a sense of deviation remains in adults with successful motor alignment who fulfil diplopia criteria after surgery and to examine the factors associated with this judgement.

METHODS

This was a retrospective study. Adult patients defined as having a successful outcome based on more than 1 year of post-operative follow-up visits were included in the study. The sense of deviation was determined at the last visit. Pre- and post-operative deviation and characteristics including age, gender, education level, occupation, diagnosis, size of deviation, extraocular movement (EOM), binocular function, and health-related quality of life (HRQOL) were recorded.

RESULTS

In total, 22 (24%) of the 91 adults with successful surgical outcomes reported a sense of deviation. No significant differences were noted between subjects with and without a sense of deviation regarding patient demographics, pre- and post-operative deviation, changes in deviation, sensory fusion or EOM. Subjects with a sense of deviation had an increased prevalence of and larger post-operative vertical deviation, poorer stereo function, and lower HRQOL scores than those with no sense of deviation. The presence of post-operative vertical deviation was associated with a sense of deviation.

CONCLUSIONS

Approximately one-fourth (24%) of adults defined as having successful surgical outcomes who still had a sense of deviation exhibited worse stereo function, higher vertical deviation size and lower HRQOL scores. The presence of 3 to 5 prism dioptres(pd) of vertical deviation would be the main factor associated with a sense of deviation post-operatively.

Factors Associated With Failure of Adult Strabismus-20 Questionnaire Scores to Improve Following Strabismus Surgery

Importance

Health-related quality of life (HRQOL) typically improves following strabismus surgery. Nevertheless, for some patients, HRQOL does not improve, and reasons for this are unknown.

Objective

To identify factors associated with failure of adult strabismus-20 (AS-20) HRQOL scores to improve following strabismus surgery.

Design, Setting, and Participants

Prospective observational case series at the Mayo Clinic, Rochester, Minnesota, comprising 276 adults, between July 2012 and August 2016.

Main Outcomes and Measures

Participants completed the AS-20 HRQOL questionnaire, diplopia questionnaire, Center for Epidemiologic Studies Depression Scale-Revised (CESD-R) (depressive symptoms), and Type-D Scale 14 questionnaire (type-Distressed [type-D] personality) both preoperatively and 6 weeks postoperatively. To assess factors associated with failure of HRQOL to improve (no change or decrease in score), univariate and multiple logistic regression analyses were performed. Each of the 4 AS-20 domains (self-perception, interactions, reading function, and general function) were analyzed separately including only patients able to improve at least by the magnitude of previously defined 95% limits of agreement. Factors assessed were age (at onset and at surgery), sex, number of previous surgeries, presence of visually obtrusive facial anomaly, visual acuity, preoperative and postoperative diplopia questionnaire scores, alignment (as a vector), presence of esotropia, presence of a vertical deviation, CESD-R scores, and type-D personality. Stepwise multiple logistic regression analyses were performed to assess factors associated with failure of AS-20 scores to improve for each domain.

Results

Of the 276 participants, the median age was 57 years (range, 18-91 years), 153 were women (55%), and 266 were white (96%). Failure to improve was associated with worse diplopia postoperatively on the self-perception (adjusted risk ratio [RR], 1.01; 95% CI, 1.00-1.02), reading function (adjusted RR, 1.02; 95% CI, 1.01-1.03), and general function domains (adjusted RR, 1.02; 95% CI, 1.01-1.03). In addition, failure to improve on the self-perception domain was associated with type-D personality postoperatively (adjusted RR, 4.26; 95% CI, 1.90-9.57) and failure to improve on the interactions domain was associated with postoperative depressive symptoms (adjusted RR, 1.04; 95% CI, 1.02-1.06) and coexisting visually obtrusive anomaly (adjusted RR, 2.12; 95% CI, 1.04-4.32).

Conclusions and Relevance

Postoperative diplopia, depressive symptoms, type-D personality, and visually obtrusive facial anomalies were associated with failure of AS-20 scores to improve (remaining the same or worsening) following strabismus surgery. The association of nonstrabismus factors may have implications for patient treatment and is worthy of continued study.

Strabismus surgery in the setting of glaucoma drainage devices in the pediatric population

PURPOSE

To evaluate outcomes of strabismus surgery performed subequent to or concomitant with glaucoma drainage device (GDD) implantation for refractory childhood glaucoma.

METHODS

The medical records of children who underwent strabismus surgery after or concomitantly with GDD implantation were reviewed retrospectively. Included were surgeries with motility and alignment data measured preoperatively and ≥3 months postoperatively. The following data were collected: demographics, visual acuity, glaucoma diagnosis, GDD type/location, pre- and postoperative sensorimotor/alignment measurements, and surgical details. Motor success was defined as ≤10^Δ horizontal and ≤4^Δ vertical residual heterotropia postoperatively.

RESULTS

A total of 25 children were included: 11 in the post-GDD group and 14 in the concomitant-GDD group. In the former, peri-GDD capsule dissection was required in 9 of 11 patients (82%). All cases had preoperative motility restriction or intraoperative scarring. Mean preoperative deviation (26.7^Δ ± 14.6^Δ) decreased by 41% postoperatively, with improved alignment in 7 patients (64%). No patients met strict motor alignment criteria for success. In the concomitant-GDD group, mean preoperative deviation (28.5^Δ ± 10.0^Δ) decreased by 39% postoperatively, with improved alignment in 11 of 14 patients (79%). Four patients (29%) met strict criteria for success. There were no surgical complications in either group.

CONCLUSIONS

Strabismus surgery in eyes with existing or planned GDDs for childhood glaucoma usually improves alignment but often does not result in success based on strict motor alignment criteria. Eyes with childhood glaucoma pose surgical technical challenges related to small orbits and exuberant GDD capsule-muscle scarring and postoperative challenges of poor vision and limited binocular function, that likely limit succcess.

The use of patient-reported outcome research in modern ophthalmology: impact on clinical trials and routine clinical practice

This review article considers the rising demand for patient-reported outcome measures (PROMs) in modern ophthalmic research and clinical practice. We review what PROMs are, how they are developed and chosen for use, and how their quality can be critically appraised. We outline the progress made to develop PROMs in each clinical subspecialty. We highlight recent examples of the use of PROMs as secondary outcome measures in randomized controlled clinical trials and consider the impact they have had. With increasing interest in using PROMs as primary outcome measures, particularly where interventions have been found to be of equivalent efficacy by traditional outcome metrics, we highlight the importance of instrument precision in permitting smaller sample sizes to be recruited. Our review finds that while there has been considerable progress in PROM development, particularly in cataract, glaucoma, medical retina, and low vision, there is a paucity of useful tools for less common ophthalmic conditions. Development and validation of item banks, administered using computer adaptive testing, has been proposed as a solution to overcome many of the traditional limitations of PROMs, but further work will be needed to examine their acceptability to patients, clinicians, and investigators.

What Did They Know Then? A Journey Among the Giants of the Past

Dr. Richard Scobee has the honorary title "The Father of American Orthoptics." In addition to his numerous accomplishments in his academic career, he had hobbies that included collecting historical stamps. In tribute to his love of things past, this lecture will delve into the remote history of ophthalmology, to see what eminent pioneers knew and wrote about eye muscle disorders and binocular vision in their treatises. Our journey will include eight personalities and their works, ranging from the 7th century through to the early 19th century, and will encompass Europe, the Middle East, Great Britain, and North America. Analyzing the writings of these masters affords glimpses into the knowledge base and philosophies that were prevalent in different centuries. Many of these individuals were innovators who pushed the boundaries of knowledge. Some of them made advances using intuition and reason, mainly through case experience and case studies, while others used the scientific method to gain new information. In many cases, the words written by these luminaries centuries ago still resonate with us today and guide us in our everyday practices. It is hoped that this journey will be enlightening for orthoptists, ophthalmologists, and allied health personnel, and confirm, as in many areas of science, that we truly stand on the shoulders of giants, the masters from the recent and the distant past.