Surgical results and factors affecting outcome in adult patients with sensory exotropia

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.

Surgical outcomes in sensory exotropia

PURPOSE

To determine success rates over time for strabismus surgery for sensory exotropia and to determine factors associated with successful outcomes.

METHODS

We retrospectively reviewed medical records of patients with sensory exotropia (best-corrected visual acuity ≤20/200 in the affected eye) who underwent strabismus surgery between May 2009 and December 2019. Patients with paralytic/restrictive exotropia and patients who did not follow up postoperatively were excluded. Surgical success was defined as exotropia of ≤10Δ or esotropia of ≤6Δ. Cox-proportional hazard models were used to evaluate covariate relationships with surgical outcome (α = 0.05).

RESULTS

A total of 94 patients (64% female) were included. Mean patient age was 27.2 years (range, 3-69). Mean follow-up was 2.35 ± 2.77 years. The mean preoperative near deviation was 39Δ ± 14.8Δ of manifest or intermittent exotropia. Successful alignment was achieved in 51 of 83 patients (61%) at 1 month, 19 of 32 (59%) at 1 year, and 8 of 16 (50%) at 5 years. We found a significant correlation (P value = 0.0476) between success and smaller surgical doses in patients that underwent one- and two-muscle surgeries.

CONCLUSIONS

In our study cohort of 94 patients, 50% of patients still had satisfactory ocular alignment at 5 years.

Triple procedure for coexistent aphakia, squint, and iris defect: single-stage strabismus correction, glued IOL, and single-pass 4-throw pupilloplasty

Posttraumatic aphakia is a serious deterrent to visual rehabilitation that usually follows sensory exotropia, thereby mandating urgent surgical intervention. In addition, abnormal iris configuration and iris defects postocular trauma can lead to amblyopia and glare and require surgical correction. However, in individuals where such multiple posttraumatic extraocular and intraocular abnormalities coexist, confusion remains about whether to perform sequential or concomitant surgeries. In these situations, an unusual triple technique consisting of strabismus correction, glued scleral fixation of intraocular lens, and single-pass 4-throw pupilloplasty is a useful cost-effective method of single-stage visual and cosmetic rehabilitation. However, it requires collaboration of experienced surgeons form multiple ophthalmic subspecialties.

Unilateral recession and resection surgery with adjustable suture in adult sensory exotropia: long-term success and exotropic drift

We included adult patients (age ≥18 years) with sensory exotropia who underwent unilateral lateral rectus recession with adjustable suture and medial rectus resection with at least 2-year follow-up. Preoperative and postoperative data was collected. Either Krimsky or alternate and prism cover testing was used to measure the angle of deviation depending on patients' fixation ability. Glasses with full refractive correction were worn if they can provide better visual acuity. Exodeviation at near fixation was used in statistical analysis.

A total of 38 patients (mean age at surgery 32 ± 13 years) were included. Median preoperative exotropia was 45 PD (IQR 40-55, range 25-70) and median initial postoperative deviation was esotropia 8 PD (IQR 0-11, range from exotropia 8 to esotropia 30). Mean follow-up time was 5 ± 2.5 years (range 2-10). Motor success, defined as a deviation within 10 PD of orthotropia, was found in 50% and 42% of patients at 2-year and last follow-up. Initial postoperative deviation and amount of lateral rectus recession were significantly associated with long-term outcome (p = .006 and 0.029). Patients with initial moderate and minimal overcorrection had higher success rates (67% and 62%) than patients with initial orthotropia or undercorrection (10%) (p = .002). Median overall rate of exotropic drift was 8 PD/year (IQR 6-13, range from esotropic drift 8 to exotropic drift 26). Time to failure in nonsuccess group was 24 months (IQR 21-24, range 2-24).

In conclusion, unilateral recession and resection surgery with adjustable suture in adult sensory exotropia achieved 50% success at 2 years. Initial postoperative moderate overcorrection results provide the highest chance for long-term success. The majority of patients developed exotropic drift with time and time to failure was 2 years.