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

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.

Quotidian Profile of Vergence Angle in Ambulatory Subjects Monitored With Wearable Eye Tracking Glasses

Purpose

Wearable eye trackers record gaze position as ambulatory subjects navigate their environment. Tobii Pro Glasses 3 were tested to assess their accuracy and precision in the measurement of vergence angle.

Methods

Four subjects wore the eye tracking glasses, with their head stabilized, while fixating at a series of distances corresponding to vergence demands of: 0.25, 0.50, 1, 2, 4, 8, 16, and 32°. After these laboratory trials were completed, 10 subjects wore the glasses for a prolonged period while carrying out their customary daily pursuits. A vergence profile was compiled for each subject and compared with interpupillary distance.

Results

In the laboratory, the eye tracking glasses were comparable in accuracy to remote video eye trackers, outputting a mean vergence value within 1° of demand at all angles except 32°. In ambulatory subjects, the glasses were less accurate, due to tracking interruptions and measurement errors, partly mitigated by the application of data filters. Nonetheless, a useful record of vergence behavior was obtained in every subject. Vergence profiles often had a bimodal distribution, reflecting a preponderance of activities at near (mobile phone and computer) or far (driving and walking). As expected, vergence angle correlated with interpupillary distance.

Conclusions

Wearable eye tracking glasses make it possible to compile a nearly continuous record of vergence angle over hours, which can be correlated with the corresponding visual scene viewed by ambulatory subjects.

Translational Relevance

This technology provides new insight into the diversity of human ocular motor behavior and may become useful for the diagnosis of disorders that affect vergence function such as: convergence insufficiency, Parkinson disease, and strabismus.

Evaluation and Management of Divergence Insufficiency-Type Esotropia

Divergence insufficiency-type ET is a common cause of distance diplopia in elderly adults. A recent prospective multicenter data collection study has provided additional guidance on management. Either base-out prism glasses or strabismus surgery were found to have high success rates, based on patient report of diplopia, and health-related quality-of-life domain scores. It was concluded that either prism or surgery were reasonable initial treatment strategies. Although allocation bias precluded formal comparison of prism versus surgery (evident in baseline differences between groups), there were hints that surgery may yield superior outcomes. For surgery, the most common approach was bilateral medial rectus recession, which was highly successful when assessed 10 weeks and 12 months postoperatively. It was unclear whether adjustable sutures were helpful, but in the vast majority of adjustable cases, additional recession at the time of adjustment was performed, suggesting that larger than standard surgical doses are needed.