Distance-near disparity esotropia: can we shrink the gap?

Development and Validation of a Nomogram for Predicting Second Surgery in Patients with Concomitant Esotropia

INTRODUCTION

This study developed and validated a nomogram for predicting the risk of second surgery in patients with concomitant esotropia (CE) based on a cohort in Beijing.

METHODS

In this retrospective cohort study, the inpatient and outpatient medical records of 419 patients with CE who underwent surgery at the Peking University First Hospital between January 1, 2005 and December 31, 2009 were collected. A total of 357 CE cases were included. For those cases 70% were randomly assigned to the training set (n = 234) and 30% to the validation set (n = 123). Demographic and clinical variables were ascertained at hospital admission and discharge and screened using multivariate Cox proportional hazards regression analysis to construct predictive models and generate a 1-, 4-, and 8-year overall survival nomogram. This nomogram provided an estimate of the risk of second surgery in patients with surgically treated CE. Internal validation was conducted using the concordance index (C-index) and calibration curve for the training and validation sets.

RESULTS

Six independent prognostic factors were identified, namely age at surgery, age at onset, amblyopia, deviation angles, surgical amount, and deviation angles 1 week after surgery, and these were entered into the nomogram. The proposed nomogram showed favorable discrimination and accuracy in the training and validation sets. The C-indexes of the training and validation sets were 0.84 (95% CI 0.79-0.89) and 0.80 (95% CI 0.78-0.82), respectively.

CONCLUSIONS

The proposed nomogram can serve as a predictive tool for prognostic evaluation of CE surgery.

Effect of prism adaptation in patients with partially accommodative esotropia: clinical findings and surgical outcomes

PURPOSE

To assess the effects of prism adaptation on the surgical outcomes of individuals with partially accommodative esotropia (PAET).

METHODS

The medical records of 51 patients with PAET who were managed surgically at single referral center were retrospectively reviewed. Patients were divided into two groups according to prism adaptation. Data about sex, age, initial angle of deviation, final angle of deviation, stereoacuity, surgical dosage, and follow-up periods were collected. The main outcome of this study was motor outcomes at 12 months.

RESULTS

Eighteen patients had a history of prism adaptation (PA group) and 33 did not (augmented surgery group, AS group). One year after surgery, 12 (66.7%) patients in the PA group and 21 (63.6%) in the AS group achieved an angle of deviation less than 5 PD. The surgical success rate in both groups did not significantly differ (p = 1). After the first prism adaptation test, six patients had an angle of deviation similar to the previous angle; however, 12 patients had larger angle, and consequently required additional prism (prism builder). Two (33.3%) patients who were prism non-builders had deviation less than 5 PD during the final visit. However, among the prism builders, four (57.1%) and five (100%) patients who had prism added once and more than once, respectively, had less than 5 PD deviation during the final visit (p = 0.03).

CONCLUSION

No significant differences were observed in terms of surgical outcomes between both groups. Nonetheless, in PA group, prism builders have better surgical outcomes than non-builders.

Combined resection-recession versus combined recession-retroequatorial myopexy of medial rectus muscles for treatment of near-distance disparity Esotropia

Purpose

To compare and evaluate the efficacy of two different surgical techniques for the treatment of near-distance disparity esotropia; combined resection–recession and recession–retroequatorial myopexy of medial rectus muscles.

Patients and methods

This prospective study included 28 patients diagnosed with convergence excess esotropia who had worn their full cycloplegic refraction and/or bifocal glasses for at least 6 months and still had near-distance disparity esotropia. The patients were divided into 2 groups; Group I underwent combined bimedial rectus muscles resection 2.5 mm from the insertion end with recession based on near-angle esotropia according to current surgical tables with 1 mm add of recession for each muscle, while Group II underwent bimedial recession based on far angle combined with retroequatorial myopexy at 13–14 mm from insertion. A satisfactory result was defined as orthophoria or esotropia <10 prism diopters (Δ) at near and distance with reduction of the near-distance disparity to <10 Δ. The patients were followed up for at least 2 years for stability of correction and late onset consecutive exotropia.

Results

In Group I, all the patients had satisfactory alignments at near and far with residual near–far disparity #10 Δ, no cases of overcorrection at far was reported; while in Group II, all cases had orthophoria at far, but 4 cases (28.6%) showed near–far disparity >10 Δ.

Conclusion

The technique of combined resection–recession is safe, easy and more effective in the treatment of near-distance disparity esotropia regardless of the level of accommodative convergence/accommodation ratio, with stability of results though longer follow-up period is still needed.

Combined recession and resection surgery in the management of convergence excess esotropia with different levels of AC/A ratio

PURPOSE

To study prospectively the effect of extirpating the proprioceptive impulse at the myotendinous junction combined with recession of the medial rectus muscles in patients with convergence excess esotropia.

METHODS

A total of 21 patients with different sizes of AC/A ratios (high, 8; normal, 12; low, 1) underwent a surgical procedure consisting of combining resection of 2.5 mm of the insertional end of the medial rectus muscles with recession from the original insertion, based on the patient's angle of esotropia at 1/3 m while wearing full cycloplegic refraction, with an additional recession of 1 mm for each rectus muscle based on current surgical tables. A satisfactory outcome was defined as orthotropia or esotropia of <10^Δ at near and distance fixations with available correction and reduction of the distance--near disparity to <10^Δ.

RESULTS

All patients, regardless of the size of AC/A ratio and the amount of near-distance disparity, had satisfactory alignments at near and distance fixations, with residual near-distance disparity of <10^Δ. Consecutive distance exotropia did not develop even when there was preoperative distance orthotropia. Outcome measures remained stable for a mean of 4.3 years. None of the 8 patients with high AC/A ratios required bifocal wear or overcorrection prescriptions to maintain alignment postoperatively.

CONCLUSIONS

This technique of combined resection and recession of the medial rectus muscle shows promise in the treatment of convergence excess esotropia. The main advantage is improvement in distance alignment while selectively reducing the near angle in patients with different levels of AC/A ratios.