Factors influencing the development and severity of dissociated vertical deviation in patients with infantile esotropia

Timing of surgery in essential infantile esotropia - What more do we know since the turn of the century?

This review summarizes the results and interpretations of studies pertaining to the long-standing debate regarding the timing of surgery in infantile esotropia, more recently referred to as essential infantile esotropia. A systematic search of studies from the year 2000 onward pertaining to the timing of surgery in infantile esotropia as listed in PubMed, Google Scholar, and the Cochrane database was performed. Appropriate cross-references from the articles were also included. Data collected included demographics, presentation, time of surgery, complications, and outcomes. Very early surgery, that is, within 6 months of the onset of infantile esotropia, offers significant advantages in terms of the quality of stereopsis and binocular vision as well as promoting the development of cortical visual processing, thereby benefiting cortical development in human infants. However, the postoperative alignment was not found to be significantly different in the very early, early, or late surgery groups. The reduction in the incidence of manifest dissociated vertical deviation postoperatively in the very early surgery group also showed measurable benefits. The results of this recent literature review demonstrated that very early surgery, within 6 months of misalignment, showed demonstrable benefits in essential infantile esotropia.

Comparison of Different Surgical Approaches to Inferior Oblique Overaction

BACKGROUND

The purpose of this study is to compare surgical outcomes of recession, anteriorization, and myotomy for the treatment of inferior oblique overaction (IOOA).

METHODS

A retrospective chart review of all patients undergoing IOOA correction from July 2010 to March 2017 at the Children's Hospital of Colorado was performed. Preoperative grading of IOOA (+0.5 to +4.0) was compared to post-operative IOOA (0 to +4.0). The goal was reduction of IOOA to 0, but any decrease in IOOA was measured.

RESULTS

There were a total of 260 patients with 357 eyes. Gender and age were similar across surgery types. A 94.6% of eyes had a decrease in IOOA with recession (n = 165) of the inferior oblique while 86.1% decreased to no IOOA. Anteriorization of the inferior oblique (n = 115) decreased overaction in 97.4% of eyes with 81.7% improving to zero degree of IOOA. Myotomy of the inferior oblique (n = 77) was found to decrease overaction in 98.7% of eyes and reduce IOOA to zero in 88.3%. There was no significant difference among type of surgery and outcome.

CONCLUSION

All three surgical interventions were found to be equally successful in reducing the amount of IOOA.

Stereopsis: are we assessing it in enough depth?

The assessment of stereoacuity is an integral part of the ophthalmic assessment, with the responses used to inform clinical management decisions. Stereoacuity impacts on many aspects of life, but there are discrepancies reported where people without measurable stereoacuity report appreciating 3-D vision. This could be due, in part, to the presentation of the stimuli. A literature review was undertaken to evaluate current assessment techniques, how they relate to patient outcomes, identify the limitations of current tests and discuss how they could be improved. Recent evidence has been collated on currently available tests, used commonly within vision clinics, with normative data provided allowing responses to the tests to be interpreted. The relevance of the results is evaluated in relation to a range of outcomes, where a reduced level of stereopsis has a negative impact on the ability of an individual to perform many tasks, and can lead to an increase in difficulty interacting in the world. Current tests are limited in the aspects of stereoacuity they assess and their ability to precisely measure stereopsis. The world is not static, yet clinical tests are limited to measuring static stereoacuity, even though higher grades of depth perception can be identified in the presence of changing depth. Presentation methods of stereoacuity tests have remained similar over time, with a limited number of disparity levels assessed. New assessment methods are becoming available that include automated staircase testing to present multiple levels of disparity using digital technology. Current clinical tests are limited in their presentation, and are poor at detecting/measuring stereoacuity in those with limited stereopsis. Given the relevance of the stereoacuity measurement to management choices and functional outcomes, new testing methods would be beneficial to fully assess stereoacuity, both static and dynamic.

Essential Infantile Esotropia: Postoperative Sensory Outcomes of Strabismus Surgery

BACKGROUND

The optimum age for Essential Infantile Esotropia surgery is a controversial subject. Sensory status was evaluated in patients who underwent surgery at different ages in a retrospective study. The setting of the study is the ophthalmology department of a teaching hospital.

METHODS

Different clinical characters were analyzed pre- and postoperatively; nine different surgeries were performed. A total of 188 patients presented valid postoperative sensorial data, divided in two groups: surgery at ≤2 years (n=69) or >2 years (n=119). Sensory status was dichotomized in binocular single vision (BSV) and exclusion. Univariate differences were assessed with the chi-square test (or Fisher exact test). To identify the independent role of factors associated with the sensory status, all variables showing in univariate analyses a significant association (p<0.05) with the outcome variable were entered into a multivariate logistic regression model. All statistical tests were two-sided.

RESULTS

Multivariate analysis confirmed that children operated >2 years were 0.4 times less likely to obtain BSV compared with children operated at ≤2 years (AOR. 0.38, 95% C.I. 0.17-0.89, p=0.025). Patients operated on by OO MR rec.+ OO LR res. + OO IO rec.-ap. (intervention type 6) were about 11 times more likely to have BSV than those by OO rec.MR + unilateral res. LR (operation type 2); AOR.: 10.67, 95% C.I.: 1.34 - 85.29, p=0.026). Twenty-nine patients (12.1%) operated at ≤2 years of age underwent a reoperation, compared to 33 (8.6%) who underwent surgery after two years (p>0.05).

CONCLUSIONS

Our findings suggest to perform EIE surgery between age 1 and 2 and, when indicated, to prefer a six-muscle approach in order to achieve a better sensory function.

Stereoscopic perception of 3-D images by patients after surgery for esotropia

PURPOSE

Patients with esotropia (ET) have generally poor stereopsis; however, it is not clear whether they can see the recently developed 3-D images stereoscopically. We investigated the ability of postoperative ET patients to have stereoscopic perception of 3-D attraction images which have large crossed disparities, and also 3-D movies which have generally small uncrossed disparities.

METHODS

Twenty-seven ET patients (infantile ET = 12, late-onset ET = 15) were examined postoperatively. They were examined with the 4-dot test, Titmus fly test, and questionnaires to determine whether they had stereoscopic vision when observing 3-D attraction images and 3-D movies. McNemar tests were used for statistical evaluations.

RESULTS

The number of patients who passed the Titmus fly test was smaller than the number that were able to see 3-D attraction images stereoscopically (fly test 13; 48%, 3-D attraction 22; 81%; P = 0.016). However, the number was not significantly different from that of those who could perceive 3-D movies stereoscopically. The number of patients who passed the Titmus fly test was significantly smaller than the number who can perceive 3-D attraction images stereoscopically in the infantile ET group (fly test 2, 17%, 3-D attraction 10, 83%; P = 0.013) but was not different in the late-onset ET group postoperatively. The minimum angle of fusion for the 4-dot test was smaller in the Titmus fly-positive patients than in the Titmus fly-negative patients (P = 0.03).

CONCLUSIONS

These results suggest that children who cannot pass the Titmus fly test might be able to experience 3-D attractions stereoscopically but not be able to see 3-D movies stereoscopically.