Measuring dissociated vertical deviations

Muscle fenestration in vertical rectus muscle surgeries

PURPOSE

To evaluate the outcome of fenestration of the vertical rectus muscles in correcting vertical deviations.

MATERIAL AND METHODS

A retrospective chart review was conducted on patients who underwent fenestration surgery on the superior rectus (SR) or inferior rectus (IR) muscles. Ductions, versions, angle of deviations before and after surgery, and surgical details were analyzed. Success was defined as vertical alignment within 4 PD of orthophoria.

RESULTS

Nineteen patients were identified. The mean age of the patients was 19.3 ± 13.1 (range; 4 to 48) years. The mean follow-up was 6.5 ± 2.7 (range, 3 to 12) months. Eleven patients presented with dissociated vertical deviation (DVD), 2 patients with sensory hypertropia, and 6 patients with sensory hypotropia. Fourteen patients had concomitant horizontal muscle surgery. The mean change of the angle of deviation was 13 ± 3 (range, 8 to 20) PD after SR fenestration. and 12 ± 2 (range; 10 to 15) PD after IR fenestration. There was a significant improvement in the post operative angle of deviation in both groups (P value <0.001). Success was achieved in 10 (77%) of patients who underwent SR fenestration and in all patients underwent ir fenestration. Only one patient in the IR group developed a 1-mm lower lid retraction.

CONCLUSION

Fenestration of the vertical rectus muscles is an effective and safe method for correcting vertical deviations. We recommend increasing the amount of fenstration in DVD to further improve the outcome.

Role of a Standardized Prism Under Cover Test in the Assessment of Dissociated Vertical Deviation

BACKGROUND

Dissociated vertical deviation (DVD) is commonly measured using a prism and alternate cover test (PACT), but some providers use a prism under cover test (PUCT). The aim of this study was to compare a standardized PUCT measurement with a PACT measurement, for assessing the magnitude of DVD.

METHODS

Thirty-six patients with a clinical diagnosis of DVD underwent measurement of the angle of deviation with the PACT, fixing with the habitually fixing eye, and with PUCT, fixing both right and left eyes. The PUCT was standardized, using a 10-second cover for each prism magnitude, until the deviation was neutralized. The magnitude of hyperdeviation by PACT and PUCT was compared for the non-fixing eye, using paired non-parametric tests. The frequency of discrepancies more than 4 prism diopters (PD) between PACT and PUCT was calculated.

RESULTS

The magnitude of hyperdeviation was greater when measured with PUCT (range 8PD hypodeviation to 20PD hyperdeviation) vs. PACT (18PD hypodeviation to 25PD hyperdeviation) with a median difference of 4.5PD (range -5PD to 21PD); P < 0.0001. Eighteen (50%) of 36 measurements elicited >4PD hyperdeviation (or >4PD less hypodeviation) by PUCT than by PACT.

CONCLUSIONS

A standardized 10-second PUCT yields greater values than a prism and alternate cover test in the majority of patients with DVD, providing better quantification of the severity of DVD, which may be important for management decisions.

Interventions for dissociated vertical deviation

BACKGROUND

The term "strabismus" describes misalignment of the eyes. One or both eyes may deviate inward, outward, upward, or downward. Dissociated vertical deviation (DVD) is a well-recognized type of upward drifting of one or both eyes, which can occur in children or adults. DVD often develops in the context of infantile- or childhood-onset horizontal strabismus, either esotropia (inward-turning) or exotropia (outward-turning). For some individuals, DVD remains controlled and can only be detected during clinical testing. For others, DVD becomes spontaneously "manifest" and the eye drifts up of its own accord. Spontaneously manifest DVD can be difficult to control and often causes psychosocial concerns. Traditionally, DVD has been thought to be asymptomatic, although some individuals have double vision. More recently it has been suggested that individuals with DVD may also suffer from eyestrain. Treatment for DVD may be sought either due to psychosocial concerns or because of these symptoms. The standard treatment for DVD is a surgical procedure; non-surgical treatments are offered less commonly. Although there are many studies evaluating different management options for the correction of DVD, a lack of clarity remains regarding which treatments are most effective.

OBJECTIVES

The objective of this review was to determine the effectiveness and safety of various surgical and non-surgical interventions in randomized controlled trials of participants with DVD.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2015, Issue 8), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to August 2015), EMBASE (January 1980 to August 2015), PubMed (1948 to August 2015), Latin American and Caribbean Health Sciences Literature Database (LILACS) (1982 to August 2015), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com) (last searched 3 February 2014), ClinicalTrials.gov (www.clinicaltrials.gov), and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 3 August 2015.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) of surgical and non-surgical interventions for the correction of DVD.

DATA COLLECTION AND ANALYSIS

We used standard procedures expected by Cochrane. Two review authors independently completed eligibility screening, data abstraction, 'Risk of bias' assessment, and grading of the evidence.

MAIN RESULTS

We found four RCTs eligible for inclusion in this review (248 eyes of 151 participants between the ages of 6 months to 22 years). All trials were assessed as having unclear risk of bias overall due to insufficient reporting of study methods. One trial was conducted in Canada and compared anteriorization of the inferior oblique muscle with resection versus anteriorization of the inferior oblique muscle alone; one in the USA compared superior rectus recession with posterior fixation suture versus superior rectus recession alone; and two in the Czech Republic compared anteriorization of the inferior oblique muscle versus myectomy of the inferior oblique muscle.Only one trial reported data that allowed analysis of the primary outcome for this review, the proportion of participants with treatment success. The difference between inferior oblique anteriorization plus resection versus inferior oblique anteriorization alone was uncertain when measured at least four months postoperatively (risk ratio 1.13, 95% confidence interval 0.60 to 2.11, 30 participants, very low-quality evidence). Three trials measured the magnitude of hyperdeviation, but did not provide sufficient data for analysis. All four trials reported a relatively low rate of adverse events; hypotropia, limited elevation, and need for repeat surgery were reported as adverse events associated with some of the surgical interventions. No trials reported any other secondary outcome specified for our review.

AUTHORS' CONCLUSIONS

The four trials included in this review assessed the effectiveness of five different surgical procedures for the treatment of DVD. Nevertheless, insufficient reporting of study methods and data led to methodological concerns that undermine the conclusions of all studies. There is a pressing need for carefully executed RCTs of treatment for DVD in order to improve the evidence for the optimal management of this condition.

Surgical management of dissociated vertical deviation associated with A-pattern strabismus

INTRODUCTION

Dissociated vertical deviation (DVD), pattern strabismus, and oblique muscle dysfunction frequently coexist, and the recognition of bilaterality, symmetry, and lateral incomitance is important in selecting appropriate surgical management. In this study, we compare 3 different surgical approaches in patients with DVD associated with A-pattern strabismus.

METHODS

This was a retrospective review of 40 consecutive patients with DVD and A-pattern strabismus who underwent strabismus surgery. Bilateral superior rectus muscle recession was performed in 9 patients, bilateral superior rectus recession and superior oblique posterior tenectomy were performed in 14 patients, and bilateral superior oblique temporal tenotomy and inferior oblique recession were performed in 17 patients.

RESULTS

Bilateral superior rectus muscle recession corrected 7(Delta) +/- 2(Delta) of A pattern, 10(Delta) +/- 3(Delta) of vertical deviation and 4(Delta) +/- 2(Delta) of DVD asymmetry. Bilateral superior rectus muscle recession combined with superior oblique posterior tenectomy corrected 17(Delta) +/- 3(Delta) of A pattern, 10(Delta) +/- 2(Delta) of vertical deviation, and 4(Delta) +/- 2(Delta) of asymmetry. Bilateral superior oblique muscle temporal tenotomy combined with inferior oblique recession corrected 30(Delta) +/- 4(Delta) of A pattern, 9(Delta) +/- 3(Delta) of vertical deviation, and 2(Delta) +/- 2(Delta) of asymmetry.

CONCLUSIONS

In patients with DVD and A patterns, the size of the A pattern and the symmetry of the DVD are of major importance for surgeons determining appropriate procedures. Bilateral superior rectus muscle recession corrects small amounts of A pattern. Larger amounts of A pattern require additional superior oblique weakening or weakening of all four oblique muscles. superior rectus muscle recession is warranted if the asymmetry is larger than 5(Delta).