Lateral rectus muscle recession and the vertical palpebral fissure height: to do or not to do inter-muscular septum dissection?

In this study, we aimed to evaluate changes of vertical palpebral fissure height （VPFH） after unilateral lateral rectus muscle recession. Twenty-five and twenty-six patients who were candidates for lateral rectus muscle recession were assigned into “with” and “without” intermuscular septum dissection study arms. The VPFH was measured at one-day before surgery and in two weeks and three months, postoperatively. Three months after surgery, significant increase of VPFH was observed in both groups （Paired t-test; P=0.005）. Also, less widening of VPFH was observed in “with intermuscular septum dissection” group （Change in VPFH in “with intermuscular septum dissection” vs “without intermuscular septum dissection” groups： 0.48 mm vs 1.34 mm; ANCOVA test; P〈0.001）. However, such results were not observed two weeks post-operatively （Change in VPFH in “with intermuscular septum dissection” vs “without intermuscular septum dissection” groups： -0.28 mm vs 0.28 mm; ANCOVA test; P=0.302）. Intermuscular septum dissection is recommended in lateral rectus muscle recession to partially prevent the undesirable increment of VPFH.

Comparison of bilateral/unilateral lateral rectus recession and unilateral recession-resection for intermittent exotropia:a Meta-analysis

AIM: To compare the effectiveness of unilateral recession-resection(R&R) and bilateral/unilateral recession(BLR/ULR) for treatment of basic type of intermittent exotropia [IX(T)].METHODS: A comprehensive literature search was performed using PubMed, EMBASE, and the Cochrane Library, to identify randomized controlled trials and comparative studies regarding the effectiveness of R&R and BLR/ULR for IX(T). Based on which, a Meta-analysis was then performed in terms of long-term success rate, overcorrection rate, and recurrence rate.RESULTS: Nine studies in total satisfy the specified eligibility criteria. BLR is at disadvantage to R&R at a short-term follow-up [<2 y, OR 0.56(0.33-0.94) for success rate; OR 2.11(1.17, 3.81) for undercorrection rate]. However, BLR achieved a higher success rate [OR 2.49(1.61, 3.86)] and a lower undercorrection rate [OR 0.40(0.23, 0.71)], compared to that of R&R at a long-term followup(>2 y). There is no significant difference was found in overcorrection rate, regardless of the length of follow-up time [OR 0.85(0.41, 1.75)]. In the treatment for small-angle IX(T), the final outcome was significantly different between the groups, demonstrating a more successful alignment [OR 0.37(0.18, 0.74)] and a lower undercorrection [OR 3.50(1.28, 7.26)] in the R&R group than in the ULR group. While for moderate-angle IX(T)(20 PD-25 PD), the effectiveness of R&R and ULR is quite equivalent with similar success rate [OR 1.08(0.65, 1.79)] and undercorrection rate [OR 0.89(0.54, 1.48)]. CONCLUSION: As regard to the effect of BLR and R&R, R&R shows an advantage over BLR at short term. But, BLR is more effective in the long term for the basic typeIX(T) in children. R&R surgery should be a better choice for the treatment of small-angle IX(T) of ≤20 PD than ULR. However, both of ULR and R&R are recommended for moderate-angle IX(T) from 20 PD to 25 PD.

Clinical risk factors for the development of consecutive exotropia:a comparative clinical study

AIM： To compare a group of patients with consecutive exotropia with patients who had ≤ 10 prism diopters （PD） esotropia or no deviation postoperatively in terms of probable clinical risk factors for the development of consecutive exotropia. METHODS： The study recruited fourteen patients who developed consecutive exodeviation during follow-up period after the correction of esotropia who were categorized as group 1 and thirty-one patients who had still ≤10 PD esotropia or no deviation at the final visit that were considered as group 2. Clinical risk factors leading the development of consecutive deviation were analyzed as the main outcome measures. RESULTS： The mean age of patients was 4.57±3.11y in group 1 and 5.10±3.52y in group 2 （P=0.634）. There was no significant difference of preoperative near and distant deviations among two groups （P =0.835, 0.928 respectively）. The mean amount of medial rectus recession and lateral rectus resection was similar in both groups （P=0.412, 0.648 respectively）. Convergence insufficiency and neurological diseases were more frequent in group 1 （P-0.007, 0.045）. Accompanying neurological disease was found to be as a significant factor increasing the risk of the development of consecutive exotropia significantly [odds ratios （OR）： 5.75 （1.04-31.93）]. CONCLUSION： Accompanying neurological disease appears to be a significant clinical risk factor for the development of consecutive exodeviation during postoperative follow-up after the correction of esotropia. However, larger studies are needed in order to interpret the results to the clinical practice and to ascertain other concurrent risk factors.