Analysis of temporal changes in thickness from conjunctiva to sclera after plication of the medial rectus muscle measured by anterior segment optical coherence tomography.

PURPOSE: We evaluated long-term changes in conjunctival bulge after medial rectus muscle (MR) tightening using the plication method. STUDY DESIGN: Retrospective and observational. METHODS: Patients who underwent MR plication for exotropia from December 2016-March 2020 at Okayama University Hospital were included. Thirty two eyes of 27 patients were enrolled. The thickness from the conjunctiva to sclera (TCS) at the limbus and insertion sites were measured using anterior segment optical coherence tomography preoperatively and 1 month, 4 months, and 12 months postoperatively. Correlations between the 1- and 12 month postoperative TCS and amount of MR tightening were analyzed. RESULTS: Preoperative and 4 month postoperative TCS at the limbus site were not significantly different (P=0.07). The 12 month postoperative TCS at the insertion site was significantly thinner than at 1 month postoperative (P<0.01), although significantly thicker than the preoperative TCS (P<0.01). No significant correlations were found between the amount of MR tightening (in mm) and 1- or 12 month postoperative TCS at the limbus (P=0.62 and P=0.98, respectively) and insertion (P=0.50 and P=0.24, respectively) sites. CONCLUSION: The TCS at the insertion site peaked at 1 month postoperatively, continued to decrease for longer than 4 months postoperatively, continuing until 12 months postoperatively. The TCS at the insertion site 12 months postoperatively is thicker than preoperatively. The TCS at both the limbus and insertion sites was not related to the amount of medial rectus muscle tightening.

Double-under muscle transposition: an effective surgical option for large-angle paralytic strabismus.

PURPOSE: To describe our surgical outcomes using a novel muscle transposition procedure, or double-under muscle transposition (DUT), in the treatment of paralytic strabismus. METHODS: In this surgery, the split halves of the superior and inferior rectus muscles opposite the paralyzed muscle are disinserted, crossed under both the remaining half and the paralyzed muscle, and anchored at opposite corners of the insertion of the paralyzed muscle. The medical records of consecutive patients who underwent DUT were retrospectively reviewed. Outcome measures were angle of deviation and duction deficit. RESULTS: Seven patients were included. Diagnoses included WEBINO (n = 1), rupture of the medial rectus muscle (n = 1), and abducens nerve palsy (n = 5). DUT alone was performed in 3 patients; DUT combined with antagonist muscle recession, in 4 patients. One patient underwent the surgery bilaterally. Mean follow-up was 17 ± 18+ months (range, 7-57). Preoperative angles of distance deviation ranged from 25Δ to 142Δ in magnitude. All except a single patient had duction limitation of grade -5. The mean change in distance deviation for DUT alone for each operated eye was 60Δ ± 6Δ (53Δ-65Δ); for combined surgery, 69Δ ± 23Δ (range, 52Δ-103Δ). Final mean angle of deviation at distance was +2Δ ± 3Δ (-4Δ to 0Δ), although an additional surgery was required for large overcorrections in 2 patients. Duction limitation improved in all patients. One patient experienced a postoperative vertical deviation. CONCLUSIONS: DUT may be an alternative for patients with severely paralytic strabismus not likely to resolve with previously reported muscle transposition surgeries. Overcorrection may occur in some cases.

Adverse reactions to 1% cyclopentolate eye drops in children: an analysis using logistic regression models.

PURPOSE: To determine the frequency, symptoms and risk factors for adverse reactions to two-times instillation of 1% cyclopentolate in children. STUDY DESIGN: Prospective, observational study. METHODS: The subjects were 646 patients who underwent cycloplegic refraction with cyclopentolate (mean age; 7.0 ± 3.5 years, age range; 0-15 years). Five minutes after instillation of 0.4% oxybuprocaine hydrochloride, a 1% cyclopentolate eye drop was instilled twice, with an interval of 10 min. Fifty minutes later, two certified orthoptists evaluated adverse reactions using a questionnaire and interviewed the patients' guardians. The relationship between the adverse reaction rates and age, gender, additional instillation, complications of the central nervous system (CNS), time of day and season were analysed using binominal and polytomous logistic regression models. RESULTS: The overall frequency of adverse reactions was 18.3% (118/646 patients). The main symptoms included conjunctival injection (10.5%, 68/646), drowsiness (6.8%, 44/646) and facial flush (2.2%, 14/646). The odds ratio (OR) of conjunctival injection increased with patient's age (p < 0.05), in boys (p < 0.01) and in winter (p < 0.001). In contrast, the OR of drowsiness decreased with age (p < 0.001). Facial flush was observed mostly in children younger than 4 years. CNS complications were not a significant risk factor for any of the symptoms. CONCLUSIONS: Adverse reactions to 1% cyclopentolate eye drops were more frequent than previously expected, but all were mild and transient. The probability of each symptom was associated with a clear age-specific trend.

Formulas to Estimate Appropriate Surgical Amounts of Unilateral Recession-Resection in Intermittent Exotropia with Distance-Near Disparity.

The purpose of this study was to derive new formulas to provide an optimal surgical procedure and optimal amount of recession-resection (RR) surgery in intermittent exotropia (IXT) with a disparity in angle of deviation depending on the fixation distance. The records of 117 consecutive patients with IXT who underwent RR surgery between March 2008 and December 2011 at Okayama University Hospital were retrospectively examined. Multivariable linear regression analysis was performed using the observed corrective angle of deviation at distance or near fixation as the dependent variable, and amounts of lateral rectus muscle (LR) recession (mm) and medial rectus muscle (MR) resection, and age at surgery (years) as independent variables. Two simultaneous formulas were derived: corrective angle of deviation at distance fixation (°)=1.8×recession (mm)+1.6× resection (mm)+0.15×age (years)-6.6, and corrective angle at near fixation (°)=1.5×recession (mm)+1.7× resection (mm)+0.18×age (years)-3.8. Comparisons of coefficient values of the formulas between distance and near fixation revealed that LR recession was more affected by the corrective angle in distance than near fixation. MR resection was more affected at near than distance fixation. We found that our new formulas estimated the appropriate amount of unilateral RR surgery.

Risk factors for excessive postoperative exo-drift after unilateral lateral rectus muscle recession and medial rectus muscle resection for intermittent exotropia.

BACKGROUND: To detect significant factors associated with excessive postoperative exo-drift in young patients with intermittent exotropia who had undergone unilateral lateral rectus muscle recession and medial rectus muscle resection. METHODS: We retrospectively examined the records of 64 consecutive patients < 18 years old who underwent surgery between April 2004 and December 2011. We sought risk factors for excessive postoperative exo-drift among patients' demographic and clinical characteristics using univariate and multivariable linear regression analysis. RESULTS: Younger patients (P = 0.007), and those with larger preoperative exo-deviation at distance (P = 0.033), a lower incidence of peripheral fusion at distance (P = 0.021) or a greater postoperative initial eso-deviation (P = 0.001), were significantly more likely to have an excessive postoperative exo-drift (> 20 prism diopters). Univariate analysis revealed significant associations between excessive postoperative exo-drift and age at surgery (P = 0.004), preoperative exo-deviation at distance (P = 0.017) and postoperative initial eso-deviation at distance (P < 0.001). Multivariable linear regression analysis showed that postoperative initial eso-deviation at distance (P = 0.008) was significantly associated with postoperative exo-drift. CONCLUSIONS: Postoperative exodrift in unilateral RR is predicted by the initial postoperative eso-deviation, which may offset the overcorrection. However, the exo-drift is greater in cases with a large preoperative exo-deviation and/or at a younger age, and should be followed carefully.

Differences in the Stability and Amount of Postoperative Exodrift with Age after Unilateral Lateral Rectus Muscle Recession and Medial Rectus Muscle Resection of Intermittent Exotropia.

We investigated variances in the stability and amount of postoperative exodrift among age groups of intermittent exotropia (XPT) patients who underwent unilateral lateral rectus muscle recession and medial rectus muscle resection. We analyzed the cases of 110 consecutive patients who underwent the surgery in 2004-2011, dividing the patients into groups by their age at surgery: <10, 10-19, and ≥20 years. We performed a regression analysis (dependent variable: postoperative exodrift (°); independent variable: number of days post-surgery) using the formula of curve lines. When the tangent line slope was = 0.01 (°/days) for each group, we defined the numbers of days until alignment became stable as the 'stable days.' We evaluated the between-group differences in the amount of exodrift calculated for the stable days. The coefficients and coefficients of determination for the fitting curves were: <10 year group: f(x)=12.2 (1-e-0.0183x) (r2=0.588, p<0.05); 10-19 year group: f(x)=10.0 (1-e-0.0178x) (r2=0.453, p<0.05); ≥20 year group: f(x)=3.40 (1-e-0.0382x) (r2=0.217, p<0.05). There were 389 , 388, and 153 stable days, and the estimated postoperative exodrift with long-term follow-up was 11.5±3.7°, 9.3±4.4°, and 4.1±3.6° for the < 10 year, 10-19 year, and ≥ 20 year groups, respectively (≥20 year vs. other 2 groups, p<0.05). Longer periods and more postoperative exodrift were associated with younger age at surgery. The postoperative evaluation was approx. ≥ 1 year post-surgery in patients aged < 20. These findings may contribute to evaluating XPT's success rate and prognoses.