Revisiting the surgical table: An analysis of surgical dose-response in Asian exotropia

BACKGROUND

Previous research on the factors associated with surgical dose-response in strabismus surgery for exotropia has yielded inconsistent results. This study determined the factors influencing surgical dose-response in exotropia patients who underwent recession and resection (R&R).

METHODS

Exotropia patients who underwent unilateral R&R at the National Taiwan University Hospital between 2006 and 2021 were evaluated. Deviation-angle differences in prism diopters (PD) were measured preoperatively and at 1 month postoperatively. Surgical dose-response (PD/mm) was defined as the difference in deviation angle (in PD) divided by the surgical dose in millimeters. Linear and non-linear regression models were used to evaluate the influence of variables including age, sex, axial length, and preoperative deviation on surgical dose-response.

RESULTS

Overall, 295 patients (162 children; 133 adults) were included. Average surgical dose-response in the pediatric and adult groups was 2.82 ± 0.60 PD/mm and 3.02 ± 0.62 PD/mm, respectively. Male sex was negatively correlated with surgical dose-response in children. The surgical dose-response was larger in adults with longer axial length (>25.64 mm) and patients with larger preoperative deviation (>42.6 PD and >38.7 PD in pediatric and adult groups, respectively). Surgical dose-responses peaked at 35.1 years.

CONCLUSION

Age, axial length, and preoperative deviation have a nonlinear effect on surgical dose-responses in exotropia patients undergoing R&R. Surgical dose-responses were larger in patients in young adulthood, with longer axial length and larger preoperative deviation angle. A table with fitted values for surgical dose-response based on age, axial length, and preoperative deviation was established for clinical reference.

Clinical manifestations and risk factors for poor visual outcomes of ocular sarcoidosis in Taiwan

PURPOSE

To assess ocular involvement in sarcoidosis and to analyze the manifestations of ocular sarcoidosis (OS) in Taiwan.

METHODS

A retrospective review was performed in 364 patients diagnosed as sarcoidosis at National Taiwan University Hospital from 2015 to 2019. The OS diagnosis was based on the revised criteria of International Workshop on Ocular Sarcoidosis. Demographics, clinical manifestations, treatment and effects, complications, visual outcomes and risk factors of poor vision (<20/200) were analyzed.

RESULTS

A total of 122 eyes of 66 patients (13 males and 53 females) with OS were identified. Bilateral involvement accounted for 84.8%. Thirty-five patients were diagnosed with definite OS, 14 with presumed OS and 17 with probable OS. The average age was 51.9 ± 14.1 years, with no significant difference in sex. Most patients presented with panuveitis (61 eyes, 50.0%) and posterior uveitis (52 eyes, 42.6%). Systemic steroid was the mainstay treatment, and immunosuppressants or anti-metabolic agents were supplemented. Common complications included cataract (50.8%), ocular hypertension/glaucoma (25.4%) and posterior synechiae (20.5%). Forty-three eyes (36.1%) and 74 eyes (62.2%) had a final vision of 20/20 and 20/40 or better, respectively. The causes of poor visual outcome were diverse, and generalized estimating equations analysis indicated that female and poor initial vision were risk factors.

CONCLUSION

Uveitis is an early sign of sarcoidosis and it might result in several complications. The overall visual outcomes were good if patients received proper treatment. Both poor initial vision and females that tended to have more severe complications were associated with poor outcome.

Acute life-threatening arrhythmias caused by severe hyperkalemia after induction of anesthesia in an infant with methylmalonic acidemia

Methylmalonic acidemia (MMA) is a very rare genetic disease of metabolism that progressively leads to neurological and renal sequelae. This report describes an unusual case of a patient with MMA who developed severe hyperkalemia and severe dysrhythmia during anesthesia. A 13-month-old male infant with MMA underwent urgent insertion of a port-a-cath under general anesthesia. A life-threatening arrhythmia suddenly occurred, with severe hyperkalemia (up to 7.4 mmol/L), immediately following induction of anesthesia. Emergent resuscitation was successfully carried out, with a complete neurological recovery after 7 days after surgery. Although MMA is a rare complication, the possibility of severe hyperkalemia should be considered in the differential diagnosis of patients with MMA presenting with wide QRS complex tachycardia. The management and intraoperative complications of this disorder are reported here, and the available literature is reviewed.