Background: Cervical dystonia (CD) is a chronic neurological disorder characterized by involuntary neck muscle contractions, leading to abnormal head postures, pain, and functional impairment. Botulinum toxin type A (BoNT-A) remains the treatment of choice, but its efficacy is highly dependent on injection accuracy. Various techniques, including palpation-guided, ultrasound-guided, and electromyography-guided (EMG), have been developed to optimize delivery, each with distinct advantages and limitations. Methods: A systematic search of PubMed and Scopus was conducted up until 30 December 2024, using defined keywords related to BoNT-A, CD, and injection techniques. Studies were included if they reported clinical outcomes of BoNT-A injection methods in adult CD patients. Data on efficacy, safety, accuracy, and muscle targeting were extracted and synthesized. Results: Seven studies comprising 239 patients were included: two randomized controlled trials, one retrospective study, one cohort study, one systematic review, one literature review, and one cadaveric study. The most common CD subtype was torticollis/torticaput (49.79%). Frequently targeted muscles included the trapezius (56.9%), levator scapulae (51.7%), and splenius capitis (48.3%). Ultrasound guidance consistently demonstrated superior injection accuracy and reduced adverse effects due to real-time anatomical visualization. EMG-guided techniques showed advantages in identifying dystonic muscles, especially when anatomy was unclear. In contrast, palpation-guided injections were less accurate and suitable only for superficial muscles. Dosing varied by product, with mean doses of 117–118 units for onabotulinumtoxinA and incobotulinumtoxinA, and 405 units for abobotulinumtoxinA. Adverse events were generally mild, including local discomfort, dysphagia, and transient muscle weakness. Conclusions: Ultrasound- and EMG-guided injections enhance the precision, safety, and efficacy of BoNT-A therapy for CD compared to anatomy-guided techniques. While ultrasound guidance improves anatomical accuracy, EMG remains valuable for functionally identifying dystonic muscles. Integration of both may offer optimal outcomes. However, further high-quality, standardized trials are needed to definitively establish best practices.

Background: Schnyder corneal dystrophy (SCD) is a rare autosomal dominant disorder characterized by bilateral corneal opacification due to abnormal cholesterol and phospholipid deposition. Mutations in the UBIAD1 gene, identified as causative in 2007, underline the condition, although its exact pathogenesis remains unclear. Case Presentation: A 55-year-old female presented with persistent photophobia, blepharospasm, and corneal discomfort. She also reported joint pain related to rheumatoid arthritis (RA), managed with Ro-Actemra (tocilizumab). The ophthalmological evaluation revealed bilateral corneal stromal deposits resembling snowflakes, with visual acuities of 0.8 (right eye) and 0.7 (left eye). Multimodal imaging confirmed stromal hyperreflective deposits. Based on the clinical findings, SCD was diagnosed, although no genetic testing was performed. Symptomatic management with artificial tears was initiated. Discussion: This case illustrates the diagnostic challenges of SCD, particularly in the absence of corneal crystals, a hallmark feature that is not universally present. Advanced imaging techniques aided diagnosis, and the coexistence of SCD and RA highlights the need for multidisciplinary care. Treatment options remain limited, although emerging therapies targeting oxidative stress and lipid metabolism show promise. Conclusions: This case highlights the importance of integrating ophthalmological and systemic care in SCD management and underscores the need for further research to expand diagnostic and therapeutic strategies for this rare disorder.