Hering's Law in Congenital Ptosis: Evaluation of the Contralateral Response to Unilateral Congenital Ptosis Repair.

PURPOSE: To determine the applicability and clinical relevance of Hering's law for the eyelids in cases of congenital ptosis. METHODS: A retrospective chart review and digital photograph analysis of patients who underwent unilateral congenital ptosis repair at a tertiary, university-based, Oculoplastics clinic was conducted. Pre- and postoperative eyelid height (marginal reflex distance), upper eyelid symmetry, and brow position were determined using ImageJ analysis software. Changes in these values, and the relationship between the change in ipsi- and contralateral eyelid heights and brow positions, were determined. RESULTS: In 51 patients, the mean change in contralateral upper eyelid position (marginal reflex distance) following unilateral repair was -0.5 mm with 29% (n = 15) demonstrating a greater than 1 mm contralateral descent. The contralateral brow position remained stable with a mean change of +0.1 mm. No significant differences were seen between the 15 patients who demonstrated a contralateral upper eyelid descent greater than 1 mm and the remainder of the cohort in terms of amblyopia rate (p = 0.71), mean preoperative marginal reflex distance (p = 0.14), mean change in ipsilateral marginal reflex distance (p = 0.32), mean change in contralateral brow position (p = 0.44), or mean postoperative upper eyelid asymmetry (1.3 mm vs. 1.2 mm). Overall, the mean upper eyelid asymmetry improved from 2.6 mm preoperatively to 1.2 mm postoperatively. None of the 51 patients underwent subsequent contralateral ptosis repair. CONCLUSIONS: Hering's law for the eyelids applies to cases of congenital ptosis but has little clinical significance due to improved upper eyelid asymmetry following unilateral surgery.

A Clinically Optimal Protocol for the Imaging of Enteric Tubes: On the Basis of Radiologist Interpreted Diagnostic Utility and Radiation Dose Reduction.

RATIONALE AND OBJECTIVES: The purpose of this study was to develop and evaluate a patient thickness-based protocol specifically for the confirmation of enteric tube placements in bedside abdominal radiographs. Protocol techniques were set to maintain image quality while minimizing patient dose. MATERIALS AND METHODS: A total of 226 pre-intervention radiographs were obtained to serve as a baseline cohort for comparison. After the implementation of a thickness-based protocol, a total of 229 radiographs were obtained as part of an intervention cohort. Radiographs were randomized and graded for diagnostic quality by seven expert radiologists based on a standardized conspicuity scale (grades: 0 non-diagnostic to 3+). Basic patient demographics, body mass index, ventilatory status, and enteric tube type were recorded and subgroup analyses were performed. Effective dose was estimated for both cohorts. RESULTS: The dedicated thickness-based protocol resulted in a significant reduction in effective dose of 80% (p-value < 0.01). There was no significant difference in diagnostic quality between the two cohorts with 209 (92.5%) diagnostic radiographs in the baseline and 221 (96.5%) diagnostic radiographs in the thickness-based protocol (p-value 0.06). CONCLUSION: A protocol optimized for the confirmation of enteric tube placements was developed. This protocol results in lower patient effective dose, without sacrificing diagnostic accuracy. The technique chart is provided for reference. The protocol development process outlined in this work could be readily generalized to other imaging clinical tasks.