Margin Reflex Distance 1 (MRD1) only characterizes the central height of the upper eyelid, depends on the examiner’s experience, and ignores eyelid contour abnormalities such as notches, peaks, and flares. Consequently, MRD1 may be insufficient for evaluating the outcomes of ptosis surgery, according to research published in BMC Ophthalmology

Researchers evaluated outcomes of unilateral ptosis correction with an objective, quantitative, and repeatable method. Outcomes were assessed based on parameters including symmetry, MRD1, peak height of the upper lid, temporal and nasal ocular surface area, and temporal/nasal (T/N) area ratio. The investigators reviewed medical records of patients with unilateral ptosis from October 2015 to December 2020. Patients with unilateral ptosis who underwent surgical correction and levator function of 5 mm or higher were eligible for the study.

The research team included 34 patients (19 women, 15 men) and separated them into 2 groups: ptotic eye (case group) and contralateral eye (control group). The mean age of patients was 58.8±12.7 years (range 15–75 years) and mean follow-up time was 19.5±7.3 months (range 8–40 months). 


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The team determined that 4 patients were diagnosed with congenital ptosis and 30 patients were diagnosed with aponeurotic ptosis. Before surgery, the mean degree of symmetry for overall eyelid contour was 36.6±27.5% (range 1–92%). After surgery, the mean degree of symmetry for overall eyelid contour was 72.4±16.5% (range 55–92%). MRD1 demonstrated a success rate of 94% in all patients; however, the overall degree of symmetry was 72%. 

T/N area ratio for contralateral eyes was 1.19 pre-postoperative, and it was 1.11 preoperatively and 1.15 postoperatively in the ptotic eye. The preoperative degree of symmetry was 35% and the postoperative degree of symmetry was 68%, indicating that T/N ratios were inconsistent with the degree of symmetry. According to the researchers, T/N ratio may not be a reliable parameter to examine eyelid contour symmetry. 

Limitations of the study include the retrospective nature and most patients had severe ptosis. Additionally, all measurements were made on 2-dimensional photographs instead of more accurate 3-dimensional images. 

“This method may help to improve surgical outcomes,” the investigators report. “In addition, using this method, surgeons can retrospectively evaluate the impact of their surgical interventions on the eyelid peak.”

Reference

Aytogan H, Ayintap E. Comparing the symmetry of upper eyelid following unilateral ptosis correction. BMC Ophthalmol. Published online December 20, 2021. doi:10.1186/s12886-021-02208-7