Purpose: This study aims to determine if ocular dominance plays a role in predicting compensatory eyebrow elevation in cases of ptosis.
Methods: This retrospective observational cohort study screened all individuals presenting to two tertiary oculoplastics practices with complaints of ptosis for entry. Primary position photographs were obtained. Ocular dominance was assessed via a modified Porta test. Ptosis was defined in bilateral cases as marginal reflex distance of <2.5 mm in both eyes and in unilateral cases as either an MRD1 < 2.5 mm or MRD1 of >1 mm lower on one side. Asymmetry in brow height was defined as a difference of >1 mm. Chi square and t-tests were performed.
Results: Sixty-eight patients from the both tertiary practices met inclusion criteria (37 male, 31 female). Concordance between the higher brow and the dominant side was 50.0% (n = 22, p > 0.05). Mean brow height on the dominant side (15.5 mm) was not statistically different than brow height on the non-dominant side (15.3 mm, p > 0.05). The concordance between the higher brow and the lower MRD1 eyelid was not significant (45.5%, n = 20, p > 0.05). The difference in mean brow height between the lower and higher MRD1 eyes was not significantly different (-0.11 mm; p > 0.05). This also held true when restricted to unilateral cases (0.28; p > 0.05).
Conclusions: Although asymmetric brow elevation can be noted in patients with ptosis, ocular dominance does not appear to be concordant with this asymmetry. Additionally, brow height does not appear to be concordant with MRD1 in cases of ptosis.
Keywords: MRD2; Ptosis; brow compensation; eyebrow; eyelid; ocular dominance.