Anophthalmic ptosis: Investigation of the mechanisms and statistical analysis

Purpose: To investigate the mechanisms producing ptosis in anophthalmic patients by comparing potential risk factors among patients with ptosis with a control group. Specific techniques for achieving optimal aesthetic results in the surgical correction of anophthalmic ptosis are recommended. Methods: Data from 94 anophthalmic patients with ptosis and 44 control patients without ptosis were retrospectively collected and analyzed. Potential risk factors for ptosis were compared between the two groups of patients by using 2-sample binomial exact tests. Univariate and multivariate logistic regression analyses were also used. Results: A direct relation between percent volume replacement by the primary implant and the occurrence of ptosis was noted (P=0.057; age adjusted, P=0.037). Those patients who had secondary implant surgery were more likely to have levator surgery for ptosis (P = 0.005; age adjusted, P = 0.039). A greater number of years of prosthesis wear was associated with clinical and intraoperative evidence of levator dehiscence (P = 0.061). No relation was observed between the occurrence of trauma (as a reason for enucleation) and the occurrence of levator dehiscence. Thirty percent of patients with ptosis who had secondary intraconal or extraconal implants and no other surgical intervention for ptosis had improvement in ptosis. Conclusions: The mechanisms producing anophthalmic ptosis should be assessed carefully before surgical repair to achieve optimal aesthetic results. Correction of volume deficiency should be offered before levator surgery for patients with anophthalmic ptosis. The patient should be advised that tilt of the prosthesis is a possible outcome of levator repair and may reflect overcorrection or insufficient volume replacement.