Strabismus patterns after cataract surgery in adults

New-onset binocular diplopia after cataract surgery in adults is a rare but significant complication. The aim of this study was to analyze causes, risk factors, and treatment outcomes. Forty consecutive patients with new-onset binocular diplopia after uncomplicated cataract surgery were enrolled in this retrospective study at a tertiary medical center. We evaluated risk factors including type of anesthesia, preoperative presence of strabismus, and others regarding their effect on the development of diplopia after cataract surgery. We further analyzed ocular alignment and motility at presentation and during the clinical course. The majority of the patients with new-onset diplopia presented after cataract surgery on the left eye (28 of 40). Vertical strabismus occurred in 37 of 40 patients, and regional (peri- or retrobulbar) anesthesia was the main risk factor for postoperative diplopia (present in 37 of 40). There were four distinct ocular dysmotility patterns in patients with vertical strabismus: deficient elevation with (type 1a) or without over-depression (type 1b), deficient depression (type 2), or normal motility (type 3). After surgery of the right eye, most patients (6 of 9) showed type 2. After cataract surgery on the left eye, type 1a was most common (20 of 24). Three patients had horizontal strabismus due to a decompensated heterophoria or convergence insufficiency. In total, 17 patients required strabismus surgery (mean 1.3 operations, range 1-3). Regional anesthesia was the main risk factor for new-onset diplopia after cataract surgery in adults. Distinct strabismus patterns were observed for left and right eyes.d