Strabismus Surgery in Orthophoric Patients With Symptomatic, Asymmetric Vertical or Horizontal Incomitance

• Published in: American journal of ophthalmology 2023-05, Vol.249, p.29-38
• Main Authors: Phanphruk, Warachaya, Hennein, Lauren, Hunter, David G.
• Format: Article
• Language: English
• Subjects: Child; Diplopia - diagnosis; Diplopia - etiology; Diplopia - surgery; Humans; Oculomotor Muscles - surgery; Ophthalmologic Surgical Procedures - methods; Retrospective Studies; Strabismus - surgery; Treatment Outcome; Vision, Binocular - physiology
• ISSN: 0002-9394; 1879-1891
• DOI: 10.1016/j.ajo.2022.12.019

•In rare cases, orthophoric patients have symptomatic strabismus due to incomitance.•Outcomes and surgical strategies for 8 such patients were reviewed.•Four surgical strategies to address incomitance were identified.•No patient had a new deviation or required reoperation.•Comitance improved by 9.5 prism diopters, and patient/surgeon satisfaction was high To report the indications, operative strategies, and surgical outcomes of patients who undergo vertical and horizontal rectus muscle surgery for incomitant strabismus despite being orthophoric in primary gaze. Retrospective, interventional case series. The setting for this study was an academic practice at Boston Children's Hospital. The patient population comprised 8 orthophoric patients who underwent strabismus surgery to treat vertical/horizontal incomitance. Observation procedures included review of surgical strategies, strabismus measurements in diagnostic gaze positions, and development of postoperative diplopia. The main outcome measures were preserved single vision in primary gaze, comitance, reoperation rate, and patient/surgeon satisfaction. Surgical strategies included the following: (1) simultaneous recession of ipsilateral antagonist rectus muscles; (2) recession or resection of 1 rectus muscle with balancing surgery on the fellow eye; (3) restricting the range of 1 muscle (combined resection and recession or posterior fixation suture); and (4) creating an acceptable deviation in primary gaze. Mean follow-up was 5.4 months (median, 2 months; range, 2-25 months). No patient had new-onset primary gaze diplopia. The median incomitance improved by 9.5 prism diopters. No patient required additional surgery. Patient satisfaction and surgeon assessment of outcomes were high. Although the risk of operating on orthophoric patients with incomitant strabismus may discourage surgeons from offering treatment, the use of specific strategies to address incomitance can preserve alignment in primary gaze while improving patient satisfaction. These strategies may also benefit patients with incomitant strabismus that is symptomatic in primary gaze.