BACKGROUND: Divergence insufficiency (DI) is an acquired comitant strabismus in aging individuals, characterized by esotropia and diplopia at distance. Treatment options include occlusion, base-out prism glasses, and a variety of surgical procedures to the horizontal rectus extraocular muscles. Here, we present a large cohort of patients with DI who underwent unilateral resection of the lateral rectus muscle. This is a simple procedure, typically performed under regional anesthesia and on the non-dominant eye. METHODS: Clinical characteristics and complaints were collected from patients with DI who underwent unilateral lateral rectus resection over a 6.5-year period. Treatment success was evaluated in terms of post-operative symptomatic deviation and the need for prisms in order to achieve sensory fusion. RESULTS: The cohort consisted of 57 patients (age 54-89 years). The majority sought surgical care after prism glasses were no longer tolerated, or after onset of a larger symptomatic deviation (typically 10 to 18 prism diopters). After surgery (minimum 6 weeks follow-up; median 10 weeks), 86.0 % showed successful results with no further treatment; an additional 10.5 % stayed free of diplopia with a post-operative prism (horizontal or vertical), and only two patients (3.5 %) required further surgery and were considered failures. CONCLUSIONS: Mild DI is usually treated with a base-out prism. Treatment of pronounced DI with unilateral lateral rectus resection was generally successful, with 96.5 % not requiring further surgery. Unilateral lateral rectus resection appears to be a valid option for treatment of DI.
BACKGROUND: Divergence insufficiency (DI) is an acquired comitant strabismus in aging individuals, characterized by esotropia and diplopia at distance. Treatment options include occlusion, base-out prism glasses, and a variety of surgical procedures to the horizontal rectus extraocular muscles. Here, we present a large cohort of patients with DI who underwent unilateral resection of the lateral rectus muscle. This is a simple procedure, typically performed under regional anesthesia and on the non-dominant eye. METHODS: Clinical characteristics and complaints were collected from patients with DI who underwent unilateral lateral rectus resection over a 6.5-year period. Treatment success was evaluated in terms of post-operative symptomatic deviation and the need for prisms in order to achieve sensory fusion. RESULTS: The cohort consisted of 57 patients (age 54-89 years). The majority sought surgical care after prism glasses were no longer tolerated, or after onset of a larger symptomatic deviation (typically 10 to 18 prism diopters). After surgery (minimum 6 weeks follow-up; median 10 weeks), 86.0 % showed successful results with no further treatment; an additional 10.5 % stayed free of diplopia with a post-operative prism (horizontal or vertical), and only two patients (3.5 %) required further surgery and were considered failures. CONCLUSIONS: Mild DI is usually treated with a base-out prism. Treatment of pronounced DI with unilateral lateral rectus resection was generally successful, with 96.5 % not requiring further surgery. Unilateral lateral rectus resection appears to be a valid option for treatment of DI.
Authors: Michael Kinori; Megha Pansara; Derek D Mai; Shira L Robbins; John R Hesselink; David B Granet Journal: Graefes Arch Clin Exp Ophthalmol Date: 2020-02-24 Impact factor: 3.117